Background and Aim: Laryngoscopy and endotracheal intubation cause increase in heart rate and blood pressure as well as abnormalities of cardiac rhythm due to reflex sympathetic discharge which is caused by epipharyngealand laryngo-pharyngeal stimulation. The aim is to study the changes in following parameters during laryngoscopyand endotracheal intubation up to 10 min with tab melatonin administration.

Material and Methods: The present study was carried out in the Department of Anaesthesiology, Government Medical College and S.S.G. Hospital, Vadodara, from November 2017 to October 2018. Randomisation was done according to computer generated list into two equal groups. Group C (Control group) - Patients received two tablets of vitamin D3 (placebo) 120 min before induction of anaesthesia.. Group M (Melatonin group) received oral melatonin tablets of 6mg (two tablets of 3mg each) 120 min before induction of anaesthesia. Vitamin D3 was used as placebo drug. Haemodynamic parameters such as heart rate: systolic, diastolic and mean blood pressures were recorded before the administration of drug (baseline), 120 min after administration of study drug, immediately after induction, at laryngoscopy and intubation, just after laryngoscopy and intubation and at 1, 3, 5 and 10 min thereafter.

Results: The mean pre operative pulse rate, the Systolic blood pressure(SBP), the Diastolic blood pressure(DBP), Mean arterial pressure(MAP) and the SpO2 were comparable in both groups but not significant statistically (p>0.05). At baseline and just before intubation, pulse rate was comparable in both groups. Nausea & vomiting was seen in one patient from study group & was treated with inj.Ondansetroniv. Hypotension was observed in 1 patient from the study group.

Conclusion: Administration of oral melatonin premedication 120 minutes before surgery results in Significant attenuation of the rise in systolic, diastolic and mean arterial blood pressure at the time of laryngoscopy & intubation and Transient increase in pulse rate which settled down within 1 minute after intubation and remained stable throughout the study period.