Evaluation of Total Blood Volume Measurement During Dialysis on the Incidence of Intradialytic Hypotension

The Evaluation of the Influence of the Use of Total Blood Volume Measurement During Dialysis on the Incidence of Intradialytic Hypotension Associated Events

Establishing the euvolemic state in hemodialysis patients -the so called "dry weight"- is an important clinical conundrum in every nephrologist's daily practice. Underestimation of dry weight (with excessive ultrafiltration) results in dialysis-induced hypotension. Currently used methods to establish dry weight, including clinical assessment, bio-impedance spectroscopy and online relative blood volume (RBV) measurements, all have their limitations. RBV measurement reflects changes in blood volume during dialysis without providing any information about the initial hydration status, or the initial absolute blood volume (ABV). Recently, researchers proposed a new method to calculate ABV, by using the principle of dilution-indicator with RBV measurement. In a small cohort study they identified a total blood volume threshold of 65 millilitres per kilogram dry weight predicting for intra-dialytic hypotension associated symptoms.

The goal of current clinical trial is to re-investigate the accuracy of the above-described method and to confirm the hypothesis of a critical threshold of 65 ml blood volume per kg dry weight in haemodialysis patients. Researchers will compare adjustment of dry weight based on the ABV measurement with standard care to see if dialysis-induced hypotension will be reduced.

Inclusion Criteria:

• hemodialysis patients of three dialysis locations of the Haga Hospital (Zoetermeer, The Hague Leyweg and The Hague Sportlaan).
• Maintenance hemodialysis, with initiation of treatment predates inclusion in the study by at least 3 months.
• Hemodialysis scheme three times weekly for four hours
• Age above 18 years.

Exclusion Criteria:

• Clinically relevant fistula dysfunction resulting in single poold Kt/V <1,2
• Severe volume overload with a contraindication to bolus fluid infusion during dialysis according to the treating physician.
• Severe cardiac dysfunction responsible for >1x intradialytic hypotension associated adverse event /week according to treating physician
• Severe liver failure with or without presence of ascites
• More than three hemodialysis sessions per week
• Single needle treatment
• Central venous access
• Residual diuresis > 500 ml/ 24h
• Inability to provide informed consent