Anaesthesia with ICI 35,868 monitored by the cerebral function analysing monitor (CFAM).

Ten patients who received bolus doses of the cremophor formulation of ICI 35,868 were monitored using the Cerebral Function Analysing Monitor (CFAM). Visual inspection of the traces obtained showed an easily recognizable pattern which was associated with an increasing depth of anaesthesia. Statistical analysis showed a high correlation between venous blood levels of the drug and changes recorded by the CFAM, although there was marked inter-patient variation. It is suggested that this variation is due to the effect of a time-lag between changes in drug concentration in the brain and venous blood.

Influence of sample site on blood concentrations of ICI 35868.

Simultaneous blood samples from an artery, a peripheral vein and a central vein were analysed for ICI 35868 concentrations following an induction dose of 2.0 mg kg-1 administered i.v. over 60 s, to five patients before cardiac surgery. Up to 60 s after the end of the administration of the drug there were wide differences in drug concentration between the sampling sites. Thus, any attempt to correlate effect with blood concentration over this early period would be problematic. From 60 s there were no significant differences in drug concentration between the three sites. Thus, as long as the mixing period is allowed for, peripheral venous sampling provides an acceptable alternative to arterial puncture in studies to correlate drug effect and concentration and for pharmacokinetic investigations.

The response of canine intracranial pressure to systemic hypotension induced with nitroglycerine.

Changes in intracranial pressure were studied in 18 greyhounds in relation to decreases in systemic arterial pressure produced by nitroglycerine. At normal values of i.c.p. (less than 12 mm Hg) GTN produced an increase in i.c.p. of 3.1 (+/- 0.6) mm Hg (mean +/- SEM). Under conditions of increased i.c.p. (12 + mm Hg) small decreases in mean arterial pressure (m.a.p.) (less than 25% control) were associated with an increase of 4.7 (+/- 0.5) mm Hg, whereas larger decreases in m.a.p. (greater than 25% control) were associated with a decrease of 3.2 (+/- 0.9) mm Hg in i.c.p. In 11 of 19 observations in which a decrease in intracranial pressure had occurred in association with systemic hypotension there was a rebound increase in i.c.p. as m.a.p. was restored. It is suggested that i.c.p. be decreased before this drug is used to produce hypotension during neurosurgery.

Disoprofol and fentanyl for total intravenous anaesthesia.

Ninety patients undergoing a variety of surgical procedures were anaesthetised with a disoprofol infusion and increments of fentanyl. The first 40 patients constituted a preliminary dose finding study and the subsequent 50 patients a dose comparison study. The second 50 patients were alternately allocated to receive a maintenance infusion of disoprofol 150 or 200 micrograms/kg/minute. Fentanyl (1 microgram/kg) at induction was followed by further small increments when indicated. Maintenance dosage of 200 micrograms/kg/minute provided good operating conditions and rapid uncomplicated recovery in spontaneously breathing patients, while 150 micrograms/kg/minute proved inadequate to prevent patient movement.

A study of three doses of ici 35 868 for induction and maintenance of anaesthesia.

Three doses (1.5, 2.0 and 2.5 mg kg-1) of diisopropyl phenol (ICI 35 868) were compared for induction and maintenance of anaesthesia in healthy females undergoing short gynaecological procedures. Induction of anaesthesia was smooth and rapid. Cardiovascular changes (which were dose-dependent) included a decrease in arterial pressure and an increase in heart rate. These changes were magnitudes comparable to those reported for other induction agents. Recovery from the effects of the drug was rapid and uneventful.

Vessel puncture with epidural catheters. Experience in obstetric patients.

The reported incidence of blood vessel puncture after placement of a needle and catheter into the lumbar epidural space in obstetric practice appears to vary between 1 and 10%. This study was undertaken to assess the incidence of blood vessel puncture related to catheter insertion. Two methods of catheter placement were used to see if there were any difference in the incidence of vessel puncture. The incidence of blood vessel puncture after direct catheter placement was found to be 9% compared to 3% after prior injection of 10 ml of 0.5% plain bupivacaine into the epidural space. (p = 0.05).