CHRONOSPHERE

By Mike Darwin

The problem of a cryonicist experiencing sudden cardiac arrest (SCA) unattended is hardly theoretical. This has occurred a number of times already, with some patients going upwards of a week before being discovered. Because SCA is only reversible within the very narrow time frame of 4-6 minutes after circulation stops, there has been little incentive to detect it, and instantly relay a call for help, outside of hospital, that is. By the time help arrived, even if it was just 5 or 10 minutes away, it would be too late. This sad state of affairs has been a source of enormous frustration for cryonicists since at least 1981 – that’s when I saw the first prototype for a wearable cardiac arrest monitoring alarm system. It had been constructed by Reg Thatcher, who was then associated with Jerry Leaf’s Cryovita Labs, in Fullerrton, CA;  and it worked. It was a marvel of engineering for its time, but no one wanted to use it. It was a bit cumbersome, the wet gel electrodes caused skin irritation, and its range was very limited.

Since Reg’s efforts, a number of people in cryonics have tried to engineer a solution to this problem, most notably Ben Best and Eugen Leitl. There is no question that the technological base exists. In fact, it has existed since at least 1981, and from the standpoint of feasibly, miniaturizing such a system to the degree that it would be tolerable for most users to wear and be compliant in its use; it has probably been possible since at least 2000. This technology has been developed not because of life or death issues, but because of sports.  Shown in Figure, 1, below are three implementations of sports heart-rate monitors with high and low alarm features.

Figure 1: At left is finger-worn sports-type digital pulse monitor which use pulse oximetery technology to detect hear beat. Center,above, is an ECG-type sports watch; the chest belt contains the ECG electrodes and transmitter which sends the heat rate count to the wrist-worn watch. At right is the Garmin Forerunner 305 GPS Heart Rate Monitor which also has full GPS capability!

The one the right, the Garmin Forerunner 305 GPS Heart Rate Monitor, is not merely a continuous heart rate monitor; it is a fully capable GPS navigator. It also calculates calorie consumption based on the user’s weight, distance traveled and hills climbed, records lap history by day and week, stores up to 200 workouts in its memory and, in addition to heart rate alarms, it also has something called a “pace alarm,” which sounds if the user is running either faster or slower than their programmed pace! Oh yes, I almost forgot, it has time/distance alarm alerts when you’ve reached a desired time or distance and it sells for a mere ~ $200 US. Other manufacturers sell similar monitors with Bluetooth capability, thus allowing the watch output to be linked to mobile phones or other Bluetooth enabled devices. For example the the Nokia Symbian S60 Smartphone shown in Figure 2, below,  can even be bundled with a Bluetooth linked Polar heart rate monitor and alarm.[1]

Figure 2: The Nokia Symbian S60 Smartphone with companion Bluetooth linked Polar heart rate monitor: yours for ~ $700, US.

So what’s the problem? Why isn’t the issue of an alarm system to detect SCA for cryonicists “a done deal?” The answer is that because of US Food and Drug Administration (FDA) regulations, the devices may not use the alarm feature for anything beyond sports training purposes – and there is no sport training reason to have the phone dial a preprogrammed number in the event of cardiac arrest. The downside to this kind elegant, compact and integrated technology as seen in Figures 1 and 2 is that it is increasingly beginning to look and act like biological systems do. It isn’t possible to peel the top of your dog’s head off and rewire him to bark only at certain times, or to stop him from scratching at the door when you want to be alone. Try to do that, and all you’ll find inside is a bunch of amorphous looking goo which you can make no sense out of. And of course, your dog will either be dead, or very, very irritated with you.

The insides of the Nokia phone or Garmin Forerunner now look a lot like the insides of a living system, and it is no longer possible to easily hack, reroute, rewire or otherwise modify their function. The potentially positive side to the Nokia Symbian is that it is a Smartphone, and therefore (again in theory) it may be possible for a skilled Smartphone applications programmer to create an “app” that would autodial the phone to a predetermined series of numbers in the event of a cardiac arrest event. Presumably the speed dial button on the phone could be used to facilitate “manual” panic alarm calls. If such an app were to prove possible, then the only uncovered contingency would be a fall that leaves the person alive, but unable to call for help. This is, unfortunately, a common scenario in stroke.

Vitalsens Vital Signs Monitor

Very recently, cardiac arrest-fall-panic alarms for medical applications that meet FDA or CE (European Union) standards have been developed. So now, 30+ plus years after cryonicists made their first attempt at it, a new range of products is entering the marketplace that will more or less do the job – and in one case do considerably more.

Figure 3: The Vitalsens remote cardiac monitor and electrode array by Vitalsens Technologies of Dublin, Ireland.

The first of these is the Vitalsens ‘plug and play’ Vitalsens vital signs monitor.[1] This is a device I’ve been waiting for since Intelesens released its V-Patch Cardiac Event Monitor, the V-Patch Medical Systems (VPMS) in 2008. The Vitalsens contains transducers for ECG, heart rate, and skin temperature which are integrated with a tiny transmitter. The unit sticks to the skin with a minimally irritating disposable adhesive pad and is worn until the user removes it. The ECG electrodes and skin temperature sensor are disposable. The transmitter component of the Vitalsens monitor also contains a motion sensing device employing a 3-axis accelerometer – this allows the device to detect “man down” situations, such as a sudden fall, even when there is no cardiac arrest or arrhythmia. Most importantly, the  Vitalsens is an ”open-source” OEM[2] device designed to transmit data via Bluetooth to a PC, or any Bluetooth compatible device; and Intellisens provides it along with PC interface software. This allows the Vitalsens to be interfaced to any existing or new monitoring product. It can thus be rapidly added to or integrated into existing medical devices or alarm/monitoring systems.

What this means in theory is that it should be possible for any cryonicists with real engineering savvy out there to adapt another device, such as a smartphone, to respond to a signal from the Vitalsens. While still no easy task, it is unarguably much better than trying to build such a system de novo, or to rewire or reprogram a Nokia Symbian S60 – or your dog. More information on the Intelisens system is available at : http://intelesens.com/index.html

The NUVANT Mobile Cardiac Telemetry System

Next up is the The NUVANT Mobile Cardiac Telemetry System from Corventis, Inc., in San Jose, CA. Corventis got 510(k) FDA approval for this system early last year, and it is now up and running. The NUVANT system uses a disposable sensor array and transmitter which they call the PiiX (Figure 4, below); “an unobtrusive, leadless and water-resistant device “designed to support patient compliance.” The PiiX transmits its data to a compact relay transmitter, the zLink, that can be worn on the belt, or otherwise be secured to the user’s person. The word ‘patient’ should probably be used here because this is an FDA approved prescription device.

Figure 4: The Corventis NUVANT PiiX is an unobtrusive, leadless and water-resistant ECG sensor and transmitter, which is also disposable. It links to a small, belt-worn re-transmitter, the zLink, which in turn communicates using mobile phone technology with Corventis’ central monitoring station.

Figure 6: The NUVANT monitoring system works by activating a belt-worn unit which communicates the arrhythmia to a central monitoring station, where it is interpreted and acted upon as deemed necessary by ECG technicians.

The NUVANT technological platform was developed primarily as a competing technology to Holter monitoring, with the added advantage of 24 hour centralized monitoring of the ECG. When the device detects an arrhythmia, it activates the belt-worn transmitter and notifies ECG monitoring technicians at the central monitoring station, who can then review the arrhythmia and advise the patient directly, or the patient’s cardiologist, as appropriate. If the patient experiences symptoms, he can activate PiiX to record and automatically transmit the ECG, via the zLink transmitter device, to the Corventis Monitoring Center.

Corventis offers three levels of service, as shown in Figure 7, below. Costs vary considerably for monitoring service, depending upon the level of surveillance selected. When the device detects cardiac arrest, or a rapidly fatal arrhythmia, such as ventricular tachycardia in a patient, it captures it and sends the ECG virtual “strip” to the Corventis central monitoring facility for action or referral to the patient’s cardiologist.

Figure 7: Varying service levels available for NUVANT monitoring system.

The service is geared primarily for detection of arrhythmias for diagnostic purposes, although a stated use of the device is to monitor for acute therapeutic interventions, presumably including summoning Emergency Medical Personnel (EMS).

The Zoll LifeVest Wearable Automatic Defibrillator

The bulk of my research activity has not been in cryobiology, but rather in the area of cerebral-ischemia reperfusion injury[2] (lack of blood flow to the brain and the injury that results from this, and as a consequence of restoring blood circulation) and the “post-resuscitation syndrome.”[3] The brain is acutely and atypically sensitive to lack of blood flow. The outer limit of recovery from cardiac arrest absent neurological deficit is 6 minutes, and the vast majority of patients cannot be recovered from cardiac arrest in any condition, if the duration is as little as 10 minutes.[4] Independent of the brain injury associated with ischemia, there is also a ~ 10% decrease in survival for each minute that cardiac arrests persists absent restoration of spontaneous circulation (ROSC). That number should put into perspective why the immediate detection of cardiac arrest is such a low commercial and medical priority – the window of time to act is just too small!

Figure 8: The graph above shows the smoothed curve for chances of survival (with and without neurological deficit) as a function of time in cardiac arrest until there is effective restoration of spontaneous circulation (ROSC). Beyond 5 minutes of cardiac arrest the neurological outcome becomes progressively worse, as indicated by shading into red on the graph. The first incidents of impaired neurocognitive function following cardiac arrest occur starting ~ 2 minutes after the start of aystole.[4-8]

Each year ~300,000 people in the US will experience SCA[9] and ~70% of them will not be within reach of an Automatic External Defibrillator.[10] Of the 30% who do experience SCA within “potential” reach of an AED, the majority of these patients will not be salvageable due to delays involved in determining the patient’s condition (i.e., the bystander determining if the victim in fact have no heartbeat), locating an AED, applying it, and waiting for it to diagnose the arrhythmia and administer the anti-arrhythmic shock.[11] Once again, the logistically imposed time delay in the context of the decay curve in recovered viability, as shown in Figure 8 above, means that only a minority of patients who need it will benefit from rapid, let alone immediate defibrillation.

For at least a decade now, implantable cardiac defibrillators (ICDs) have been available.[12, 13] These units place the entire defibrillator assembly under the skin of the chest and within the patient’s thorax. They work well, but the procedure to implant them is both invasive and costly, and the batteries have a limited life, requiring re-operation every few years to replace them.[14] Because the devices and the surgical and medical management associated with their use are so costly, insurance carriers will typically only pay for ICDs in patients who have both extremely high and documented ongoing risks of sudden cardiac arrest.

Figure 9: This is very recent data (2006-07) from All-Japan Utstein Registry of the Fire and Disaster Management Agency. They selected a subpopulation of SCA their patients with out-of-hospital cardiac arrest due to ventricular fibrillation (VF), where there was witness present who was over 18 years of age and who immediately started CPR. The study ran from January 1, 2006 to December 31 2008 and the outcomes measured were survival and good neurological outcome (CPC 1 or 2). There were 24479 adults in the analysis with a mean time to bystander CPR of 1 minute. Adjusted odds ratio of the average effect per a minute was 0.23 with 95% Confidence Intervals (CI) 0.17 to 0.31.The introduction of high impulse no-pause for ventilation CPR was associated with a significant improvement in survival despite the fact that it is still not in widespread use.  As can be seen, even with essentially immediate initiation of bystander CPR, survival from cardiac arrest is not greatly improved over that achieved with defibrillation, as seen in Figure 8, above. Abstract 260: The Effect of Time to Bystander Cardiopulmonary Resuscitation on Survival From Out-of-hospital Cardiac Arrest From All-Japan Utstein Registry Data: A Validation of 3-Phase Sensitive Model. Yonemoto, N, Yokoyama, H, Nagao,K, Kimura,T, Hiroshi,N. Circulation. 2010;122:A260

This leaves a lot of people with known risks with no protection against SCA other than bystander CPR and the Emergency Medical System (EMS). Representative survival following cardiac arrest under excellent conditions of bystander and EMS response is shown in Figure 9, above and it is not greatly different than when the return of spontaneous circulation is achieved by the use of defibrillation, even absent CPR (Figure 8).[5, 7] The focus of my research towards solving this problem has been to find better methods of CPR as well as drugs that will allow for cerebral recue following periods of brain ischemia in the range of 6-30 minutes. My reason for focusing on these strategies is that because cryopreservation procedures cannot be started on humans until after pronouncement of medico-legal death, all cryonics patients will necessarily experience some normothermic ischemia. Furthermore, since it is also not legally permissible to restore spontaneous circulation to cryonics patients, they will necessarily be reliant upon some form for closed-chest circulatory support. at least until such time as extracorporeal support can be initiated.

Medical patients are not constrained to suffer “irreversible cessation” of spontaneous circulation following an incident of SCA and they can thus legally, if not practically, be immediately defibrillated. However, as has just been pointed out, only those at the highest risk qualify for ICD placement. On average, the long-term risk of sudden death after myocardial infarction (MI) (once a person has been medically stabilized for ~ 30-60 days), is between 1 – 2% per year.[15] During the first 30 days after an MI the risk is in the range of 25 to 50% and for a subpopulation of MI patients, the risk remains high. The patients with the highest risk are those who have already had (and survived) one episode of cardiac arrest; they face a ~ 20% yearly chance of another cardiac arrest. Patients with a large MI, ones in whom there has been destruction of a large area of heart muscle, also face a seriously elevated risk of SCA. A good marker for the amount of the myocardium destroyed after an MI is the ejection fraction.[16] Patients with ejection fractions above 40% have about the same risk as other post-MI patients, a ~ 1 – 2% incidence of SCA per year.[16] However, the risk of sudden death increases with lower ejection fractions, and becomes substantially higher at values of 30% or below. For this reason, anyone who has had a heart attack should have their ejection fractions measured – and should know what their ejection fraction is. Other patients who will be at greatly elevated risk, are those with infarcts in certain areas of the heart, those with co-morbidities such as diabetes, advanced age with atherosclerosis, and those with cancers and a prior history of MI.

