What is the optimal effect-site concentration of remifentanil for minimizing the cardiovascular changes to endotracheal intubation during induction with propofol in elderly patients?.

Abstract

The addition of remifentanil during propofol TCI (target controlled infusion) attenuates the hemodynamic changes induced by endotracheal intubation. This study examined the optimal effect-site concentration of remifentanil to minimize the cardiovascular changes to endotracheal intubation in elderly patients. Fifty ASA 1 or 2 elderly patients scheduled for elective surgery under general anesthesia were assigned randomly to one of two groups according to the effect-site concentration of remifentanil. Each group was administered 4 microgram/ml of propofol TCI with 1 ng/ml (group R1) or 3 ng/ml (group R3) of remifentanil. The heart rate (HR), systolic (SAP), mean (MAP) and diastolic arterial pressure (DAP) were measured at pre-induction, before and after endotracheal intubation. After intubation, the HR, SAP, MAP and DAP increased significantly in the two groups compared with the pre-intubation values. However, the HR, SAP, MAP and DAP for group R3 were lower than group R1 for 5 min after intubation. In elderly patients administered 4 microg/ml of propofol TCI, we suggest that the optimal effect-site concentration of remifentanil to minimize the cardiovascular changes to endotracheal intubation is 3 ng/ml rather than 1 ng/ml.