ANALGESIC EFFICACY OF TWO DIFFERENT DOSES OF NALBUPHINE 0.8 MG AND 1.6 MG AS AN ADJUVANT TO ROPIVACAINE 0.75% FOR ELECTIVE LOWER LIMB SURGERIES: RANDOMIZED DOUBLE-BLIND INTERVENTIONAL STUDY

Background And Aim: Intrathecal Nalbuphine as an adjuvant with Ropivacaine providing profound analgesia with lesser side effects. We aimed to compare the analgesic efficacy of two different doses of intrathecal Nalbuphine (0.8mg versus 1.6mg) as an adjuvant to 0.75% isobaric Ropivacaine for elective lower limb Orthopaedic surgeries.

Material And Method: It was a Prospective Randomized Double-blind Interventional study in a total of 90 patients posted for elective lower limb surgeries under spinal anaesthesia, age 18-60 years, either gender, ASA I and II, weight 40-70 kg, height ≥ 145cm allocated in 3 groups, all of whom received 2.5ml total drug volume, Group A- Ropivacaine 2ml +0.5ml normal saline, Group B- Ropivacaine 2ml + 0.8mg Nalbuphinein 0.5ml normal saline, Group C- Ropivacaine 2ml+ 1.6mg Nalbuphine in 0.5 ml normal saline. We recorded the onset of sensory and motor block, total duration of analgesia, sedation, VAS (Visual Analogue Scale) and side effects.

Results: Onset of motor and the sensory block was earlier in Nalbuphine groups as compared to Ropivacaine alone. Analgesia was prolonged in 1.6mg Nalbuphine>0.8 mg Nalbuphine>Ropivacaine alone. VAS Score for rescue analgesia (>3) was achieved at 240 min in group B &C, and 210 min in groups A. Haemodynamic variables and sedation were comparable in all three groups and statistically non-significant. Hypotension, nausea and vomiting were higher in group C.

Conclusion: Nalbuphine dose 0.8mg and 1.6mg doses are equivalently effective as an intrathecal adjuvant in providing prolonged analgesia with isobaric Ropivacaine, but 0.8 mg is the optimal dose with lesser side effects.