CALCIUM-CHANNEL BLOCKERS ATTENUATE CARDIOVASCULAR-RESPONSES TO TRACHEAL EXTUBATION IN HYPERTENSIVE PATIENTS

Purpose: Hypertensive patients exhibit exaggerated cardiovascular resp onses to tracheal extubation. This study was undertaken to examine the inhibitory effects of calcium channel blockers, nicardipine and dilti azem, on haemodynamic changes after tracheal extubation. Methods: Sixt y hypertensive patients (ASA physical status II) undergoing elective o rthopaedic (upper and lower extremity) surgery received, in a randomiz ed, double-blind manner, 30 mu g.kg(-1) nicardipine, 0.2 mg.kg-1 dilti azem or saline (as a control) (n = 20 of each) iv before tracheal extu bation. Changes in heart rate (HR), mean arterial pressure (MAP) and r ate-pressure product (RPP) were measured before and after tracheal ext ubation. Results: The HR, MAP and RPP increased after tracheal extubat ion in the control group (P < 0.05). The increases in these haemodynam ic variables were attenuated with nicardipine or diltiazem. The inhibi tory effects of diltiazem on these cardiovascular responses to trachea l extubation were greater than those of nicardipine (HR; 86 +/- 7 vs 1 01 +/- 10, RPP; 11437 +/- 1575 vs 14675 +/- 2874, mean +/- SD, P < 0.0 5).