Evaluation of the effect of added fentanyl to hyperbaric bupivacaine for spinal anesthesia

Background : Potentiating the effect of the intrathecal local anesthetics by intrathecal injection of opiods for intra-abdominal surgeries is known. The objective of this study is to investigate the pain-relieving effects of intrathecal fentanyl to bupivacaine in elective caesarean surgery.

  Materials and Method : In a double blind clinical trial 60 patients candidate for elective cesarean section. They were studied in two groups. Cases in the control group received 12.5 mg of bupivacaine and in the study group received 8 mg of bupivacaine and 20 µg fentanyl. The parameters taken into consideration were hemodynamic stability, visceral pain, nausea and vomiting, intraoperative shivering, the amount of intraoperative administered dose of fentanyl and ephedrine and postoperative pain.

  Results : The average blood pressure changes after 5, 10, 20, 60 minutes were lower in the study group. Shivering and ephedrine dose during operation were lower in study group and statistically significant respectively (p=0.01, p=0.001, respectively). Duration of analgesia after operation increased from (115.5 ± 7.5 min) in control group to (138.5 ± 9.9 min) in study group, but the quality of analgesia during peritoneal manipulation did not change. Pulse rate and vomiting during operation were not statistically different between two groups.

  Conclusion : Reduction of local anesthetic dose with adding fentanyl may cause hemodynamic stability, increasing the postoperative pain-free time, decrease shivering and vasopressor consumption in spinal anesthesia and reduction of the amount of blood pressure drop during elective cesarean surgery