To investigate clinically important hypotension and bradycardia after induction of anesthesia with propofol, we analyzed data from a Phase IV stepwise study involving 25,981 patients, 1722 institutions, and 1819 anesthesiologists. In Step 1, propofol was used for induction only. In Step 2, propofol was used for induction and then maintenance by intermittent injection. In Step 3, an induction dose was followed by a maintenance infusion. Participants were to be 18-80 yr of age and ASA physical status I-III; they could not have a continuing pregnancy or prior adverse anesthetic experience. Detailed data on demographic, perioperative, and outcome variables were recorded on data collection forms. The overall incidence of hypotension (systolic blood pressure < 90 mm Hg) was 15.7%; 77% of the episodes were recorded within 10 min of induction of anesthesia with propofol. Bradycardia (heart rate < 50 beats/min) occurred in 4.8% of patients, with 42% of the episodes in the first 10 min. Only 1.3% of patients had both hypotension and bradycardia. The incidence of hypotension was significantly higher for the elderly, females, Caucasians, those undergoing abdominal and integumentary procedures, and those given propofol with opioids, benzodiazepines, or propranolol. Bradycardia was significantly more common when propofol was combined with opioids or chronically taken beta-adrenergic receptor-blocking drugs. Bradycardia and hypotension were not commonly associated. Giving this new drug by protocol, even inexperienced anesthesiologists incurred few adverse hemodynamic changes. Hemodynamic changes were transient and rarely (< 0.2%) required drug therapy. Cardiovascular changes and drug interactions were predictable and manageable based on knowledge of the pharmacology of propofol.
By Hug CC Jr, McLeskey CH, Nahrwold ML, Roizen MF, Stanley TH, Thisted RA, Cynthia Walawander, White PF, Apfelbaum JL, Thaddeus H Grasela