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BACKGROUND: Many years ago regular intermittent bolus administration of epidural local anaesthetic solution was recognized to produce more effective analgesia than continuous infusion, but only recently has the development of suitable pumps allowed the former technique's wider evaluation. METHODS: In this randomized, double-blind trial, 40 primigravid patients had a lumbar epidural catheter inserted, and plain ropivacaine 0.2% 15-20 ml was titrated until analgesia and bilateral sensory block to T10 were produced (time zero). Patients were then given either an infusion of ropivacaine 2 mg ml(-1) with fentanyl 2 microg ml(-1) at 10 ml h(-1), or hourly boluses of 10 ml of the same solution. Pain, sensory block and motor block were measured frequently. If requested, additional 10 ml boluses of the study mixture were given for analgesia. RESULTS: There were no differences between the two groups in patient characteristics, obstetric/neonatal outcome, or in sensory or motor block. A total of 12 (60%) patients in the continuous group required one or more additional boluses compared with 4 (20%) patients in the intermittent group (95% CI 9.6-61.7%, P=0.02). Therefore the intermittent group received a lower total drug dose than the infusion group (P=0.02). Duration of uninterrupted analgesia (time to first rescue bolus) was longer in the intermittent group (P<0.02). CONCLUSIONS: The intermittent group required fewer supplementary injections and less drug to maintain similar pain scores, sensory and motor block compared with the continuous group. This represents a more efficacious mode of analgesia.

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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.

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Seventy-four patients undergoing laparoscopic gynaecological surgery were randomly allocated to two groups receiving cyclizine 50 mg or ondansetron 4 mg at induction of anaesthesia. Anaesthetic and postoperative analgesia regimens were standardised. Approximately half of the patients in each group experienced some degree of postoperative nausea and vomiting (cyclizine, 56%; ondansetron, 54%). There was no difference between groups in respect of pre- and postdischarge incidence. Mean (SD) time to eye opening was significantly prolonged in the cyclizine group [10 (4) min vs. 8 (2) min; p < 0.001], but this had no influence on discharge times. Cyclizine and ondansetron appear equally effective in preventing postoperative nausea and vomiting but the 10-fold price differential favours cyclizine.

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Forty patients undergoing spinal anaesthesia for a variety of surgical procedures were randomly allocated to receive 3 ml of ropivacaine 5 mg ml(-1) in glucose 10 mg ml(-1) or 50 mg ml(-1). Onset of sensory block to T10 was significantly faster (P=0.03) with the glucose 50 mg ml(-1) solution (median 5 min, range 2-20 min) than with the 10 mg ml(-1) solution (median 10 min, range 2-25 min). Maximum extent of cephalad spread was virtually the same in both groups (10 mg ml(-1) median T6/7, range T3-T10; 50 mg ml(-1) median T6, range T3-T10) with similar times to regression beyond S2 (10 mg ml(-1) median 210 min, range 150-330 min; 50 mg ml(-1) median 210 min, range 150-330 min). Complete motor block was produced in the majority of patients (10 mg ml(-1) 90%; 50 mg ml(-1) 85%) and the time to complete regression was the same in both groups (median 120 min, range 90-210 min). A block adequate for the projected surgery was achieved in all patients.

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