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8-Apr-2011 11:23:54 AM
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Some interesting reading....
http://www.hse.gov.uk/research/crr_pdf/2002/crr02451.pdf
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8-Apr-2011 12:23:28 PM
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Only skimmed it but 1. reinforced how serious harness hang syndrome is, and 2. the point about not laying down a patient suspected of it - placing them in a sitting position instead.
Also about pumping the legs - I very much doubt anyone would do so given other injuries would be more likely of greater concern?
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9-Apr-2011 9:51:42 AM
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Very topical read for me at the moment as the mob I work for are about to purchase new rescue harnessess for us. The bit about manufacturers not including suspension tests in their gear is still true. I have tried on at least 6 new models in the last week and found them all wanting. Yes they are huge with padding everywhere, quick release buckles, fast tensioning systems and large, fancy, shiny rings front back and all over but they weigh heaps and are mighty uncomfortable when suspended for even a short time. One manufacturer refused to allow us to hang in their harness to test em so they got sent packing. My climbing harness while not suited to industrial rescue is generaly very comfortable to sit in and I have offered it to some of the reps so they can do their own comparison re comfort but they are never keen on the idea.
With some of the crap gear out there for industrial use combined with a lot of peoples inability to fit and adjust a harness properly and an attitude that because I have a lanyard and harness I'm now "birdman" and able to take wonderfull risks it's a wonder more arn't injured.
From a climbing point of view we all should be aware of suspension/harness hang syndrome and how lethal it can be in a very short time for ourselves, buddies and in case we have to help others.
Have the Araps rescue crew had to deal with anyone suffering the effects?
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9-Apr-2011 8:28:36 PM
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thanks for the link - really interesting read.
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10-Apr-2011 10:33:08 PM
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The Australian Resus Council did a bit of work with this and published the following in 2009:
http://www.resus.org.au/policy/guidelines/section_9/guideline-9-1-5july2009.pdf
specifically:
"Some agenicies maintain that rescuers maintain victims in a sitting position and avoid lying them flat for 30 minutes. There is NO EVIDENCE to support this practice as a treatment for suspension trauma and it may be harmful. Care of the airway takes precidence over any injury."
This is what is now taught on first aid and rope access courses.
Richard
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11-Apr-2011 11:37:41 AM
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Good point Richard. From the references in that document I found this link:
http://www.hse.gov.uk/research/rrpdf/rr708.pdf
Page 20 is very interesting:
There are no studies that have been designed to answer this question. In a number of harness suspension studies subjects experienced presyncope and even in some cases syncope. All subjects were successfully recovered by lying supine. Several authors give opinions about an alternative recovery position but in none of the studies were subjects recovered in the semirecumbent way later suggested. There is no evidence of so-called “reflow syndrome” or reperfusion injury being reported in suspension orthostasis.
Only anecdotal evidence suggests that the standard first aid [putting the patient in a lying position] may have any adverse effect.
This refers to a hypothetical situation where low-oxygen blood could have pooled in the legs and once the subject is removed from the harness it could all flow back to the body at once and cause massive strain on the heart (potentially cardiac arrest). This was the basis of previous recommendations to put patients into a sitting position if they have no airway blockages or other major injuries (including the PDF I linked above).
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11-Apr-2011 11:53:05 AM
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On 11/04/2011 gordoste wrote:
>This refers to a hypothetical situation where low-oxygen blood could have
>pooled in the legs and once the subject is removed from the harness it
>could all flow back to the body at once and cause massive strain on the
>heart (potentially cardiac arrest). This was the basis of previous recommendations
>to put patients into a sitting position if they have no airway blockages
>or other major injuries (including the PDF I linked above).
>
Also triggers redox signalling leading to apoptotic pathways being activated due to generation of superoxides and other radicals.
P
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11-Apr-2011 5:03:00 PM
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My wife's favorite quote comes from paragraph one of p.24:
Orthostatic shock and typical respiratory obstruction may lead to death when hanging on a rope; the probability of survival after hanging 2 hours is small; death may occur during hanging or after detachment from the rope when rescued.
