Inline blood gas analysis by gas chromatography in patients during and after coronary artery surgery

A system was evaluated of measuring Pao2 and Pao2 by an inline sensor in the brachial artery and gas chromatography. Eight patients having coronary artery vein grafts were studied during anaesthesia, operation, perfusion and for 24 hours afterward. Compared to conventional blood gas analysis by polarography (electrodes), the chromatographic method gave readings for Pao2 which were not significantly different during normothermia. During hypothermic perfusion, the chromatographic system read significantly higher than the bench electrode, due at least in part to a difference in temperature correction. For Pao2 the correlation between the two methods was close and differences were clinically insignificant. The Sentorr blood-gas analyser provides a sensitive, accurate indicator of changes in oxygenation, ventilation and circulation during anaesthesia and in the intensive care unit.