Abstract

BACKGROUND
Endobronchial intubation should elicit significant circulatory responses. We examined the effects of alfentanil on hemodynamic and catecholamine responses to endobronchial intubation in elderly patients. METHODS: A total of 60 patients aged over 60 years requiring endobronchial intubation were randomized into three groups of 20 patients each. Anesthesia was induced with thiopental 4~6 mg/kg followed by saline (placebo) or alfentanil 10 or 30microgram/kg given as a bolus over 30 s. Succinylcholine 1 mg/kg was given for neuromuscular block. Laryngoscopy and intubation were performed 1 min later. RESULTS: The intubation significantly increased systolic arterial pressure and heart rate. The maximum pressure changes from pre-intubation values in both alfentanil groups (58+/-27 and 33+/-30 mm Hg in 10 and 30microgram/kg, respectively) were significantly lower compared with that of 83+/-35 mm Hg in the control group. The tachycardiac response was not significantly affected by alfentanil 10microgram/kg, but attenuated by alfentanil 30microgram/kg. The plasma norepinephrine concentrations were increased, which was not affected by alfentanil 10microgram/kg, but was significantly attenuated by alfentanil 30microgram/kg. Both doses of alfentanil abolished the increase of plasma epinephrine concentrations. Three patients in the 30microgram/kg group received ephedrine for hypotension. CONCLUSIONS: This study showed that endobronchial intubation elicited significant pressor response, and that alfentanil 30microgram/kg is more efficacious in attenuating the hemodynamic and catecholamine responses, although potential hypotension warrants a caution of its use, in elderly patients.

• Keywords: Alfentanil;Catecholamines;Endobronchial intubation;Hypertension;Tachycardia