Attenuation of haemodynamic responses to laryngoscopy and endotracheal intubation with intravenous dexmedetomidine: A comparison between two doses

BACKGROUND AND AIMS: Laryngoscopic manipulation and endotracheal intubation are noxious stimuli capable of producing tachycardia, arrhythmias and hypertension. The aim of this study was to arrive at an optimal dose of dexmedetomidine by comparing two doses with placebo to attenuate stress response during laryngoscopy and endotracheal intubation. METHODS: It was a randomised, prospective, double-blind placebo-controlled study. After Institutional Ethical Committee clearance, ninety patients of American Society of Anesthesiologists Physical Status 1 were enrolled in the study and divided into three equal groups. Group A received normal saline, Group B received injection dexmedetomidine 0.5 μg/kg and Group C received injection dexmedetomidine 0.75 μg/kg as infusion over 10 min. The general anaesthesia technique was standardised for all three groups. The primary outcome measures were haemodynamic response at 1, 3 and 5 min after intubation. The secondary outcome measures were to note down any adverse effects associated with drugs. The statistical package used was SPSS version 15. RESULTS: Groups were well matched for their demographic data. There was a statistically significant difference (P < 0.05) between dexmedetomidine and normal saline in heart rate, systolic, diastolic and mean arterial pressures at all time points after tracheal intubation with dexmedetomidine 0.75 μg/kg being most effective. Sedation scores were more with dexmedetomidine. None of the patients had any adverse effects such as hypotension, bradycardia, respiratory depression and fall in oxygen saturation. CONCLUSION: Dexmedetomidine in a dose of 0.75 μg/kg intravenous is the optimal dose to attenuate stress response to laryngoscopy and endotracheal intubation.