Central Venous Oxygen Saturation as a Hemodynamic Parameter in Critically ill Patients

ABSTRACT

PURPOSE: Mixed venous oxygen saturation (Smvo2) and other hemodynamic parameters are highly useful in the monitoring of critically ill patients, but the measurement of S m v o2 requires catheterization of the pulmonary artery. In contrast, central venous oxygen saturation (Scvo2) can be easily obtained with a central venous catheter, which is less invasive. To assess if Scvo2 could be a useful value in the treatment of critically ill patients, we evaluated the agreement and the relationship between Scvo2 and Smvo2. Furthermore, the correlations of Scvo2 with other additional parameters were investigated. METHODS: During 18 months, 83 patients in the intensive care unit (ICU) of Ajou university hospital were included. S c v o2, Smvo2, the cardiac index (CI), the oxygen extraction ratio (OER), the oxygen uptake (Vo2), and the oxygen delivery (Do2) were obtained by using a pulmonary artery catheter. RESULTS: There was a difference between Scvo2 and Smvo2 (76.32 +/- 7.86 vs 73.79 +/- 6.31, p < 0.001). The relationship between the two measures showed a meaningful correlation (r=0.700, p < 0.01). Scvo2 also had correlations with the CI (r =0.326, p < 0.05), the OER (r =-0.467, p < 0.01), the Vo2 (r =-0.393, p < 0.01), and the Do2 (r =0.422, p < 0.01). CONCLUSION: Although the Scvo2 value cannot replace the S m v o2 value, it shows a relation with Smvo2 and other parameters. Thus, Scvo2 is suggested as a hemodynamic value for use with critically ill patients.