The relationship between tourniquet pressure and underlying soft-tissue pressure in the thigh.

Soft-tissue pressures in specimens of the lower extremities of cadavera, obtained following hip disarticulation, were measured directly beneath a pneumatic thigh tourniquet to establish the relationship between the tourniquet pressure and underlying soft-tissue pressure. It was found that the tissue pressure was consistently lower than the tourniquet pressure and that the percentage of tourniquet pressure reflected in the underlying tissue varied inversely with the circumference of the thigh. It was also found that the pressure decreased with increasing depth of the soft tissue.the use of a pneumatic tourniquet is potentially associated with injury to underlying muscles, vessels, and nerves if excessive pressure occurs beneath the tourniquet. In order to minimize the risk of soft-tissue injury, the lowest tourniquet pressure that maintains a bloodless field should be used. A nomogram based on data generated in this experiment is provided as a guide to determining appropriate tourniquet pressures.