Spinal anesthesia efficacy of bupivacaine combined with different doses of fentanyl for Cesarean delivery

Objective To assess the efficacy of bupivacaine in combination with different doses of fentanyl for spinal anesthesia in patients undergoing cesarean delivery, and to discuss the ideal dosage of fentanyl for this type of operation.Methods A total of 120 ASA Ⅰ or Ⅱ patients with single and term birth were randomly assigned into 4 different groups (n=30 each): 0.5% bupivacaine 6 mg (group B), 0.5% bupivacaine + fentanyl 5 μg (group BF1), 0.5% bupivacaine + fentanyl 10 μg (group BF2), and 0.5% bupivacaine + fentanyl 15 μg (group BF3). Each patient received an epidural catheter placed at L2-3 vertebra interspace and subarachnoid space injection. The highest sensory block level, anesthetic efficacy (analgesia, muscle relaxation and stretch reaction), and side effects were recorded.Results The sensory block level was higher in group B than that in other three groups, while the incidence of epidural and intravenous medication was higher in group B (P0.05). The excellent rate of anesthetic efficacy was higher in group BF2 and BF3 than in group B and BF1(P0.05 or P0.01). Compared with group B, the incidence of pruritus was increased in groups BF1, BF2 and BF3, especially group BF3.Conclusion Subarachnoid space injection of 0.5% bupivacaine + 10 μg fentany could reach the anticipated anesthetic efficacy for cesarean delivery.