Suspension Trauma / HHS treatment recommendations

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Suspension Trauma / HHS treatment recommendations

Postby fuzzy-hair-man » Oct 12, 2006 9:44 pm

In my web travels I found this site:
http://www.suspensiontrauma.info/

Which seems to give very good advice on HHS or Suspension Trauma, it is the best site that I have seen for recommending what to do with the patient after you have got them off rope.

Hope it helps
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Suspension Syndrome

Postby cavedoc » Oct 13, 2006 1:49 am

It is indeed an interesting site. I think their explanation of HHS as a type of shock is pretty good. But I take their recommendations on what to do about it with a large grain of salt. They don't cite any sources for their information. A quick electronic search of the medical literature doesn't come up with much either. Perhaps they something beyond speculation but I don't know. I have asked them to send more information on how they came up with their recommendations. In the mean time, my own speculation is that their advice to not lay someone down is potentially harmful. They say that someone is unconscious because of poor blood flow to the brain. I'll buy that. But if they are still unconscious, they need to get blood flow to the brain ASAP. Saving the kidneys does no good if the brain is cooked by an extra 30 minutes with inadequate oxygen. So I hope to hear from them. Maybe they're basing their recommendations on some real science.

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Postby Ralph E. Powers » Oct 13, 2006 2:26 am

Maybe, but I recall reading that the primary problem with HHS is that the blood becomes toxic due to lack of oxygen and once circulation is restored then the toxins in the blood that's pooled in the legs can shock the heart and cause an arrest.
Allowing the person to go into a sitting position may be okay... if they've no other injuries (i.e. spinal or cranial from say a large rock fall). But a rescuer may not know that if the vic/patient is unconcious.
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Re: Suspension Syndrome

Postby Dwight Livingston » Oct 13, 2006 7:59 am

cavedoc wrote:They don't cite any sources for their information. A quick electronic search of the medical literature doesn't come up with much either.


There's a review of studies on harness suspension syndrome, written by Paul Seddon in England, that you can download at http://adventureguides.com.au/PDFs/HSE% ... Report.pdf.
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harness hang and the reflow hypothesis

Postby cavedoc » Oct 13, 2006 10:27 am

Ralph E. Powers wrote:Maybe, but I recall reading that the primary problem with HHS is that the blood becomes toxic due to lack of oxygen and once circulation is restored then the toxins in the blood that's pooled in the legs can shock the heart and cause an arrest.


I've heard this many times as well. What makes me question this is the practice of anesthesiologists during some surgeries. One technique done is to put a tourniquet on the leg and blow it up so that there is no blood flow. The surgeon does surgery on the leg and there is no bleeding. After 90-120 minutes, the tourniquet (basically a blood pressure cuff) is taken down and blood flow starts again. There is perhaps less pooling than in a harness hang situation but the amount of anaerobic metabolism is going to be the same, just much longer than some of the reports of death after 15 minutes of hanging in the harness. So there's all this acidic, potassium laden blood in the leg that returns to the patient after surgery just like harness hang, (allegedly), and despite this happening in most hospitals every day, no one is dying. I asked an anesthesiologist about this and he said that they breathe a little faster to get rid of the CO2 for a few minutes and that's it. No problems.

Same deal for some heart surgeries. They put a clamp across the aorta for up to 60 minutes and then release it with no particular precautions. In this case you have the whole lower half of the body that has no blood supply for an hour, and no sudden deaths happen when blood supply is re-established.

I'm not denying that harness hang is an issue. I just question whether the explanation of the danger is accurate. Maybe there is a reason why 15 minutes of disturbed blood flow then flow re-establishment is dangerous on rope, but 90 minutes in an OR is not. It seems like a question that could be answered with animal experiments, including the question of what to do when you get someone off the rope. But if anyone has done the experiments I haven't managed to find the information.

I just want to know if guidelines on what to do are based on speculation or real evidence. And I'm very open to what evidence might be out there, I just can't find it.

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Postby cob » Oct 13, 2006 11:44 am

Ralph E. Powers wrote:Maybe, but I recall reading that the primary problem with HHS is that the blood becomes toxic due to lack of oxygen and once circulation is restored then the toxins in the blood that's pooled in the legs can shock the heart and cause an arrest.


