Electroencephalogram bispectral index predicts hemodynamic and arousal reactions during induction of anesthesia in patients undergoing cardiac surgery

Objective:To evaluate hemodynamic and clinical responses to induction of an esthesia and intubation at 3 different values of the electroencephalogram b ispectral index (BIS). Design: Prospective randomized trial. Setting: University-affiliate hospital. Participants: Forty-five patients undergoing elective coronary artery bypas s graft surgery. Interventions: Patients were assigned to 3 groups (n = 15 for each group). Anesthesia was induced with midazolam, sufentanil, and pancuronium. In each group, sufentanil was titrated to a BIS value of 60, 50, or 40 before intu bation. Mean arterial blood pressure, heart rate, incidence of coughing, te aring, and need for fluid replacement or injections of norepinephrine were recorded before intubation as well as immediately and 1 and 2 minutes after intubation. Measurements and Main Results: Thirteen patients intubated at a BIS value o f 60 coughed and 14 experienced tearing after intubation, whereas no patien t of the other groups showed signs of arousal. Mean arterial blood pressure remained stable in the BIS 60 and 50 groups, whereas in the BIS 40 group i t decreased significantly to lower values before and after intubation, Pati ents in the BIS 40 group needed significantly more fluid replacement and in jections of norepinephrine compared with the other groups. No significant c hanges in heart rate were detected. Conclusions: Electroencephalogram BIS predicts hemodynamic and arousal reac tion resulting from induction of anesthesia and endotracheal intubation. BI S value should be kept at 50 before intubation to ensure safe hemodynamic c onditions during induction of anesthesia in cardiac surgical patients. Copy right (C) 2000 by W.B. Saunders Company.