Background
Many opioids were added to intrathecal local anesthetics to provide longer duration of analgesia; however, we have to choose the additive with the longest analgesic time and least intra and post-operative side effects. In this study, nalbuphine was compared to fentanyl and pethidine as additives to hyperbaric bupivacaine used in spinal anesthesia for lower limb surgeries.
Patient and Method
One hundred patients of both genders ASA I, and ASA II posted for lower limb surgeries under spinal anesthesia were assigned randomly into four groups: Group B, received an intrathecal injection of 0.5% hyperbaric bupivacaine (3 ml+ 1 ml sterile water; n=25). Group N, received intrathecal injection of 0.5% hyperbaric bupivacaine (3 ml+ 1 ml nalbuphine 500μg; n=25).Group F, received intrathecal injection of 0.5% hyperbaric bupivacaine (3 ml+ 1 ml fentanyl 25μg; n=25). Group P, received intrathecal injection of 0.5% hyperbaric bupivacaine (3 ml+ 1ml ethidine 10 mg ; n=25).We record the onset of sensory and motor blocks, peak sensory and motor block times, sensory block levels and two segment regression time using pin prick method, and motor block level using modified Bromage scale (table1) and any intra or post-operative complications.
Results
The mean onset of sensory block is significantly decreased in groups N, F, and P compared with group B, while the peak sensory time was none significantly changed among the whole four groups, In contrast the mean onset of the motor block in the four groups included was non considerably different while the mean time for peak motor block was significantly short in both the N group (nalbuphine and bupivacaine) and P (pethidine and bupivacaine) group when compared to B (bupivacaine alone) and F (fentanyl and bupivacaine) groups.there was significant prolongation of both two segment regression time and the first analgesic request time in groups N, F and P ( all narcotics and bupivacaine) compared with group B( bupivacaine alone).
Conclusion
nalbuphine, fentanyl, and pethidine as adjuvants to spinal anesthesia prolong the duration for first rescue analgesia with minimal hemodynamic and respiratory complications; however, nalbuphine with the dose of 0.5 mg has the best quality of spinal block when added to intrathecal 0.5% heavy bupivacaine in patients undergoing lower limb surgeries.