Oxygen consumption measurement: agreement between the closed-circuit PhysioFlex anesthesia machine and the Deltatrac II indirect calorimeter.

Unlabelled: We designed this study to ascertain whether, for the purpose of clinical interpretation, the direct measurement of O(2) consumption with the PhysioFlex closed-circuit anesthesia machine and with the Deltatrac II indirect calorimeter are interchangeable. Oxygen consumption was measured using the two instruments successively in critically-ill, mechanically-ventilated patients. Measurements were recorded as the mean of 10 consecutive, minute-by-minute, stable readings.