The effects of low-dose midazolam for induction of high-dose fentanyl anesthesia for coronary artery bypass graft.

A small dose of midazolam 0.06 mg/kg or diazepam 0.15 mg/kg was used for induction of high-dose fentanyl (50 μg/kg) anesthesia in patients undergoing coronary artery bypass grafting operation. Hemodynamic variables were measured 5 min after the injection of midazolam or diazepam, after the end of the fentanyl infusion, and following endotracheal intubation. Midazolam and diazepam caused a slight but significant decrease in mean arterial pressure (-9.8%) and -11.8%), respectively) and a further significant depression was observed in the diazepam group but not in the midazolam group after fentanyl. Although the cardiac index was maintained in patients who received madazolam, a significant decrease was observed in the diazepam group (-28.5%) after administration of fentanyl. Heart rate was decreased in the diazepam group but not in the midazolam group. Therefore, a small dose of midazolam may be a suitable induction agent for high-dose fentanyl anesthesia in patients with coronary artery disease.