In a prospective, randomized, double-blind clinical study, we have studied 100 children, aged 2-12 yr, to compare halothane and sevoflurane in outpatient dental anaesthesia. All patients were unpremedicated and received inhalation induction using nitrous oxide in oxygen supplemented with either halothane (maximum inspired concentration 5%) or sevoflurane (maximum inspired concentration 8%). Time to loss of the eyelash reflex was more rapid using sevoflurane although time to adequate anaesthesia (to allow insertion of a mouth prop) was slower in the sevoflurane group. The incidence of cardiac arrhythmia was higher during halothane (62%) than during sevoflurane anaesthesia (28%) (P < 0.005) and the arrhythmias were more often ventricular in origin. The two agents were comparable in terms of ease of use and quality of anaesthesia, and times to eye opening and satisfying discharge criteria were similar. We conclude that sevoflurane has qualities that have made halothane the most used inhalation agent for children, and that it is superior to halothane in dental outpatients where cardiac arrhythmias are a particular problem.

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Sedation was studied in 30 patients requiring overnight ventilation in the intensive therapy unit (ITU). Patients received an infusion of either alfentanil or pethidine, supplemented with midazolam. The infusion rates were adjusted to provide optimal sedation as judged by a nurse, and measurements were made of quality of sedation, recovery and serum cortisol concentration. In addition, blood concentrations of alfentanil were measured to permit pharmacokinetic and pharmacodynamic analysis. Satisfactory sedation was achieved in both groups. The required infusion rate for alfentanil was between 0.4 and 0.5 micrograms kg-1 min-1. Recovery was good in both groups, apart from one patient in the alfentanil group, in whom recovery was greatly prolonged and alfentanil pharmacokinetics were abnormal. A difference was found in the metabolic response to surgery between the two groups, the response in the alfentanil group being significantly less marked.

Twenty patients in the intensive care unit received an infusion of atracurium to permit mechanical ventilation. The duration of infusion ranged from 38 to 219 h and the average rate of infusion during the study was 0.76 mg kg-1 h-1. In 14 patients an increase in atracurium requirement occurred within the first 72 h of the infusion. Recovery from neuromuscular blockade after a prolonged infusion was sufficiently rapid to avoid pharmacologically induced reversal. In six patients maximum plasma concentrations of laudanosine were 1.9-5 micrograms ml-1, and there was no evidence of cerebral excitation.

The Datex Relaxograph is a recently introduced electromyographic monitor of neuromuscular transmission. It has been assessed in patients requiring neuromuscular blockade and the results compared with those obtained simultaneously with a force transducer. There was a good correlation between the two methods of measurement for both twitch height and train-of-four ratio (correlation coefficients 0.93 and 0.97, respectively). The Datex Relaxograph proved easy to use in the clinical setting.

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.

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Summary Ninety patients undergoing a variety of surgical procedures were anaesthetised with a disoprofol infusion Key wordsAnaesthetics, intravenous; disoprofol. Analgesic, narcotic; fentanyl.Intravenous anaesthesia without inhalational supplements is theoretically attractive particularly at a time when argument continues over the possible harmful effects of waste anaesthetic gases. The fact that intravenous anaesthesia appears to be used by only a few enthusiasts reflects both the difficulty of some techniques and the absence of a completely suitable agent. There are few methods of total intravenous anaesthesia which combine good operating conditions and rapid recovery without the aid of muscle relaxation, and few if any intravenous hypnotic agents are useful without the addition of analgesics.A new intravenous induction agent, disoprofol (2-6 di-isopropyl phenol) has some of the properties required of an agent to maintain anaesthesia. Induction of anaesthesia has been reported to be smooth and recovery rapid, even when multiple doses had been administered.' This paper reports on the authors' experience of 90 administrations of disoprofol for total intravenous anaesthesia and in particular on the attempt to find a suitable dose regimen. MethodNinety patients aged between 18-75 years and ASA category 1 or 2 gave informed consent to the investigation. Patients with a history of atopy or allergy were excluded, as were patients weighing more than 100 kg and those who had received Cremophor within the previous 12