Sufentanil added to hyperbaric bupivacaine for subarachnoid block in Caesarean section.

BACKGROUND AND OBJECTIVE: Subarachnoid block is a widely used technique for Caesarean section. Its quality can be improved by adding opioids to the local anaesthetics. We studied the quality of the block and its maternal-fetal repercussions when different doses of sufentanil were combined with hyperbaric bupivacaine using the intrathecal route in pregnant women undergoing Caesarean section.

METHODS: This was a prospective, randomized, double-blind, controlled trial with 80 pregnant women, ASA I-II, who were scheduled for elective Caesarean section under subarachnoid block. Patients were distributed into four groups according to the dose of sufentanil used: no sufentanil (Group 1, control) or 2.5, or 5.0 or 7.5 microg sufentanil (Groups 2-4, respectively). In every group, the local anaesthetic used was hyperbaric bupivacaine 0.5% (12.5 mg) and the total volume of the solution 4 mL. The onset time of the block, maximum level of sensory block, motor block level, duration of analgesia, maternal side-effects and maternal-fetal cardiovascular repercussions were evaluated.

RESULTS: Onset of the block was significantly shorter in the groups receiving opioids compared with the control group. Analgesia was significantly prolonged in Groups 3 and 4. The occurrence of pruritus and somnolence was significantly higher in the group receiving sufentanil 7.5 microg than in other groups. With the exception of pruritus, no differences were observed between groups with respect to cardiovascular or other maternal effects.

CONCLUSIONS: The addition of sufentanil 5.0 and 7.5 microg to hyperbaric bupivacaine provided adequate anaesthesia for Caesarean section and good postoperative analgesia. Pruritus was the most common side-effect and had a significantly higher incidence when a dose of sufentanil 7.5 microg was used.