To meet the need of these patients, particularly those who are in the high risk window period following an MI, the LifeVest wearable cardiac defibrillator (WCD) was developed by Zoll Medical (the same company that now manufactures the AutoPulse vest-CPR machine[3]).The LifeVest is the first wearable defibrillator, and in contrast to an ICD, the LifeVest is worn outside the body, rather than being implanted in the chest, as shown in Figure 10, below.[17-20]

Figure 10: The Zoll LifeVest wearable cardiac defibrillator consist of a halter-worn set of monitoring and defibrillation electrodes and a shoulder strap or belt-worn monitor, electronics package and battery pack.

The LifeVest continuously monitors the patient’s ECG with novel, dry, non-adhesive, non-irritating sensing electrodes to detect potentially lethal cardiac arrhythmias. If a life-threatening rhythm is detected, the device alerts the patient prior to delivering a counter-shock, thus allowing patients who are conscious to delay the treatment shock, or to prepare themselves physically and psychologically; for instance, to sit down if standing, or to pull over to the side of the road, if driving. If the patient becomes unconscious, the LifeVest defibrillation electrodes secrete an electroconductive gel and deliver an electrical shock to restore normal rhythm. Approximately 35,000 patients have used the LifeVest so far, with a 98% cardioversion rate to normal rhythm on the first shock.[21, 22] The overall survival rate is 92%, with patients either remaining at home following the shock, or admitted conscious to the Emergency Department (ED).[18, 23]

Since its release in 2002, when the device was manufactured by its original developer LifeCor (subsequently acquired by Zoll Medical) it has gone through 4 generations of development, with each generation resulting in more compact and lighter weight units.

The LifeVest is covered by most health plans in the United States, including commercial, state, and federal plans as Durable Medical Equipment (DME) for those patients at high risk of cardiac arrest, including:

• Primary prevention [ Ejection fraction (EF) ≤35% and Myocardial Infarction (MI), Non Ischemic Cardiomyopathy (NICM), or other Dilated Cardiomyopathy (DCM)] including:
  • After recent MI (Coverage during the 40-day ICD waiting period)
  • Before and immediately after CABG or PTCA (Coverage during the 90-day ICD waiting period)
  • Listed for cardiac transplant
  • Recently diagnosed NICM (Coverage during the three-to-nine month ICD waiting period)
  • New York Heart Association (NYHA) Class IV heart failure
  • Terminal disease with life expectancy of less than one year
• ICD indications when patient condition delays or prohibits ICD implantation
• ICD explantation (patients who have had removal of an ICD but who are stillest risk of SCA)

Figure 11: The risk of sudden cardiac death (not successfully resuscitated) per 1,000-person years for men and women by age.[24]

Can Cryonicists Benefit from a WCD?

While the indications for use of a WCD like the LifeVest are clear in cardiac disease, what, if any, are the indications in the cryonics setting? Figures 11-13 should help to clarify that somewhat. As can be calculated from Figure 11, the cause of death in 4 of every 5 people older than 65, is heart disease. Some of these deaths will be due to end-stage congestive heart failure, but many will result from SCA. These data would suggest that male cryonicists, in particular those with a family history of cardiac disease, are people who should at least consider the use of WCD after age 70. Mortality from SCA is so high by >75 years that very serious consideration should be given to use of a WCD in both men and women.[15, 25]

Figure 12: The multivariable-adjusted relative risk for sudden cardiac death by quartile of the Omega-3 Index compared with other, more traditional circulating heart risk factors. The quartiles at presumed highest risk (black bars) are set at a relative risk of 1.0. Each subsequent lighter bar represents the risk at each decreasing (or, for HDL and omega-3 index, increasing) quartile. CRP, C-reactive protein; Hcy, homocysteine; TC, total cholesterol; Tg, triglycerides. Source: Physician’s Health Study. These risks factors, combined with others, may allow younger cryonicists to determine their risk of SCA, and thus decide whether to make use of WCD.

Cryonicists with diabetes who have suffered a MI have a 40% risk of experiencing lethal SCA in the following year (Figure 13, below).[26] That risk declines some with survival to the end of the second year, but still remains above 30% for the rest of the patient’s life! This subpopulation of cryonicists might also want to consider use of a WCD, or if medically indicated, an ICD. It is, of course, possible to greatly refine the risks of SCA by doing testing, such as cardiac “treadmill” testing wherein the ECG is monitored (preferably in conjunction with real-time echocardiography) during stressful exercise. An abnormal ECG and/or “stress echo” is highly predictive of the presence of coronary artery disease and thus the risk of SCA. Similarly, blood chemistry parameters, such as HDL/LDL ratio, homocysteine levels and C-reactive protein and triglyceride levels, when considered together and in the context of age and family history, can also be powerfully predictive of the risk of SCA/D as can be seen in Figure 12, above.

Figure 13: The risk of sudden cardiac death for diabetics in the first year following a myocardial infarction. The risk for male diabetics approaches 50%!

Effort on the part of cryonicists with programming and statistics backgrounds offers the prospect of taking SCA risk factor data from multiple sources and integrating them into a more comprehensive risk factor assessment program. This would allow those cryonicists with the highest risk of SCA to determine if the use of a WCD is appropriate for them.

The cost of the Life-Vest has been impossible for the author to determine so far. Since the device is sold only by prescription (and it is costly), Zoll refuses to discuss a specific “direct consumer retail price,” and instead asks for specific insurance coverage information, or a prescription by a physician. Monthly cost data are available for the UK via the NHS, and the price quoted there is in the range of 27 to 32 pounds sterling per patient, per month.

Interface Capability?

The Life Vest is a less ‘electronically compact’ system and it uses an auditory alarm that is accessible. This raises the possibility that the device can be “hacked” and the alarm output signal be coupled to a mobile phone triggered to dial a pager, or another number where 24/7/365 emergency notification service. It may even be possible to work with Zoll to custom engineer such a device as a plug-in to the unit, as long as it was not being added for any medical indication. Cryonics should still qualify as being ‘exempt’ from being a medical indication, since notification that a person is dead or dying, with no intent to render medical services, is not currently considered medicine. Obviously, if the device delivers a shock and the cryonicist is still alive, the cryonics organization will disregard the alert from the device.

Summary

A variety of FDA approved medically approved devices to detect and treat SCA are now on the market in both the US and Europe. Rapid technological advance in microelectronics and telecommunications has made these devices small enough and lightweight enough to be considered for use by cryonicists wishing to avoid the predicament of experiencing SCA, with or without a long delay to discovery. Careful consideration to adopting the use of a WCD should be given by cryonicists who are 75 or older, or who have specific medical conditions, or other risk factors that put them at high risk of SCA. Intangible factors, such as living alone, which greatly amplifies the risk of remaining undiscovered for prolonged periods of time following SCA, and the increased sense of personal security that may result from use a WCD[18] should also be factored into the decision to use or forego a WCD, or an SCA detection device.

References

1.            Harper R, Donnelly N, McCullough I, Francey J, Anderson J, McLaughlin JA, Catherwood PA: Evaluation of a CE approved ambulatory patient monitoring device in a general medical ward. Conf Proc IEEE Eng Med Biol Soc, 2010:94-97.

2.            Grace P: Ischaemia-reperfusion injury. Br J Surg 1994 81(5):637-647.

3.            Homer-Vanniasinkam S, Crinnion JN, Gough MJ: Post-ischaemic organ dysfunction: a review. Eur J Vasc Endovasc Surg 1997, 14(3):195-203.

4.            Mullie A, Van Hoeyweghen R, Quets A: Influence of time intervals on outcome of CPR. The Cerebral Resuscitation Study Group. Resuscitation 1989, 17 Suppl:S23-33; discussion S199-206.

5.            Becker LB, Ostrander MP, Barrett J, Kondos GT: Outcome of CPR in a large metropolitan area–where are the survivors? Ann Emerg Med 1991, 20(4):355-361.

6.            Martens PR, Mullie A, Calle P, Van Hoeyweghen R: Influence on outcome after cardiac arrest of time elapsed between call for help and start of bystander basic CPR. The Belgian Cerebral Resuscitation Study Group. Resuscitation 1993, 25(3):227-234.

7.            Swor RA, Boji B, Cynar M, Sadler E, Basse E, Dalbec DL, Grubb W, Jacobson R, Jackson RE, Maher A: Bystander vs EMS first-responder CPR: initial rhythm and outcome in witnessed nonmonitored out-of-hospital cardiac arrest. Acad Emerg Med 1995, 2(6):494-498.

8.            Troiano P, Masaryk J, Stueven HA, Olson D, Barthell E, Waite EM: The effect of bystander CPR on neurologic outcome in survivors of prehospital cardiac arrests. Resuscitation 1989, 17(1):91-98.

9.            Kong MH, Fonarow GC, Peterson ED, Curtis AB, Hernandez AF, Sanders GD, Thomas KL, Hayes DL, Al-Khatib SM: Systematic review of the incidence of sudden cardiac death in the United States. J Am Coll Cardiol, 57(7):794-801.

10.          Bardy GH, Lee KL, Mark DB, Poole JE, Toff WD, Tonkin AM, Smith W, Dorian P, Yallop JJ, Packer DL et al: Rationale and design of the Home Automatic External Defibrillator Trial (HAT). Am Heart J 2008, 155(3):445-454.

11.          Lofgren B, Molgaard O, Pedersen AK, Krarup NH: [Resuscitation with automatic external defibrillator]. Ugeskr Laeger 2007, 169(42):3584-3585.

12.          Corrado D, Calkins H, Link MS, Leoni L, Favale S, Bevilacqua M, Basso C, Ward D, Boriani G, Ricci R et al: Prophylactic implantable defibrillator in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia and no prior ventricular fibrillation or sustained ventricular tachycardia. Circulation, 122(12):1144-1152.

13.          Celiker A, Olgun H, Karagoz T, Ozer S, Ozkutlu S, Alehan D: Midterm experience with implantable cardioverter-defibrillators in children and young adults. Europace, 12(12):1732-1738.

14.          Hauser RG, Maisel WH, Friedman PA, Kallinen LM, Mugglin AS, Kumar K, Hodge DO, Morrison TB, Hayes DL: Longevity of Sprint Fidelis implantable cardioverter-defibrillator leads and risk factors for failure: implications for patient management. Circulation, 123(4):358-363.

15.          Adabag AS, Luepker RV, Roger VL, Gersh BJ: Sudden cardiac death: epidemiology and risk factors. Nat Rev Cardiol, 7(4):216-225.

16.          Dai SM, Zhang S, Chen KP, Hua W, Wang FZ, Chen X: Prognostic factors affecting the all-cause death and sudden cardiac death rates of post myocardial infarction patients with low left ventricular ejection fraction. Chin Med J (Engl) 2009, 122(7):802-806.

17.          Schott R: Wearable defibrillator. J Cardiovasc Nurs 2002, 16(3):44-52.

18.          Beauregard LA: Personal security: Clinical applications of the wearable defibrillator. Pacing Clin Electrophysiol 2004, 27(1):1-3.

19.          Reek S, Meltendorf U, Klein HU: [A wearable defibrillator for patients with an intermittent risk of arrhythmia]. Dtsch Med Wochenschr 2002, 127(41):2127-2130.

20.          Morrison D, Smith J: Taking a vested interest in a wearable cardioverter defibrillator. Nursing 2009, 39(6):30-32.

21.          Auricchio A, Klein H, Geller CJ, Reek S, Heilman MS, Szymkiewicz SJ: Clinical efficacy of the wearable cardioverter-defibrillator in acutely terminating episodes of ventricular fibrillation. Am J Cardiol 1998, 81(10):1253-1256.

22.          Chung MK, Szymkiewicz SJ, Shao M, Zishiri E, Niebauer MJ, Lindsay BD, Tchou PJ: Aggregate national experience with the wearable cardioverter-defibrillator: event rates, compliance, and survival. J Am Coll Cardiol, 56(3):194-203.

23.          Feldman AM, Klein H, Tchou P, Murali S, Hall WJ, Mancini D, Boehmer J, Harvey M, Heilman MS, Szymkiewicz SJ et al: Use of a wearable defibrillator in terminating tachyarrhythmias in patients at high risk for sudden death: results of the WEARIT/BIROAD. Pacing Clin Electrophysiol 2004, 27(1):4-9.

24.          Straus S, Bleumink, GS, Dieleman JP, van der Lei, J, Stricker, BH, Sturkenboom, MC.: The incidence of sudden cardiac death in the general population. J Clin Epidemiol 2004 57(1):98-102.

25.          Calleja AM, Dommaraju S, Gaddam R, Cha S, Khandheria BK, Chaliki HP: Cardiac risk in patients aged >75 years with asymptomatic, severe aortic stenosis undergoing noncardiac surgery. Am J Cardiol, 105(8):1159-1163.

26.          Kucharska-Newton AM, Couper DJ, Pankow JS, Prineas RJ, Rea TD, Sotoodehnia N, Chakravarti A, Folsom AR, Siscovick DS, Rosamond WD: Diabetes and the risk of sudden cardiac death, the Atherosclerosis Risk in Communities study. Acta Diabetol, 47(Suppl 1):161-168.

Selected Bibliography: Wearable Cardiac Defibrillators

1. Auricchio et al., “Clinical Efficacy of the Wearable Cardioverter-Defibrillator in Acutely Terminating Episodes of Ventricular Fibrillation,” Am J Card, 1998, 81(10):1253-1256.

