Spinal analgesia with plain 0.5% bupivacaine administered at spinal interspace L2-3 or L4-5

Forty patients (age range 60-79 yr) undergoing transurethral surgery were allocated randomly to receive 0.5% plain bupivacaine 4 ml at the L2-3 (n = 20) or L4-5 (n = 20) space. The solution was injected over 30 s with the patient in the sitting position. The patient was kept sitting for 2 min, then placed supine and, 5 min later, placed in the lithotomy position. No significant differences were found in onset time, extent and duration of analgesia or duration of motor block.