Spinal anesthesia and lumbar lordosis.

Hyperbaric bupivacaine 0.5% (3.0 ml) was injected intrathecally in two groups of 20 patients. Both groups of patients lay in the lateral position with their hips flexed at 90 degrees. In group F, the hip flexion was maintained for 5 minutes after turning supine. In group S, the hips were straightened before the patients were turned to the supine position. The technique of hip flexion to reduce the lumbar lordosis did not significantly limit the height of anesthetic blockade. The distribution of height of anesthetic blockade showed marked bimodality (P less than 0.05) in both groups, in group F at T4 and T9 and in group S at T3 and T9. Cardiovascular side effects were minimal and equal in both groups.