Blood, urine, and breath levels after rapid intravenous infusion of ethanol.

A re-evaluation of alcohol as an intravenous anaesthetic provided an opportunity of studying the changes in venous blood, urine, and breath levels under controlled conditions. Twelve volunteer patients were given 0.8 g./kg. in 8% w/v solution over four to six minutes. Despite standardization of technique there was a great variation in the peak urinary concentration and also some variation in the time at which urinary level exceeded that of blood, but this latter always occurred within 30 minutes of infusion. From one hour after infusion there was a constant mean rate of decline of both venous and urinary concentrations. While urinary/venous blood ratios varied greatly they remained fairly constant in each individual patient. The average ratio (1.35) was similar to that of other published papers. With a modification of gearing (58:1 to 67:1) the standard Ethanographe gave good correlation of breath with venous blood concentrations at low levels when patients were able to operate the machine themselves. At high levels, however, with a two-minute period of rebreathing in the unconscious patient, the correlation was poor.