Uhhhh... I heard/read something a little bit different. That a lack of oxygen has nothing to do with it. The blood continues to flow into the legs more or less unimpeded (and oxygenated) thru the femoral artery, but it is more restricted from flowing out through the femoral vein, (the sit harness pinches the vein off more than the artery) and therefor not as much of the blood is able to flow to the kidneys and liver and get "scrubbed", hence the build up of toxins in the lower extremities.

I just tried to look it up in my anatomy book and on the net, but am unable to find a clear picture of the 2s relative positions to each other.

A tourniquet impedes the blood flow in and out, not just out. Perhaps as the blood again begins to flow after the removal of a tourniguet, it is only able to pick up so much toxins as it flows thru the muscles?

Roger, does this make any sense?

tom

ps, some years back I had surgery on one of my hands and they used a tourniquet. The only side effect I noticed was extreme pain after about an hour.
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Postby cavedoc » Oct 13, 2006 12:46 pm

cob wrote: A tourniquet impedes the blood flow in and out, not just out. Perhaps as the blood again begins to flow after the removal of a tourniguet, it is only able to pick up so much toxins as it flows thru the muscles?

Roger, does this make any sense?

tom


Absolutely. And this is the main difference I see between the two things. But I just don't know how the pooling effect works with a dilution effect. The pooling could lead to shock, which I think is why people to die, but I just don't think it leads to death when you lie a patient down afterward. One could say that the pooling leads to a larger volume of acidified blood and that might be dangerous. Or one could say that with a tourniquet the initial flash will be more concentrated and therefore more dangerous. Either way, I speculate that the amount of anaerobic metabolism is the same, minute for minute. One can make cogent arguments either way. The only way to know is to do some experimentation, which is difficult with human beings with a phenomenon that doesn't happen all that often. We need an animal model.

If there has been experimentation I would like to hear about it. In the absence of it I am leary of anyone taking the recommendation to not lay someone down as a standard of care. I think we really just don't know.

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Re: Suspension Syndrome

Postby cavedoc » Oct 13, 2006 1:54 pm

Dwight wrote:There's a review of studies on harness suspension syndrome, written by Paul Seddon in England, that you can download at http://adventureguides.com.au/PDFs/HSE% ... Report.pdf.


OK. Found it now. Yes, these studies do support the shock model and point out how dangerous this really is. But I'm still looking for something on the reperfusion aspect. Thanks for the link.
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Re: Suspension Syndrome

Postby RT » Oct 14, 2006 12:39 pm

Dwight wrote:
cavedoc wrote:They don't cite any sources for their information. A quick electronic search of the medical literature doesn't come up with much either.


There's a review of studies on harness suspension syndrome, written by Paul Seddon in England, that you can download at http://adventureguides.com.au/PDFs/HSE% ... Report.pdf.

Remove the last dot.
http://adventureguides.com.au/PDFs/HSE% ... Report.pdf
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Re: harness hang and the reflow hypothesis

Postby fuzzy-hair-man » Oct 15, 2006 8:39 pm

cavedoc wrote:I've heard this many times as well. What makes me question this is the practice of anesthesiologists during some surgeries. One technique done is to put a tourniquet on the leg and blow it up so that there is no blood flow. The surgeon does surgery on the leg and there is no bleeding. After 90-120 minutes, the tourniquet (basically a blood pressure cuff) is taken down and blood flow starts again.


The example of surgery is only one leg though not both of them as would be the case with HHS maybe this pushes it over the edge?

I also take it the patient is unconsious, maybe this has implications for the amount of accumulation of blood toxins in the legs, as there is decreased muscle activity compared to a motionless consious patient?.

Like others were suggesting, it may seem that the large quantity of poisoned blood in the legs is the problem, a torniquet stops this by blocking blood flow into and out of the legs. That doesn't explain how a 90 - 120 minute torniquet period can still cause little or no ill effects but HHS a serious problem in relatively few minutes.

Maybe your legs will use as much energy (and therefore produce poisoned blood) as they can given the blood supplied to the legs, ie turn off the tap returning blood and the legs will keep producing poisoned blood until it fills the legs.
Turn off the supply to the legs and the return from the legs and the legs ability to produce the poisons is limited.

The other thing I'd say is there is a differnce in the activity taken place before each of these events (a risk factor to HHS is exhaustion) so there is high blood flow to all areas of the body prior to the patient becoming motionless.
Contrasted with the hospital patient and they have probably been lying down for a while (if it was planned).

