Induction and maintenance of propofol anaesthesia

A simple, manually controlled infusion scheme for continuous administration of propofol was derived by simulation of a computer algorithm designed to achieve a predetermined blood concentration of propofol within 2 minutes and to maintain a constant blood level for the duration of surgery. The manual infusion scheme for a target blood propofol concentration of 3 μg/ml, consisted of a loading dose of 1 mg/kg followed immediately by an infusion of 10 mg/kg/hour for 10 minutes, 8 mg/kg/hour for the next 10 minutes and 6 mg/kg/hour thereafter. An overall mean blood propofol concentration of 3.67 μg/ml was achieved within 2 minutes and maintained stable for the subsequent 80–90 minutes of surgery. The decrease of systolic and diastolic arterial pressures at induction was much less than that previously described after larger induction doses of propofol and there was a negligible haemodynamic response to largyngoscopy and intubation or to the subsequent surgery. The quality of induction and maintenance of anaesthesia was satisfactory in every patient.