Tuesday, March 28th, 2017

Problems with Defining Death as the Irreversible Cessation of Circulation: What Would We Measure and Why? by Noam Stadlan, MD

February 16, 2011 by  
Filed under New Posts

 The Va’ad Halacha (VH) of the RCA recently circulated a document with the title “Halachic Issues in the Determination of Death and in Organ Transplantation.”   As has been demonstrated elsewhere, the paper is an attempt to educate rabbis and the public regarding the problems with defining death using neurological criteria (commonly referred to as ‘brain death’), without providing any of the known rebuttals against these critiques.   In doing so, the VH can only be seen as supporting the stated alternative to ‘brain death,’ which is to define death as the irreversible cessation of circulation (or some variant on that theme). 

Yet the VH paper does not address the conceptual and logical problems that result from defining death as the irreversible cessation of circulation (ICC).  Elsewhere (see here) I have pointed out some of the logical inconsistencies in applying the ICC definition of death.  The problems with ICC identified in this paper stem, for the most part, from the lack of a precise anatomic and/or functional definition of a human being.  Here I would like to discuss an even more basic problem with the ICC definition which has not yet been connected to the halachic context:  The medical/scientific assumptions that underlie this definition are no longer true.  As a result, the practical steps for determining death are no longer consistent with the claimed conceptual basis. 

What Do We Mean When We Refer to Criteria to Determine Death?

Rabbi J. David Bleich, in his article “Time of Death” (within Judaism and Healing), describes a three tiered system for establishing criteria for determining death[1].

  1. A philosophical/metaphysical conception of death (which has no practical application since it cannot be measured)
  2. A more practical description of death that is based on an analysis of Halachic material
  3. Practical criteria.  These criteria obviously are designed so that a person who fulfills these criteria matches the description of death in the second step.

 

Rabbi Bleich also provides appropriate information to fill in the tiers:

1.   Death is defined as when the soul has left the body

 2.  The irreversible cessation of circulation is the hallmark of death[2]

 3. If a person lacks circulation or respiration, and 20-30 minutes have passed by (he gives a few different sources for times), the person is dead[3].

A Review of Problems Related to Anatomy

Many Halachic sources have been quoted as giving support for the idea that death is defined by the irreversible cessation of circulation, including statements by Rashi in Yoma, responsa of the Chacham Tzvi[4] and the Chatam Sofer, and others.  However, these opinions were promulgated in a time when two somewhat interrelated assumptions could be made, neither of which is currently true:  The body is an interdependent entity, and, when the heart irreversibly ceases to beat, circulation has irreversibly ceased.

Before the era of transplants, artificial organs, and machines that provide circulation, the body could accurately be seen as an interdependent whole.  The failure of one organ meant that every other organ would fail soon thereafter.  If the heart stopped, every other organ would not receive blood and nutrition and would cease to function soon after the heart did.  If the brain ceased functioning, it would no longer signal the diaphragm to move, the lungs would stop working, and the rest of the body would no longer receive oxygen, swiftly resulting in total body failure. 

Yet in the modern era, ventilators can take over for the brain signals, dialysis machines can substitute for kidneys, and pumps and artificial hearts can pump blood.  Therefore, failure of one organ system does not automatically result in failure of the entire body.  Under the old conception of the body, every organ system failed at essentially the same time, and it was not necessary to identify what parts of the body were crucial to the identity of the person (or the home of the soul in more metaphysical terms).  In the modern era, organs can fail or be removed at different times.  For example, the brain can cease to function while the heart still beats.  A kidney can be preserved without circulation even 20-30 minutes after the heart has ceased to pump.   More importantly,  any organ or part of the body with intact blood vessels can be attached to a pumping machine, will have circulation, and therefore will have preserved function.   Since the parts of the body can fail at different times and somewhat independently of each other, it is necessary to identify which portions of the anatomy and which functions are essential to the continued life of a person, and which are not necessary.   One can no longer assume that failure of circulation in one part of the body implies that the circulation has failed in every part of the body.  Therefore, if the lack of circulation is the criterion for death, it is necessary to identify which part of the body needs to lack circulation in order for death to be declared.  Use of the word ‘body’ without further clarification is no longer precise enough to apply in all cases.

