Effectiveness of self-applied tourniquets in human volunteers

Background. Tourniquets are not commonly used in routine extremity trauma, but can be vital for hemorrhage control in austere conditions. Objective. To determine the effectiveness in human volunteers of currently available self-applied tourniquets for extremity hemorrhage. Methods. Seven tourniquets were tested on the thigh for elimination of detectable distal pulse by Doppler auscultation at the popliteal artery (experiment I, n = 18 subjects). The tourniquets that were effective in ≥80% of subjects in experiment I were tested for effectiveness on the upper arm by auscultation at the radial artery (experiment II, n = 12 subjects). Results. Three of the seven tourniquets were effective in all subjects in experiment I; a fourth tourniquet was effective in 88%. Three of the four successful devices were also 100% effective in experiment II; the fourth was effective in 75%. Failure of tourniquets to eliminate distal Doppler pulse signal was due to inadequate mechanical advantage for tightening, device failure (breakage), or intolerable pinching or circumferential pain prior to pulse elimination. The Combat Application Tourniquet (North American Rescue Products, Inc.), the Emergency & Military Tourniquet (Delfi Medical Innovations, Inc.), and the Special Operations Forces Tactical Tourniquet (Tactical Medical Solutions, LLC) were all found to be 100% effective in elimination of distal arterial pulse in both the arm and the leg in all subjects. Conclusion. Some commercially available tourniquets do not reliably occlude arterial blood flow and may not be successful in preventing extremity exsanguination in a trauma patient. Potential purchasers of such devices should bear this in mind when selecting a device for clinical use.