2. Meltendorf et al., “The Wearable Defibrillator ?a new Method to prevent Sudden Death,” PACE, 2000; 23(4, part II):606.

3. Reek et al., “The Wearable Cardioverter Defibrillator (WCD^®) for the prevention of sudden cardiac death ?a single center experience,” Z Kardiol, 2002; 91:1044?052.

4. Schott, “The Wearable Defibrillator,” J Cardiovasc Nurs, 2002; 16(3):44-52.

5. Reek et al., “Clinical Efficacy of the Wearable Defibrillator in Acutely Terminating Episodes of Ventricular Fibrillation Using Biphasic Shocks,?PACE, 2002, 25(4, part II):577.

6. Reek et al. “A wearable defibrillator for patients with an intermittent risk of arrhythmia,” Dtsch Med Wochenschr, 2002; 127(41):2127-30.

7. Capucci et al. “Cost-effective use of a new wearable cardioverter defibrillator to protect patients at risk of SCA,” Europace, 2003, 4(Supplement 1):A44-A45.

8. Gasparini et al. “A new wearable defibrillator: Initial single center experience,” Europace, 2003, 4(Supplement 1):A45.

9. Pignatelli et al. “Use of a new wearable cardioverter defibrillator to reduce the risk of sudden cardiac death,” Europace, 2003, 4(Supplement 1):A45-A46.

10. Suzzani P et al. “The lifecor lifevest™ wearable cardioverter defibrillator,” Europace, 2003, 4(Supplement 1):A46.

11. Lang et al., “Morbidity and Mortality of UNOS Status 1B Cardiac Transplant Candidates at Home,” J Heart Lung Transplant, 2003; 22:419-426.

12. Reek et al., “Clinical Efficacy of a Wearable Defibrillator in Acutely Terminating Episodes of Ventricular Fibrillation Using Biphasic Shocks,” PACE, 2003, 26:2016-2022.

13. Beauregard, “Personal Security: Clinical Applications of the Wearable Defibrillator,” PACE, 2004; 27(1):2-3.

14. Feldman et al., “Use of a Wearable Defibrillator in Terminating Tachyarrhythmias in Patients at High Risk for Sudden Death: Results of WEARIT/BIROAD,” PACE, 2004, 27:4-9.

15. Chung et al., “Robust Long-Term Cardiac Monitoring Using Dry, Non-adhesive Capacitive Electrodes,” JACC, 2004; 43(5, suppl A):141A.

16. Joseph et al., “Compliance and Effectiveness of the Wearable Defibrillator Vest,” JACC, 2004; 43(5, suppl A):300A.

17. Meltendorf, “Using the Wearable Cardioverter Defibrillator a strategy for bridging high risk patients after CABG,” Heart Rhythm, 2005; 2(5, suppl):S32.

18. Wase, “Wearable Defibrillators: A New Tool in the Management of Ventricular Tachycardia/Ventricular Fibrillation,” EP Lab Digest, 2005; 12:22-24.

19. Szymkiewicz et al., “Analysis of Sudden Cardiac Arrests During Wearable Defibrillator Use,” Circulation, 2006; 114 (18, suppl II):II-349.

20. Gronda et al., “Heart Rhythm Considerations in Heart Transplant Candidates and Considerations for Ventricular Assist Devices: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates?006,” J Heart Lung Transplant, 2006; 25(9):1043-1056.

21. Losordo et al., “Intramyocardial Transplantation of Autologous CD34⁺ Stem Cells for Intractable Angina: A Phase I/IIa Double-Blind, Randomized Controlled Trial,” Circulation, 2007; 115:3165 – 3172.

22. Traub et al., “Sudden cardiac arrest aborted by a wearable cardioverter-defibrillator in newly diagnosed non-ischemic cardiomyopathy,” Heart Rhythm, 2007; 4(5, suppl):S101.

23. Choudhuri et al., “Arrhythmic Events During the 40/90 days ‘Cooling Off’ Period: Clinical Utility of the Wearable Defibrillator,” Circulation, 2007; 116: II_348.

24. Wang et al., “Ventricular Fibrillation remains the Primary Presenting Rhythm: Results from the Wearable Cardioverter Defibrillator Human Study,” Circulation, 2007; 116: II_934 – II_935.

25. Freeman et al., “Is Severe Post-shock Bradyarrhythmia In Patients Using Wearable Defibrillators Common or Serious?” Circulation, 2007; 116: II_931.

26. LaPage et al., “A Fatal Device-Device Interaction between a Wearable Automated De?brillator and a Unipolar Ventricular Pacemaker,” PACE, 2008; 31:912?15.

27. Abi-Samra et al., “Wearable Defibrillator: Effective Bridging Substitute for ICD Implants,” Europace, 2008; 10: i160.

28. Mortada et al., “Sudden Cardiac Death” in: Jeremias A, Brown DL (eds). Cardiac Intensive Care, 2nd Edition, Elsevier, St. Louis (in press).

29. Szymkiewicz, et al. “A Comparison of Compliance and Effectiveness of Wearable Defibrillators and Home AEDs in Out-of-Hospital Sudden Cardiac Arrest,” Circulation, 2008; 118: S_1466.

30. Lewicke et al., “Exploring QT interval changes as a precursor to the onset of ventricular fibrillation/tachycardia,” Journal of Electrocardiology, 2009; 42(4):374-9.

31. Szymkiewicz, et al., “Incidence and causes of inappropriate defibrillation during wearable defibrillator use,” Heart Rhythm, 2009; 6(5): S74.

32. Morrison et al., “Taking a vested interest in a wearable cardioverter defibrillator,” Nursing, 2009; 39(6):30-2.

33. Dillon et al., “An evaluation of the effectiveness of a wearable cardioverter defibrillator detection algorithm,” Journal of Electrocardiology, 2009; (June, electronic ahead of print).

34. Saltzberg et al., “Characteristics of Peripartum Cardiomyopathy Patients Using a Wearable Cardiac Defibrillator,” Journal of Cardiac Failure, 2009; 15(6):S59.

35. Lee et al., “Role of wearable and automatic external defibrillators in improving survival in patients at risk for sudden cardiac death,” Curr Treat Options Cardiovasc Med, 2009;11(5):360-5.

36. Klein et al., “Bridging a Temporary High Risk of Sudden Arrhythmic Death. Experience with the Wearable Cardioverter Defibrillator (WCD),” PACE, 2009 Nov 2 [Epub ahead of print]

37. Prochnau, “Successful use of a wearable cardioverter-defibrillator in myocarditis with normal ejection fraction,” Clin Res Cardiol, 2009 Nov 17. [Epub ahead of print]

38. Zareba et al., “Sudden Cardiac Arrest in End-Stage Renal Disease: Successful Resuscitation With Wearable Cardiac Defibrillator,” Circulation, Nov 2009; 120: S701 – S702.

39. Klein et al. “The Wearable Cardioverter Defibrillator: Bridge to the Implantable Defibrillator,” Cardiac Electrophysiology Clinics, 2009;1(1):129-46.

40. Everitt et al., “Use of the Wearable External Cardiac Defibrillator in Children,” PACE, 2010 Feb 23. [Epub ahead of print].

41. Chung et al. “Aggregate national experience with the wearable cardioverter-defibrillator vest: event rates, compliance and survival,” JACC, 2010;55(10 suppl 1):A10.

[2] OEM stands for original equipment manufacturer, but in reality means a manufacturer of equipment that may be marketed by another manufacturer!

[3] Which the author most emphatically does not recommend for use in cryonics!

By Mike Darwin

Cooling as the First Last Aid

Unarguably one of the simplest, and also the most powerful and effective cryonics first aid measures, is to cool the patient.  At first glance, this would seem to require little in the way of preparation. After all, how hard is it to get ice and put it on the patient? The answer depends on the answers to two other questions: “How quickly do you want it done” and “where do you live?”

In cases of unexpected cardiac arrest, much valuable time can be lost running out to get ice. In many cases, the next-of-kin or the person on the scene cannot do this, because they must wait for the hospice nurse, the Coroner/Medical Examiner (C/ME), emergency medical technicians (EMTs), paramedics, or the patient’s physician to arrive and pronounce medico-legal death and/or release the patient from the C/ME system. There is also the obvious consideration that most people don’t have 30 pounds of ice in their home freezers, let alone 300 pounds. Even if you live down the street from a 24-hour convenience store well stocked with ice, it will take at least 20 minutes to go there, purchase the ice, transport it home, and pack it effectively around the patient. (Pay attention to that word effectively; more on that shortly.)

An Alternative to Ice?

In Europe, and most of the rest of the world, there is an added problem which severely compromises fast and effective cooling, principally that ice is simply not available most of the time, and is virtually never available in quantity, without advanced notice and preparation.  Even well traveled North Americans seem unable to internalize the understanding that in most of the rest of the world, ice is a rare commodity, and it is viewed neither as a luxury, nor a necessity. What’s more, this is not simply a matter of the relative wealth of nations, but rather is rooted in cultural differences. The abundance of 24-hour retailers selling ice in North America is an artifact of North American culture and tastes. Wealthy nations, with an arguably higher standard of living (unarguably, if you consider mortality and morbidity to be the ultimate yardstick), have neither water ice in quantity, nor 24-hour convenience stores. London, one of the undisputed great cities of the world, has few 24-hour shops and virtually no easy access to ice in quantity, day or night. The same is true of Moscow, Mumbai, Munich, and Paris.

Another factor to consider is that per capita, vastly fewer non-North Americans have private transportation, and in many of the big cities of the world, including London, most or even all mass transit stops at midnight, and does not resume until 0400 or 0500.

The growing number of cryonicists living in these environments needs a workable alternative to ice, and they need a realistic approach to getting help in an emergency, because another problem that is especially acute for cryonicists in Europe is that they live quite far from each other. They are also handicapped by the fact that there are no full time personnel or often even volunteers available to help. Thus, having a workable, immediately available alternative to ice is essential.

Even in the US, cryonicists living in remote areas, small towns, or who face logistical problems in getting ice in an emergency would profit from having an “instantly” available source of refrigerant that did not require a dedicated freezer, or consume all the household refrigerator’s freezer capacity. Elderly cryonicists, and others at high risk of unexpected of cardiac arrest who cannot maintain a dedicated freezer full of ice (and change it out regularly†), could also benefit greatly from an always ready ice-substitute with an indefinite shelf life.

Ice (or more properly water) has enormous heat absorbing capacity in the form of its latent heat fusion (333.55 kJ/kg)[1] and I want to make it clear that there is really nothing else that can compete with ice as a safe, practical refrigerant for inducing hypothermia in cryopatients.  In other words, ice is always the first choice for use in cooling cryopatients when it is available.

When ice isn’t available, or going out to get it would delay the start of cooling, the next best thing is ammonium nitrate and water. When ammonium nitrate is mixed with water, an endothermic (heat absorbing) reaction occurs, which absorbs 26.2 kJ of heat per mole of ammonium nitrate. This happens because ammonium nitrate, like any salt dissolving in water, breaks into its constituent ions, in this case the ammonium and nitrate ions, which absorbs energy from their surroundings. The formation of new bonds between these ions and surrounding water molecules then releases that energy. However, since ammonium and nitrate ions are relatively large, the water molecules have relatively weak interactions with their diffuse charges. So, with little thermodynamic payback during this bond formation, the immediate effect of adding water to ammonium nitrate is to reduce the temperature of the mixture to about 0.5ºC (33ºF).[2]

A mole of ammonium nitrate is 80 grams, so if we compare ammonium nitrate to the heat absorbing capacity of melting ice, the comparison is surprisingly favorable, with ice absorbing 26.68 kJ of heat per 80 grams, compared to 26.2 kJ for ammonium nitrate. Of course, this analysis omits three important points, namely that 120 grams of water are required for each 80 g of ammonium nitrate, the specific heat of water (4.18 J g⁻¹ K⁻¹ c_p for water (liquid) at 25ºC) is almost as twice as high as a 40% ammonium nitrate and water mixture (and thus is better able to absorb heat), and that the lowest point that a water-ammonium nitrate slurry reaches is 0.5ºC, as opposed to 0 degrees C for ice (and in practice the temperature is actually ~+3ºC as opposed to 1.5 to 2.0ºC for ice under real-world working conditions).[3],[4]

Figure 1: Instant cold packs use a binary system of ammonium nitrate (NH₄NO₃) and water. The product is activated by squeezing (and thus rupturing) the inner bag containing the water, initiating dissolution of the NH₄NO₃ prills (which are porous). NH₄NO₃ undergoes and endothermic (heat absorbing) “reaction” as it dissolves in water. The typical chemical cold pack quickly reached a temperature of 0.5ºC, which is maintained for ~30 minutes. There is a modest increase in cooling capacity if these cold packs are chilled before use.

Ammonium nitrate cooling packs are a staple in first aid kits, and are widely used in athletics for primarily the same reason they should be used in cryonics: delay in cooling, even a slight one, reduces the effectiveness of hypothermia in mitigating injury. It is better to have a more costly, slightly less efficient product immediately available, than to lose valuable time after an injury going for ice. The most widely available “instant cold pack” product is Kwik Kold,™ manufactured by the health care giant Allegiance. Kwik Kold™ is a binary product consisting of an outer plastic bag which contains small (1-2 mm) pellets of porous ammonium nitrate (prills† ) and another bag that contains water. The product is activated by squeezing and bursting the water packet, and then mixing it with the ammonium nitrate, to begin the endothermic reaction.

