Neostigmine as an Adjuvant to Epidural Anaesthesia With 0.5% Bupivacaine for Vaginal Hysterectomy: A Comparative Study

Various drugs have been used as epidural adjuvants to enhance the quality and duration of surgical anaesthesia. We aimed at evaluating the effects of Neostigmine, an acetylcholine esterase inhibitor, as an adjuvant to epidural anaesthesia with 0.5% Bupivacaine for vaginal hysterectomy. In this clinical comparative randomized study, 60 ASA I & II patients requiring vaginal hysterectomy were randomly divided into two groups comprising 30 each. Control group: receiving epidural15ml of 0.5% Bupivacaine +0.6ml saline. Neostigmine group: receiving 15 ml of 0.5% Bupivacaine +0.6ml Neostigmine. Both groups were given an initial epidural top-up dose for postoperative analgesia. Time of onset, maximum sensory level achieved, degree of motor blockade, time of two segmental dermatomes regression, total duration of analgesia, perioperative hemodynamic changes and side effects were studied. The data obtained was compiled systematically and analyzed statistically using student-t test and chi-square test. Value of P<0.05 was considered significant. There were significant differences between the two groups (P<0.001) regarding: onset of sensory and motor blockade, time to attain maximum sensory level,all of which were earlier in Neostigmine group. The degree of motor blockade, time for 2 segmental dermatomes regression, total duration of motor block, postoperative analgesia and haemodynamic stability were comparable in both the groups. The mean arterial pressure in Neostigmine group, showed a delayed rise, though they were in the normal range. There were no major side effects noted in any of the patients. In conclusion, Neostigmine is a safe adjuvant to 0.5%Bupivacaine in epidural anaesthesia which provides early onset of sensory and motor blockade, with minimal effect on duration of blockade and perioperative hemodynamic stability, without any major side effects.