Arterial Occlusion Effectiveness of Space Blanket‒Improvised Tourniquets for the Remote Setting.

INTRODUCTION: Control of severe extremity hemorrhage by tourniquet can save lives. In remote areas or in mass casualty incidents with multiple severely bleeding victims, lack of conventional tourniquets may make it necessary to improvise tourniquets. METHODS: Occlusion of the radial artery and delayed onset of capillary refill time resulting from windlass-type tourniquets were experimentally investigated by comparing a commercial tourniquet and a space blanket‒improvised tourniquet with a carabiner as a rod. This observational study was conducted on healthy volunteers in optimal application circumstances. RESULTS: Operator-applied Combat Application Tourniquets were deployed more swiftly (27 s, 95% CI: 25.7-30.2 vs 94 s, 95% CI: 81.7-114.4) and achieved 100% complete radial occlusion compared with improvised tourniquets, as assessed by Doppler sonography (P<0.001). When space blanket‒improvised tourniquets were used, traces of radial perfusion persisted in 48% of the applications. In Combat Application Tourniquets, capillary refill times were significantly delayed (7 s, 95% CI: 6.0-8.2 vs 5 s, 95% CI: 3.9-6.3) compared with those when using improvised tourniquets (P=0.013). CONCLUSIONS: Improvised tourniquets should be considered only in dire circumstances with uncontrolled extremity hemorrhage and when no commercial tourniquets are available. Complete arterial occlusion was achieved in only half of the applications using a space blanket‒improvised tourniquet when a carabiner was used as a windlass rod. The speed of application was inferior to that for Combat Application Tourniquets. Similar to Combat Action Tourniquets, the correct assembly and application of space blanket‒improvised tourniquets on upper and lower extremities have to be trained. TRIAL REGISTRATION: ClinicalTrials.gov identifier: BASG No.: 13370800/15451670.