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Abstract: TH-PO288

Interactions Between Intradialytic Central Venous Oxygen Saturation, Ultrafiltration Rate, and All-Cause Mortality in Maintenance Hemodialysis Patients

Session Information

Category: Dialysis

  • 801 Dialysis: Hemodialysis and Frequent Dialysis


  • Zhang, Hanjie, Renal Research Institute, New York, New York, United States
  • Preciado, Priscila, Renal Research Institute, New York, New York, United States
  • Rosales M., Laura, Renal Research Institute, New York, New York, United States
  • Kooman, Jeroen, Maastricht University Medical Center, Maastricht, Netherlands
  • van der Sande, Frank, Maastricht University Medical Center, Maastricht, Netherlands
  • Kotanko, Peter, Renal Research Institute, New York, New York, United States

In hemodialysis patients, low central venous oxygen saturation (ScvO2) and high ultrafiltration rate (UFR) have been associated with adverse outcomes. Here we explore the interactions between ScvO2 and UFR in relation to all-cause mortality.


We conducted a retrospective study in maintenance hemodialysis patients with central venous catheters as vascular access. During a 6-month baseline period, Crit-Line (Fresenius Medical Care, Waltham, MA) was used to measure continuously intradialytic ScvO2. We defined four groups by median ScvO2 and median UFR. The follow-up period was 3 years. We constructed a Cox proportional hazards model with adjustment for age, diabetes, and dialysis vintage to assess the association between ScvO2 and UFR and all-cause mortality during follow-up.


Baseline comprised 5,231 dialysis sessions in 216 patients. The median ScvO2 was 58.8% and median UFR was 6.8 mL/kg/h. During follow-up, 44 patients (20.4%) died. Kaplan-Meier analysis (Figure 1A) showed that worst survival was observed in patients with lower ScvO2 combined with higher UFR (group 4). The same result was observed in univariate Cox analysis. In multivariate analysis with adjustment for age, diabetes, and vintage, this association was mitigated (Figure 1 B).


Intradialytic ScvO2 is an important effect modifier that should be considered when interpreting the relationship between UFR and outcomes. In patients with higher intradialytic ScvO2, high UFR may be better tolerated, and fluid overload can be prevented easier while imposing high UFR in patients with low intradialytic ScvO2 may lead to worse outcomes.

Figure 1A.
Kaplan-Meier analysis of survival probabilities in the four subgroups of patients based on the level of ScvO2 and UFR above and below the median of 58.8% and 6.8 mL/kg/h, respectively.
Figure 1B.
Crude and adjusted hazard ratios (HR) for all-cause mortality associated with ScvO2 and UFR levels below or above the median population. CI, confidence interval.


  • Commercial Support – Renal Research Institute