Comparative Efficacy of 2mg and 5mg Intrathecal Nalbuphine as an Adjuvant to Ropivacaine in Elective Lower Limb Surgeries

Abstract

Background: Spinal opioids can provide profound analgesia with fewer central and systemic adverse effects than with opioids administered systematically. In this prospective, randomised, double-blind study, we compared the efficacy of 2 mg and 5 mg intrathecal Nalbuphine as an adjuvant to Ropivacaine in elective lower limb surgeries.

Materials and Methods: 90 patients aged 18-60 years, ASA grade I and II, undergoing elective lower limb surgery were randomly divided into two groups. Groups A and B, who received 2 mg and 5 mg nalbuphine, made up to 0.5 mL volume with normal saline, added to 3ml of isobaric 0.75% ropivacaine, (total volume of 3.5 mL) respectively. The hemodynamic parameters following administration of the drug, onset of sensory block, onset of motor block, duration of motor block, two-segment regression time of sensory block, quality of analgesia, duration of analgesia, and the incidence of adverse effects were compared between the groups.

Results: The onset of both sensory and motor blockade was faster with the addition of 2 mg and 5 mg of nalbuphine with ropivacaine; however, it was not statistically significant (P > 0.05). Two‑segment regression time and duration of analgesia and motor blockade, the duration of sensory blockade, VAS readings, and haemodynamic variability were comparable between the two groups. Incidence of adverse effects were more in group B which is statistically significant difference (P<0.05).

Conclusion: It was found that when compared with 5 mg of nalbuphine, 2mg nalbuphine is equally good as an adjuvant to isobaric 0.75% ropivacaine in elective lower limb surgeries with prolonged analgesia, a reliable block with equal efficacy but with fewer side effects.