Brain Death and Organ Donation
While we did not learn the topic of brain death and organ donation in our beit midrash this week, it was certainly the topic of the week, and it is worth laying out what the halakhic debate around organ donation is all about.
It is unquestionably a mitzvah of pikuach nefesh, saving of life, to give organs after one's death. There are times where up to 8 lives can be saved with the organs from one body. While a person does not fulfill mitzvot after death, signing an organ donor card, or a living will is a mitzvah in that it is an act that will lead to the giving of life to others.
When some rabbis come out against organ donation, it is not the mitzvah of organ donation per se that at is under debate. It is the issue of when the organs are taken from the body. Organ donors are usually people who die under tragic circumstances, where the body is still healthy, although the person has suffered a fatal injury, such as a gunshot to the head or a stroke. These injuries can destroy the brain or cause it to cease to function. A person will be declared brain dead only when her upper brain (which controls consciousness and the like) and brain-stem (which controls breathing) have ceased to function. In these cases there is no possibility that the person will regain consciousness, and because the brain-stem has ceased to function, the person will also stop breathing. Nevertheless, because the heart has an internal pace-maker, it will continue to beat for a few hours after breathing has stopped. Without artificial intervention, the lack of oxygen will eventually lead to the heart to stop beating, even on its own, and the person will have suffered pulmonary and cardiac death.
In the past, then, there was no need to precisely define the moment of death. Brain death would automatically lead to the cessation of breathing, which would then lead to the cessation of circulation a few hours later. However, nowadays, it is critical to define the exact moment of death for two reasons - we have artificial respirators, and we have the possibility of organ donation. Artificial respirators allow for a person's lungs to continue to bring oxygen into the body - and the heart - even after brain-stem death. And the possibility of organ donation hinges on when the moment of death is defined. If it is defined when brain-stem death occurs, the organs can be removed after the body is taken off the respirator, and they will be in a healthy state. If, however, death is defined as the moment that the heart stops beating, then in those hours between the removal of the respirator and the cessation of the heart-beat the organs will become oxygen-deprived and will no longer be usable for transplantation.
At what moment, then, does halakha define to be the moment of death? One gemara, Yoma 85a, seems to address this question directly. The Gemara discusses a person who is underneath a collapsed building and may still be alive. In such a case, we can remove the rubble, even on Shabbat, because we may be able to save this person. What happens, the Gemara asks, if when we uncover the person his entire body is crushed? How are we to know whether he is still alive -and we must continue to save him - or whether he is definitely dead, and we should stop our salvage effort, because it would be a violation of Shabbat? The Gemara brings a Tannaitic debate on this issue, where the first, anonymous opinion states that we check the nose, and "others" state that we check the heart. This would seem to be the debate between defining life based on breathing or based on circulation. However, it is questionable whether the position of "the heart" is speaking about circulation. The best place to test for circulation is not the heart, but the wrist, and it is possible that the Gemara means to test breathing by the rising and falling of the chest. More to the point, many Rishonim have the text as "the navel" and not "the heart" and this is much more consistent with the following Gemara.
Regardless of how this position of "others" is understood, in the continuing discussion the Gemara clearly favors the opinion that says the nose, stating that all would agree that checking the nose suffices. In halakha, both Rambam (Shabbat 2:19) and Shulkhan Arukh (OH 329:4) state that we determine life base on whether there is breath coming from the person's nose. And throughout history Jews have always tested for life or death by placing a feather under a person's nose to see if she was still breathing.
If, then, the definition of death is cessation of autonomous breathing, why do some poskim require cessation of circulation? This is really a new criterion, and it was first introduced when the larger world recognized and used circulation as a sign of life. How was this made consistent with the Gemara? Either by emphasizing the rejected opinion that (possibly) states "heart," or by saying that breathing was not the definition of life, only a sign of life, and that the actual definition was circulation. And, until very recently, this issue was academic, as cessation of blood flow occurred soon after cessation of breathing, and very little was at stake in pinpointing death more precisely.
Now, of course, this question is of critical importance. It should thus be clear that if one were to use the traditional halakhic definition of autonomous breathing, that brain-stem death would constitute halakhic death, because the person can no longer breath on her own. Those who want to use circulation as the definition are introducing a new criteria into halakha. They may do so by claiming that breathing is only a sign of life, not the definition, but if so, there is no evidence that the definition is circulation. The definition of life - if we are coming up with new definitions - could just as easily be the functioning of the brain.
Thus, brain-stem death, with the focus on cessation of autonomous breathing, is the traditional definition of halakhic death. And, brain-stem death as an new, independent definition of death, makes at least as much sense, if not more, than using the cessation of circulation as the definition. First - there is possible Talmudic support for brain-stem death as a per se definition: the famous Gemara that a decapitated animal is considered to be dead, although there a number of questions about how relevant that Gemara is. Secondly, I believe that for many of us, it is intuitively obvious that if a person's brain has ceased to function and there is no possibility of recovery, and that the person is not breathing, and the heart is beating only because of its internal mechanism, that it does not make sense to call the person alive. His heart may still be functioning, as it winds down, like a fan that has been shut off and is petering out, by why should the circulation of blood on its own define life? I am not saying that this is the only possible definition, but once we are treating breathing as a sign, and not as the definition, brain-stem death is a more reasonable of a definition of death than circulatory death is.
I, thus, am a strong proponent of the brain-stem death as the halakhic definition of death. This definition not only allows for a person who has suffered brain-stem death to be taken off of a respirator, but also allows for a person to donate her organs to be used after brain-stem / respiratory death.