Anaesthesia for caesarean delivery: low-dose epidural bupivacaine plus fentanyl

To determine the acceptability of epidural bupivacaine-induced sixth thoracic (T6) sensory blockade and the analgesic efficacy of epidural fentanyl 50 microg, 24 parturients undergoing elective caesarean section were given a test dose of lidocaine 60 mg plus epinephrine followed by 10 ml of either 0.5 % bupivacaine (control group) or 0.5 % bupivacaine plus 50 microg fentanyl (fentanyl group) in a randomized double-blind manner. Fifteen minutes later loss of pinprick sensation was determined. Additional local anaesthetic was titrated to achieve T6 sensory blockade. Intraoperative pain intensity was assessed using a 10 cm visual analogue scale (VAS); total dose of bupivacaine and need for i.v. rescue fentanyl were recorded. The incidence of intraoperative respiratory depression, nausea, vomiting and pruritus were documented. Mean (+/- SD) volume of bupivacaine was 14.1 +/- 3.05 ml versus 13 +/- 1.48 ml for the control and fentanyl groups respectively. The most severe intraoperative VAS for pain was significantly (P=0.023) lower in the fentanyl group (0.4 +/- 0.08 cm) than in the control group (3.1 +/- 0.3 cm). Rescue fentanyl was administered in 40% and 0% of patients in the control and fentanyl groups respectively. The incidence of side-effects was unaffected by treatment group. Apgar scores were similar in the two groups. We conclude that following administration of 10-15 ml 0.5% bupivacaine plus fentanyl 50 microg, T6 sensory blockade is associated with good intraoperative analgesia without obvious maternal or neonatal respiratory depression.