Evaluation of intrathecal neostigmine in different doses added to bupivacaine for postoperative analgesia

Background: Neuraxial administration of neostigmine alongwith local anaesthetics improves the quality of intraoperative analgesia and also provides postoperative pain relief for longer duration. The present study was conducted to study the efficacy and safety of intrathecal neostigmine with bupivacaine in two different doses. Methods: Ninety patients of ASA I and II undergoing lower abdominal and lower limb surgeries under spinal anaesthesia were enrolled and divided into 3 groups of 30 each. Group A: Bupivacaine control group, Group B: Bupivacaine plus 50mcg neostigmine and Group C; bupivacaine plus 150mcg neostigmine. Haemodynamic parameters, sensory and motor characteristics along with side effects were recorded. The post operative pain assessment was done by visual analogue scale score at hourly intervals for the first four hours, then two hourly intervals for the next 6 hours and thereafter at 24 hours. It was scaled from a score of 0 meaning no pain to a score of 100 meaning worst pain perceived. Time of two segment regression of sensory blockade and total duration of motor block was significantly prolonged in group B and C as compared to the control group. Results: The mean total duration for analgesia was significantly prolonged in Group B (340±8.36) and Group C (700±8.65) when compared to group A (263.30±7.57) (p<0.05). Conclusion: We conclude that intrathecal neostigmine results in effective postoperative analgesia prolonging sensory and motor block without hemodynamic and respiratory depression in the intra and postoperative period.