|Image Credit: Staff Sgt. Terri Reece|
Western University of Health Sciences
|This post was peer reviewed.|
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As we walk onto the scene wearing our bulletproof vests, we see a spray of blood up the white wall of the apartment, leading us to our patient. He is holding direct pressure on his arm where he had been shot. As soon as the pressure is removed, bright red, pulsatile blood sprays from the wound. Quickly, the paramedics I am riding with that day apply a tourniquet to the patient’s arm, and the bleeding is stopped.
Tourniquets have been used in the military through many wars, although their use was inconsistent, which led to poor outcomes for those with devastating limb injuries. At the start of the Iraq War, tourniquet use increased but was still inconsistent resulting in approximately 2% of soldiers dying from isolated limb exsanguination. There has been an increasing body of evidence showing favorable outcomes associated with tourniquet use. Due to the more consistent use of tourniquets through wartimes, exsanguination from isolated limb injuries is no longer considered a top cause of preventable death of US soldiers.
The types of injuries in which tourniquet application is generally accepted includes traumatic amputations, open fractures, and arterial injuries with uncontrollable bleeding. For the greatest survival benefit, the tourniquet must be applied before the onset of hypovolemic shock. An observational study by Kragh, et al., found a survival rate of 90% in patients who had a tourniquet applied prior to the onset of shock, compared to an 18% survival rate for patients with application after shock onset. When applied, the tourniquet should be tightened to the point in which it stops the bleeding and the distal pulse in the extremity is no longer palpable. Failure to do so leads to a partially ineffective tourniquet and increases the rate of complications.
Complications of tourniquet use have frequently been used to argue against their routine use in civilian medicine. The most commonly seen complications associated with tourniquet use include nerve palsies, limb shortening, and re-bleeding (which often leads to further complications and hypovolemia).
In one study the percentage of patients that experienced issues with nerve palsies at the level of the tourniquet was 1.7% in the first study group and 1.5% in the second study group. This complication was often due to over-tightening of the tourniquet leading to compression of peripheral nerves. This risk can be decreased with proper training of the providers that will be applying tourniquets.
The rate of limb shortening (cases in which the amputation stump had to be shortened due to damage associated with the tourniquet) was also evaluated and found an incidence of 0.4% in both study groups. This is a rare complication associated with tourniquet use.
Re-bleeding of the injury can result from an ineffective or partially effective tourniquet (defined as evidence of a persistent distal pulse). This can lead to further complications such as venous congestion, hematoma, and compartment syndrome. Partially effective tourniquets have also been associated with death of patients, although this is rare. While the complications of a partially effective tourniquet can be dire, patients with partially effective tourniquets still have a higher survival rate than patients who receive a completely ineffective tourniquet (evidenced by continued bleeding), or no tourniquet. It is important to note that application of one tourniquet does not always stop the bleeding. Application of one tourniquet was completely effective in only 53% of patients; while 34% required application of 2 or more tourniquets, side by side, to effectively control bleeding.
Tourniquets have been shown to significantly decrease mortality in serious limb injuries that place the patient at risk for exsanguination. Complication rates associated with tourniquet use are low and can be minimized with proper training on application techniques. Some key points to remember
- Tourniquets must be applied prior to the onset of shock for the best chance of survival.
- Tourniquets should be tightened to the point that there is an absence of a distal pulse, and that the bleeding from the wound stops.
- The incidence of complications with tourniquet application is low, and the benefits may outweigh the potential complications.[1,2]
1. Kragh JF, Littrel ML, Jones JA, et al. Battle Casualty Survival with Emergency Tourniquet Use to Stop Limb Bleeding. J Emerg Med. 2011;41(6):590-7.
2. Kragh JF, Walters TJ, Baer DG, et al. Practical Use of Emergency Tourniquets to Stop Bleeding in Major Limb Trauma. J Trauma. 2008;64(2 Suppl):S38-49.
3. Kragh JF, O'neill ML, Walters TJ, et al. Minor Morbidity with Emergency Tourniquet Use to Stop Bleeding in Severe Limb Trauma: Research, History, and Reconciling Advocates and Abolitionists. Mil Med. 2011;176(7):817-23