Comparison of ropivacaine 0.5% (in glucose 5%) with bupivacaine 0.5% (in glucose 8%) for spinal anaesthesia for elective surgery.

BACKGROUND Hyperbaric solutions of ropivacaine have been used successfully to provide spinal anaesthesia. This study was designed to compare the clinical efficacy of hyperbaric ropivacaine with that of the commercially available hyperbaric preparation of bupivacaine. METHODS Forty ASA grade I-II patients undergoing lower-abdominal, perineal or lower-limb surgery under spinal anaesthesia were recruited and randomized to receive ropivacaine 5 mg ml(-1) (with glucose 50 mg ml(-1)), 3 ml or bupivacaine 5 mg ml(-1) (with glucose 80 mg ml(-1)), 3 ml. The level and duration of sensory block, intensity and duration of motor block, and time to mobilize and micturate were recorded. Patients were interviewed at 24 h and at 1 week to identify any residual problems. RESULTS All blocks were adequate for the proposed surgery, but there were significant differences between the two groups in mean time to onset of sensory block at T10 (ropivacaine 5 min; bupivacaine 2 min; P<0.005), median maximum extent (ropivacaine T7; bupivacaine T5; P<0.005) and mean duration of sensory block at T10 (ropivacaine 56.5 min; bupivacaine 118 min; P=0.001). Patients receiving ropivacaine mobilized sooner (ropivacaine mean 253.5 min; bupivacaine 331 min; P=0.002) and passed urine sooner (ropivacaine mean 276 min; bupivacaine 340.5 min; P=0.01) than those receiving bupivacaine. More patients in the bupivacaine group required treatment for hypotension (>30% decrease in systolic pressure; P=0.001). CONCLUSIONS Ropivacaine 15 mg in glucose 50 mg ml(-1) provides reliable spinal anaesthesia of shorter duration and with less hypotension than bupivacaine. The recovery profile for ropivacaine may be of interest given that more surgery is being performed in the day-case setting.