PROPOFOL ADMINISTERED BY A MANUAL INFUSION REGIMEN

We have evaluated the clinical utility and blood propofol concentratio ns produced with two different infusion regimens for propofol, given t o supplement 67% nitrous oxide-morphine anaesthesia. Patients received a standardized three-step infusion of propofol based either on body w eight (weight-corrected group) or on a mean body weight of 70 kg (stan dard dose group). Both groups showed similar cardiovascular stability and recovery times. In the 48 patients studied, isoflurane was used as a supplement in nine (two in the weight-corrected group). Apparently steady state blood propofol concentrations were 3.41 (SD 0.69) mu g ml (-1) in the weight-corrected group and 3.46 (0.79) mu g ml(-1) in the standard dose group. These results suggest that for patients weighing 60-90 kg body weight, a standard dose infusion regimen may be a suitab le starting point. In routine clinical practice, the need for isoflura ne supplementation may be avoided by subsequent titration of the infus ion rate according to clinical response. Computer simulation of the ac tual infusion rates used in each patient has allowed retrospective com parison of the predictive performance of different pharmacokinetic des criptors for propofol. The variables described by Tackley and colleagu es provided a more accurate prediction of the measured blood propofol concentration than did the variable set reported by Gepts and colleagu es.