RE: More is Better (anesthetic)
Lee Corbin writes:
[quoting Stathis]
> It may also reassure you that in the worst possible case - the patient
is
> actually awake, but paralysed - the pain experienced is nowhere near
what
> you would imagine a fully awake person with no drugs on board would
> experience. I once met a young girl, about 10, who had apparently been
awake
> during the first part of a cardiac operation, when her chest was being
cut
> open with an electric saw. What does it feel like when your chest is
being
> cut open with an electric saw? It is "an itchy, scratchy sort of
feeling."
> Thank God for fentanyl!
Ditto!
Thanks for the clinical explanations.
The "physiological stress" you mention above: it happens when
grave surgery is inflicted on tissue? Is it the body's violent
reaction to take emergency action in some way when it senses
something really bad is happening? How does fentanyl (in this
case) work? By locally suppressing the body's reaction, or
what?
Fentanyl is an artificial opioid type analgesic, like morphine or heroin,
differing mainly in that it has a relatively short half-life in the body.
Huge doses of fentanyl are used in cardiac surgery because it is a
relatively benign drug which doesn't adversely affect the cardiovascular
system like volatile anaesthetics, for example. (Heroin is also a very
benign drug, which causes no long term ill effects even after decades of
regular use, something most people don't know.) Opioids don't work locally,
but rather on the central nervous system: the pain signals are generated and
travel up the peripheral nerves as per usual (even in someone under a GA),
but in the awake patient the unpleasantness of the pain is diminished ("I
can still feel the pain, but it doesn't bother me"), along with the
associated reflex release of adrenaline and other stress hormones; in the
anaesthetised patient, it is just the release of stress hormones which is
reduced.
--Stathis Papaioannou
_
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http://www.carpoint.com.au/sellyourcar
RE: More is Better (anesthetic)
Stathis writes > [Lee wrote] > > I'm glad that even the appearance of pain in an unconscious patient > > is disturbing to physicians. That's very good. For the body to be > > experiencing pain---and presumably sending pain signals to the brain > > ---too closely resembles pain being experienced but with no memory > > trace being left. > > The main reason for giving opiods when the vital signs are affected as if > the patient is in pain is not because we believe the anaesthetised patient > is actually in pain, but because it imposes a physiological stress which > could cause the patient physical harm. I see. I'm a little disappointed because I'm still scared of this idea that just preventing memory formation may sometimes be used in place of anasthetics. > It may also reassure you that in the worst possible case - the patient is > actually awake, but paralysed - the pain experienced is nowhere near what > you would imagine a fully awake person with no drugs on board would > experience. I once met a young girl, about 10, who had apparently been awake > during the first part of a cardiac operation, when her chest was being cut > open with an electric saw. What does it feel like when your chest is being > cut open with an electric saw? It is "an itchy, scratchy sort of feeling." > Thank God for fentanyl! Ditto! Thanks for the clinical explanations. The "physiological stress" you mention above: it happens when grave surgery is inflicted on tissue? Is it the body's violent reaction to take emergency action in some way when it senses something really bad is happening? How does fentanyl (in this case) work? By locally suppressing the body's reaction, or what? Lee
RE: More is Better (anesthetic)
Lee Corbin writes: > It's interesting that during an operation, while the patient is well and > truly unconscious, the same physiological response to a painful stimulus is > seen as in an awake person: when the surgeon makes the first incision, heart > rate and blood pressure immediately rise. If you give the patient more > opioid analgesic (like morphine or fentanyl), this response is attenuated - > again, just as in an awake patient with pain who is given opiods. Another > strategy is to use local anaesthetic in conjunction with the general > anaesthetic, so that the part of the body the surgeon is working on is numb. > It sounds silly: why would you want to make it numb when the patient is > unconscious? The reason is, as you [Pete Carlton] suggest, because of the > associated physiological response to painful stimuli which is present > even when there is (presumably!) no conscious experience of pain. I'm glad that even the appearance of pain in an unconscious patient is disturbing to physicians. That's very good. For the body to be experiencing pain---and presumably sending pain signals to the brain ---too closely resembles pain being experienced but with no memory trace being left. The main reason for giving opiods when the vital signs are affected as if the patient is in pain is not because we believe the anaesthetised patient is actually in pain, but because it imposes a physiological stress which could cause the patient physical harm. It may also reassure you that in the worst possible case - the patient is actually awake, but paralysed - the pain experienced is nowhere near what you would imagine a fully awake person with no drugs on board would experience. I once met a young girl, about 10, who had apparently been awake during the first part of a cardiac operation, when her chest was being cut open with an electric saw. What does it feel like when your chest is being cut open with an electric saw? It is "an itchy, scratchy sort of feeling." Thank God for fentanyl! P.S. How about this? You get to create a person from whole cloth down in your torture chamber, and give him the most wonderful conceivable experiences. He or she manages to pack in more benefit, thrills, joy, exuberance, zest for life, satisfaction, and contentment than any hundred normal people all put together. There is just one catch: since you like killing people, you have him painlessly put to sleep when he's 20. Is this pastime you so enjoy down in your torture chamber a good or bad thing? Is it right to do this? It's a very bad thing. As I have said before, the prospect of death is in itself bad, even in the absence of pain. It is why I would not be happy with the idea of dying even though a relatively recent backup of my mind has been made. The backup would have to be current up to a fraction of a second, such as would be the case if one or more copies of my mind were being run in parallel. If I died then, I would lose no experiences, so it wouldn't really be dying. --Stathis Papaioannou _ SEEK: Over 80,000 jobs across all industries at Australia's #1 job site. http://ninemsn.seek.com.au?hotmail
RE: More is Better (anesthetic)
