A Comparison of Central and Mixed Venous Oxygen Saturation in Circulatory Failure
published online 21 January 2008.
Objective
The purpose of this study was to evaluate whether central venous oxygen saturation can be used as an alternative to mixed venous oxygen saturation in patients with cardiogenic and septic shock.
Design
Prospective clinical study.
Setting
A tertiary intensive care unit in a university hospital.
Participants
Twenty patients with cardiogenic or septic shock requiring a pulmonary artery catheter and inotropic support.
Interventions
None.
Measurements and Main Results
The central venous oxygen saturation overestimated the mixed venous oxygen saturation by a mean bias (or an absolute difference) of 6.9%, and the 95% limits of agreement were large (−5.0% to 18.8%). The difference between central and mixed venous oxygen saturation appeared to be more significant when mixed venous oxygen saturation was <70%. The changes in central and mixed venous oxygen saturation did not follow the line of perfect agreement closely in different clinical conditions. The central or mixed venous oxygen saturation had a significant ability to predict the status of cardiac output state, but this ability was reduced when the effect of hyperoxia was not considered.
Conclusion
Central and mixed venous oxygen saturation measurements are not interchangeable numerically.
⁎Department of Intensive Care, Royal Perth Hospital, Perth, WA, Australia
†School of Population Health, University of Western Australia, Perth, WA, Australia
Address reprint requests to Kwok M. Ho, MBBS, MPH, FRCP (Glasg), FANZCA, FJFICM, Royal Perth Hospital, Intensive Care Unit, Wellington Street, Perth, WA 6000, Australia
ABSTRACT