Tag: EMS

Cryonics sets example for emergency medicine

One of the most neglected aspects of cryonics is that its procedures, and the research to support them, can have important practical applications in mainstream fields such as organ preservation and emergency medicine. Contrary to popular opinion, cryonics does not just involve an optimistic extrapolation of existing science but can set the standard for these disciplines. As a matter of fact, that is exactly what cryonics, and cryonics associated research, has been doing over the last 25 years.

The most striking example is the progress in vitrification as an alternative for conventional cryopreservation. Although the idea of eliminating ice formation at low subzero temperatures has been discussed since the beginning of cryobiology, vitrification as a serious research agenda was largely driven by the demand for ice-free preservation of the human brain. Over the last decades this research has culminated in the development of the least toxic vitrification agent to date, 21st Century Medicine’s M22.

The contributions of cryonics to mainstream science and medical practice are not confined to cryobiology. Researchers Jerry Leaf and Mike Darwin made impressive progress in the formulation of bloodless whole body organ preservation solutions to resuscitate dogs from ultraprofound hypothermic temperatures, an intervention that is increasingly being recognized as essential to stabilize trauma victims. In the mid 1990s, Mike Darwin and Steve Harris conceived and developed the idea of using liquid breathing with perfluorocarbons as a method to induce rapid hypothermia. They further validated a multi-modal medications protocol to resuscitate dogs from up to 17 minutes of normothermic cardiac arrest without neurological damage.

Although progress has slowed considerably in the non-cryobiology research areas over the last 10 years, it is encouraging to observe that some of the procedures that are routine in cryonics  stabilization protocol  are starting to catch on in mainstream emergency medicine practice as well. For example, contemporary cryonics stabilization protocol has been strongly shaped by the idea that the best strategy to limit brain injury after cardiac arrest is to combine a number of different interventions: cardiopulmonary support, induction of hypothermia, and administration of circulation-supporting and neuroprotective medications.

It is therefore very encouraging to learn that the Wake County EMS group in North Carolina has achieved impressive results in treating out-of-hospital cardiac arrest victims using a protocol that closely follows elements of current cryonics stabilization protocol. Systematic implementation of immediate induction of hypothermia, continuous compression CPR, and the use of an impedance threshold device (ResQPOD) produced an almost 400% improvement in survival and vast improvements in neurological outcome. A PowerPoint presentation about their experience and protocols are available at their website.

Such real world outcomes do not only inspire confidence in the procedures cryonics organizations can use to protect patients from brain damage after cardiac arrest, it should also serve as a wake-up call to relaunch an aggressive research agenda to push the limits of hypothermic and normothermic resuscitation. In absence of this, it will only be a matter of time before cryonics activists can no longer claim that “we did it first.”

HT Mike Darwin

Benefits of voice recording technology

In his January 2008 Journal of Emergency Medical Services (JEMS) article, “Nothing but the Truth,” Criss Brainard provides examples of two cases where voice recording technology could aid in clearing the names of emergency personnel who had been accused of inappropriate conduct during patient transport. While cryonics standby team members may not need to worry about such allegations, it is obvious that voice recording can be useful in clarifying any questions regarding the specifics of a case. In fact, nearly every aspect of a cryonics case can be voice recorded including logistical operations, start of procedures, medication administration, physiological measurements, descriptions of complex procedures, and real-time reporting of equipment malfunctions and concerns.

Voice recording technology has existed for at least as long as cryonics has, and yet cryonics organizations have rarely made consistent use of it during standby, stabilization, transport and cryopreservation. Instead, cryonics has often relied solely on the services of a “scribe,” whose duty it is to take written notes of all procedures. Voice recording not only provides a more accurate and reliable method of documentation, but also can free up a person to assist with procedures when a clip-on microphone is used. This feature also enables use of voice recorders by multiple team members, including team members performing procedures that are often hard to observe by the scribe, such as surgery. The utility of voice recording can be further strengthened by training team members how to describe specific technical cryonics procedures and to recognize important events.

Brainard points out that the San Diego Fire Department has used voice recording as a standard practice for over two decades to provide objective information about thousands of cases. He writes:

As a best practice, every EMS system should want the truth, good or bad. We should ensure that we’re on the front end of an incident, equipped with all the facts, not just recollections of the facts. If we make a mistake, we must own it; and if we’re being falsely accused, we should want that to come out also.

In addition, voice recording makes case reporting more rigorous and less prone to speculation, which helps to improve quality of care for future patients. Lack of voice recording shrouds cryonics in an aura of secrecy that damages credibility and makes it difficult to factually defend actions of cryonics team members.

Sustained abdominal compression

Conventional CPR typically generates around one-third to one-fourth of normal cardiac output, which is not sufficient to meet cerebral energy demands. In cryonics patients, cardiac output may be further compromised because many patients are atherosclerotic and/or have gone through a prolonged period of shock / multiple organ failure prior to pronouncement of legal death. However, conventional chest compression techniques can be improved and augmented to produce higher cardiac output and cerebral blood flow.

In cryonics, chest compression techniques range from manual chest compressions to mechanical high impulse active compression-decompression cardiopulmonary support (CPS). A recent technology that has been introduced to cryonics is the use of a mechanical load-distributing band CPS device, the Autopulse. Cerebral blood flow can be further augmented by using a respiratory impedance valve (such as the ResQPOD) and administration of vasoactive medications, such as epinephrine and vasopressin.