Kwik Kold has a number of drawbacks, the first being its high cost. Ammonium nitrate is one of the least expensive bulk chemicals in the developed world, since it is most widely used as fertilizer. A case of 50 6” x 9” Kwik Kold packs retails for  ~$165.00 US, and several cases would be necessary in situations where there would be a long delay to obtaining water ice.[5] By contrast, purified ammonium nitrate purchased from scientific suppliers would cost about a third as much, $18.00 US/kg, and ammonium nitrate purchased as fertilizer would cost only $0.50 per kg. Because ammonium nitrate has been used as an expedient explosive in terrorist bombs in the US and elsewhere (ammonium nitrate was the principal explosive used by Timothy McVeigh in the Oklahoma City bombing of the Murrah Federal Building) it can typically only be purchased in agricultural form as a bulk product in 22.73 kg (50 lb) bags, and most retailers require documentation of the end-use – and often will refuse to sell it, except to known parties (farmers or agricultural concerns in their area), or to businesses with a substantial history (both credit and operational) as well as a credible use for the product.

Figure 2: Coarse mesh polyester lingerie laundry bags are ideal for holding both NH₄NO₃ prills and water ice. They are inexpensive and widely available in a variety of sizes and shapes. The bag shown above was purchased at Walmart for less than a dollar. A penny coin is shown for scale.

It is desirable to obtain ammonium nitrate in bulk not only because of of its affordability, but because it is desirable to repackage it for cryonics applications. Because Kwik Kold and similar products are dispensed in plastic bags, the refrigerating ability of the ammonium nitrate-water mixture is greatly reduced. The plastic bags limit the area of contact between the patient and the refrigerant, create micro-environments of stagnant (non-conducting) air between the bags and the patient’s skin, and slow dissolution of the ammonium nitrate in water.  Ideally, the ammonium nitrate should be packaged in coarse-mesh (see Figure 2, above) bags through which water can be continuously recirculated over the patient’s head, as shown in Figure 3, below.

This simple device can be easily fabricated from off the shelf items available at most Wal-Mart (Asda or Tesco in Europe) and hardware stores, such as Home Depot, for about $90 US.  This device, as well as its other applications, will be discussed in detail shortly. For now, it is sufficient to point out that the problem of purchasing bulk quantities of ammonium nitrate inexpensively needs to be solved, if for no other reason than because of the greatly increased efficiency of cooling that can be achieved. In a situation where ice may be unavailable for 12 to 24 hours, 20 to 30 kg of ammonium nitrate may be needed to hold the patient’s temperature near 0ºC. This would be cost-prohibitive for most cryonicists unless fertilizer prills are available.

Another advantage to custom packaged ammonium nitrate is that it can be stored indefinitely in air tight containers. Ammonium nitrate in instant cold pack products slowly absorbs moisture from the air, and from water vapor migrating through the plastic of the internal water reservoir bag. This results in some loss of heat absorbing capacity, but more importantly, it causes the ammonium nitrate to clump, reducing its surface area, and slowing its ability to absorb heat. Over a period of several years (depending upon storage conditions) most of the water may be lost from the water reservoir bag due to evaporation through the plastic. This would necessitate the removal of the ammonium nitrate to another bag, and the addition of a precise amount of water; hardly an acceptable option in an emergency. Nevertheless, unless and until bulk quantities of ammonium nitrate become available for last aid applications, Kwik Kold and similar products are definitely preferable to no ice at all, or to significant delays in initiating post-arrest cooling.

The message here is that there is a viable alternative to ice for non-North American cryonicists, as well those cryonicists in the US who are at high risk of unexpected death, and who cannot maintain a dedicated freezer for storage of ice (which must also be replaced frequently to prevent re-crystallization and consolidation†).

Figure 3: Schematic of a simple head refrigeration device employing nylon mesh bags filled with NH₄NO₃ prills through which water is recirculated. This allows for cooling with about the same efficiency as if water ice were used. See Figures 14-16, below.

The Basics of Effective External Cooling

The first requirement for maximally effective external cooling is that all of the surface area of the patient be continuously in contact with refrigerant that is as near to 0ºC as possible. It is not possible to go lower than 0ºC, because the patient would freeze in the absence of cryoprotection. This constraint on the temperature of the refrigerant has profound implications for the rate at which cooling is possible. To understand why this is so, and to understand the importance of uniform and continuous contact of the patient’s skin with the refrigerant, it is first necessary to understand how cooling occurs.

A good place to start is with the simplest situation and the one most frequently encountered in sudden and unexpected arrest, where cardiopulmonary support is not possible. This situation is simple, in the sense that the only kind of cooling that will be possible is external cooling with ice (or another appropriate refrigerant) and cooling of the head/brain will be by conduction alone. This is so because the human head is a solid consisting of gels (skin, muscle, brain) and bone. Convection does not occur in solids, and the kind of cooling we get in such a situation is called non-Newtonian cooling or non-convective cooling. Conduction cooling is comparatively “simple” because the parameters which determine its behavior are fewer than in convective cooling, where there is a complex interplay between conduction, convection and radiation†. However, while cooling within the patient’s head is purely conductive, cooling at the interface between the scalp and the other skin of the head will typically be convective, since it will involve not only conduction, but also convection (air movement in a morgue cooler, or liquid movement from melting ice, or even convection of water in an “unstirred” ice water bath).

Very recently, the French forensic pathologists Baccino, Cattaneo, Jouineau, et al.,[6] conducted a series of experiments using pig heads to empirically determine the rate of cooling under a variety of conditions, all of which are of importance to cryonicists. While pig heads are not human heads, the data from this study map the spotty and less rigorous data obtained in human cryonics cases. These data show something that may seem surprising, principally that cooling in an unstirred water bath at 0ºC is not even twice as effective as cooling in a still (unstirred) air bath at 0ºC, as shown in Figure 19 below.

Figure 4: Cooling rate observed in porcine heads subjected to unstirred air or water cooling at 0^oC from data by Baccino, et al. [6]

The reason for this is the limitation imposed by the very low value for the heat conductivity of the human head. This has the following important practical implications:

1)         External conductive cooling of the human head/brain is extremely slow, even under ideal conditions of maximum surface contact with ice at 0^oC, where the melt water is filmed over the patient’s head.[7],[8]

2) Once the surface of the patient’s head reaches 0^oC, the brain cannot be cooled any faster regardless of the type or amount of conductive media used. In other words, using more conductive refrigerating media, or delivering them at higher flow rates than necessary to keep the skin at 0^oC, will not work, and may well be counterproductive (i.e., consume limited battery power and cause splashing and aerosolization of potentially biohazardous cooling bath water).[9],[10]

3)         If conditions are less than ideal because of poor contact with refrigerant (and retention of melted ice water in plastic bags) then cooling is slower still, and this is undesirable.

4)         The basic requirement of uniformly cooling the surface of the patient’s head to near 0^oC is, in practice, quite difficult to achieve, because holding refrigerant in contact with the patient’s head involves problems associated with melting ice, which is messy, damaging to bedding and furnishings, and can cause a slip hazard if dripped onto the floor. Containing ice (or NH₄NO₃ –water) in plastic bags results in considerable loss of contact with the skin, and reduces the efficiency of cooling, by causing melt water to be retained; creating a relative convective and conductive barrier. It is also virtually impossible to keep ice bags in position around the patient’s head during movement from one location to another (or for that matter, even when the patient is not being moved as can be seen in Figure 5, below)..

While there is no easy solution to problems 1 and 2 above, there is a solution to problems 3 and 4: an enclosure to hold ice or another acceptable refrigerant around the patient’s head in situations where there is no portable ice bath (PIB)†. This is a critical component of the Last Aid Kit (LAK), that should also contain a number of basic items to help improve patient care, when a Transport Team is not available. Why is having an “ice holder” to keep ice around the patient’s head so important? Again a look at Figure 5, below, is proof that a picture is worth a thousand words. The patient in this picture is being cooled with ice bags and Kwik Kold packs. As just noted, this cuts the effectiveness of ice dramatically by confining it to bags, and it is also messy, which decreases compliance and creates a real danger of slipping and falling for personnel, when tile or linoleum floors become wet and slick (something that is especially likely in institutions with well waxed and polished floors; and inside ambulances).

Figure 5: Cryopatient on a mechanical heart-lung resuscitator being cooled during transport using ice bags and endothermic chemical cooling packs (Kwik-Kold™).

It is also a waste of valuable personnel. The man in the vest and white shirt in the middle of the picture above was a paramedic and he was not happy about the wet floor in his ambulance. Ambulance companies in many states, and in most European countries, can be used to provide Standby and Transport assistance, as happened in the case above, but they will not be inclined to do so under conditions which expose their costly vehicles, and even more valuable personnel, to water damage.

In fact, ice in bags is such a poor refrigerant that  if your head were a bowl of potato salad, you probably wouldn’t eat it if sat around at room temperature as long as the center of your head will above or at room temperature while being cooled with ice bags—there would be too much of a chance it would have spoiled. Figure 6, below, shows just how bad ice bags are at cooling, both in absolute terms, and relative to immersion in ice water (both stirred and unstirred). Even four and a half hours after the start of ice-bag cooling, the patient’s core temperature is still above room temperature: ~ 24 degrees C!

Leaving aside the grossly inefficient nature of cooling with ice bags, how well refrigerated is the patient’s head in the photo above, and how long can anyone be expected to hold those ice bags in place by hand? This photo is not unique, in fact, to the extent it is unique it is because it shows a diligent effort being made to keep this patient’s head well refrigerated. Unfortunately, many pictures of cryopatient Transports show little or no ice around the patients’ heads and, as is the case here, comparatively poor contact of the ice bags with the surface of the head.

Figure 6: Comparison Of Cooling Methods: Above are actual cooling curves for three adult human cryopreservation patients receiving mechanical CPS support, using ice bags, the Portable Ice Bath (PIB), and the PIB augmented by SCCD (squid) cooling. Patient A-1133 weighed 56.8 kg, patient A-1169 weighed 57.3 kg, and patient A-1049 weighed 36.4 kg. As this data indicates PIB cooling is approximately two times as efficient as ice bag cooling. The SCCD appears to increase the rate of cooling by an additional 50%over that of the PIB (roughly adjusting for the difference in the patients’ body mass).[11]

Increased Convenience = Increased Compliance

Some cryopatients will have minimally cooperative family, or family who are not capable of sustained cooperation due to age, infirmity, or psychological limitations. There have been cases where both husband and wife were signed-up cryonicists, and yet when one arrested the other did not pack the patient’s head in ice with a resultant 4-hour delay until brain cooling was begun.[12] Why? How could this happen? The answer is, because they were provided with neither the tools nor the instructions to respond appropriately. Resources need to be readily at hand, and members need to be repeatedly told what to do in an emergency, and given clear, easy to use instructions on how to do it. While most of you reading this may think yourselves immune to making an error such as leaving your spouses’ head unrefrigerated for ~ 4-hours, you should take into consideration the effects that advanced age, and the emotional trauma of an unexpected loss, might have on you.

Morticians do scarcely any better. What is needed is a simple device and a simple procedure which can be rapidly implemented with supplies on hand – something that the first responder only has to do only once, and from which they can then walk away from, till more skilled help arrives on the scene. If anyone questions the need for this, consider the numbers: historically ~ 30% of Alcor members have arrested with little warning, or no Standby team present. Since the Cryonics Institute does not offer Standby, presumably most of their members could benefit. Most cryonicists will not have a portable ice bath (PIB), and most will have few other resources in an emergency. So, the issue of effective cooling of just the patient’s head is non-trivial, and in practice it can only be accomplished with a device that holds the ice, or other refrigerant, in uniform and direct contact with the patient’s head.

Figure 7: A simple, expedient head ice positioner (HIP) fabricated from a plastic garment storage box and a piece of foam pipe insulation. The thermoplastic typically used to manufacture these materials is notoriously liable to fracture during cutting and drilling. The cutout in the HIP pictured above was made using a (repeatedly) heated disposable box-cutting knife

In its simplest implementation a head ice positioner (HIP) is an open-topped box with a U-shaped cut-out to accept the patient’s head as shown in Figure 7, above. This is easily and inexpensively fabricated from off-the-shelf materials and is certainly better than nothing at all. The HIP above was made from a tall plastic garment storage box (26 x 36 x 36 cm) and a section of polyethylene foam water pipe insulation, at total materials cost of $8.56 US. This design has only one serious functional impediment and that is that there is no provision for draining off ice melt before it reaches the level of the U-shaped cut-out for the patient’s neck. It would also be desirable to have a 20-liter plastic bucket or a 20 liter water carboy to collect the melt water, and allow it to be disposed of in a safe and sanitary manner (water that has been in direct contact with a patient should be treated as biohazardous waste).  The drainage problem can be solved by installing a bung fitting with a threaded hose barb, or a tap near at the bottom side of the container as shown in Figure 8, below, or by installing a hand-pumped siphon device.  A second overflow drain, installed just below the level of the cut-out which can be left open when the patient is not being moved (to allow water to automatically flow into the waste container) can also be incorporated into the design.

Figure 8: Off-the-shelf drain/tap kit of the kind used on ice water dispensers installed on the side of HIP to drain off melt water.

The HIP above is simple and inexpensive and will serve in situations where both personnel and ice or other refrigerant are abundant. In such situations, patient contact with the refrigerant can be facilitated by a dedicated staff or family member, excess water can be drained, and refrigerant can be replenished, as needed. However, this is far from desirable. At very least, this HIP should be equipped with an insulating shroud which reduces heat-leak into the container and conserves refrigerant. Such a shroud can be a fabric “box” with either closed cell polyethylene foam or Dacron “foam” (such as NuFoam) on all sides to provide insulation.