There were trials with humans into HHS but they were stopped very quickly once they realised how serious the condition could be. Perfectly health subjects unconsious in 6 - 10 minutes, I think beyond that is some what conjecture. Partly because the condition was not known to exist and so deaths were attributed to other causes ie exposure, or hypothermia so not much was learnt about the condition as a result of these deaths. (Several deaths in France were considered possibly attributable to HHS perviously thought to be exposure related)
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Re: harness hang and the reflow hypothesis

Postby cavedoc » Oct 15, 2006 11:10 pm

fuzzy-hair-man wrote: A bunch of reasonable questions


I can't argue with your reasons of why it might be different in a harness. The experiments that the French did underline how dangerous it can be, but at the same time, is this controlled situation more like the operating room than underground? I just don't know. The French experiments don't seem to address what to do afterward. And that is why I'm concerned with definitive statements on how a rescued harness hang patient should be treated.

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Re: harness hang and the reflow hypothesis

Postby cob » Oct 16, 2006 8:28 am

fuzzy-hair-man wrote:I also take it the patient is unconsious, maybe this has implications for the amount of accumulation of blood toxins in the legs, as there is decreased muscle activity compared to a motionless consious patient?.
****
The other thing I'd say is there is a differnce in the activity taken place before each of these events (a risk factor to HHS is exhaustion) so there is high blood flow to all areas of the body prior to the patient becoming motionless.
Contrasted with the hospital patient and they have probably been lying down for a while (if it was planned).


My own experience in surgery with a tourniguet is not perfectly analogous, as the tourniquet was on my arm, not my leg, but none of the above were issues in my case.

I came in off the street after a "light-duty" day of work (carpenter), and within a halfhour was sitting in a chair, and fully conscious while the doc was cutting on me. I bring it up only because the tourniquet is an oft used and well understood surgical tool that the doc was completely comfortable with, and afterwards I got only the usual post-op instructions, to take it easy for a few days etc etc.

I do find it a curiousity that 2 things which on the surface seem to be very similar, can have such drasticly different effects on the human body, one causing severe medical difficulties, even death, and the other being considered as no more serious than stitches.

Roger, I wonder if their recomendation is coming out of experience, in that they have found that victims who are allowed to lay down are FAR more likely to have difficulties, than those who stay on their feet. It may not come from a controlled experiment, but if rescuers report that 70-80% of victims who lay down go into shock, while only 20% of those who walk do... Of course, one has to make allowances for the differing levels of exhaustion in vics, because those who want to lay down are obviously more exhausted than those who don't, and maybe that is the reason those who lie down go into shock and the laying down is just circumstantial.

Like you say, "first do no harm".

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Re: harness hang and the reflow hypothesis

Postby cavedoc » Oct 16, 2006 9:53 am

cob wrote:Roger, I wonder if their recomendation is coming out of experience, in that they have found that victims who are allowed to lay down are FAR more likely to have difficulties, than those who stay on their feet. It may not come from a controlled experiment, but if rescuers report that 70-80% of victims who lay down go into shock, while only 20% of those who walk do...
tom


Maybe. If they have data, I'd love to see it. You and I both should have to chance to evaluate it. Still no word from them. Maybe someone will send me something now that the weekend is over. I'll be sure to repost it if they do.
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Postby fuzzy-hair-man » Oct 16, 2006 8:08 pm

The report that Dwight posted (I haven't read it all) mentions a thing call 'Rescue Death' in other words it there have been several people recorded who have been pulled off rope in otherwise perfect health and no serious injuries as the result of the fall but they have died within hours or days of being taken off rope, autopsies have then been done to find the cause(s) of thier deaths. I won't try to explain these but generally consistant with blood pooling and the build up of blood toxins.

I think this is where the treatment aspect of someone recently released from the rope is coming from.

Incidently the report Dwight posted seems to make a lot of the same recomendations as the website however it does have references which is useful.
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Postby Stridergdm » Oct 16, 2006 10:19 pm

To state the obvious: one difference between the HHS situation and the OR is that the patient is prepped for the surgery. He's already starting in a stable condition, warmed, most likely balanced blood chemistry, etc.

The patient hanging in a harness is already most likely starting in a compromised position, probably lowered core temp, blood sugars lowered due to exhaustion, and finally probably whatever effects dumping adrenline into the system has on him. And things are only getting worse from there.

Whether this is the difference between a HHS patient and an OR patient, I really don't know. I leave that up to those of you with Dr. before your name. :-)
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