Suspension Syndrome
WildMedEtrier Summaries
This presentation was given by Roger Mortimer MD, FAAFP, Fellow of the Academy of Wilderness Medicine (FAWM), International Commission for Mountain Emergency Medicine (ICAR), member of suspension committee and National Cave Rescue Commission instructor. A summary editorial of past and present information from Dr. Mortimer can be read at:
https://www.wemjournal.org/article/S1080-6032(10)00320-0/full
Depending on when you last researched or obtained training in this arena, you may know this by a variety of names; “suspension trauma” being the most recent reiteration but then everyone agreed it’s not really a traumatic incident but rather distributive shock and late rhabdomyolysis, hence, the new moniker (the harness is not the problem...)
The gist of many tables of both experimental trials and postmortem data analysis is that unresponsiveness can repeatedly be replicated in single digit minutes when a person is suspended fully motionless, with deaths often falling into the ½ - several hour range after being suspended.
I.e., this can happen as fast as a simulated hang in an inappropriate harness for lift evac training or SAR. (I’m guessing many of you have felt that hapless moment of exposure in an OSHA rear clip harness; the unique combination of higher geometry calculation and yoga required to rerig the harness to front point clip in while in full suspension – i.e., you feel this guy’s pain...)
Or, it could be really drawn out, discovered, for example, 2 days later when a person notices they can’t walk from muscle pain and that their urine looks like Cherry Coca Cola. Death can be delayed by days due to rhabdomyolysis…
The pathophysiology is straightforward; muscles are not contracting and when the muscle pump of the legs is not engaged venous blood pools in legs; think of a parasympathetic Vaso-vagal response that can’t be lowered to the ground to recover. Dang. A roll your eyes “must carry the 40 pound tank Lifepak 15 cardiac monitor for no reason to a person who fainted call” just became an unexpected medical cardiac arrest.
It used to be advocated to keep the victim upright; the concern was for returning acidotic blood and too much blood volume to the heart, increasing any hypothermia after drop, inducing cardiac arrythmias, and/or return of muscle breakdown (causing kidney problems and rhabdomyolysis) if the person was laid down. And it was recommended to leave the harness on.
However, studies show there is no ventricular distension in relation to the harness being taken off. Kidneys will be affected by myoglobin release, but the heart won’t be, and this is a triage issue of sorts. Potassium yes, a relative problem, but think of tourniquet protocols – 2 hours not an issue.
Delay in laying the patient down continues an exacerbation of what is happening pathophysiologically; there is no research to support keeping a suspension syndrome patient upright.
Treatment:
A sit harness does not compress the great vessels – leave it on or take it off.
The International Commission for Alpine Rescue (ICAR) recommends treating the patient like any other trauma resuscitation.
Suspended persons should be lowered or rigged to redirect tension as soon as possible and positioned supine.
If person is conscious while still on the rope, have them reduce venous pooling by cycling their legs.
Use of foot loops or Etriers engages the muscle pump while on the rope.
If suspended more than 2 hours, monitor K+ and CK.
Practice self-evacuation techniques while on load; OSHA back clip harnesses can be difficult to master rerigging the load point to front center where you can play a more active part in self-rescue.
Set-up pre-rigged lowering system for single line uses such as free rappels.
That’s all I got.
Kind regards,
kl