Lower extremity neuropathies associated with lithotomy positions

Background: The goal of this project was to study the frequency and natural history of perioperative lower extremity neuropathies, Methods: A prospective evaluation of lower extremity neuropathies in 991 ad ult patients undergoing general anesthetics and surgical procedures while p ositioned in lithotomy was performed. Patients were assessed with use of a standard questionnaire and neurologic examination before surgery, daily dur ing hospital stay in the first week after surgery, and by phone if discharg ed before 1 postoperative week. Patients in whom lower extremity neuropathi es developed were observed for 6 months. Results: Lower extremity neuropathies developed in 15 patients (1.5%; 95% c onfidence interval, 0.8-2.5%). Unilateral or bilateral nerves were affected in patients as follows: obturator (five patients), lateral femoral cutaneo us (four patients), sciatic (three patients), and peroneal (three patients) . Paresthesia occurred in 14 of 15 patients, and 4 patients had burning or aching pain. No patient had weakness. Symptoms were noted within 4 h of com pletion of the anesthetic in all 15 patients. These symptoms resolved withi n 6 months in 14 of 15 patients. Prolonged positioning in a lithotomy posit ion, especially for more than 2 h, was a major risk factor for this complic ation (P = 0.006). Conclusions: In this surgical population, lower extremity neuropathies were infrequent complications that were noted very soon after surgery and anest hesia. None resulted in prolonged disability. The longer patients were posi tioned in lithotomy positions, the greater the chance of development of a n europathy. These findings suggest that a reduction of duration of time in l ithotomy positions may reduce the risk of lower extremity neuropathies.