Comparison of Fentanyl and Nalbuphine as an Adjuvant to Bupivacaine for Spinal Anesthesia in Lower Limb Surgeries

Opioids commonly used as adjuvant anaesthetics during spinal anesthesia, are favored technique for lower limb surgeries. Nalbuphine is an opioid adjuvant that acts as antagonist at μ-receptors and agonist at k-receptors that work reasonably potent analgesia. In this study we compare the efficacy of epidural Fentanyl with bupivacaine versus Epidural Nalbuphine with Bupivacaine for post-operative pain relief in lower limb surgeries.

Altogether 80 patients of lower limb surgeries were randomly allocated into two groups. 40 patients in Group I (Inj. 0.5% Bupivacaine (H) 2.5ml + Inj. Fentanyl 25mcg (0.5ml) and 40 patients in Group II (Inj. 0.5% Bupivacaine (H) 2.5ml+ Inj. Nalbuphine 5mg (0.5ml). Age of patients ranged from 18-65 years of age and male:female ratio in the present study was 1: 0.5. Patients in both the above groups were comparable on age, gender, anthropometric variables, and baseline hemodynamic variables.

In the study the mean age (36.30±14.10) of group II was comparatively more than the group I (33.88±9.42) while the mean weight (61.80±11.33) of group II was also comparatively more than group I mean weight (53.80±15.59). And the mean value of duration of surgery for the group I was (112.93±12.22) while it was (110.63±10.26) for group II. A significant difference was found in weight. The intergroup comparison of level of motor blockade where in group I the level of motor blockade was (65.0%) at 2 min (B/S-1) while in group II level of blockade (70.0%) at 2 min (B/S-1) after that from 8 min to 130 min it was (100%). The level of sensory blockade of group I (72.5%) at 2 min while it was (72.5%) at 6 min after that it was NA from 8 min to 130 min and in the group II level of sensory blockade (50.0%) at 2 min and (50.0%) at 8 min after that it was (100%) from 10 min to 130 min. During Intergroup Comparison of VAS significant differences was found at 30 min and 480 min.

Nalbuphine when compared to Fentanyl is almost safe and hemodynamically stable drug that can be used as an adjuvant in combined spinal epidural anesthesia with similar safety profile as for Fentanyl.