The importance of insulation extends beyond conserving refrigerant and eliminating the mess and hazards associated with condensation. In cases where the patient must be left unattended, such as in a C/ME’s or hospital morgue, insulation is essential to prevent rapid melting of ice by convectively stirred, and much warmer, refrigerated air. Morgue coolers vary in temperature between 4ºC and 15ºC, and typically are set in the range of 7ºC to 12 ºC.  Morgue crypts in some large cities are often poorly refrigerated due to antiquated equipment and limited budgets (the latter resulting in economizing on electricity by keeping the crypt temperature high). It is thus critical to provide as much refrigerant as feasible, and to protect it against avoidable heat leak as much as possible.

Every attempt should be made to cool the core of the patient’s head to as close to 0 ºC as possible, before surrendering care of the patient to third parties, who may have little or no interest in continuing further cooling. Even under the best of circumstances, where the patient’s core (brain) temperature has reached 1-2 ºC, it must be understood that the patient’s body and neck represent a considerable heat sink and, in the case of the neck, a very considerable heat leak into the insulated enclosure of the HIP. These constraints also make it desirable that the HIP be monitored and frequently replenished with refrigerant such that the patient’s head never becomes exposed or uncovered with refrigerant.

Yet another limitation of the HIP just described is that it will not fit into some models of morgue refrigerators. While most end-loading (hatch type) morgue refrigerators have a hatch opening of 50 cm, with an available clearance of ~30 cm, most side-loading units, and some older hatch type units, have much less clearance (~20 cm).

Figure 9: Typical single body morgue refrigerator of the kind commonly used in the US, Canada and the UK.

A more sophisticated implementation of the HIP would not only hold ice or other suitable refrigerant in good contact with the entire surface of the patient’s head, but would also be insulated (excluding the neck opening) to an r-value of ≥ 3.0, with a reasonably compact insulating material that will experience minimal thermal drift over a 10-year lifespan and is non-toxic and non-irritating (acceptable materials would be closed cells foams such as polyethylene or polyester foam (NuFoam), or polyester wool batting (20 oz ). Ideally this HIP would be collapsible, and weigh no more than 5 pounds, so that even the frail elderly can handle and position it. A prototype of this device has been constructed and details will be available here in the near future.

Figure 10: The EZ-Basin in-bed shampoo basin is an inflatable device designed to allow for wet shampooing of bed-fast patients’ hair. It is inexpensive ($20 US), and has the advantage of being flexible, allowing it to be used in morgue coolers and other confined spaces where a rigid HIP will not fit.

Another excellent alternative for use in morgue coolers, or other areas where space is confined, is an inflatable shampoo basin, either used as is, or modified to improve its insulating (and thus ice holding) capability (Figure 10). This secure, form-fitting basin cushions patients neck and shoulders while attendant washes hair. The EZ Shampoo basin, marketed by Medline Industries, is an inflatable basin used for shampooing the hair of people confined to bed. It is based on the same principle as inflatable plastic pools for small children, and measures 28W x 24L x 6D, and folds up for easy storage. The insulating characteristics of the basin can be greatly improved either by filling it with expanding polyurethane foam (which will set hard in a few days), or by making slits in the air cells large enough to allow it to be stuffed with Dacron polyester wool from an inexpensive pillow (Figure 11). The slits can then be closed with vinyl repair material, all temperature foil-backed gutter repair tape, or any other durable, long lasting tape that will not dry out and become brittle over time. If stuffing the EZ-Basin is being done expediently in an emergency, then duct tape may be used.

Figure 11: The EZ-Basin can be made into a more reliable HIP by filling the air cells with either polyurethane foam or Dacron polyester wool. The lack of insulation on the bottom can be addressed by placing a cut-out of closed cell polyethylene foam inside, or preferable securing a slab of the same material to the outside bottom of the EZ-Basin. Adhesive backed Velcro strips are a good way to accomplish the latter, since they allow for the foam insulation to be removed and rolled up for more compact storage.

The EZ-Basin has several disadvantages, which can be overcome with varying degrees of ingenuity and effort. The first is that there is no insulation on the bottom of the basin – just a single ~ 10 mil sheet of vinyl. This can be remedied either by attaching a sheet of 1″ or 1/2″ expanded polyethylene foam to the bottom, or placing a cut out of such foam inside the EZ-Basin, as shown in Figure 11. The second disadvantage is that it is quite shallow, with a depth of only 6″. A reasonably good compromise when using it as a HIP in a morgue cooler is to used bagged, crushed or cubed ice heaped up over the ice that is in direct contact with the patient’s skin. Finally, The EZ-Basin has no insulating top or cover. In an emergency, any reasonably good insulating material can be used to completely cover the top (and preferably the sides, as well) of the EZ-Basin, such as a blanket, fiberglass building insulation, or Dacron polyester wool insulation removed  from a pillow, or purchased from a discount retailer in the form of quilter’s batting. If such open, “porous” insulation is used, once it is in place it should be covered with a sheet of plastic, such as a plastic trash bag, to improve its insulating qualities, and prevent warming of the refrigerant, and the patient’s head, due to air convection from the morgue refrigerator fan.

Figure 12: The EZ-Basin HIP as it would be used in the event of unexpected cardiac arrest in the home on an emergent basis.

The EZ-Basin is available from on line retailers in both the US for ~ $20:

http://www.bing.com/shopping/inflatable-ez-shampoo-basin-ez-shampoo-basin/specs/F9A27B32DB5777797B4B?q=shampoo+basin&FORM=EE

and the UK for ~ 17 pounds:

http://www.handyhealthcare.co.uk/mobility-aids/bathing/hair-washing/economy-shampoo-basin.html

Making Iceless Cooling  More Efficient: A More Sophisticated Implementation

As previously noted, outside the United States and Canada, ready access to ice is problematic or nearly impossible. The problem with using chemical cooling packs in place of ice is that they rapidly lose their heat absorbing capacity and then become barriers to effective heat exchange. Additionally, since the refrigerating liquid inside the packs is not stirred and is isolated from the skin by a barrier of plastic and often trapped air as well, heat exchange is very slow and inefficient.

The solution to this problem is to construct a device which circulates the water required to drive the endothermic reaction of NH₄NO₃ prills with water continuously through the NH₄NO₃ prills and over the patient’s head. Such a device, the CephaCool, is shown in Figures 14 through 16, below.

The implementation showed below uses an inexpensive evaporative (swamp) cooler pump that operates on wall current, and is available at most hardware and large retail outlets for about $15.00 US. However, a better approach would be to use a self contained, cordless, battery operated sump or bilge pump, such as the Attwood Waterbuster Cordless Pump shown in Figure 13, below.

Figure 13: The Atwood cordless bilge pump is a fully submersible pump  that runs up to 5 hours on three alkaline D batteries (6-3/8” high x 5-1/4” diameter).and pumps up to 200 gallons per hour at a head of 4’.

Figure 14: The CephaCool head cooling device is completely made from off the shelf items easily procurable at most hardware and large national retailers such as Target or Wal-Mart ( Asda or Tesco in the UK). The HIP portion of the device is fabricated from an Igloo beverage cooler. The refrigerant bags which hold the NH₄NO₃ prills are laundry bags used to contain and protect and delicate items of apparel during machine washing at home and available from Wal-Mart or Target. The drain valve, drain ballast and all connecting tubing are lawn watering items and again are available at most hardware stores as well as Wal-Mart and Target. The cushioning foam on the cervical cut-out is standard polyethylene household water pipe insulation of the kind used to reduce the risk of pipes freezing in the winter or to reduce heat loss from hot water pipes. It is available at most hardware and home improvement stores including the large national chain stores such as Lowes or Home Depot.

Figure 15: The circulating pump in this implementation, as previously noted, is a low capacity evaporative cooler water pump. The diffuser ring and the on-off valve controlling flow to the diffuser ring are both lawn watering items readily available at most hardware stores and at Wal-Mart and Target. The interior splash guard was made from vinyl heet goods purchased at Wal-Mart.

Figure 16: The temperature monitors, both the circulating liquid temperature and pharyngeal temperature monitors are off-the-shelf consumer indoor outdoor thermometers. The pharyngeal temperature monitor shown above also has adjustable high and low alarm features. These items typically sell for $12.00 to $15.00 US and are available at hardware, auto supply, home improvement and large national chain discount retailers.

The CephaCool, as shown above, can be assembled from parts totally ~$75.00 US. With the exception of the cervical cut-out, no tools are required to assemble the components into a fully functional device. All items either slip together or are held together with industrial strength Velcro. If the Atwood cordless bilge pump is used in place of an AC evaporative cooler pump (highly recommended for safety reasons and mandatory if NH₄NO₃ is to be used as the coolant) the cost increases by ~$25.00 to 30.00 (the Atwood retails for ~42.00).

The CephaCool or a device like it, along with a generous supply of NH₄NO₃ prills should be something that every non-North American cryonics group has as a standard piece of equipment available to members upon request or for a modest fee. Members living outside of North America who are at high risk or who have relatives who are at high risk may want to consider acquiring such a device and keeping at the ready for unexpected emergencies.

How Much NH₄NO₃ ?

Preliminary experiments indicate that approximately 20-25 kg of ºC are required to cool a 5 kg mass of ground beef to ~4ºC. Another 5 kg is required to cool to 2ºC. Maintenance of temperature at 2-4ºC requires ~0.5 kg per hour depending upon whether or not the circulating pump is run continuously or intermittently. If operated intermittently (2-3 minutes per 30 minutes) the requirement for NH₄NO₃ prills drops dramatically to ~200 g/hr. It is important to understand that NH₄NO₃ is not a good refrigerant for maintenance cooling; there is no substitute for ice. However, it can serve as an effective “bridge” cooling material, until ice becomes available.

Cool It!

Of course, none of these tool and techniques is of any use unless they are acquired and made ready. Properly, this should be something advocated and assisted by the cryonics organizations. However, after almost 6 years of urging such actions be taken, the author has given up, and decided that the only course of action is to attempt to communicate the resources and the importance of using them directly to other cryonicists, rather than relying on any intermediary.

References

1.         Mohr P, Taylor, BN, Newell, DB.: CODATA recommended values of the fundamental physical constants: 2006. Rev Mod Phys 2008, 80:633-730.

2.         Bowen N: Properties of ammonium nitrate, III. J Phys Chem 1926, 30(6):736-773.

3.         CRC: Handbook of Physics and Chemistry, 44th Edition; 1962.

4.         Bothe J, Beyer, KD.: Experimental determination of the NH4NO3/(NH4)2SO4/H2O phase diagram. J Phys Chem A 2007, 111(48):12106-12117.

5.         Cardinal: Kwik-Kold: http://www.cardinal.com/us/en/distributedproducts/ASP/103B.asp?cat=med_surg. 2011.

6.         Baccino E, Cattaneo, C, Jouineau, C, Poudoulec, J, Martrille, L.: Cooling rates of the ear and brain in pig heads submerged in water implications for postmortem interval estimation of cadavers found in still water. Am J Forensic Med Pathol 2007, 28(1):80-85.

7.         Gulyás B, Dobai, J Jr, Szilágyi, G, Csécsei, G, Székely, G Jr.: Continuous monitoring of post mortem temperature changes in the human brain. Neurochem Res 2006, 31(2):157-166.

8.         Brinkmann B, Henssge, C, Schmitt, M, Eilers, U, Wischhusen, F. : Determination of  the time of death by measurement of rectal temperature in cadavers immersed in water. Beitr Gerichtl Med 1984, 42::103-106.

9.         Nelson D, Nunneley, SA.: Brain temperature and limits on transcranial cooling in humans: quantitative modeling results. Eur J Appl Physiol Occup Physiol 1998, 78(4):353-359.

10.       Henssge C, Beckmann ER, Wischhusen, F, Brinkmann, B.: Determination of the time of death by measurement of central brain temperature. Z Rechtsmed 1984, 93(1):1-22.

11.       Darwin M: Transport Protocol for Cryonic suspension of Humans: http://www.alcor.org/Library/html/1990manual.html. Fullerton, CA; 1986.

12.       Best B: The Cryonics Institute’s 82nd Patient : http://www.cryonics.org/reports/CI82.html. 2007.

†Ice recrystalizes and consolidates into a more or less solid mass over time which it makes it very difficult to use effectively for cooling and requires expenditure of  a great deal of time breaking it up into useable chunks. This process is not only time consuming but is messy and can can result injury due to haste in an emergency. Ice stored in “frost free” freezers fairly rapidly disappears due to partial melting and vaporization during the heating cycles which occur at ~6-hour intervals. These heating cycles (which vaporize ice that has formed on the refrigerating coils) also very rapidly (days) convert crushed and cubed ice into a sold mass of ice.

Footnotes

† Prills are small beads of chemicals or metals made by spraying the material into an environment (spray tower) cold enough to facilitate solidification.

† Even when ice is stored in non-frost-free chest type freezers re-crystallization and consolidation of cubed or shaved ice occurs over a period of several months.

† The first person in cryonics to consider this problem was the mathematician and cryonicist Art Quaife, who did extensive mathematical modeling of this problem in the late 1970s.

† As will be discussed at length later, a head ice positioner (HIP) should be used even when a PIB is available because it solves the problem for how to uniformly circulate cold water over the patient’s head.

By Mike Darwin

Determining and Documenting Cardiopulmonary Arrest

In situations where irreversibility has been established by a properly executed medical directive not to pursue cardiopulmonary resuscitation (CPR) or defibrillation (especially in cases where the patient is of advanced age, in poor health, or is terminally), it still necessary to objectively determine and document cardiopulmonary arrest.

