Calcium Channel Blockers Attenuate Cardiovascular Responses to Tracheal Extubation in Hypertensive Patients

Abstract

Hypertensive patients exhibit exaggerated cardiovascular responses to tracheal extubation. This study was undertaken to examine the inhibitory effects of calcium channel blockers, nicardipine and diltiazem, on haemodynamic changes after tracheal extubation. Sixty hypertensive patients (ASA physical status II) undergoing elective orthopaedic (upper and lower extremity) surgery received, in a randomized, double-blind manner, 30 μg·kg−1 nicardipine, 0.2 mg·kg−1 diltiazem or saline (as a control) (n = 20 of each) iv before tracheal extubation. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and after tracheal extubation. The HR, MAP and RPP increased after tracheal extubation in the control group (P < 0.05). The increases in these haemodynamic variables were attenuated with nicardipine or diltiazem. The inhibitory effects of diltiazem on these cardiovascular responses to tracheal extubation were greater than those of nicardipine (HR; 86 ±7vs 101 ± 10, RPP; 1 1437 ± 1575vs 14675 ± 2874, mean ± SD,P < 0.05). Compared with nicardipine, administration of diltiazem produced greater attenuating the circulatory responses to tracheal extubation in hypertensive patients.