On Wed, May 02, 2007 at 09:10:29PM +0530, shiv sastry wrote: > er... what will they do if they get this chap's heart beating again?
I wouldn't. I would perfuse him, and freeze him. > Use him as an organ donor I suppose. That's a possibility, but I presume this is about throwing up the window of viability a whole lot wider. > Every organ has an "ischemia time" - i.e time without oxygen or circulation > before its cells start showing signs of death. It's not fixed, if you can pre/postmedicate. Premeds are fantastic, but postmedication does make one heck of a difference. > Off the top of my head I recall that ischemia time at body temperature for > the > liver is 15 minutes, for a kidney it's about half an hour and for muscles it > can be as long as 6 hours. Heart, being muscle will probably last longer > than > liver or kidney (or retina for that matter). I have heard my own father's > intestinal sounds (caused by movement of the intestine) five minutes after I > declared him dead, shut his eyes and kissed him one last time. > > "Cardioplegia" is a technique that is used in open heart surgery and I have > been on open heart teams using that in the early 1980s in Pondicherry. This > "cardioplegia" was combined with physical cooling of the body to reduce body > temperature and reduce oxygen demand of the body. Hypothermia has been there in the OP for a long while now. > It has been known for a long time that people who drown in cold water can > sometimes be revived even after their heart appears to have stopped, and > that appears to be what this guy is talking about. > > The questions the article has NOT answered is the fact that brain tissue will > be dead, and secondly, there is nerve tissue in the heart itself that There is no fixed time for brain death. A lot of the damage cascades appear hours and days after the ischemic event. A whole of them are blockable. > regulates heartbeat and that too will be dead after 5 minutes of non I've seen dogs doing just fine after 16 min of normothermic ischaemia. No pre-meds, just arrest with wall current across the heart. > oxygenation so a restarted heart may need an artificial pacemaker. The other > "little" problem is that when even 5% of "trillions" of cells die, they > release fairly toxic chemicals and when you do restart the heart all these You can block apoptotic cascades. > chemicals spread out through the body into every cell and cause secondary > problems that can kill. No mention of that in this rather sensational news > item. Yes, but, well, it's press. By definition, they've got very little clue. > Apart from the errors - such as suggesting that stopping heart massage is a > random whim. The author of the article is bullshitting like mad. -- Eugen* Leitl <a href="http://leitl.org";>leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE
