Effects of hyperbaric spinal ropivacaine for caesarean section: with or without fentanyl

Adding various opioids to the local anaesthetic solution administrated intrathecally improves the analgesic potency of spinal analgesia. The purpose of this study was to evaluate the efficacy and safety of intrathecal fentanyl 10 microg added to 15 mg hyperbaric ropivacaine in patients undergoing caesarean section under spinal anaesthesia.

Thirty-seven healthy, full-term parturients were randomly assigned into two groups: Group S (saline group, n=17) received 15 mg hyperbaric ropivacaine in 2.5 mL + 0.5 mL saline; Group F (fentanyl group, n=20) received 15 mg hyperbaric ropivacaine in 2.5 mL + 10 microg fentanyl in 0.5 mL, intrathecally. Characteristics of spinal block, intraoperative quality of spinal anaesthesia, time to first feeling of pain (complete analgesia), time to first request of analgesics postoperatively (effective analgesia), side-effects and fetal outcomes were evaluated.

Regression of sensory block to L5 was significantly prolonged in the fentanyl group compared with the saline group (P = 0.001). Time to the first feeling of pain (130.6 +/- 15.8 min vs. 154.3 +/- 31.1 min; P = 0.008) and the first analgesic requirement (161.2 +/- 32.6 min vs. 213.0 +/- 29.3 min; P < 0.001) were significantly shorter in the saline group compared with the fentanyl group. Side-effects, umbilical arterial and venous blood gases did not differ between the groups. Apgar scores were similar in both groups and no infants had an Apgar score < or =7 at 5 min.

The addition of fentanyl 10 microg, to hyperbaric ropivacaine 15 mg, for spinal anaesthesia increased the duration of analgesia in the early postoperative period in patients undergoing caesarean delivery.