Comparison of Enhancement of Analgesic Effect of Intrathecal Neostigmine by Intrathecal Clonidine and Transdermal Nitroglycerin Patch on Bupivacaine Spinal Anesthesia.

Background: Relief of pain is very important goal intraoperatively and postoperatively. Neostigmine has been used successfully intrathecally with other agents such as clonidine and opioids for pain relief. Aims: This study aims to compare and evaluate the efficacy and safety of combining intrathecal (IT) neostigmine with IT clonidine and transdermal nitroglycerin (tNTG) patch for the relief of pain in patients after surgery. Settings and Design: This was a randomized, prospective, and comparative study Materials and Methods: In this study, recruited patients were randomly allocated into three groups. Groups I, II, and III received intrathecally 25 µg of neostigmine + 15 mg hyperbaric 0.5% bupivacaine, 25 μg of neostigmine + 25 µg clonidine + 15 mg hyperbaric 0.5% bupivacaine, and 25 µg of neostigmine + tNTG patch (3 cm x 5 cm, 5 mg/24 h) +15 mg hyperbaric 0.5% bupivacaine, respectively. Heart rate, mean arterial pressure, analgesic properties, and complications were assessed and compared among groups. Statistical Analysis: Mean and standard deviation were calculated. Test of analysis between two groups was done by t-test and among three groups by ANOVA, then P value was calculated. Results: Duration of analgesia was significantly longer in Group III in comparison to Group II (7.142 ± 1.81 vs. 4.408 ± 0.813 h) and was significantly longer in Group II in comparison to Group I (4.408 ± 0.813 vs. 2.583 ± 0.493 h). Analgesic requirement was significantly less in Group III in comparison to Group II (1.9 ± 0.76 vs. 2.5 ± 0.51) and was significantly less in Group II in comparison to Group I (2.5 ± 0.51 vs. 3.1 ± 0.48). Sedation score was found significantly high in Group II than other groups. Conclusion: Both IT clonidine and tNTG patch with bupivacaine + neostigmine spinal anesthesia were found effective in pain control. Results were found better with tNTG patch. [ABSTRACT FROM AUTHOR]