In most countries, including the U.S., Canada, and the U.K., there are currently neither statutory rules, nor standardized criteria for the certification of death following irreversible cessation of cardiorespiratory function (or for that matter following so-called “brain death,” or more properly, pronouncement of death in the presence of mechanically assisted cardiopulmonary function using neurological criteria)†.[1],[2],[3],[4] As a result, current practice varies from certifying death as soon as an attempt at cardiopulmonary resuscitation is abandoned, to waiting 10 minutes, or longer, after the onset of respiratory and cardiac arrest (apnea and aystole).[5],[6],[7] Criteria used to determine apnea and aystole may vary widely from institution to institution within the same city, and additional criteria may also be required, such as the presence of fixed, unresponsive pupils (either dilated or in mid-position), absence of a corneal reflex (a response when the clear “window” of tissue covering the eye is touched with a finger tip, a gauze pad, or a cotton-tipped swab), and/or absence of response to painful stimuli such as knuckling (rubbing) the sternum or moderately depressing the globe of one eye.[1],[8] In some institutions, asystole may be determined only by careful auscultation of the chest (listening for a heartbeat with a stethoscope), while in others, the absence of a carotid pulse is considered adequate. Acceptable times for absence of heartbeat and breathing vary from immediately following failed cardiopulmonary resuscitation, to periods as short as 3 minutes or as long as ten minutes.[9],[10],[4],[11],[12]

The typical criteria taught to physicians for pronouncing death are an examination that includes, at a minimum, the general appearance of the body, no response to verbal or tactile stimulation, no pupillary light reflex (pupils fixed and dilated or fixed in mid-position), absence of breath sounds, and absence of heart sounds.[13]

MAYOR (singing): As mayor of the Munchkin City

In the county of the Land of Oz,

I welcome you most regally.

BARRISTER (singing): But we’ve got to verify it legally.

To see…If she…

Is morally, ethic’ly

CITY FATHER NO. 1:Spiritually, physically

CITY FATHER NO. 2: Positively, absolutely

ALL THE CITY FATHERS: Undeniably and reliably DEAD!

– From the film The Wizard of Oz, 1939.

In the U.S. and most of Europe, the use of painful stimuli such as deep the sternal rub or nipple twisting are now considered inappropriate, although this practice continues in some institutions and by some physicians, and still widely used in Eastern Europe and the developing world. In the scant published literature on the topic, there are some physicians who advocate additional testing for a corneal reflex (blinking when the cornea is touched with a gauze pad or cotton swab), but this is considered duplicative of pupillary reaction to light by other authors, since both reflexes require some intact brainstem function in order to occur.

Admonitions are also universally given to be aware that drug intoxication has the ability to produce complete cessation of brain function, including the electroencephalogram (EEG) (and can be completely reversible) and that total paralysis can also closely simulate death; as can certain critical illnesses such as end-stage liver disease (stage IV hepatic coma) that can make a live patient appear dead. Similarly, physicians are cautioned that profound shock (from blood loss or infection) and profound hypothermia (body temperatures below 32.2ºC or 90ºF) often require far more careful clinical examination because of reduced brain and body metabolism. Infants and children under the age of 5 are surprisingly resilient and have been known to recover completely after prolonged periods of apparent clinical death (cardiorespiratory arrest).

The problem with all these methods is that they are subjective and do not lend themselves to objective documentation. Within the fraternities of medicine and law enforcement, such lack of objective documentation is taken for granted, and this lack of rigor (surprisingly) results in fewer than a dozen cases each year (coming to public attention in the U.S. via the media) of patients awakening in the morgue, moving on the autopsy table as necropsy is begun, or otherwise being determined to have been mistakenly been pronounced dead. (A Google search using the key words “mistakenly declared dead” is all that is needed to find a roster of such cases occurring across the U.S. and around the world).

Thus, the question arises, “what criteria should be used by laypersons to determine “irreversible” cardiopulmonary arrest in the cryopatient?”

Figure 1: Procedure for application of supraorbital pressure.

Field Determination of Irreversible Cardiopulmonary Arrest (ICPA)

First, remember, looks can be deceiving. A visit to most extended care facilities (ECFs) or hospitals would probably reveal a patient or two whose status appeared questionable on initial observation. Second, follow the guidelines below to both determine the patient’s cardiopulmonary status, and to objectively document the signs used to determine “irreversible cardiopulmonary arrest” (ICPA). Above all, remember it that it is ICPA you will be determining, not death.

Field pronouncement of ICPA should follow the following protocol:

1) Whenever possible (and this should be an integral part of the Last Aid Kit (LAK)) a video recorder should be used to document the protocol, and once turned on it should be left on without interruption until the examination is completed. This secures a continuous record and establishes a documented time line. Absent this, remember that later generation mobile phones and virtually all smart phones have embedded cameras, and often video recording capabilities.

2) Use the mechanical or electronic stopwatch in the kit to formally measure the requisite time intervals for the various determinations. (Mechanical stopwatches have the advantage of not needing batteries.)

3) The patient must demonstrate lack of response to verbal or tactile stimulation. This should include calling the patient by name, and application of supraorbital pressure, as shown in Figure 1, above.

4) There must the simultaneous and irreversible onset/presence of apnea and unconsciousness in the absence of the circulation. Apnea should be demonstrated by using a clean, highly polished mirror as shown in Figure 2 below, to document that there is no fogging due to respiration for a period of 3 minutes. Apnea should be confirmed by auscultating the chest as shown in Figure 4, below, following determination of aystole (cardiac arrest) by auscultation, or use of the CapNoMask as shown in Figure 7, below.

5) Absence of circulation, as documented by absence of a carotid pulse on palpation, and the absence of heart sounds on auscultation using a quality stethoscope, as shown in Figure 3, below.

Figure 2: Portable mirror with case for determining that respirations have ceased.

6) One of the following is fulfilled:

−     The patient meets the criteria for not attempting cardiopulmonary resuscitation.

−     Attempts at CPR have failed, as documented in writing by an authorized person (attending physician or EMS personnel).

−     Treatment has been withdrawn because it has been determined to be of no further benefit to the patient and not in his/her best interest to continue, and/or in respect of the patient’s wishes, as documented in writing by the patient, or per the patient’s medical record, or per written instruction from the patient’s primary care physician, or other authorized health care provider.

Figure 3: High quality Rappaport-Sprague stethoscopes such as the one shown above are available at many home health care retail outlets for under $30.00 US.

7) The patient should be observed for a full 5 minutesto confirm that irreversible cardiorespiratory arrest has occurred.  The absence of mechanical cardiac function can be confirmed and documented with increased accuracy using any one (or a combination of) the following, if available:

−     Recorded absence of heart (and breath) sounds using the phonocardiomonitor described in Figure 5 below.

−     Absent blood pressure readings (including plethysographically acquired pulse) on the automatic blood pressure and pulse monitor, as shown Figure 6, below.

−     No exhaled carbon dioxide indication on the Capnomask shown in Figure 7, below.

Figure 4: The chest should be auscultated in multiple areas to ensure that heartbeat has ceased. The locations shown in the diagram above are good locations to listen. Regardless of what type of stethoscope head is used, always auscultate with the flat, diaphragm side of the head, as shown at far right, above. Be certain that this head is selected for listening by lightly tapping the diaphragm with a finger while the ear pieces are positioned in the ears.

8) Given, as per 6 above, that no further attempts are appropriate to restore the patient to present life, any spontaneous return of cardiac or respiratory activity during this period of observation should prompt a further five minute period of observation starting from the next point of cardiorespiratory arrest.

Figure 5: A phonocardiometer is a simple device consisting of a microphone (piezoelectric or conventional) and an amplifier and speaker. Alternatively, the microphone-amplifier assembly may be connected to a wireless transmitter to allow remote monitoring of the patient’s heart beat. The use of audible, rather than electrical monitoring of the heart eliminates the risk of pulse-less electrical activity (PEA) of the heart being confused with an actual “perfusing” heartbeat. PEA may continue for an hour or more after cardiorespiratory arrest has occurred. The unit pictured at left, above, was fabricated by Fred Chamberlain, III in 1975.A commercially available unit is the iWorx/CB Sciences (www.iworx.com) of Denver, NH, HSM-300, a simple device which converts the sound waves, created by the heart valves opening and closing, into voltages which can be recorded and displayed. A piezo-electric sensor, mounted on the side of the HSM-300 picks up the vibrations that are created by the heart sounds. The piezo crystals on the sensor convert the changes in pressure created by the vibrations into voltages. These voltages may be recorded along with the ECG of the subject to identify the specific heart sounds that occur during ventricular contraction and relaxation. The silver-colored sensing element of the HSM-300 is placed on the chest of the subject at one of the four prescribed auscultation areas. These areas are located over sections of the heart and large vessels containing the valves that create the heart sounds that can be heard with a stethoscope. The sensor of the HSM-300 picks the low frequency sound waves of the heart sounds and converts these waves into voltages that can be seen on a computer screen. The output of the HSM-300 is amplified so that the recorded waves are about 1V in amplitude

9) After 5 minutes of continued cardiorespiratory arrest, the absence of pupillary responses to light, of pupillary and corneal reflexes, and of any motor response to supra-orbital pressure, should be confirmed as shown in Figure 1.

10) The time of ICPA is recorded as the time at which these criteria are fulfilled, using the Documentation of Cardiorespiratory Arrest Form (DCAF) present as an addendum to this document.

11) Documentation should include the exam conducted, a description of the physical location where the patient was found or experienced cardiac arrest, the physical condition of the body, any significant medical history or trauma, the conditions that precluded resuscitative efforts, any contact with medical, police, or EMS personnel, and in whose custody the patient was left (i.e., EMS, C/ME, police or other peace officers, mortician, or cryonics organization representative).

Figure 6: Noninvasive plethysographically acquired automatic pulse and blood pressure monitors such as the ones shown above are another option for documenting the onset and continuing presence of cardiorespiratory arrest. State of the art machines such as the one shown on the left also incorporate oxygen saturation monitoring, but are quite costly (although they can often be leased). Another option is older used equipment, such as Critikon Dinamap 1846 SX noninvasive blood pressure and pulse monitoring system, shown at the right, above. These can be acquired refurbished from used medical equipment dealers for several hundred dollars.

12) Double check your findings with every available resource. If there is an ECG monitor attached to the patient at the time of cardiac arrest, make a recording (in two leads). Leave the leads on the body as confirmation of your assessment. If you have an automatic external defibrillator (AED) in the home (increasingly common), confirm it gives a “No Shock Advised” message when attached to the patient, and document this with videography.

Figure 7: The CapNOMask consists of and end-tidal CO2 detector that has been interfaced with a non-fenestrated mask that is easily affixed with an elastic strap. Any exhaled breaths from the patient will turn the indicator some shade of yellow or gray. Absence of any change in the indicator is definitive evidence of respiratory arrest.

Figure 8: Varying Presentations of post cardiac arrest or postmortem lividity, also called postmortem hypostasis, occurs when blood settles or pools in the lowest (dependent) areas of the body under the influence of gravity. Wherever the patient is in contact with a surface under pressure, the small vessels are prevented from filling with blood (A, D, E) and remain pale and uncolored with blood. Lividity becomes “fixed,” in other words will not redistribute if the patient is moved, 6-12 hours after cardiac arrest (E). This is often accompanied by staining of the tissues with hemoglobin (cherry red, as seen in E, above) as a consequence of red cell breakdown (hemolysis).

13) In the event the patient is discovered after the development of postmortem changes, such as rigor mortis or livor mortis (dependent lividity), it is sufficient to document these changes using ICPA form, auscultate the chest for 1-minute to establish absence of heart or breath sounds, and check for the absence of a carotid pulse. It is not necessary under such circumstances to repeat these observations or to wait the required 5-minutes for simple clinical determination of ICPA. Various presentations of livor mortis are shown in Figure 8. Livor mortis occurs when blood settles to the more dependent (lowest) areas of the body under the force of gravity where it distends the venules and the capillaries, and discolors the skin a violet or purplish red color. Livor mortis presents anywhere from twenty minutes to three hours after cardiac arrest, becomes “fixed” 4-5 hours post arrest, and peaks 6-12 hours after the onset of cardiac arrest. Lividity becomes fixed when the blood clots and/or when red cells undergo hemolysis and the tissues become stained with hemoglobin. Prior to this time, lividity may redistribute if the patient is moved. Dependent areas of the patient that are in contact with a surface and under pressure will not develop lividity. The presence of rigor or livor mortis is absolute contraindications to the initiation of CPR. If present, the location and extent of rigor or lividity should be noted on the Body Diagram that accompanies the Documentation of Cardiorespiratory Arrest Form (DCAF) present as an addendum to this document.

Caveats and Cautions

The above protocol offers no guarantees, but does provide substantial documentation of the patient’s actual condition using a nearly universal collection of accepted clinical criteria and specific methods to document irreversible cardiopulmonary arrest. “Irreversible” in this context must be understood to mean that it is either physically impossible to carry out resuscitation and/or that it is medically inappropriate or rejected as an assault on his person by the patient. Determination of medical contraindication to resuscitation must come from a physician(s) acting independently of any cryonics organization and without other conflicts of interest. Examples of the latter would be if such a physician were in any way involved with business entities related to cryonics, stands to take from the patient’s estate, and has personal or family relationships with the patient which could arguably cloud his judgment, or is paid a fee dramatically greater than the “usual and customary fee” for performing this service.

At a minimum, meticulous use of this protocol should help to protect the first responder who is giving last aid to the patient from any criminal or civil liability that might accrue as a result of erroneous or malicious accusations that he acted incompetently or recklessly in determining ICPA before proceeding with last aid measures, or even simply failing to notify and activate the EMS. Regardless of whether last aid measures are undertaken prior to pronouncement of medico-legal death; it is prudent to follow this protocol as completely as possible.

The Hazard of Electrocardiography

Restoration of any signs of life due to application of cryonics procedures, by definition, defeats the universal requirement of irreversibility or permanence which is inherent in all legally, medically and socially accepted definitions and criteria for determining and pronouncing death – from the Common Law definition as defined in Black’s Law Dictionary[14] to the commonsense definition as defined in Webster’s.[15] The criterion that the “permanence” or “irreversibility” of the loss vital signs obtain is also called for in the Harvard Criteria,[16] the American Medical Association’s guidelines,[8] the landmark Kansas statue defining death and the Uniform Declaration of Death Act[17]†.

