Human "Suspended Animation" Trials To Start This Month 104
An anonymous reader writes in with news about a UPMC Presbyterian Hospital trial starting this month which brings us one step closer to suspended animation. "The researchers behind it don't want to call it suspended animation, but it's the most conventional way to explain it. The world's first humans trials will start at the UPMC Presbyterian Hospital in Pittsburgh, with 10 patients whose injuries would otherwise be fatal to operate on. A team of surgeons will remove the patient's blood, replacing it with a chilled saline solution that would cool the body, slowing down bodily functions and delaying death from blood loss. According to Dr. Samuel Tisherman, talking to New Scientist: 'We are suspending life, but we don't like to call it suspended animation because it sounds like science fiction... we call it emergency preservation and resuscitation.'" We covered this story a few months ago when it was announced.
Re:I'm not a doctor, but... (Score:5, Informative)
First, I am a doctor, and I know both Drs Tisherman, and Rhee, having met both in person and having read many of both of their papers. They are both stellar leaders in the field of trauma surgery. I am therefore posting as AC to avoid the perception of any even quasi-official criticism. These are my thoughts on the subject and are meant only to educate the readership, not to try to detract from the work cited
Second, I'm not jumping on " confused one"'s post, just taking an opportunity to correct a minor misconception, and use it as a hook to provide some detail as I understand them.
cold enough to shut everything off, but not cold enough to damage cells. Basic principle originates in all those "miraculous" drowning victims who fall through winter ice and are resuscitated 20 or 30 minutes later.
The "miraculous drowning victims" to which you refer usually survive due to the mammalian diving reflex [wikipedia.org], which is a distinct event (although hypothermia is involved) involving a slowing of the heart, vasoconstriction, and a closing of the glottic opening due to the face being submerged. The principle this proposed technique is using is more of a physio-chemical slowing of the reactions in the whole body, but of prime importance the heart, kidneys, and brain (and to a lesser extent the liver and lungs).
The proposed candidate patients (I presume, not having read their IRB nor their treatment protocol) would involve patients with penetrating trauma (knife or GSW) that have already had a resuscitative thoracotomy [wikipedia.org] (as per my interpretation of the New Scientist article [newscientist.com]). This means that the patient is either in extremis [merriam-webster.com], or has lost vital signs (no B/P, no pulse), at this point, under certain criteria, the chest is opened and the heart prolapsed from the pericardium, the aorta is cross-clamped and open massage or defibrillation is performed along with massive volume resuscitation. For these patients, this is literally, pulling out all the stops to try to save them. It often has a low survivability (~7%) as there is literally nothing else that can be done....until this trial.
The effect would be to suspend cellular aerobic metabolism [wikipedia.org] and induce a state of hypometabolism that could be sustained by anaerobic metabolism [wikipedia.org]. Not quite the suspended animation of science fiction. This would limit the amount of oxygen radicals that can lead to reperfusion syndrome [wikipedia.org], but this is not a given.
The questions that remain: how will humans as a "higher lifeform" with a more temperamental neurological makeup deal with this hypometabolic state? Will they be able to cool them fast enough in the hectic conditions of a trauma-code to be useful? What will their neurological status be? What about the blood already lost - the patient will likely need significant transfusions, will this reduce the effectiveness of the treatment due to transfusion related lung injury [wikipedia.org] or transfusion related immunosuppression [sciencedirect.com]. Will the patient tolerate the hypothermia as this is traditionally considered a part of the lethal triad [wikipedia.org], for that matter, saline is a very acidic substance (to the body), how will they tolerate that acidosis (also part of the triad). I hope they are able to obtain useful information about these (and other) questions that may make this a viab