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The disposition kinetics of propofol have been determined in 12 patients (6 female) receiving 2.5 mg/kg for induction of anaesthesia which was maintained using 1.5% halothane and 67% nitrous oxide in oxygen. Patients were premedicated with oral diazepam 10 mg and were undergoing body surface surgery. Peripheral venous samples were collected up to 8 h after injection of the drug. Whole blood propofol concentrations were determined by high pressure liquid chromatography using fluorescence detection. Data analysis indicates a 3 compartment model, with a terminal half-life of 286 (s.e.m. +/- 36) min, clearance of 1803 +/- 125 ml/min, and volume of distribution of 755 +/- 109 litres. These values are significantly different from those reported previously by Adam et al., (1983) for the Cremophor formulation of the drug. Seven of the patients showed significant secondary peaks of the blood concentration associated with recovery from anaesthesia.

The problems of anaesthetising infants and small children for major craniofacial surgery are discussed. A series of 23 patients is presented to illustrate the practical difficulties.

Incremental doses of propofol (10-20 mg) have been used to supplement nitrous oxide in oxygen anaesthesia for patients undergoing body surface surgery. After premedication with morphine 0.15 mg/kg, anaesthesia was successfully induced in 21 patients with 2.5 mg/kg propofol. One patient with labile hypertension suffered a pronounced cardiovascular response to the induction of anaesthesia, but without operative sequelae. The mean maintenance rate of propofol was 73.4 micrograms/kg/min. When compared with 10 patients receiving incremental doses of Althesin, recovery to giving correct date of birth was significantly faster in patients receiving propofol (P less than 0.01); when compared with 11 patients receiving an induction of thiopentone 5 mg/kg and nitrous oxide/oxygen/halothane, more patients receiving propofol had recovered to giving correct date of birth by 10 min after the end of anaesthesia (P less than 0.001). However, use of propofol was associated with pain on injection in 9 out of 20 patients, and apnoea of greater than 30 s in 8 patients.

The influence of an emulsion formulation of 2,6-diisopropylphenol (propofol) on blood coagulation and fibrinolysis, and on the neuroendocrine responses to surgery has been investigated in 12 patients who received incremental doses of propofol to supplement 67% nitrous oxide in oxygen as anaesthesia for body surface surgery. The effects were compared with those in 10 patients who received Althesin to supplement nitrous oxide in oxygen in a similar manner. When pre-operative values were compared with data obtained after 30 min surgery, no significant effects on coagulation or fibrinolytic indices were found in either group. Both groups, however, showed a significant fall in haemoglobin concentration 30 min after induction of anaesthesia (P less than 0.05); and a fall in haematrocrit value was observed in those patients who received propofol (P less than 0.05). No changes in total white cell counts or platelet counts were observed. Both groups of patients showed a significant rise in blood glucose 30 min after induction of anaesthesia (P less than 0.001). After 3 h values were not significantly different from preoperative levels. The mean plasma cortisol levels fell in both groups 30 min after induction of anaesthesia, but returned to control values by 3 h. The mechanism causing this decrease is not known.