Lower ScvO2 and Higher Relative Blood Volume Associated with Higher Mortality Risk

San Diego—Clinicians are increasingly conducting monitoring of relative blood volume (RBV) and central venous oxygen saturation (ScvO2) in hemodialysis patients. Researchers previously demonstrated that, at higher levels of SCVO2, RBV had only a small effect on risk of mortality; however, at lower ScvO2 levels, RBV tended to drive mortality risk. Hanjie Zhang and colleagues recently conducted a retrospective multicenter cohort study to further examine the association between RBV and ScvO2 values on all-cause mortality.

Results of the study were reported during a poster session at Kidney Week 2018 in a poster titled All-Cause Mortality in Relation to Intradialytic Relative Blood Volume and Central Venous Oxygen Saturation among Hemodialysis Patients.

The study population included hemodialysis patients with central venous catheter as vascular access from 17 Renal Research Institute clinics from January 2012 to June 2017 where the Crit-Line® Monitor is used. The monitor allows for monitoring of extracorporeal hematocrit and ScvO2. The cohort was stratified into two groups depending on their RBV and ScvO2 at 3 hours into hemodialysis.

A total of 151 patients representing 3937 hemodialysis treatments participated in the study. Median follow-up was 2.8 years. The group with RBV >91.74% and ScvO2 <56.72% at 3 hours into hemodialysis (n=52) was labeled right corner patients (based on the position from a previous study).

The results indicate a significantly increased mortality in patients with lower ScvO2 and higher RBV levels compared with others. The higher hazards ratios for all-cause mortality in those patients were corroborated in multivariate Cox analysis with different levels of adjustments.

“We found that patients with lower ScvO2 and higher RBV levels had higher mortality. These findings may be related to patients’ volume status and cardiac function,” the researchers said.

Source: Zhang H, Preciado P, Chan L, Thijssen S, Kotanko P. All-cause mortality in relation to intradialytic relative blood volume and central venous oxygen saturation among hemodialysis patients. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2018, October 26, 2015, San Diego, California.

Funding for this study was provided by Fresenius Medical Care North America