RESUMO
BACKGROUND: Dexmedetomidine is an alpha-2 adrenergic agonist with sedative, anxiolytic, and analgesic properties. This study was designed to evaluate the inhibitory effects of preoperative administration of 0.5 µg/kg dexmedetomidine on hemodynamic responses caused by endotracheal intubation in elderly patients undergoing treatment for hypertension. METHODS: Forty elderly (≥ 65 years old) patients who had been receiving hypertension treatment, had American Society of Anesthesiologists physical status II, and were scheduled to undergo elective noncardiac surgery were randomly selected and assigned to 2 groups. Group C received normal saline and group D received 0.5 µg/kg dexmedetomidine intravenously over 10 min just before endotracheal intubation. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded preoperatively in the ward, immediately after study drug administration, and at 1, 3, and 5 min after endotracheal intubation. RESULTS: Compared to group C, group D showed significantly lower SBP and MAP at 1, 3, and 5 min as well as significantly lower DBP and HR at 3 and 5 min after endotracheal intubation. CONCLUSIONS: In elderly patients receiving hypertension treatment, a single preanesthetic dose of dexmedetomidine (0.5 µg/kg) effectively suppressed the hemodynamic responses to endotracheal intubation.