Extradural ropivacaine and bupivacaine in hip surgery.

We studied 126 patients undergoing elective hip surgery; they received 20 ml of 0.5%, 0.75%, 1.0% ropivacaine or 0.5% bupivacaine extradurally in a double-blind design. Sensory block (pinprick), motor block (modified Bromage scale), quality of analgesia and neuromuscular block were assessed intermittently. Heart rate and arterial pressure were measured at regular intervals. A total of 115 patients were evaluated for efficacy. Onset of analgesia, onset of motor block and maximum cephalad spread (T4) did not differ between the groups. Duration and quality of analgesia and motor block increased with the concentration of ropivacaine. Ropivacaine 1.0% provided a longer duration of analgesia and motor block, more intense motor block and more patients with satisfactory analgesia than 0.5% bupivacaine. More patients treated with the higher concentrations of ropivacaine required treatment for hypotension and bradycardia.