Abstract
Background: Tracheal extubation significantly alter haemodynamic responses and produces unwanted airway reflexes. Aim is to study the effect of dexmedetomidine on attenuation of these changes and its side effects.
Methods: Fifty patients with ASA I & II aged 18 to 60 years were selected for elective surgeries under general anaesthesia. Ten minutes before reversing the neuromuscular blockade, patients were randomly allocated to receive either dexmedetomidine 0.5 mcg/kg body weight diluted in 10 ml saline (Group D, n=25) and Normal Saline 10 ml intravenously (Group C, n=25) on double blind design. Haemodynamic parameters were assessed before, during and after extubation. Time to extubation and eye opening, laryngospasm, bronchospasm and bouts of cough were recorded. Extubation quality was rated using 5-point scale. Sedation was rated using Ramsay Sedation Scale.
Results: Haemodynamic changes and incidence of coughing were significantly lower in dexmedetomidine group compared to Saline group (P < 0.001). Time to extubation and eye opening were prolonged in Group D (p< 0.001). Episodes of tachycardia (p < 0.001), hypertension (p = 0.001), coughing (p = 0.001) and agitation (p < 0.001) were more in Group C. Significant number of patients in Group D were drowsy (5/25; 20%, score of 3) and asleep (1/25; 4%, score of 4) but responded to verbal commands following extubation as compared to Group C (15/25; 60%, score of 2) who were co-operative and oriented. Extubation quality was better in Group D (p < 0.001).
Conclusion: Infusion of dexmedetomidine 0.5 µg/kg over 10 minutes before extubation attenuates the airway and haemodynamic reflexes during emergence from anaesthesia and facilitates smooth extubation without causing respiratory depression and undue sedation. But may prolonged time to extubation and eye opening.

Key words: Dexmedetomidine, Tracheal extubation, Hemodynamic responses, Airway reflexes.