DWK Fraser, CD, BA, PCP @DWKF
Views are my own, and do not represent my employers in any way.
If you asked any researcher to name some prehospital interventions that truly proved their worth during the recent conflicts in Iraq and Afghanistan they would, almost universally, include tourniquets and TXA on their list. Yet there is still, despite a huge volume of well documented research, widespread resistance and misinformation about these two interventions.
During an EMA Licensing Exam I recently watched someone take a tourniquet off a complete amputation. He looked at his watch, said “Ten minutes, time to loosen the tourniquet”, and proceeded to remove it from his patient. Looking at me he asked “Is it bleeding again?” “Of course it’s bleeding again!” was my reply.
I looked at his instructor, and I was floored. This is what the first aid groups are teaching people about tourniquets? Something very important has been lost in the knowledge translation.
Here are several published studies which look at tourniquet use in the modern context.
The first one we’ll look at was conducted at a US Army Combat Support Hospital (CSH) outside Baghdad over a 7 month period in 2006. 232 patients had 428 tourniquets applied on 309 injured limbs. 194 patients had tourniquets applied in the prehospital setting. The remainder had them applied in the CSH. “The 5 casualties indicated for tourniquets but had none used had a survival rate of 0% versus 87% for those casualties with tourniquets used.” The most common complication (less than 2% of patient) suffered a transient nerve palsy. Let me say that again. Less than 2% of patients had complications, and the most common one was that their limb hurt or felt funny from the tourniquet compressing a nerve. And it went away. There were no amputations associated with tourniquet use in this study.
While this study isn’t without some problems, most glaringly the use of the quality & presence or absence of a radial pulse as the determinant of shock, it is very noteworthy that early tourniquet placement was associated with a better outcome and such a low complication rate makes it THE prehospital intervention for hemorrhage that can be tourniqueted.
Law Enforcement Applied Tk to upper extremity due to arterial bleeding post stabbing. This required an additional full rotation of torsion bar to achieve hemorrhage control by EMS
The second is a follow up to the first, and when we add another 267 patients we get virtually identical data: an overall 87% survival rate, higher in those who received tourniquets early and lower in those who didn’t receive one at all or until the CSH, with a <2% complication rate and no amputations.
This is not to say that any intervention is without risk. The use of improvised tourniquets and prolonged application times are associated with worse outcomes, and there are some documented cases, with improvised tourniquets, that DID result in amputations after long (17 hour) application.
It is critical that medical providers train with their tourniquet of choice under all potential conditions. Application effectiveness does not improve under real world conditions! Lower extremity application continues to have the highest failure rate, likely due to the higher occlusion pressures needed (300mmHg!).
The inherent efficacy of tourniquet products contributes to high failure rates under combat conditions, pointing to the need for superior tourniquets and for rigorous deployment preparation training
What is the objective to loosening a tourniquet? To prevent loss of limb? To decrease complications like transient nerve palsies? If those are your objectives, relax, the tourniquets have this one. Put it on, and don’t take it off. We’ve got the EMS evidence to back this up.