Intraoperative lower extremity compartment pressures in lithotomy-positioned patients.

PURPOSE: Measurement of anterior leg compartment pressures in eight patients (16 limbs) who were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery.

METHODS: Anterior leg compartment pressures were measured in eight patients (16 limbs) by using a slit catheter, whereas subjects were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery.

RESULTS: Compartment pressures had minor elevations after initial lithotomy positioning, and gradually increased over time. Levels elevated to 30 mmHg at an average of five (range, 3.5 to 6) hours. The maximum recorded leg compartment pressure was 70 mmHg. The addition of Trendelenburg positioning was noted to consistently increase compartment pressures. All pressures returned to less than 10 mmHg shortly after removing the limb from the stirrups and placing the limb supine. No patients developed clinical evidence of compartment syndrome.

CONCLUSIONS: Leg anterior compartment pressures rise when limbs are placed in the lithotomy position for prolonged periods of time. The rise in pressure is increased with the addition of Trendelenburg positioning. Anterior compartment pressures reached a threshold of 30 mmHg at an average of five hours. The results of this study suggest that lithotomy positioning of the lower extremities has the potential to initiate leg compartment syndrome when the period of positioning approaches five hours. Removing the limbs from the stirrups and placing them in the supine position allows the pressure in the compartments to return to normal.