A Prospective Randomised Study Comparing the Effects of Intrathecal Hyperbaric Levobupivacaine, Bupivacaine and Ropivacaine Using Nalbuphine as an Adjuvant in Elective Infraumbilical Surgeries

Context: Hyperbaric bupivacaine (BN) (0.5%) was the gold standard drug of choice for intrathecal use in spinal anaesthesia. Numerous studies have examined the usefulness and efficacy of ropivacaine (RN) and levobupivacaine (LN) when used as an isobaric local solution, which offers a significant margin of safety. Hyperbaric RN (0.75%) and LN (0.5%) introduced recently in the anaesthesia practice provide a better and wider margin of safety in terms of decreasing the local anaesthetic systemic toxicity. We assessed and compared the effectiveness and efficiency of hyperbaric solutions, specifically 0.5% LN, 0.5% BN and 0.75% RN, in terms of motor and sensory blockade, haemodynamic stability and complications; the rationale for conducting this prospective study was to provide a higher margin of safety intrathecally. Aims: The primary objective of this study was to compare the duration of motor blockade of hyperbaric LN, BN and RN with nalbuphine adjuvant. Materials and Methods: Our study was a prospective double-blind block randomisation trial carried out in three groups, LN, BN and RN, with 40 patients in each group using nalbuphine as an adjuvant. Statistical Analysis Used: The onset, duration and regression of both motor and sensory parameters of the three hyperbaric local anaesthetic solutions were noted and analysed using the Chi-square test and analysis of variance. Results: On comparison, the onset of motor blockade was fastest in Group BN and slowest in Group LN ( P = 0.245). The motor regression time was significant in Group BN ( P = 0.020). On analysing the sensory parameters, the onset was comparable with Group BN and the fastest regression was noted in Group RN ( P = 0.049). The effective total analgesic duration and the time for first rescue analgesia showed statistical insignificance ( P = 0.158). Conclusion: The onset, duration and prolonged motor blockade characteristics were more pronounced in hyperbaric BN compared to LN and RN. The onset of sensory blockade is delayed in hyperbaric LN, and the sensory regression time was significantly faster in RN compared to BN and LN.