I'm not sure she'll ever let me climb again.
To echo a previous question, anyone know if the Araps rescue team have experienced this malady in any of their rescues?
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11-Apr-2011 8:13:03 PM
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On 11/04/2011 IdratherbeclimbingM9 wrote:
>On 11/04/2011 Miguel75 wrote:
>>My wife's favorite quote comes from paragraph one of p.24:
>>
>>Orthostatic shock and typical respiratory obstruction may lead to
>death
>>when hanging on a rope; the probability of survival after hanging 2 hours
>>is small; death may occur during hanging or after detachment from the
>rope
>>when rescued.
>>
>>I'm not sure she'll ever let me climb again.
In dayes of yore, ye olde subject of hang-draw-&-quartering was revivede before proceeding...
~> This suggests the hanging part can't be that fatal and is easily overcome, even with old tech methods?
Heh, heh, heh.
>>To echo a previous question, anyone know if the Araps rescue team have
>>experienced this malady in any of their rescues?
Why restrict to them(?), go for a wider net I say!
I have been around a while and although I am aware of harness hang syndrome, I have never heard of an instance of it occurring in Australia.
Before the flame throwers come out, I am not saying it hasn't happened, only that it is rare enough that I have not read/heard of an instance in the last 45 years...
☺
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11-Apr-2011 10:31:44 PM
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On 11/04/2011 IdratherbeclimbingM9 wrote:
>I have been around a while and although I am aware of harness hang syndrome,
>I have never heard of an instance of it occurring in Australia.
>Before the flame throwers come out, I am not saying it hasn't happened,
>only that it is rare enough that I have not read/heard of an instance in
>the last 45 years...
>☺
Wasn't there a case last year of a canyoner being given up for dead because he/she was hanging from a rope for a number of hours and the body wasn't recovered for a day or so after?
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6-Oct-2011 8:21:44 PM
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On 11/04/2011 TooFatToClimb wrote:
>Wasn't there a case last year of a canyoner being given up for dead because
>he/she was hanging from a rope for a number of hours and the body wasn't
>recovered for a day or so after?
I don't know.
The canyoning deaths that I have heard of usually involved drowning.
(Sorry for the late reply, as I have only just tripped over this thread again).
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7-Oct-2011 8:17:09 AM
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After 5-30 minutes? Whilst still concious? Haven't many of us spent way more time than that in manky hanging belays? Several off us have spent 1hr+ at a time hanging in harnesses with the frinj show we are working on at the moment pretty much everyday. You mean we should add HHS to the JSA? I don't want to have to think about anything else in the JSA! That document is rapidly reaching book proportions!
And I'm unaware of any rescues for HHS at the Mt.
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7-Oct-2011 8:42:06 AM
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That's my question - i'm aware that once unconscious and slumped in the harness, it's all bad, but the rescue doc seemed to suggest that even conscious, it could happen in 5-30m.
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7-Oct-2011 9:11:59 AM
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Its been discussed before
http://www.chockstone.org/Forum/Forum.asp?Action=Display&ForumID=1&MessageID=93601&Replies=42
I think it would be difficult recruiting volunteers for a study looking at how long an unconscious person can hang in a harness before they die :)
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7-Oct-2011 9:18:58 AM
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It can happen if conscious if you make the effort not to move.....there was study done by US caving society who got guys to sit in a harness and not move and some did pass out very quickly...around the 5-10 minute mark.....some had no affect so the effect is not constant across the board...no one died though so they may have been lucky?
Most awake climbers will move slightly even without realising to reduce the pressure but if climber has a head injury and is hypothermic etc, the natural impulses are lessened meaning they have a greater chance that it could happen. Happened several year back to some uni students who both got caught abseiling down near a waterfall in the Blueys the cause of death was said to be a combination of Hypothermia and HHS.
