Calcium channel blockers attenuate cardiovascular responses to tracheal extubation in hypertensive patients.
OBJECTIVE
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.


METHODS
Sixty hypertensive patients (ASA physical status II) undergoing elective orthopaedic (upper and lower extremity) surgery received, in a randomized, double-blind manner, 30 micrograms.kg-1 nicardipine, 0.2 mg.kg-1 diltiazem or saline (as a control) (n = 20 of each) i.v. before tracheal extubation. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and after tracheal extubation.


RESULTS
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 +/- 7 vs 101 +/- 10, RPP; 11,437 +/- 1,575 vs 14,675 +/- 2,874, mean +/- SD, P < 0.05).


CONCLUSIONS
Compared with nicardipine, administration of diltiazem produced greater attenuating the circulatory responses to tracheal extubation in hypertensive patients.
Department of Anaesthesiology, University of Tsukuba Institute of Clinical Medicine, Ibaraki, Japan.
Y
Y
Fujii
S
S
Kihara
S
S
Takahashi
H
H
Tanaka
H
H
Toyooka
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004110:Diltiazem / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000627:therapeutic use; D019637:Orthopedic Procedures
D002121:Calcium Channel Blockers; D009529:Nicardipine; D004110:Diltiazem