Physiological evaluation of the U.S. Army one-handed tourniquet

Objective: To provide a physiological assessment of the U.S. Army one-handed tourniquet (OHT). Methods: An OHT was self-applied by 26 subjects, to maximal tolerable tightness, to the proximal arm or thigh under different conditions and positions, and the presence of blood flow was assessed using Doppler ultrasonography or occlusion plethysmography. Results: Doppler sound was eliminated at the radial artery for all subjects with OHT application but was not stopped at the popliteal or dorsalis pedis artery for any subjects. The OHT reduced forearm blood flow by 79% but decreased leg blood flow by only ∼50%, regardless of condition and position of application to the thigh. Conclusions: The OHT appears to effectively minimize blood flow in the arm but not in the lower extremities, and clinical assessment of blood flow disappearance by Doppler ultrasonography may underestimate the magnitude of actual blood flow to the limb.