A comparison of arterial and arterialized venous concentrations of halothane.

Abstract

SUMMARY From seven patients under halothane anaesthesia twelve duplicated pairs of simultaneous arterial and carefully arterialized venous samples of blood were drawn, all at least 15 minutes after any change of vaporizer concentration. The mean difference of concentration (arterial minus arterialized venous) was 6.7% of the arterial, with 95% confidence limits of single differences (after allowing for experimental error) of ±18.4% or, omitting one patient with hypotension, +12.0%