Tourniquet Conversion

 So far, an estimated 25,000-50,000 amputations having already occurred on the Ukrainian side of the war. Patients with tourniquets may not reach definitive care for 24 hours or more after tourniquet placement. Tourniquet times of less than 2 hours have a negligeable impact on limb salvage rates; tourniquet times over 4 hours are associated with reduced limb salvage rates. Amputation of a tourniqueted limb is very likely after 24 hours. Therefore, assessing whether stable patients who arrive at our near-frontline medical facility are candidates for a tourniquet conversion is a priority. "Tourniquet conversion" refers to the process of replacing a tourniquet with a simple pressure dressing. 

While civilian prehospital medical personnel are generally taught to never remove a tourniquet once placed, in the US military tourniquet conversion is a basic-level medical intervention. The TCCC guideline, taught to all US military members, is "every effort should be made to convert tourniquets in less than 2 hours if bleeding can be controlled by other means". Temporary tourniquet placement of up to 3 hours, with no resulting tissue damage, is also a common technique used by surgeons.

The process for converting a tourniquet is:

1) pack the wound and apply pressure for 3 minutes

2) apply pressure dressing

3) slowly release tourniquet over 1 minute, watching for bleeding. If bleeding resumes, re-tighten the tourniquet. Re-attempt conversion in 2 hours, as long as it hasn't been more than 6 hours since original application.

4) If conversion is successful, note release time and leave loosened tourniquet on the limb, just above the wound, in case tourniquet re-application is needed later.

Tourniquet conversion is contra-indicated in patients who are in shock, have an amputation below the tourniquet, or who cannot be monitored closely for bleeding. Tourniquets that have been on for more than 6 hours should not be converted. Intermittent reperfusion (Loosening a non-covertable tourniquet temporarily at intervals in an attempt to preserve the limb), is a common surgical technique. However, in field situations without ability to replace lost blood, this is dangerous and ineffective, and not recommended by TCCC.

A 2019 study in rats found that tourniquet application reduced uptake of prophylactic antibiotics in the ischemic limb, both during tourniqueting, and for up to 72 hours after release. https://www.sciencedirect.com/science/article/abs/pii/S0020138319305431

Impact of time and distance on outcomes following tourniquet use in civilian and military settings: A scoping review