Its just more a case of of rescuers being aware that the situation could happen and anyone stuck just hanging, especially if mobility has been compromised could suddenly be in a life threatening situation if not rescued quickly.
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7-Oct-2011 10:37:14 AM
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On 7/10/2011 Wendy wrote:
>After 5-30 minutes? Whilst still concious? Haven't many of us spent way
>more time than that in manky hanging belays? Several off us have spent
>1hr+ at a time hanging in harnesses with the frinj show we are working
>on at the moment pretty much everyday. You mean we should add HHS to the
>JSA? I don't want to have to think about anything else in the JSA! That
>document is rapidly reaching book proportions!
but you should definately be mentioning a quick response time in your "rescue plan" thats attached to you JHEA
ahhhh paperwork.... :D
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7-Oct-2011 4:31:48 PM
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It's been a while since studying this. My understanding is that HHS is caused by decreased circulating blood volume due to the harness leg loops occluding the femoral/great saphenous veins thus restricting the venous return to the heart. Without adequate circulating blood volume perfusion can not be sustained = death.
Crush injury is just that, blunt trauma causing injury/insult to an area of the body. Crush syndrome, which is where I think the confusion with HHS is, generally takes 1hr+ where both arterial blood and venous return are restricted (the classic is the tractor pinning the farmers legs) which results in cellular death and the release of associated cellular matter, which is returned to circulation when the mechanism is removed.. Potassium is the major offender, which in excessive concentrations can send the heart into a potentially lethal rhythm. On scene amputation is generally the treatment of choice to prevent this happening. To a lesser degree, or if you happen to survive the cardiac arrest, the release of myoglobin may lead to kidney failure.
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7-Oct-2011 5:32:44 PM
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On 7/10/2011 davidn wrote:
>I'm sure I've read and should remember that - thanks for the reminder.
Hereyagodavidn...
It's been a while since studying this. My understanding is that BSS (boulderer splat syndrome) is caused by decreased circulating blood volume due to the beanieless forehead veins occluding the femoral/great saphenous veins thus restricting the venous return to the heart. Without adequate circulating blood (known as being pumped), volume perfusion can not be sustained = death.
Crush injury is just that, blunt trauma causing injury/insult to an area of the body. Crush syndrome, which is where I think the confusion with BSS is, generally takes 1hr+ where both arterial blood and venous return are restricted (the classic is the tractor pinning the farmers legs) which results in cellular death and the release of associated cellular matter, which is returned to circulation when the mechanism is removed.. Potassium is the major offender, which in excessive concentrations can send the heart into a potentially lethal rhythm. On scene amputation at the neck is generally the treatment of choice to prevent this happening. To a lesser degree, or if you happen to survive the cardiac arrest, the release of myoglobin may lead to kidney failure.
~> Found a second reference, so you can't use HHS as an excuse to not go roped up climbing anymore...
Heh, heh, heh.
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7-Oct-2011 6:20:20 PM
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One of my mates put me onto this thread. I recently presented to the Vic Scout Caving Team some research that I did on HHS. Basically it’s not very nice and it will kill you. There are various factors associated with how long you remain conscious for when hanging in a harness, ie free hang no wall to kick off on, factors such as fatigue, hydration level, if you are hypothermic any injuries that you may have etc. Some people can hang to up to 1 hour, others as little as 5 minutes. You are in serious danger once you have passed out. In the presentation there is a bibliography of references and there are some really good papers on professional research on industrial harnesses.
DRSABCD still applies with HHS, if the victim is not breathing you need to get them into a position to commence CPR. The other important thing is that if you have a victim who has passed out on rope they are at risk of renal failure - even though they look fine they need to get to a hospital that has dialysis facilities quickly. The kidneys are very susceptible to oxygen depletion.
Link to my ppt given to VSCT as part of training
http://www.dodgey.com.au/Buchan%20Caving.aspx
and select the harness hang syndrome link
Happy to be contacted on this - note I'm not a medico.
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