Résumé
Laryngoscopy and tracheal intubation frequently induce a cardiovascular stress response, characterized by hypertension, tachycardia and increased serum concentrations of catecholamines. Three qroups each contained 10 patients undergoing elective surgery under general anaesthesia were studied. Preanesthetic medications were nothing, oral diazepam 10 mg and oral clonidine 10 mg in each group. Heart rate, systolic arterial pressure, diastolic arterial pressure, HR, SAP, DAP and MAP were recorded. Estimation of plasma concentrations of catecholamines were performed. There were lack of significant changes in HR and MAP in the clonidine group in comparison to control group but diazepam group showed a significant reduction in HR. Plasma norepinephrine showed a significant decrease in both groups. It also showed a significant correlation between plasma norepinephrine concentration and MAP only in the clonidine group. Although clonidine has some side effects as sedation and dry mouth. It is preferable than diazepam as a premedicant agent as it causes analgesia, anxiolysis and sedation