Stathis writes > It's interesting that during an operation, while the patient is well and > truly unconscious, the same physiological response to a painful stimulus is > seen as in an awake person: when the surgeon makes the first incision, heart > rate and blood pressure immediately rise. If you give the patient more > opioid analgesic (like morphine or fentanyl), this response is attenuated - > again, just as in an awake patient with pain who is given opiods. Another > strategy is to use local anaesthetic in conjunction with the general > anaesthetic, so that the part of the body the surgeon is working on is numb. > It sounds silly: why would you want to make it numb when the patient is > unconscious? The reason is, as you [Pete Carlton] suggest, because of the > associated physiological response to painful stimuli which is present > even when there is (presumably!) no conscious experience of pain. I'm glad that even the appearance of pain in an unconscious patient is disturbing to physicians. That's very good. For the body to be experiencing pain---and presumably sending pain signals to the brain ---too closely resembles pain being experienced but with no memory trace being left. Yes, yes, yes, by all means, let's diminish pain in all its forms. > Returning to the topic of torture with memory loss, consider the most > extreme case. You are to be tortured for the rest of your life. Aren't you glad that people on this list can entertain hypotheticals without freaking out? People realize that there is a "Suppose that" implied in your sentence? People here can think the unthinkable? > When you get really old you will become demented, or, if you escape > that fate, you will have a stroke or a myocardial infarct which will > result in brain damage and complete loss of memory and other cognitive > facilities, just before you die or end up a vegetable. Yet more fun. > Therefore, anyone who is tortured will eventually have their memory > of the experience completely erased, and it should be OK to torture > people. NOT! :-) Lee P.S. How about this? You get to create a person from whole cloth down in your torture chamber, and give him the most wonderful conceivable experiences. He or she manages to pack in more benefit, thrills, joy, exuberance, zest for life, satisfaction, and contentment than any hundred normal people all put together. There is just one catch: since you like killing people, you have him painlessly put to sleep when he's 20. Is this pastime you so enjoy down in your torture chamber a good or bad thing? Is it right to do this?
Re: More is Better (anesthetic)
Pete Carlton wrote: The discussion about whether it would be okay to use anesthetic that worked only by removing memories is missing one important piece: that the effects of pain are not just floating "experiences" perceived by the "mind", but have very real effects on the body - high stress levels, release of stress hormones, behavioral trauma, etc. Before stating whether you'd be willing to undergo torture followed by memory loss, it also has to be specified what the long term effects of repeated stress would be. If it's stipulated in the thought experiment that there would be -no- lasting effects at all; i.e., no way in principle that you or someone else could tell after the torture that you'd been tortured as opposed to merely sedated, then it doesn't look like such a bad deal. It's interesting that during an operation, while the patient is well and truly unconscious, the same physiological response to a painful stimulus is seen as in an awake person: when the surgeon makes the first incision, heart rate and blood pressure immediately rise. If you give the patient more opioid analgesic (like morphine or fentanyl), this response is attenuated - again, just as in an awake patient with pain who is given opiods. Another strategy is to use local anaesthetic in conjunction with the general anaesthetic, so that the part of the body the surgeon is working on is numb. It sounds silly: why would you want to make it numb when the patient is unconscious? The reason is, as you suggest, because of the associated physiological response to painful stimuli which is present even when there is (presumably!) no conscious experience of pain. Returning to the topic of torture with memory loss, consider the most extreme case. You are to be tortured for the rest of your life. When you get really old you will become demented, or, if you escape that fate, you will have a stroke or a myocardial infarct which will result in brain damage and complete loss of memory and other cognitive facilities, just before you die or end up a vegetable. Therefore, anyone who is tortured will eventually have their memory of the experience completely erased, and it should be OK to torture people. --Stathis Papaioannou _ REALESTATE: biggest buy/rent/share listings http://ninemsn.realestate.com.au
Re: More is Better (anesthetic)
The discussion about whether it would be okay to use anesthetic that worked only by removing memories is missing one important piece: that the effects of pain are not just floating "experiences" perceived by the "mind", but have very real effects on the body - high stress levels, release of stress hormones, behavioral trauma, etc. Before stating whether you'd be willing to undergo torture followed by memory loss, it also has to be specified what the long term effects of repeated stress would be. If it's stipulated in the thought experiment that there would be -no- lasting effects at all; i.e., no way in principle that you or someone else could tell after the torture that you'd been tortured as opposed to merely sedated, then it doesn't look like such a bad deal.On Jul 1, 2005, at 10:52 PM, Stathis Papaioannou wrote:I have not undergone conscious sedation myself, but I have administered the anaesthetic (midazolam, diazepam, propofol, fentanyl) for hundreds of gastroscopies and colonoscopies. Sometimes the patients are more or less fast asleep for the whole experience. Other times, they seem to be fully awake, talking to you with only a slight slurring of their voice, as if they have had a few beers. In fact, benzodiazepines are not that dissimilar to alcohol pharmacologically, and patients who go into delirium tremens from alcohol withdrawl are treated with large doses of diazepam. (It is ironic that any adult can buy as much alcoholic beverages as he wants, but for diazepam, which basically has all the effects of alcohol but is much safer, a prescription is needed.) The dose of the anaesthetic agent in conscious sedation is titrated according to how the patient responds: if he is very anxious the anaesthetist might give more midazolam, which is primarily given for its anxiolytic effect rather to induce amnesia, while if he is complaining of pain more fentanyl is given. Not everyone has complete amnesia for the procedure afterwards, but even if amnesia were guaranteed, certainly no doctor would deliberately allow a patient to suffer just because he won't remember it. The only situation I can think of where midazolam might be used primarily for its amnestic effect is with young children (you squirt it up their nose!) who need to have a series of unpleasant treatments, and would become very distressed each time if they could remember the details of their last experience.--Stathis Papaioannou
