Intravenous propofol anaesthesia using a computerised infusion system.

Propofol offers many advantages as a total intravenous anaesthetic agent compared with other agents. However, considerable experience is necessary in order to give an uncomplicated anaesthetic. A mathematical model which describes the pharmacokinetic behaviour of the drug was incorporated into a computerised delivery system which enables the anaesthetist to achieve and maintain a target blood concentration of propofol and to manipulate this at will. The system was used to provide general anaesthesia for 33 healthy patients who underwent general surgery. A strong statistical relationship was found between measured blood propofol concentrations and the corresponding computer predictions (y = -0.50 + 1.36x). No significant differences in this relationship were found between patients who breathed spontaneously (y = -0.71x + 1.43x) and those who received intermittent positive pressure ventilation (y = -0.33 + 1.32x).