Tourniquets revisited

Controversy swirls about optimal control of life-threatening hemorrhage from an injured extremity whether in combat in the Middle East or in trauma care at home. Left unanswered are four critical questions: (1) What is the simplest tourniquet available? (2) Can it be used below the elbow and the knee? (3) Is pain a factor? (4) What data support so called "Pressure Points?"

To address these questions, we measured the effects of three common tourniquets on arterial pulses (Doppler signals) at wrist and ankle of 10 healthy adult volunteers of either sex. We recorded ease of application (1-3, with 3 easiest) by the applicant and pain experienced by the subject (none, light, moderate, severe). Tourniquets were applied sequentially to arm, forearm, thigh, and leg. Tourniquet success was defined as sustained elimination of distal pulse. Pressure points were brachial artery in arm and cubital fossa, common femoral artery (groin), and popliteal artery (knee). The same criteria defined success. All numerical data were meaned and standard error (SE) computed. Significance of apparent differences was assessed with Student's t test for paired observations.

Mean age was 36.5 +/- 6.0 years; blood pressure was 123 +/- 6/72 +/- 4 mm Hg. All three tourniquets (sphygmomanometer, 1/2 inch rubber tubing, cloth and windlass) were successful in all patients in all four locations with two exceptions. Thighs of two subjects were too large for the sphygmomanometer and one person experienced test terminating pain with the rubber tube on arm and thigh and with the cloth and windlass on the thigh. Manual (digital) occlusion of the brachial artery in the arm was possible in all but one subject; however, the Doppler signal at the wrist returned within 40.6 +/-6.5 seconds in all but one of the other nine subjects. Pressure point control of the common femoral artery resulted in identical findings except that the pulse returned within 20.6 +/- 4.7 seconds despite sustained pressure. Attempts at control of the brachial artery at the elbow and the popliteal artery at the knee were less successful.

Our data indicate that all tourniquets can be used successfully below the knee or elbow. The cloth and windlass is the easiest to apply. It is probably the most readily available or simplest to procure/improvise. Pain is irrelevant. "Pressure Point Control" of extremity arterial hemorrhage is a euphemistic misnomer.