Microsomal fractions were prepared from the liver of rabbits to investigate the effects of paraquat (methyl viologen) on generation of metabolites of halothane under the optimal aerobic and anaerobic conditions. Halothane (CF3CHClBr) is known to undergo oxidative and reductive biotransformation in the hepatic mixed function oxidase system including cytochrome-P450 reductase and cytochrome P450....

The time interval since previous anaesthesia was compared in a surgical population in South Wales and in patients who developed jaundice after halothane. There was a significant difference in the pattern of time interval since previous general anaesthetics in the surgical population and in those patients who developed jaundice after halothane. In the group who developed jaundice there was an "e...

The effect of halothane on experimental ischaemic muscle pain has been studied in 18 human volunteers. The submaxiTniim effort tourniquet test was used in this investigation because it has been shown by previous workers to be a sensitive experimental test of analgesia. Two concentrations of halothane (0.25 and 0.35%) were compared with nitrous oxide (30%) in a controlled experiment. It was foun...

Anaesthesia with nitrous oxide and oxygen, alone or supplemented with methoxyflurane or halothane, was administered for dental extractions in 256 patients (204 children and 52 antenatal women). Anaesthesia was regarded as "good" in 69 per cent of patients with methoxyflurane and 75 per cent with halothane, but only 50 per cent with unsupplemented nitrous oxide and oxygen. A further trial was ca...

This open labelled, randomised, controlled study was designed to compare the induction and recovery characteristics of sevoflurane and halothane anaesthesia in children. Forty American Society of Anaesthesiologist (ASA) physical status class 1 or 2 children (aged 1-10 year, weighed less than 25 kg) scheduled for elective urological procedure lasting less than one hour were allocated randomly to...

The independent effects of halothane and carbon dioxide on central mechanisms regulating respiratory frequency were investigated in 12 vagotomized, artificially ventilated cats. Changes in respiratory pattern analysed from the phrenic neurogram revealed that increasing PaCO2 at a constant depth of halothane anaesthesia caused a progressive increase in TE with various changes in TI, whereas incr...

The effect of halothane 2 per cent on neuromuscular transmission and its interaction with both tubocurarine and suxamethonium was investigated in twenty patients undergoing surgery, using the twitch response to ulnar nerve stimulation. Ventilation was constantly controlled throughout the procedure. Halothane did not cause any depression of the twitch response in the absence of tubocurarine; a s...

The use of a halothane meter in routine paediatric anaesthesia with controlled ventilation is described. The results demonstrate the accuracy achieved in the control of the alveolar halothane concentration. Measurement of the alveolar halothane concentration revealed responses to surgical stimulation otherwise obscured by neuromuscular blockade, and this may indicate insufficient depth of anaes...

Extracellular activity was recorded from single spinal dorsal horn neurons in both chronic cat and acute rat models. This was done to define the effects of anesthesia on the processing of sensory information elicited by nonnoxious tactile stimulation of peripheral receptive fields (RFs). In the chronic cat model, baseline data were obtained in physiologically intact, awake, drug-free animals be...