Background: The purpose of this study was to evaluate the effect of a single pre–induction intravenous dose of dexmedetomidine 1mcgkg on cardiovascular response resulting from laryngoscopy and endotracheal intubation.

Methods: Sixty patients ASA grade I and II scheduled for  elective surgery under general anaesthesia were randomized into two groups(dexmedetomidine  group{B} and placebo group{A},n=30 in each group).Haemodynamic parameters and adverse effects were recorded before intubation and during intubation.

Result: In the present study,two groups were comparable. Mean(±SD)heart rate(beats/min) increased from the basal value of 84.20±13.16 to 107.07±11.47 (21.4%) during laryngoscopy and endotracheal intubation in group A whereas in group B it increased from basal value of 82.97±7.69 to 84.13±7.33(2.38%) (p<0.01).Mean (±SD) SBP increased from basal value of 125.40±10.97 to 143.61±11.59 mm Hg(12.58%) in group A whereas in groupB it increased from 126.93±7.63 to 128.60±9.62 mm Hg(1.56%) (p<0.01).Mean DBP increased from basal value of 80.90±5.58 to 92.57±5.89 (13.04%) in group A whereas in groupB it increased from basal value of 81.63±4.19 to 83.00±6.49 (2.4%) (p<0.01). Mean arterial pressure increased from basal value of 95.71±7.02 to 109.57±7.31 (12.8%) in groupA whereas in groupB it increased from96.74±4.87 to 98.17±7.01(2.04%) (p<0.01). Thus the increase in heart rate, SBP, DBP and MAP were significantly lower in Dexmedetomidine group (p<0.01).

Conclusion: Preoperative administration of a single IV dose (1µg/kg) of dexmedetomidine can be used as an adjuvant  to anesthetic induction to attenuate  haemodynamic responses during laryngosopy and endotracheal intubation.