CPR and Other Modern Technologies Can Restore and Maintain Circulation:  When is Circulatory Death? 

The development of alternate sources of circulation is not only the basis for the anatomic challenge discussed above, but undermines the very basic assumptions of the ICC definition. Transplanted hearts, artificial hearts, bypass pumps, and even chest compressions (CPR) can all provide circulation to a body.  No matter what the status of the body, as long as arteries and veins are present, circulation can be supplied.  Artificial hearts, transplants, and circulation machines are obviously not universally available.  But CPR certainly is.  CPR is usually viewed as a way to restart the heart, but what it actually does is supply circulation.  During chest compressions, a pulse can usually be palpated.  In fact, chest compressions can provide adequate blood flow for long periods of time.[5]  Therefore, as long as arteries and veins are present, circulation is never irreversibly lost.  All that is needed are some chest compressions.

The advocates of the ICC definition of death face a serious challenge.  If they insist that the irreversible cessation of circulation is indeed the criterion for death (tier 2 in the system described above), then the practical advice (tier 3) on how to determine that irreversibility must change.  Death can no longer be declared while a body still has intact arteries and veins.  Waiting 20-30 minutes after cessation of circulation is no longer enough to ensure irreversibility.  The waiting period needs to be days at least, or even more, until the arteries and veins have deteriorated to the point where they no longer can support circulation.  And, while they are waiting, if someone happens to push on the person’s chest and move the blood, the person has to be considered alive by strict application of the ICC criterion.

The Problematic Distinction between ‘Permanent vs.  Irreversible’

One option for the ICC advocates is actually one that the Va’ad Halacha paper criticizes (page 8), albeit indirectly.  The paper discusses ‘non-heart beating donors’, also known as ‘donation after cardiac death’.  In this situation, a family wishes to donate the organs of a patient who has sustained severe neurological injuries, but is not ‘brain dead.’  The patient either does not breathe on his own, or breathes minimally, not enough to sustain the body for a significant period of time.  Therefore, when the ventilator is disconnected, the body does not receive adequate amounts of oxygen.  After being deprived of oxygen for a period of time, the heart stops.  This event is followed by a waiting period of a specific amount of time, and then the patient is declared dead based on the cessation of circulation. 

The problem with this approach is highlighted when the heart is taken out and transplanted into another body, and provides circulation in that new body.  How can death be declared based on the concept that circulation has been irreversibly lost, when that same heart can provide circulation?  Indeed, in one report, physicians waited only 75 seconds after the heart had stopped to declare death, harvested the heart, and transplanted it into another child where it functioned normally.[6]

 The moral/philosophical basis for these actions was to make a distinction between ‘permanent’ and ‘irreversible.’[7]   ‘Permanent’ is defined as a situation that will not reverse on its own.  In other words, permanent describes the situation where the body will not regain circulation on its own without outside help, and the outside observer has made the determination that outside help will not be provided.   Irreversible is defined as something that can not be reversed, no matter what efforts are exerted.  In the situation described above, the person can be declared dead when it is determined that the body can no longer restart the heart on its own (  Indeed, this has been the topic of a number of recent studies and discussion in the medical literature.[8] (It should be clear that the issue of the heart restarting is independent of brain function or any other body function – it is focused solely on the heart)

This concept theoretically could be applied by the backers of the ICC definition of death.  However, making a distinction between permanent and irreversible means that the declaration of death is based on the intent and actions (or lack of actions) of the observer, and is no longer based solely on an intrinsic quality of or finding in the body.  In other words, the person observing could supply circulation (either by CPR, or some machines), and the body would be alive.  However, if the observer decides that he is not going to supply circulation, then the person is dead, and the observer in fact has no obligation to treat a dead person.  Therefore, any patient whose heart has stopped beating(cardiac arrest) could be declared dead based on permanent (but not irreversible) loss of circulation, even if it was possible to resuscitate them.  Once the time frame where the possibility of autoresuscitation had passed(usually thought to be 2-5 minutes, see reference 8), there would be no obligation to perform CPR, even if that CPR had the potential to return the person to the status of an intact, normally functioning human being.   Since the obligation to save and preserve life is a highly valued concept in Halacha, it is doubtful that this approach will be acceptable.

