Automated cuff occlusion pressure effect on quality of operative fields in foot and ankle surgery: a randomized prospective study.

BACKGROUND Limb occlusion pressure, which is present when blood flow ceases, has not had a practical method described for attainment. An automated tourniquet system was modified to set tourniquet pressure based on measurement of limb occlusion pressure (LOP). In this single surgeon randomized prospective study, the effectiveness of this system was assessed on patients undergoing foot and ankle surgery. MATERIALS AND METHODS Two hundred forty-four patients were randomized to the study group of automated pressure (n = 112) or to the control group (n = 132). The primary outcome measure was tourniquet pressure used for either group. Secondary measures included the time to set the pressure and number of patients failing LOP measurement. The tourniquet field was assessed intraoperatively and postoperatively in a blinded manner. RESULTS The tourniquet pressure was significantly lower in the study group at 198.5 ± 20.2 mmHg compared to 259.6 ± 4.4 in the control group (p < 0.001). The time to measure the LOP was 20 ± 6 seconds. Six patients failed to be measured. The quality of the surgical field was judged to be better in the study group based on all three methods of assessment. CONCLUSION LOP measurement was a practical way of setting tourniquet pressures for limb surgery. The automated pressure averages were lower than those routinely used by most surgeons for thigh tourniquets.