Postoperative Analgesia With Intrathecal Neostigmine; Two Different Doses Of 75 μgms And 50 μgms With Heavy Bupivacaine

This study was conducted to compare post operative analgesia and side effects of intrathecal neostigmine with two different doses of 75 μgms and 50 μgms with bupivacaine heavy 0.5 %( 15mg). 90 patients of ASA grade I and II were randomly selected from a routine list of general surgery, plastic surgery, gynaecology and orthopaedic units of the hospital under spinal anaesthesia were randomly allocated to three groups of 30 patients each. 75 μgms neostigmine groups had prolonged post operative analgesia (less number of rescue analgesia and longer time to first analgesia) compared to other two groups (p<0 .001). The time to first analgesia in 75 μgms groups is 236.2±1.6 min(Mean +/-SD) , in 50 μgms groups is 183.9±3.36 min(Mean +/-SD), in control group is 138.5±5.1 min(Mean ±SD).Nausea and vomiting was more in 75 μgms groups (30%) compared to 50 μgms neostigmine group (16%). Bradycardia was more frequent in the 75 μgms group (26%) compared to 50 μgms neostigmine group (13%). Hypotension was also more frequent in the 75 μgms group (36%) compared to the 50 μgms neostigmine group (20%). This study concludes that though post operative analgesia is better with 75 μgms neostigmine group compared to 50 μgms neostigmine group, side effects are also more frequent in the 75 μgms neostigmine group.