Evaluation of the effect of transdermal nitroglycerine patch on intrathecal dexmedetomidine as additive, on postoperative analgesia after abdominal hysterectomy

Abstract

Aim: The aim of this study is to evaluate the effect of transdermal nitroglycerin on intrathecal dexmedetomidine as additive, on postoperative analgesia after abdominal hysterectomy. Materials and Methods: Totally 140 patients of the American Society of Anesthesiologists Grade I or II, posted for abdominal hysterectomy under spinal anesthesia, were randomized to four groups using computer-generated random number list. Group B received 3 ml of 0.5% hyperbaric bupivacaine with 0.5 ml normal saline and placebo patch, Group BN received 3 ml of 0.5% hyperbaric bupivacaine with 0.5 ml NS and transdermal nitroglycerin (t-NTG), Group BD received 3 ml of 0.5% hyperbaric bupivacaine with 5 mcg (0.5 ml) dexmedetomidine and placebo patch and Group BDN received 3 ml of 0.5% hyperbaric bupivacaine with 5 μg (0.5 ml) dexmedetomidine and t-NTG patch. Outcomes measured include the total duration of analgesia, onset, and duration of sensory and motor block and any adverse effects. Results: The total duration of analgesia was longest in Group BDN (349.9 ± 40.6 min). It was significantly longer than Group BD (252.3 ± 34.0 min) and Group B and BN (130.5 ± 18.8, 138.3 ± 19.2 min). Time taken for two segment regression was comparable in Group B (79.9 ± 14.4 min) and Group BN (87.1 ± 22.6 min), but it was significantly longer in Group BD (122.5 ± 17.2 min) and Group BDN (136.4 ± 25.5 min). There was no significant difference in other variables between the groups. Conclusion: Transdermal nitroglycerine itself does not exhibit any analgesic potential of its own but, it enhances the analgesic potential of intrathecal dexmedetomidine.

Keywords

• Analgesia
• dexmedetomidine
• spinal anesthesia
• transdermal nitroglycerin patch