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Treating the Dead

Posted by kdawson on Tue May 01, 2007 10:05 PM
from the pining-for-the-fjords dept.
Biotech Science
FlyByPC writes "According to a NewsWeek article, oxygen deprivation doesn't kill patients as much as the resumption of oxygen does. This discovery could bring about new ways of resuscitating people whose hearts have stopped."
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  • Parrots have recently been discovered to follow this exact same pattern during periods of deprivation from their beloved fjords.

  • Makes a little bit of sense. . . (Score:5, Interesting)

    by MagusSlurpy (592575) on Tuesday May 01 2007, @10:15PM (#18950449) Homepage
    I remember reading somewhere in the last few months (possibly here on /.) that the new preferred version of CPR was 10 compressions to one breath, as opposed to the traditional 3. More compressions = less oxygen. . .

    • Re:Makes a little bit of sense. . . (Score:4, Interesting)

      by dbIII (701233) on Tuesday May 01 2007, @10:31PM (#18950607)
      No - just more blood flow. I heard this from a doctor many years ago when I asked about the number of compressions - what they were taught was to keep things going as fast as you can mangage for as long as you can and just a few breaths. It's just made it into all of the first aid courses recently after working out how long people can keep it going. I beleive people have survived after requiring CPR for many hours (jellyfish sting) so it has to be something two people can keep up indefinately but fast enough to work.

      A few years ago I recall hearing something about people drowning in very cold water and care having to be taken to restore oxygen slowly (Australian ABC Radio Heath Report - Dr Norman Swan), but I don't know what the primary source for that information was.

    • Make it simpler.... (Score:4, Informative)

      by zoltamatron (841204) on Tuesday May 01 2007, @10:39PM (#18950687)

      I forget the actual numbers, but the idea was really to simplify the procedure [americanheart.org]. It's more important to get blood flowing through the heart than do the breaths, so this way inexperienced people spend less time fumbling around with the breaths and more time pumping.

    • Re:Makes a little bit of sense. . . (Score:5, Informative)

      by necro81 (917438) on Tuesday May 01 2007, @10:58PM (#18950839) Journal
      I'm not sure if the guidelines vary by country, but the U.S. guideline was 15 compressions for every 2 breaths (5 + 1 if two people are working). The guidelines [ahajournals.org] were changed to 30 + 2 [washington.edu] at the end of 2005. The reason for the change, as others have mentioned, is that the circulation of blood is most important. Rescue breathing takes time, is harder to do correctly than chest compressions, and takes time (consider it an operational overhead). Also, the compression of the chest causes some air movement on its own, though it is shallow.

    • Re:Makes a little bit of sense. . . (Score:5, Informative)

      by sharky611aol.com (682311) on Tuesday May 01 2007, @11:24PM (#18951003)
      Wow, way too much pseduoinformation here. I'm ACLS certified, so take this to the bank:

      First off, a public service announcement. The current guidelines (which are actually backed up by some pretty good science) are a ratio of 30:2 compressions to breaths. Another important thing to note is that the rate of compressions is 100/min. This is faster than you think and believe it or not is incredibly difficult to do. For the tempo, think "Another One Bites the Dust" (and pardon my irony).

      Ok, now on to the reasoning behind the change. ("Well, I could explain it better, but I'd need charts, and graphs, and an easel.") Essentially, the flow of blood through the arteries and into the myocardium requires the creation and maintenance of a pressure head. Research has shown that it takes about 5-7 compressions to create that pressure head, and every time you stop pumping, you lose that pressure. Now only when this pressure head exists is oxygen being delivered to the myocardium, thus any time you stop pumping, you're creating a period of time in which oxygen is not being delivered. And apparently 30:2 was the best ratio for oxygenating blood in the lungs and delivering blood to the heart.

      Here's the official guidelines and all the studies behind them in all their linky goodness. http://circ.ahajournals.org/content/vol112/24_supp l/ [ahajournals.org]

      • Re:Makes a little bit of sense. . . (Score:4, Insightful)

        by NIckGorton (974753) on Wednesday May 02 2007, @01:10AM (#18952161)
        Actually the primary reasoning for the change was largely to keep it simple. This means there is ONE ratio to remember for all lay-rescuer (single person) CPR for anyone that is not an infant.

        There is not a single 'ideal' compression to ventilation ratio. We know that for garden variety cardiac arrest due to V-Fib, ventilation in the first minute or so is probably almost meaningless. We also know that for hypoxic arrests (like a drowning) that ventilation is far more important. We also know that VFib makes up a greater percent of adult arrests and hypoxic arrests are more common in kids (all of whom get the same ratio.) Moreover the AHA made this decision knowing that they didn't even know the ideal ratio for the single most common type of arrest in the community (from VFib.) The 30:2 ratio was a way of keeping it simple that is not perfect for every kind of arrest, but is a reasonable compromise to try to deliver at least a reasonably acceptable type of CPR to all victims of arrest.