Figure 9: The Premature Burial painted by Dutch artist Antoine Wiertz is as evocative today of the discomfort and anxiety felt by much of humanity when contemplating the prospect of ambiguity or error in determining when death occurs (and being certain of its permanence) as it was when Wiertz painted it in 1854.

What this means is that the decision to provide cardiopulmonary support at any time after the patient’s medico-legal death has been pronounced must, at a minimum, satisfy the criterion of irreversibility by not restoring any spontaneous signs of life including movement, agonal gasping, agonal respiration, return of mechanical or electrical activity in the heart (ECG), or return of electrical activity in the brain (EEG). Absent pharmacological intervention, it is inevitable that one, or even all of these signs, including consciousness and responsiveness to verbal stimuli, will return in a significant number of cryopatients subjected to prompt cardiopulmonary support.

While a waiting period of 5 or 10 minutes after cardiac arrest has been proposed as sufficient to prevent the return of cerebral function under normal clinical conditions,[12] this is by no means assured, and in many patients mild hypothermia and compensatory metabolic changes associated with peri-mortem pathologies that cause chronic ischemia or hypoxia (such as congestive heart failure or chronic obstructive pulmonary disease) or a prolonged agonal period, may extend the window of cerebral recoverability well beyond this interval. Additionally, on no account will such a short waiting period, or even a waiting period as long as 20 minutes, insure that there is not a return of spontaneous cardiac activity,[18] agonal gasping, or reflexive movements in response to chest compressions or other manipulations which stimulate the spinal cord.[19],[20] Indeed, agonal gasping has been documented in one study to occur in 46% of arrests secondary to myocardial infarction or other primary cardiac causes, and in 32% of arrests from other etiologies. It is also important to note that there appears to be a “plateau effect” where there is less than one-third variability in survival with intact to moderate neurological disability between moderate (5-15 min) and prolonged (>15 min) periods of cardiac arrest.[18, 21] The best estimate of the upper limit of survival in cardiac arrest in the pre-hospital setting is based upon the observation that there are no survivors of normothermic arrest beyond an interval of 30 minutes from the time of witnessed collapse to initiation of basic cardiac life support (BCLS); although survival does occur in a few cases where the interval between arrest and BCLS is estimated to have been as long as 30 minutes.[22]

PEA Reconsidered

In many patients dying slowly the cessation mechanical contraction of the heart is followed by an interval of continued electrocardiographic activity; pulseless electrical activity (PEA), formerly known as “electromechanical disassociation” (EMD). The likely frequency of PEA in the population of cryopatients who experience slow deaths is the reason why ECG is never used as a monitoring or validating modality for determining or pronouncing medico-legal death (since some clinicians and nurses are unwilling to pronounce if PEA is present). The fact that PEA was likely to return in a significant fraction of patients undergoing CPR was deemed irrelevant since survival following PEA was considered virtually non-existent. Thus, in unmonitored cryopatients, PEA was considered simply an undesirable artifact of cardiopulmonary support which, especially if undetected (i.e., no ECG monitoring in place), was irrelevant. Indeed, in many hospitals in the U.S. terminal patients exhibiting PEA are still disconnected from the ECG monitor and then pronounced using clinical criteria.[23, 24]

Figure 9: Understanding Pulseless Electrical Activity (PEA)

However, the medical perception, as well as the medical reality, of the incidence and prognosis of survival in cases of PEA in patients presenting with sudden cardiac death (SCD), as well as in patients suffering from other causes of cardiac arrest is undergoing a sea-change. In the past the PEA was exceedingly rare and its presence in either in-hospital or out-of-hospital cardiac arrest patients was considered a “hopeless” cardiac rhythm that few if any patient’s survived.

For reasons not yet fully understood PEA has gone from being a rare presenting rhythm in cardiac arrest to the most common presenting rhythm in both in-hospital[23, 24] and out-of-hospital cardiac arrests (17). While the prognosis for survival of patients with PEA is still poor, it is by no means hopeless and appears to be steadily improving.[7],[25] The likely return of PEA during CPS in cryopatients may thus take on added medico-legal significance and the return of PEA, ventricular fibrillation, or other non-perfusing rhythms in cryopatients with implanted automatic defibrillators (increasingly likely as indications for use and application of these devices rapidly expands) would result in these devices administering counter-shocks with accompanying visible movement of the patient.

In the home hospice or ECF setting this problem can best be avoided by not using ECG monitoring in any form to either detect or verify the presence of medico-legal death. Rather, the use of conventional clinical criteria, technologically augmented such as by use of plethysographically acquired pulse and blood pressure or detection of cardiac arrest by a phonocardiomonitor using piezoelectric or conventional microphones is mandated.

High Risk Members and Continuous, Long-Term Digital Video and Audio Recording

Again, as a result of the exponential growth in computing power over the last 60 years, it is has become easily technically possible and affordable to continuously digitally record the entire interior of the average 2-3 bedroom home for periods of up to 2 weeks at a time on a single hard drive, at which point the recording is, in the normal course of affairs, overwritten one day at time so that, depending upon the quality of the recording desired, 1-2 weeks of continuous video surveillance of the entire dwelling is always available.

Figure 10: Cylon Body Worn Surveillance System. Wearable DVR: 16 x 9 screen size 720 x 576, resolution 4”, display video playback – MPEG-4 SP with stereo sound. Near DVD quality up to 720×480 @ 30 f/s (NTSC), 720×576 @ 25 f/s (PAL), AVI file format. WMV9 up to 352×288 @ 30 f/s, and 800 KBit/s. Exview Camera: Instant auto focus, Hi Resolution – 1 Lux 2 CIF image, rugged, waterproof, heat resistant and  can be integrated into helmets and headwear. (Photos courtesy of The Audax Group, Plymouth, South Devon, UK, http://www.audaxuk.com/cylon/index.htm)

The advent of compact, reliable and wearable video recording equipment that could be deployed on the person(s) of those administering last aid to the patient, as well as the ready and affordable availability of continuous, forensically certifiable, digital video recording equipment, with the capability of uninterrupted recording of 2-weeks of ~250 to 450 frame per second, high quality color video (each terabyte of memory now costs approximately $400.00) have not been exploited by cryonics organizations‡. High capacity digital video recorders which allow for fast and easy data searches, provide self-schedule management, automatic data backup,  e-mail event alert, and offer IP Address Dispatch (for use with dynamic IP), and control of multiple systems from a remote location[26] are now in wide use in law enforcement, government and business . In-house and in-field (mobile) versions of forensic video systems are rapidly becoming the standard of practice for law enforcement where they are used to protect police officers against accusations of abuse or misconduct.[27],[28] One example widely used by law enforcement around the world is the Cylon Body Worn Surveillance System (Figure 10). The unit consists of a compact, waterproof DVR, and a high resolution color camera (worn on a headset) as shown in Figure 4, above. The DVR can store 400 hours of Mpeg-4 quality full color video and audio recording on it 100 GB hard drive and has a battery life of ~12-hours at its peak, 30 fps recording rate. Since the unit is built for law enforcement it has time/date stamping and event marking capability as well as sophisticated graphical user interface software which allows for rapid search and retrieval of recorded material.[29]

Documentation of Cardiorespiratory Arrest Form (DCAF)

The Documentation of Cardiorespiratory Arrest Form follows the format of data collection used for death certificates in all 50 US States, as well as in Canada and the UK. The information requested on the DCAF is absolutely critical to have available as soon as the patient’s physician or the C/ME arrive. In order for a death certificate to be issued, which is a necessary prerequisite to release of the patient’s body to a cryonics organization or its representative mortician or Funeral Director, all of this information must be available to the physician or mortician filling it out. Failure to have this information at hand and in an organized form can and has resulted in significant delays in the release of cryonics patients of to cryonics organizations resulting in many hours of additional ischemic time. It is strongly recommended that all persons with cryonics arrangements have a DCAF filled out in advance and stored in their Last Aid Emergency Response kit.

Addendum: Documentation of Cardiorespiratory Arrest Form (DCAF):

End of Part 2

Footnotes

† Some may find this statement disagreeable and will point to the 1981 report by the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research entitled Defining Death: A Report on the Medical, Legal and Ethical Issues in the Determination of Death, or to the diverse and wildly different state laws for determining death, which, at last count, came in 27 different flavors, as evidence of statutory criteria. In fact, close reading of all these laws devolves to the final common denominators that  death “constitutes an irreversible cessation of vital functions” as determined by physicians or others so authorized “”based on ordinary standards of medical practice” or “according to usual and customary standards of medical practice” or “in accordance with reasonable medical standards” or “in accordance with accepted medical standards”… In short, there are no discrete diagnostic modalities or procedures specified by law.

† An excellent review of the medico-legal definition of death and the problem presented by the requirement for permanence or irreversibility can be found in Persons, Humanity, and the Definition of Death by Lizza, JP. Persons, Humanity, and the Definition of Death. Boston: Johns Hopkins University Press; 2006..

‡ An upend example is the Toshiba EVR RAID-5 32 channels DVR 480 fps (15fps per cam) security video recorder which can accommodate up to 4 terabytes of memory and retails (1 terabyte) for just under $6,000. Such a system would allow continuous video surveillance of every room of a large residence with 6-weeks of audio-video storage capacity.

References

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2.Pearle M: Texas law on pronouncement of death. Healthtexas 1993, 49(1):8.

3.Das C: Death certificates in Germany, England, The Netherlands, Belgium and the USA. Eur J Health Law 2005, 12(3):193-211.

4.Cole D: Statutory definitions of death and the management of terminally ill patients who may become organ donors after death. Kennedy Inst Ethics J 1993, 3(2):145-155.

5.Doig C, Rocker, G.: Retrieving organs from non-heart-beating organ donors: a review of medical and ethical issues. Can J Anaesth 2003, 50(10):1069-1076.

6.Marchand L, Kushner, KP. : Death Pronouncement: survival tips for residents: http://www.aafp.org/afp/980700ap/rsvoice.htmlAmerican Family Physician 1998, N/A(July).

7.van Walraven C, Forster, AJ, Stiell, IG.: Derivation of a clinical decision rule for the discontinuation of in-hospital cardiac arrest resuscitations. Arch Intern Med 1999, 159:129-134.

8.AMA: Guidelines for the determination of death. . JAMA 1981, 246(19):2184-2186.

9.Brook N, Waller, JR, Nicholson, ML.: Nonheart-beating kidney donation: current practice and future developments. Kidney Int 2003, 63(4):516-529.

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11.Daemen J, de Wit, RJ, Bronkhorst, MW, Yin, M, Heineman, E, Kootstra, G.: Non-heart-beating donor program contributes 40% of kidneys for transplantation. Transplant Proc 1996, 28(1):105-106.

12.DeVita M, Snyder, JV., , Jun;: Development of the University of Pittsburgh Medical Center policy for the care of terminally ill patients who may become organ donors after death following the removal of life support. Kennedy Inst Ethics J 1993, 3(2):31-43.

13.Heidenreich C, Weissman, DE.: Death Pronouncement and Death Notification: What the Resident Needs to Know: http://www.journeyofhearts.org/kirstimd/AMSA/pronounce.htm. In.: EPERC (End-of-Life Physician Education Resource Center). 2000

14.Garner BA: Black’s Law Dictionary

Thompson West; 2004

15.Webster’s Revised Unabridged Dictionary Springfield: G & C. Merriam Co.; 1913.

16.Ad Hoc Committee of the Harvard Medical School to examine the definition of brain death: a definition of irreversible coma. . JAMA 1968, 205:337-340.

17.Uniform Determination of Death Act. In. Chicago: National Conference of Commissioners on Uniform State Laws 1981.

18.Vukmir R, Bircher,, N, Radovsky, A, Safar, P.: Sodium bicarbonate may improve outcome in dogs with brief or prolonged cardiac arrest. Crit Care Med 1995, 23:515-522.

19.Jain S, DeGeorgia, M.: Brain death-associated reflexes and automatisms. Neurocrit Care 2005, 3(2):122-126.

20.Dosemeci L, Cengiz,. M, Yilmaz, M, Ramazanoglu, A., : Frequency of spinal reflex movements in brain-dead patients. 2004, 36(1):17-19.

21.Clark J, Larsen, MP, Culley, LL, Graves, JR, Eisenberg, MS.: Incidence of agonal respirations in sudden cardiac arrest.

. Ann Emerg Med 1992 21(12):1464-1467.

22.DeBehnke D: Resuscitation time limits in experimental pulseless electrical activity cardiac arrest using cardiopulmonary bypass. Resuscitation 1994 27(3):221-229.

23.Parish D, Dane, FC, Montgomery, M, Wynn, LJ, Durham, MD, Brown, TD.: Resuscitation in the hospital: relationship of year and rhythm to outcome. Resuscitation 2000, 47:219-229.

24.Parish D, Dinesh, KM, Francis, C, Dane, C.. Success changes the problem: Why ventricular fibrillation is declining,why pulseless electrical activity is emerging, and what to do about it. Resuscitation 2003, 58 31-35.

25.Stiell I, Wells, GA, Field, BJ, et al.: Improved out-of-hospital cardiac arrest survival through the inexpensive optimization of an existing defibrillation program. JAMA 1999, 281:1175-1181.

