Correlation of hepatic venous saturation and mixed venous saturation: pooled analyses

In critical care, monitoring adequate tissue oxygenation is essential. Mixed venous oxygen saturation has traditionally been considered the gold standard for measuring cardiac output, which represents systemic oxygen delivery. Studies have shown that hepatic vein saturation is correlated with mixed venous oxygen saturation and mortality. The primary aim of this study was to determine the correlation between hepatic vein saturation and mixed venous saturation, and the impact of clinical characteristics on this correlation.

A systematic review of the literature was performed to identify manuscripts. They must have included patients who received simultaneous mixed venous saturations and hepatic vein saturations, and the data for both must have been explicitly shared. Data were pooled from these studies to analyze the correlation between mixed venous saturation and the corresponding hepatic vein saturation.

A total of 13 studies with 333 patients were included in the final analyses. The average age across these studies was 60.3±5.2. The pooled correlation between the mixed venous saturation and hepatic vein saturation was 0.88, demonstrating a strong correlation between the two. The average mixed venous saturation was 73.3±5.0 while the average hepatic vein saturation was 59.5±11.1.

In these pooled analyses, hepatic vein saturation has a strong correlation with mixed venous saturation. This correlation is not significantly impacted by patient age, weight, or clinical setting. Nonetheless, further prospective studies are needed for confirmation.