        That is a good thing for lay-rescuers, but the AHA understands that people who are more highly trained and knowledgeable will guide their actions based on that knowledge. For example, if my partner grabbed his chest and collapsed, I would run to the phone, call 911. Return to him, check for a pulse, and if he had none, start wailing on his chest like a crazed weasel on crack. I would not even consider breaking compressions to give a breath till at least minutes had passed - or more trained people arrived and ACLS could be initiated. If however, I pulled him out of a pool, I would check for breathing and if none, give two full rescue breaths. Then check for a pulse, if none, start CPR with probably about a 15-20:2 ratio. I would stop for a moment at 1 minute. If he had a pulse, I would continue breathing for him a full minute or two before I ran to the phone. If he had no pulse, I would give two last breaths and run for the phone.

        Those are drastically different methods that I chose knowing that they would give him the best chance in either situation. But if you try to teach lay-rescuers that, you will get blank stares and some shitty-assed CPR. So it is better to make things as simple as possible and make them so at least everyone gets 'reasonable' CPR.

        Nick

  • What about the brain though. (Score:4, Insightful)

    by mpn14tech (716482) on Tuesday May 01 2007, @10:19PM (#18950481)
    It does not do any good to have a working body if I am still brain dead at the end of the process.
    It might be useful so organs could be used for a transplant.

  • This makes sense in a lot of ways. (Score:5, Interesting)

    by Cadallin (863437) on Tuesday May 01 2007, @10:31PM (#18950615)
    Trying to chill the body of someone in Cardiac arrest, for example, makes perfect sense. People survive hypothermia, even with after they stop breathing and their heart stops beating, remarkably well. I've read about Russians having used this technique during open heart surgery. They lacked machinery like cardiac pumps, so they cooled the patients down and stopped the heart and breathing, while doing the surgery on a bed of ice. It apparently worked far, far better than our technophile medicine in the USA would lead us to believe.

    It even makes sense to me why sudden resumption of oxygen should be lethal. Oxygen is extremely toxic and aerobic organism, such as ourselves, had to evolve complex cellular machinery in order to utilize it for metabolic efficiency, while keeping the oxygen from damaging cellular structures, especially DNA. The sudden surge in oxygenated blood would probably overload this system. Apoptosis in this case may be a protective step by killing the cell before its DNA becomes damaged and possibly cancerous. Thus, flooding the heart with oxygen causes the whole heart to "take one for the team," and shut down completely.

    The discovery that the cells are still alive, and can be revived with special treatment is extremely encouraging for the development of better techniques.

  • Yeah, reprofusion injury http://en.wikipedia.org/wiki/Reperfusion_injury [wikipedia.org].

    I wrote about that >20 years ago, when I was writing for a biotechnology newsletter. After >20 years of research, they understand it much better today.

    Every surgeon knows about reprofusion injury. You can go to Barnes & Noble and look it up in a surgery textbook.

    I don't understand why Newsweek says it's new or that it wasn't known in 1993. I assume those doctors came up with some new detail in its treatment.
  • anyone else get the world of warcraft ad above this story?

    with the panel that reads "RESURRECT FOR FREE"?

    • Re:This was discovered in the US? (Score:5, Interesting)

      by FooAtWFU (699187) on Tuesday May 01 2007, @11:21PM (#18950983) Homepage
      This is one of the big arguments against socialized medicine: since you can make $$$ off medicine, lots of people go into medicine to make $$$ and come up with new and interesting stuff. And this cannot be entirely replaced by government funding. And after the companies have made their billions off the drugs, the patents expire, and after a few decades you've got trillions of dollars worth of medical knowledge that you wouldn't have been able to get otherwise. The cost of this? The poor cannot afford the good medicine.

      Other arguments against socialized medicine include: years-long queues for certain sorts of procedures (which aren't strictly Necessary, but may be Incredibly Useful), the sheer cost of paying for it, and a tricky sort of little moral hazard problem with implications against freedom. (Specifically, if the government has to pay for your health care, then a - you're probably less likely to try and take preventative measures to maintain your health since the Government will deal with it and you won't have to pay for it as heavily as you would otherwise; this contributes to a larger problem: b- being unhealthy means more money out of the federal budget, so the government has a big incentive to make unhealthy activity illegals, and the next thing you know, they could be forcing tofu cubes down your throat screaming "it's good for you!!!!!" when all you want is a hamburger, a simple hamburger, for the love of all that is holy - well, figuratively speaking, anyway; you get the idea.)

      The unarguable fact that's in support of socialized medicine is "it will make certain peoples' lives better". It will also probably make people's lives worse - rich people, healthy people who pay taxes, and Future people. For typical middle-class people, it's less than clear.

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