[Reliability of propofol target-controlled infusion in elderly patients].

BACKGROUND: Propofol target-controlled infusion (TCI) is now commonly used for the induction and maintenance of anesthesia. In this study, we measured the propofol plasma concentrations of elderly patients to evaluate our hypothesis that propofol TCI is reliable for use in elderly patients. METHODS: We measured plasma concentrations of propofol in 10 elderly patients undergoing elective general anesthesia. Propofol TCI was commenced at a target plasma concentration of 3 microg x ml(-1) using a TCI pump. The target concentration was kept at 3 microg x ml(-1) for 2-3 hours. Arterial blood samples were drawn for measurement of the propofol plasma-concentration analysis at 30, 60, 90, 120 and 180 minutes after the induction of anesthesia, and at the emergence from anesthesia. RESULTS: The measured plasma concentrations of propofol were not significantly different from the target plasma concentrations. The mean estimated and measured plasma concentrations at emergence were at about 1 microg x ml(-1), respectively. CONCLUSIONS: We concluded that propofol TCI is a reliable method for maintaining anesthesia even in elderly patients, whereas the individual differences of the elderly patients was greater than those obtained from normal patients.