Halothane anaesthesia of normal and dystrophic hamsters

Induction, carried out in a small clear-plastic box with 3·5% (v/v) halothane in 30:70 (v/v) oxygen: nitrous oxide, was quiet and rapid. Recovery was almost instantaneous. 2% halothane in the oxygen-nitrous oxide mixture was sufficient for maintenance anaesthesia. The anaesthetic mixture was given by face mask in an open circuit specially designed to function at low gas-flow rates. The halothane content of the muscle and blood after 25 min anaesthesia was estimated by gas chromatography of n-heptane extracts. The mean level(± s.e.m.) in blood was 22·8±2·7 mg/1OO ml (n=4), and in dystrophic muscle 226±36·8 mg/100 g wet weight of tissue (n=4): there was a positive correlation (r=0·94) between them ( p<:0·02).