highly significantP <0.0001
A highly significant heart rate elevation following direct laryngoscopy and endotracheal intubation was recorded in all three groups (P <0.0001), but heart rate rise duration was longest in the placebo group and of shortest duration in the clonidine group (Mean HR at 15 minutes: 80.80±15.41 in the placebo vs 65.53±12.43 in clonidine group).