Metabolism of halothane during and after anaesthesia in man.

The metabolism of halothane during and after anaesthesia was studied in eight patients of different age and body weight by estimating the concentration of halothane and one of its metabolites (bromide) in the blood. A gas chromatograph with an electron capture detector was used to estimate halothane, while blood bromide levels were measured by neutron activation analysis. There was an initial burst of bromide production during 20 minutes of halothane administration. Bromide levels then fell, but not to control levels, and remained so until the recovery of the patient from anaesthesia. In the postanaesthetic period, bromide production took place on a larger scale than before.