 

Circulation Provided by a Person’s Own Heart vs. Artificial Support

Another option that might be available to the supporters of the ICC definition of death is to make a distinction between circulation provided by a person’s own heart and that provided by artificial means.  However, it appears to me that modern poskim accept that circulation does not have to be provided by a person’s own heart.  In other words, circulation provided by a transplanted heart, bypass pump, or artificial pump all qualify as circulation   So, if this argument is employed, it would be necessary to explain how in one situation artificial circulation qualifies as circulation, and in a different situation it does not. 

The next option would be to gloss over the irreversibility issue (tier 2), but to maintain that the practical parameters of existing definitions (tier 3) are the part of the definition that is immutable:  Death is declared only after circulation has ceased and has been absent for 20-30 minutes.  This approach not only ignores the obvious disconnection between the theoretical basis for the definition and the practical application, but in fact is not applied in all situations.  For example, during some complex surgeries, the heart is stopped, and the body ceases to have circulation, in some cases for over 30 minutes[9].  This person should be considered dead by the ICC criterion.  However, the vast majority of patients wake up, and the majority function normally after the surgery.  Unless these patients are going to be labeled as dead, this approach does not seem logical.

What Is Circulation?

The strict definition of the word circulation means something that moves in a circuit.  Obviously the usual assumption in the context of this discussion is that circulation refers to movement of blood.  The purpose of the blood in the body essentially is to bring oxygen and nutrients to organs, and take away carbon dioxide and waste products.  Since the heart is dependent on the oxygen and glucose supplied by the blood, prior to the availability of artificial circulation, if the blood did not provide these functions, the heart would fail and the organs would then quickly fail as well.  Artificial pumps can move any fluid through arteries and veins.  Therefore, it is necessary to establish the criteria for circulation, and the basis for deciding on those particular criteria.  For example, does flowing water in arteries and veins qualify as circulation?  Does the blood have to carry oxygen?  Is there a minimum blood flow? A minimum blood pressure? Does one red blood cell moving 1 milimeter per minute qualify as circulation?  If any moving fluid qualifies Halachically as circulation, then the category of Halachic circulation will include fluids that do not supply organs with oxygen, glucose, or needed chemicals.  From the point of view of the continued function of the body, it would be as if there was no circulation at all.  If a body were attached to a pump or artificial heart that just pumped water through the arteries and veins, the tissues of the body would cease to function very quickly and would be irreversibly damaged in less than 30 minutes(just as if there were nothing moving in the blood vessels at all).  However, because the circulation qualified as Halachic circulation, the body would in fact have to be considered alive as long as the water flowed, potentially forever, or until the power source in the pump ceased to function.

I suggest that the use of the word ‘circulation’ up until now has contained an unstated qualification:  Circulation has actually meant circulation adequate to support the tissues of the body.  This leads to two discussions.  The first is:  What is the Halachic status of inadequate circulation?  The logical answer, based on the discussion above, is that circulation that is not adequate to support tissue does not fulfill the criteria to be considered circulation in the Halachic sense.  Of course, the exact definition of which tissue and how much support can be parsed and discussed.  But the underlying conclusion is that not all fluid flow, whether it is blood or otherwise, fulfills the criteria to be considered circulation in the Halachic sense.[10]

