Effects of Adding Intrathecal Fentanyl as Adjunct to Hyperbaric Bupivacaine in Vaginal Hysterectomy: A Double Blinded Randomized Controlled Trial

Abstract

Introduction: Spinal anesthesia is the preferred means for gynecological surgeries. Adjuvants to local anesthesia for spinal anesthesia may enhance quality and duration of analgesia. Our study aimed to evaluate efficacy and safety of fentanyl added to bupivacaine for spinal anesthesia.

Methods: A prospective, randomized, double blind study was conducted on 60 ASA I or II adult female patients undergoing vaginal hysterectomy under spinal anesthesia. Patients were randomly divided into two groups. Patients in Group B (n=30) were administered 3 mL of 0.5% hyperbaric bupivacaine with 0.4 ml NS and Group F (n=30) were given 3 mL of 0.5% hyperbaric bupivacaine with 0.4 ml (20μg) fentanyl intrathecally. Hemodynamic variables (i.e. heart rate, noninvasive blood pressure, oxygen saturation), onset of motor and sensory block, duration of sensory and motor blockade and any side effects observed were recorded intraoperatively and postoperatively.

Results: The duration of sensory and motor blockade was significantly prolonged (P<0.05) in fentanyl group (268.6±55.4 and 182.8±43.87) compared to control group (235.03±51.97 and 149.47±38.75). Similarly, the onset of sensory and motor block was significantly earlier (P<0.05) in group F (5.2±2.55 and 7.8±2.91) compared to group B (6.63±2.88 and 9.97±3.28). There was no significant statistical difference in the incidence of side effects and changes in hemodynamic variables in both the groups. No adverse events were observed during study.

Conclusion: Addition of fentanyl to hyperbaric bupivacaine for spinal anesthesia offers early onset, better surgical analgesia, prolongs the duration of analgesia without any significant adverse effects.