PHARMACOKINETIC PROFILE OF THE INDUCTION DOSE OF PROPOFOL IN PATIENTSWITH SEVERE BURNS

The pharmacokinetics of propofol were studied in nine severely burnt p atients undergoing general anaesthesia with enflurane/fentanyl for esc arectomy. All patients received an intravenous bolus dose of propofol 2 mg/kg, and blood concentrations of propofol were measured over the s ubsequent 12 hours using high performance liquid chromatography with f luorescent detection. Propofol blood concentrations, showing a very ra pid initial decline and a long terminal elimination phase, were best f itted by a triexponential function describing a 3-compartment open mam illary model with rapid distribution from the central compartment, ext ensive redistribution and elimination from the central compartment. Wh en compared with nonburnt normal controls, the patients with burns sho wed lower propofol blood concentrations, lower baseline albumin blood levels (p less than or equal to 0.001), smaller areas under the concen tration-time curve (p less than or equal to 0.001), larger volumes of distribution (p less than or equal to 0.001), and higher total body cl earance (p less than or equal to 0.001). Pathophysiological systemic r esponses to the burn injury and particularly the presence of oedema an d changes in albumin concentrations were probably responsible for the significant alterations in the disposition kinetics of propofol in the patients with burns.