FIO2 Influences SvO2 Interpretation and Fick-based Cardiac Output Assessment

Increased FIO2 Influences SvO2 Interpretation and Accuracy of Fick-based Cardiac Output Assessment in Cardiac Surgery Patients

In this study, the investigators sought to clarify the influence of FIO2 levels on the variables in the Fick equation and then assessed the influence of each variable on the accuracy of Fick-CO measurements in patients undergoing cardiac surgery.

Patients who are aged ≥20 years, are undergoing planned elective cardiac surgery, and provided signed informed consent are included in the present study. Any patients with an intra-cardiac shunt are excluded.

The patients are randomly assigned to 2 groups: FIO2 <0.7 or FIO2 >0.85. And during the surgery, the oximeter values are kept ≥98%. Intra-operatively, FIO2, PaO2, SaO2, SvO2, PvO2, Hb, blood pH values, body temperature and TD-CO are recorded.

Inclusion Criteria:

• undergoing planned elective cardiac surgery
• agree to sign informed consent

Exclusion Criteria:

• intra-cardiac shunt