Comparative evaluation of oral melatonin and oral clonidine for the attenuation of haemodynamic response to laryngoscopy and tracheal intubation - A prospective randomised double blind study

Abstract

Background and Aims: Laryngoscopy and endotracheal intubation cause significant derangement of the haemodynamic parameters proving detrimental for some patients. Clonidine, an α-2 adrenoreceptor agonist, and melatonin, the pineal hormone, have been used for the attenuation of these haemodynamic responses. This study was designed to evaluate the effect of oral melatonin and clonidine in attenuating the haemodynamic responses to laryngoscopy and intubation. Materials and Methods: In this prospective randomised double-blind study, 60 American Society of Anaesthesiologists (ASA) grade I and II patients aged 20-60 years of either gender scheduled to undergo elective surgery under general anaesthesia were randomly divided into Group M and Group C and orally received 6 mg of melatonin and 0.2 mg of clonidine, respectively, 120 min before the induction of anaesthesia. The haemodynamic parameters-heart rate (HR), systolic blood pressure, diastolic blood pressure, mean arterial pressure and rate -pressure product(RPP) were recorded before and 120 min after the administration of the study drug, before induction, immediately after intubation and at 1, 3, 5 and 10 min following intubation. Sedation was assessed using the Ramsay Sedation Scale. The qualitative and quantitative variables were analysed using Chi square test and unpaired student t test, respectively. For intragroup comparison of quantitative data, paired t test was applied. A P value <0.05 was considered as statistically significant. Results: A significant difference was noted between the groups regarding HR and RPP 0, 1, 3 and 5 min after intubation. The Ramsay sedation score ranged between 2 and 3 at all time intervals. Conclusion: Although both the drugs are effective, oral melatonin proved superior to oral clonidine in attenuating the haemodynamic response to laryngoscopy and tracheal intubation without any side effects.