Dose-response effects of intravenous clonidine on stress response during induction of anesthesia in coronary artery bypass graft patients.
This study was designed to evaluate the dose-response effects of different doses of clonidine on the stress response to laryngoscopy and endotracheal intubation. In a randomized, double-blind study, 48 coronary artery bypass grafting (CABG) patients received 0, 2, 4, or 6 micrograms/kg clonidine as an intravenous (IV) infusion during a 15-min period 30 min prior to induction of anesthesia with etomidate (0.3 mg/kg), fentanyl (5-7 micrograms/kg), and pancuronium (0.1 mg/kg). Sedation was assessed prior to induction of anesthesia. Cardiovascular variables and catecholamine plasma levels were measured at predefined intervals. Additional bolus doses of etomidate and fentanyl for suppression of stress-induced reactions were administered if predefined limits of heart rate and blood pressure were exceeded. Clonidine 4 and 6 micrograms/kg significantly attenuated hemodynamic and adrenergic reactions to stress, reduced pharmacologic interventions, and increased sedation. However, clonidine 6 micrograms/kg was not more effective than 4 micrograms/kg, and clonidine 2 micrograms/kg was equally effective as placebo. We conclude that clonidine 4 micrograms/kg IV is the appropriate dose to attenuate the stress response to laryngoscopy in CABG patients. Side effects limiting the use of IV clonidine were not observed.
Kulka
P J
PJ
Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Bergmannsheil, Bochum, Germany.
Tryba
M
M
Zenz
M
M
D001794:Blood Pressure / Q000187:drug effects*; D003000:Clonidine / Q000008:administration & dosage*; D001026:Coronary Artery Bypass; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005045:Etomidate; D005260:Female; D005283:Fentanyl; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007262:Infusions, Intravenous; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D010197:Pancuronium; D011669:Pulmonary Wedge Pressure / Q000187:drug effects
D010197:Pancuronium; D003000:Clonidine; D005283:Fentanyl; D005045:Etomidate