Although these interventions can improve cerebral blood flow during CPS, it is a well documented fact that many cryonics patients do not benefit from such improvements. Administration of vasoactive medications requires intravenous access which is often difficult to obtain in the typical cryonics patient. Similarly, the use of an impedance valve requires a patent airway which requires rapid and successful intubation of the patient. Clearly, it would be beneficial to have a technology that can be rapidly applied, is non-invasive, and does not require special technical knowledge or manual skills.

Abdominal compression appears to be such a technology. An air-inflatable cuff is positioned on top of the abdomen and secured in place. In some versions of the technology, a contoured cuff follows the lower border of the rib cage to minimize the chance of interference of the cuff with lung inflation during positive pressure ventilation. Constant abdominal compression is achieved by inflating the cuff during chest compressions. Abdominal compression increases coronary and cerebral blood flow by a) increasing intrathoracic pressure, b) increasing functional arterial resistance, and c) redistributing blood volume above the diaphragm out of the abdominal compartment (in: Biomedical Engineering Fundamentals, 2006).

In a recent study by Lottes et al. (2007), sustained abdominal compression was able to raise coronary perfusion pressure as much as vasopressor drugs. Progressively better results were obtained when abdominal pressure was increased from 100 mmHg to 500 mmHg. Optimal results were obtained when abdominal compression was used in combination with vasopressor drugs. This technology has also been evaluated in humans; Chandra et al. (1981) reported increased mean arterial, systolic, and diastolic blood pressure during CPR following cardiac arrest in humans.

Advantages of sustained abdominal compression in cryonics include: low fabrication costs, light in weight, indefinite shelf life, no refrigeration requirements, no electrical power requirements, easy to apply, immediate onset of action, constant effect over time (unlike medications), and immediately reversibility of the procedure.

The disadvantages of sustained abdominal compression are not evident but warrant careful consideration: (a) Abdominal compression may exacerbate ischemia-induced abdominal hemorrhage – this disadvantage is highly speculative since rupture of the inner lining of the gastric mucosa is a biochemical, not mechanical, event. It is clear, however, that abdominal compression is contra-indicated in patients with abdominal swelling and related gastrointestinal complications. The band and cuff may also interfere with placing a gastric tube to administer an antacid (I owe this point to Stephen Van Sickle). (b) Reversal of abdominal compression may rewarm the upper part of the body as a result of warmer blood having increased access to the upper torso and brain – this, again, is speculative and depends on the question of whether abdominal compression induces selective cooling of the torso. If such a scenario is possible, this effect might be limited by not reversing compression until internal cooling is started. The question remains, however, if better perfusion of the brain will offset slower cooling of the brain as a result of decreased surface cooling. (c) The inflatable cuff may interfere with the Autopulse technology – it is not likely that the two technologies will interfere because the lower part of the Autopulse band does not come into contact with the upper part of the abdominal compression cuff.

Another concern that has been raised about using this technology in cryonics concerns the possibility that abdominal binding has the effect of shunting blood to the upper torso and brain. The resulting lack of perfusion, and subsequent collapse of the vascular bed in the lower extremities, may make raising and cannulating the femoral vessels very difficult, if not impossible. An opposite view is that abdominal compression may actually facilitate femoral cannulation because it creates a bloodless field and enhances visibility of the vein by inflating and distending it (I owe this point to Brian Wowk). It should also be noted that not all cryonics stabilization cases are followed by blood washout through the femoral vessels. Examples include remote cases without blood washout, local cases, and cases in which the patient is cryoprotected in the field (in which surgical access may be obtained through median sternotomy or the cerebral vessels).

It remains to be seen if sustained abdominal compression becomes more popular in resuscitation medicine. Provided this technology is as effective as documented in the Lottes paper, contemporary cryonics stabilization procedures may benefit from such a simple technology to increase blood flow to the brain during CPS.

Selected Bibliography

Lottes AE, Rundell AE, Geddes LA, Kemeny AE, Otlewski MP, Babbs CF.
Sustained abdominal compression during CPR raises coronary perfusion pressures as much as vasopressor drugs.
Resuscitation. 2007 Dec;75(3):515-24.

Wik L, Naess PA, Ilebekk A, Steen PA.
Simultaneous active compression-decompression and abdominal binding increase carotid blood flow additively during cardiopulmonary resuscitation (CPR) in pigs.
Resuscitation. 1994 Jul;28(1):55-64.

Babbs CF, Blevins WE.
Abdominal binding and counterpulsation in cardiopulmonary resuscitation.
Critical Care Clinics. 1986 Apr;2(2):319-32.

Koehler RC, Chandra N, Guerci AD, Tsitlik J, Traystman RJ, Rogers MC, Weisfeldt ML.
Augmentation of cerebral perfusion by simultaneous chest compression and lung inflation with abdominal binding after cardiac arrest in dogs.
Circulation. 1983 Feb;67(2):266-75.

Chandra N, Snyder LD, Weisfeldt ML.
Abdominal binding during cardiopulmonary resuscitation in man.
JAMA. 1981 Jul 24-31;246(4):351-3.