The second discussion is more fundamental:  Why does the circulation need to be adequate to sustain tissue? Is it just a theoretical requirement, or is it necessary for some tissue to actually be present and receive  the circulation?  Furthermore, if tissue needs to be present  what tissue does that have to be, and does the tissue have to possess the potential to benefit from the circulation?  In other words, does the fact that blood is circulating make a person alive, or is it the fact that there are some tissues that are functioning or have the potential to function as a result of that circulation that make the person alive?  Part of this discussion obviously refers back to the discussion above regarding the anatomic basis for a human being.   However, a fundamental distinction is necessary between the circulation itself, and the effects of the circulation.  If the circulation itself is all that is necessary for life, than any tissue with circulation is considered alive, no matter if the tissue itself has irreversibly ceased to function.  In fact, taken to the extreme, any set of tubing with flow, or even blood flow could demand the label of being alive.  The circulation pump itself could be considered alive, since it not only provides flow, but the blood flows through it. 

Similarly, if tissue is a necessary recipient of the circulation, but there isn’t a stipulation regarding the condition of the tissue, then a body from the morgue can be attached to a pump and would fulfill the criteria for life.  

It hopefully has become clear that circulation only has meaning when it provides support to tissue that has the potential to benefit from that support.  The final step is to define which, if any, tissue that needs to be.  As noted in the anatomic discussions, the brain is the only organ that has not been transplanted, replaced, or amputated without a concomitant declaration of death.  Therefore, it appears that the circulation definition of life actually refers to circulation that supplies the functioning or potentially functioning brain.  Any other application results in logical incoherence.

One Definition of Death, Or Two?

The VH paper (page 12) notes that there really is only one definition of death.  The paper supports the circulatory criterion for death.  However, it also notes with approval some non-circulatory criteria for death.  It quotes Rabbi J David Bleich (page 90) as stating, “It is not the mere beating of the heart that indicates life, but that heartbeat is the primary example of vital motion in a living body, which is not germane in the case of a heart removed from the body.”  Rabbi Bleich does not define the exact meaning of ‘vital motion’, but at least seems to acknowledge that heart beat by itself is not enough for life, and that there must be something more than circulation.  Elsewhere, Rabbi Shlomo Zalman Auerbach is quoted as stating, “It is correct that if a brain is completely and absolutely dead, [the person] is considered dead.”[11]  It appears that modern poskim accept that circulation by itself is not the only criterion for death.  However, if there is only one actual definition of death, is it circulation, or “the complete and absolute death of the brain”?  Circulation can continue in a body when the brain has been removed.  Therefore, unless the VH paper wants to contradict this posek (or have two different definitions of death), it is necessary for it to amend its definition of death from the cessation of circulation to at least the cessation of circulation to the brain. 

Concluding Thoughts and Challenges

The definition of death based on the irreversible cessation of circulation was accepted in a time when hearts could not be replaced and machines were not available to provide circulation.  In the present medical era, circulation can be provided by machines, transplanted hearts, or even chest compressions during CPR.  Therefore, circulation is never irreversibly lost until the arteries and veins have decomposed to the point where they can no longer transport fluid.  Furthermore, since it is possible for fluids that do not support tissue function to be pumped throughout the body,  the term circulation needs to be defined with precision   The logical outcome of an analysis of these assumptions is that  circulation, the flow of fluid, is only halachically relevant if it supplies a functioning or potentially functioning brain. 

In view of the above analysis, the advocates of defining death based on the irreversible cessation of circulation have limited options that produce logically cogent results.  The most logical option is to realize that changes in medical prowess have required a change in the practical details of the definition of death.  Defining death by neurological criteria can be seen as a logical extension of previous practical definitions when the underlying unstated assumptions are examined.  It could in fact be argued that previous halachic definitions of death, including cessation of circulation, were in fact testing for the irreversible loss of neurological function.  It was just not realized at the time that this was the underlying phenomenon that needed to be examined.  The other options for the ICC advocates are not very palatable:

  1. change the practical criteria for declaring death so that death is declared when the blood vessels have decayed(a process that takes days)
  2. Attempt to redefine exactly what is meant by irreversible loss of circulation- something that brings a different set of problems as noted above(permanent versus irreversible).
  3. hold fast to all the present definitions and criteria, admitting or perhaps denying that they defy logic and medical knowledge