26.Toshiba EVR Series Security DVR With 4 Terabytes of Memory [http://www.mp50.com/8070/DVRUPG1RT525TR5.asp]

27.Castro H: Police cars get digital cameras; Seattle department first to use new wireless capability. In.: Seattle Post-Intelligencer Reporter

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28.Digital video recorders give more reliable, accurate footage to police March, 2007. [http://www.policeone.com/police-products/vehicle-equipment/in-car-video/articles/99438/]

29.Cylon Body Worn Surveillance System [http://www.intelcam.co.uk/]

ahn S, Sullivan, FJ, DeLuca, AM, Bacher, JD, Liebmann, J, Krishna, MC, Coffin, D, Mitchell, JB. Hemodynamic effect of the nitroxide superoxide dismutase mimics. Free Radic Biol Med 1999;27((5-6)):529-35.

25.Darwin M. Transport Protocol for Cryonic Suspension of Humans, Fourth Edition. 1990.

By Mike Darwin

Sudden Death and Unexpected Death: Is there a Difference and Does it Matter?

Most cryonicists understand what sudden death is: it is cardiac arrest due to sudden cardiac arrest (SCA), rapidly fatal stroke, accident, homicide, and yes, even suicide. Most sudden cardiac arrests are caused by myocardial infarction (MI), with stroke and accident being the next two most likely causes. Other than sudden death, people die in one of three ways, as illustrated in Figure 1, below.  Death from a chronic, progressive, fatal illness in one of the forms shown in Figure 1 is what most cryonicists expect to befall them, if they expect to die at all; being optimists, quite a few expect interventive gerontology to come to their rescue before they confront such unpleasantness. However, the reality is that it simply isn’t possible for any of us to know how, let alone when, we are going to arrest and, strange as it may seem, that applies even to those of us who are already terminally ill and “dying” now.

Which brings us to the issue of unexpected death: Unexpected death includes all forms of sudden death, but also encompasses deaths from things like cancer and other “predictable” illnesses that occurred sooner (or later) than expected, and as a consequence preclude or derail preparations made to deal with it. It is unfortunately all too common for someone who is terminally ill to either experience cardiac arrest (unexpectedly) sooner than was predicted, or to rally, live days or even months longer than was anticipated, and then arrest unexpectedly after the Standby team has stood-down or downsized dramatically. Too few cryonicists appreciate this reality, and as a consequence, many are caught unprepared.

Figure 1: The three patterns of “predictable” death: Historically death from malignancies (pattern 1) has resulted in a relentless and comparatively predictable decline with a brief period (~2-4 weeks) of sharp decline near the end of the illness. As targeted and rationally designed pharmacological treatments for neoplasms become available over the next decade, death from cancer may become less predictable. Congestive heart failure and chronic obstructive pulmonary disease (pattern 2) are characterized by progressive disability punctuated with acute episodes of acute decompensation the outcome of which (for any given episode) is difficult or impossible to predict. The third category of patients suffering from progressive frailty (often as a result of sarcopenia, osteoporosis and diffuse deterioration in cognitive and motor faculties) or dementia (pattern 3) may arrest suddenly and without warning secondary to heart attack, stroke, or pulmonary embolism, or they may provide warning (in widely variable amounts) in the form of the refusal (or inability) to take in food and fluids, or develop pneumonia, urosepsis, or some other infectious process.

The take-home-message in all of this is very simple; 25% to 30% of cryonicists will arrest with little warning or no Standby team present. While it is true that the number of sudden and unexpected deaths can almost certainly be reduced among cryonicists; that is a topic for another article. As it stands now, the chances of North American cryonicists experiencing cardiac arrest without Standby, due solely to medical causes, are presented in Figure 2, below. Approximately 57% of all deaths in the US are sudden in nature with the balance, of approximately 43%, presumably being candidates for Standby and Transport. However, this presumes there are no financial or logistic barriers to your cryonics organization deploying in a timely fashion. Not considered are snow storms, hurricanes, fuel shortages, or even more mundane problems, such as traffic jams or a breakdown in the complex web of communications and logistics required to get rescue team members organized and deployed. For cryonicists living outside the US, things may be better or worse, in terms of the medical and other causes of sudden death, but beyond that, at least for now, the odds of getting rapid and effective emergency care in the event of unanticipated cardiac arrest are almost nil.

Figure 2:  Approximate U.S. distribution of predictable deaths by cause based on 2004 data. Note that ~57% of all deaths occur sufficiently suddenly, or under circumstances such as accidents, which preclude standby or other cryonics stabilization measures. Chart derived from data: [National Vital Statistics Report, Volume 53, Number 5 (October 2004)].

The obvious problem with unexpected arrests is that they usually prevent Standby, and even when a response team is available locally, such emergencies invariably result in delay. Many cryonicists seem to have the same two ideas about sudden or unexpected arrest: 1) it isn’t going to happen to me, and 2) if it does, I’ll be a Coroner’s or Medical Examiner’s (C/ME’s) case and I’ll either be autopsied, or be unable to receive any emergency cryonics care until the C/ME releases me, too many hours later. The fact is, that both of these assumptions are often wrong. Cryonicists in seemingly good health, with few or even no risk factors for SCA or stroke, have arrested suddenly. Sometimes this has occurred as a result of undetected atherosclerosis, but it has also happened due to cardiac arrhythmia unrelated to coronary heart disease, and as a result of accidents, suicides and even homicides. Cryonicists have arrested as a result of falling off a ladder, being hit by an automobile while walking the dog, due to impulsive, self-inflicted gunshot wound to the chest, and from a pulmonary embolism due to a blood clot (that silently formed in the leg) suddenly breaking free and cutting off blood flow to the lungs. The unexpected is, by definition, just that; unexpected.

In most cases of SCA, the patient becomes a C/ME case with the C/ME at least taking custody of the body and, worst case, performing a complete autopsy (including dissection of the brain). This is not the case in many instances of unexpected death where the person was terminally ill and often already enrolled in a hospice program.  It is also often not the case when an elderly nursing home or hospital patient dies suddenly under unremarkable conditions. If the C/ME is contacted at all in such cases, usually he will immediately (or very quickly – 15 to 20 minutes) issue a release number and allow the patient to be “disposed of” in the same manner as if the death was outside his purview. In at least a dozen cryonics cases the C/MEs have even waived taking custody and performing an autopsy where the “death” occurred at home from SCA or in the setting of chronic illness, and in one case, even though the death was a result of a motor vehicle accident (the member was fatally struck by a car skidding on an icy street while she was walking her dog). CM/Es have enormous discretionary power and how they behave is often dictated more by their personal inclination and mood than it is by the law. A fair number of CM/Es have allowed cryonicists to pack a patient (or in some cases just his head) in ice in the morgue cooler, while others have autopsied cryopatients for no reason, other than to show their contempt for cryonics, and the people who practice it.

Thus, it is not the case that all sudden or unexpected deaths invariably end in the CM/E’s office with “hopelessly” long delays until meaningful emergency care can be started or with no possibility of beneficial intervention because of autopsy. In those cases where cryonics first aid is possible, the quality of that care can make a huge difference in the amount of damage the patient sustains. My purpose here is to lay out a variety of things that you can do to improve your readiness in such an emergency, ranging from fairly simple and inexpensive things, to more complicated and costly preparations. All of the things I will be discussing in these articles will provide stand-alone benefit. In other words, each one will work to improve your chances independently of the others. At the same time, these preparations are largely synergistic, in that when used together, they will help reduce the amount of damage you are likely to sustain if you arrest absent a skilled cryonics team waiting in the next room.

Defining Death?

“[Determination of Death.] An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards.”

– Uniform Determination of Death Act as proposed by the National Conference of Commissioners on Uniform State Laws, May, 1980.

“Theoretically, even destruction of an organ does not prevent its functions from being restored. Any decision to recognize “the end” is inevitably restricted by the limits of available medical knowledge and techniques. Since “irreversibility” adjusts to the times, the proposed statute can incorporate new clinical capabilities. Many patients declared dead fifty years ago because of heart failure would have not experienced an “irreversible cessation of circulatory and respiratory functions” in the hands of a modern hospital.”

– Defining Death: A Report on the Medical, Legal and Ethical Issues in the Determination of Death prepared by the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research

In The Uncertainty of the Signs of Death and the Danger of Precipitate Interments in 1740, Jean-Jacques Winslow advanced the proposition that putrefaction was the only sure sign of death.

The Problem of Pronouncement

As Coroner, I must aver

I thoroughly examined her

And she’s not only MERELY dead,

She’s really, most SINCERELY dead.

—Coroner, after examining the remains of the Wicked Witch of the East, from the film The Wizard of Oz, 1939.

Despite its obvious importance and its restriction to the medical and law enforcement professions (coroners are typically peace officers, and have full police authority) both the criteria and the specific procedures used to pronounce death are surprisingly casual and ill defined. While U.S. law governing the minutiae of who may legally pronounce death varies somewhat from state to state, in general the authority to pronounce, or legally declare death, is reserved for physicians, C/ME’s and their deputized or authorized personnel, and in many states, registered nurses participating in an authorized hospice program.  A search of medical textbooks, peer-reviewed publications, hospital, extended care facility, and even hospice standard operating procedure (SOP) manuals reveals a striking absence of standardized protocols for diagnosing death. In fact, to find any documented or specified procedure at all is the exception, rather than the rule.

A singular problem with cryonics last aid is that the patient actually be clinically dead, and not a candidate for resuscitation before any last aid procedures are applied.  In circumstances where an attending physician, nurse, or other legally authorized person has pronounced death and the patient is not a C/ME’s case, there should be no problem with carrying out the last aid procedures described in these articles. This will particularly be the case in situations where the patient is wearing a medical alert bracelet (and possibly a medical jump drive) with instructions to carry out these procedures (i.e., pack in ice, administer CPR, and so on).  In cases where medico-legal death has not been pronounced, the application of last aid carries with it unknown and possibly serious risks. In such situations it will be up to the member (now patient) and to those around him in positions of authority to decide whether the risk of proceeding outweighs the potential benefit.

While it may seem easy to objectify this decision, in fact it is a highly personal decision and one which ideally should take into account the particulars of the situation at hand; particulars which are often impossible to predict in advance. Since the first cryonics case in 1967 there have been at least 20 instances where one or more a last aid maneuvers have been carried out prior to the legal pronouncement of death. None of these cases resulted in either medical or legal problems. However, this is not a guarantee that such problems could not occur in the future. In order to make an informed decision about applying last aid measures in the absence of legally certified death it is necessary to understand the risks. Those risks, in order of seriousness, are that:

a)      The authorities (physician, nurse, C/ME, other peace officer, or even the prosecutor, decide that the patient was not medically dead (i.e., “irreversible” cardiopulmonary arrest) before last aid procedures were started and that some or all of such procedures either caused or hastened death.

b)      The authorities are concerned that last aid procedures may have been initiated before medical death occurred and that an autopsy is necessary to resolve the issue.

c)      The authorities believe that the patient was a candidate for resuscitation and, while not disputing the absence of cardiopulmonary function, decide that CPR and activation of the emergency medical system (EMS) by calling 911 should have been undertaken.

d)     One or more empowered authorities are irritated, offended, or threatened by cryonics in general or last aid procedures in particular, and decide that they are ground for either declaring the patient a C/ME’s case or for carrying out a post mortem examination.

Individual circumstances will have a great deal to do with whether last aid is prudent , not the least of which will be the temperament and prejudices, as well as the formal policies and procedures, of the relevant authorities. To the extent possible, members should investigate these factors in advance, and at regular intervals, being mindful that CM/E’s are elected or appointed officials, and that they remain in office for highly variable periods of time. It is also important to realize that CM/Es are not in the office round the clock, 365 days a year, but rather have chief deputies and executives under them who are empowered to act in their stead. Discussing your cryonics arrangements and the last aid measures you wish carried out with these legal authorities is of paramount importance – especially in the event you charge those around you with the responsibility of acting before medico-legal death occurs. The same injunction to determine the “lay of the land” with regard to cryonics and last aid measures, also applies to your primary care physician, and to other members of your healthcare team who may have responsibility for you when medico-legal death occurs.

Beyond the disposition of these professionals, the circumstances under which arrest occurs will likely have a profound bearing on the advisability of undertaking even the simplest last aid measures.  In the past, elderly members in poor health or who suffered from well documented coronary artery disease have arrested suddenly only to be discovered by friends or family beyond the window where resuscitation was possible, or in situations where explicit, written instructions were in place that neither CPR nor defibrillation were desired by the member in the event of cardiac arrest. In some of these situations close friends or family members have honored the patient’s wishes and packed the patient’s head in ice prior to medico-legal pronouncement. This has been especially beneficial (and understandable) in rural environments where there would be a long delay between calling EMS personnel and their arrival on the scene. In other instances patients have been packed in ice (head) after EMS personnel arrived, but before formal pronouncement of death. In still other cases patients have received more sophisticated last aid, including CPR and more extensive icing in the interval between cardiorespiratory arrest and the arrival of the home hospice nurse or family physician that is authorized to pronounce medico-legal death.

In all such cases it is absolutely essential that if a decision to proceed with any form of last is made, that the patient’s condition of “irreversible” cardiorespiratory arrest be systematically and thoroughly documented prior to proceeding with any last aid measures. The first step in such documentation is to establish unequivocal evidence of irreversibility in the form of written instructions from the patient that he not be resuscitated in the event of cardiopulmonary arrest, that the patient has unequivocal injuries (decapitation/dismemberment) or postmortem signs that would preclude resuscitation (such as the presence of rigor mortis, livor mortis, or evidence of decomposition), or that the patient has failed medically sanctioned resuscitation (failed effort by EMS to achieve resuscitation on the scene). Written directions not to resuscitate, failed resuscitation and the presence of clearly lethal injuries or postmortem changes are the only true signs of irreversible cardiopulmonary arrest. Cardiopulmonary arrest in all other situations constitutes a prognosis of death, not its diagnosis.