Effect of Different Doses of Oral Melatonin as a Premedication for Attenuation of Intubation Response

Abstract

Background And Aims: Airway manipulation during laryngoscopy and tracheal intubation acts as a powerful noxious stimuli leading to adverse cardiovascular responses, especially in patients with hypertension, coronary artery diseases etc. Melatonin is an endogenous sleep-regulating hormone exhibiting inhibitory actions on central nervous system, may also have role in attenuating hemodynamic responses to laryngoscopy and intubation. We hypothesized that, melatonin 9 mg is better than 6 mg in attenuating intubation response to laryngoscopy and endotracheal intubation. Material And Methods: The randomized control study was conducted on 80 patients scheduled to undergo elective surgeries under general anesthesia with endotracheal intubation. Group A received oral melatonin 6 mg and group B received 9 mg melatonin, 120 minutes before surgery. Hemodynamic parameters were recorded at baseline, 30, 60, 120 minutes after drug administration, pre-induction, post induction and every minute after intubation till 5 minutes then at 10th minute. Sedation scores were assessed using Ramsay sedation scores. Results: In group A, baseline mean HR was 84.78 ± 9.59 beats per minute (95% CI:65.6 - 103.96) and postintubation at 1minute it was 88.25 ± 13.68 bpm (95% CI:60.89 -115.61). In group B, baseline mean HR was 83.27 ± 14.84bpm (95% CI:59.81-108.09) and postintubation at 1minute it was 83.28 ± 14.84 bpm (95% CI:53.6 - 112.96).In group A,baseline mean MAP was 95.07 ± 9.05 mmHg (95% CI:76.98 - 113.18) and postintubation at 1minute it was 87.88 ± 14.89mmHg (95% CI:58.1 - 117.66).In group B, baseline mean MAP was 95.15 ± 10.54 mmHg (95% CI:74.07 - 116.23) and postintubation at 1minute it was 88.35 ± 15.67 mmHg (95% CI:57.01 - 119.69). Pressor response to tracheal intubation was attenuated in both groups and no statistical significance was noted between two groups.Both groups had sedation scores of 2-3.Conclusion: Both oral melatonin 6 mg and 9 mg when administered 120 minutes before induction of anaesthesia were effective in attenuating the hemodynamic responses to laryngoscopy and intubation.