 

This last option deserves a small comment.  For the Jew who believes in following Torah and Mitzvot, defining death ultimately is a Halachic issue.  However, it is clear that the specifics of how Halacha defines death have changed over time.  Why and how that has changed is not the topic of this discussion, but the unassailable truth is that we no longer use feathers or mirrors on a routine basis in ascertaining death.  The scientific and medical understanding of the body and the ability to preserve parts of the body while others fail necessitate an appraisal of how death has been determined in the past, specifically with regard to unstated assumptions based on the medical knowledge of the time.  The ideal definition of death should produce coherent consistent results when applied to all technically feasible situations that require a determination of the life and death status of a person or collection of tissue.   

The definition of death based on neurological criteria fulfills that requirement.  An acknowledgement of the primacy of neurological function in establishing  the presence of human life doe not have to be seen as a deviation from past Halachic definitions of life and death.  It actually is consistent with previous halachic definitions if the underlying medical assumptions are taken into account.   Adhering to a logically incoherent position that flies in the face of medical and scientific knowledge is perhaps a much greater break with the process of how Halacha has been established in the past.  As such, it behooves the ICC advocates to properly clarify their criterion for determining death.


[1] Rabbi Avraham Steinberg describes this as well, and credits an article by Stuart Youngner.

[2] Rabbi Bleich mentions the idea of vital functions that also need to be absent.  Unfortunately, he does not give a specific definition of what he means, and therefore it is hard to apply this concept.  This is discussed in detail in (meorot reference).

[3] Rabbi Bleich also notes that in the modern era, when blood pressure and pulse can be measured more accurately, the amount of time necessary to wait may be less.  Rav Shlomo Zalman Auerbach also is quoted as giving a 20-30 minute time frame after the determination of cessation of movement, respiration, and circulation.

[4] It should also be noted that Rashi and the Chacham Tzvi believed that heart function was related to respiration.

[5] In this report, chest compressions were done for 1 hour and 40 minutes and the patient did quite well. Ugeskr Laeger. 2010 Nov 15; 172(46):3191-2.

[6]“ Pediatric Heart Transplantation after Declaration of Cardiocirculatory Death”  Mark M. Boucek, M.D., available here:  http:/www.nejm.org/doi/full/10.1056/NEJMoa0800660#t=article

[7] This is best described by Dr. James Bernat in his article:   “How the Distinction between “Irreversible” and “Permanent” Illuminates Circulatory–Respiratory Death Determination”

J Med Philos (2010) 35 (3): 242-255.  

[8] A systematic review of autoresuscitation after cardiac arrest *

Hornby, K. MSc; Hornby, L. MSc; Shemie, S. D. MD

Critical Care Medicine

Volume 38(5), May 2010, pp 1246-1253

[9] In this case report, the patient had no pulse and no circulation for 44 minutes. “Brain tissue oxygen pressure, carbon dioxide pressure, and pH during hypothermic circulatory arrest.

Hoffman WE. Charbel FT. Edelman G. Ausman JI.

Surgical Neurology. 46(1):75-9, 1996 Jul.

[10] I raised this idea briefly in the discussion of the application of medical knowledge to the different Halachic definitions of death by neurological criteria.  Total cessation of blood flow is sometimes cited as a necessary part of the determination of death based on physiological decapitation.  While blood flow tests can show no blood flow, there is a lower limit of detection, so that a very small amount of blood flow might not be detected.  In the face of loss of function of the brain, the concept of inadequate blood flow can be applied to the small amount of flow that may be present (its presence cannot be ruled out with total certainty).  Since this small amount of blood flow is not adequate to sustain tissue function, it is inadequate flow and therefore not Halachically considered circulation.

[11] From Prof. Avraham Steinberg, “Determination of Death: Survey of Viewpoints,”

[in Hebrew] Assia 14 (1994): 5-16. as quoted by Josh Kunin

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