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Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis
Published on: October 2, 2020
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Difference between true functional haemoglobin and pre-dialysis haemoglobin is associated with plasma volume
Esteban Siga1, Miguel Fernandez, Mario Galarza
1Dialisis Madariaga, Avenida Buenos Aires y Calle 21, 7163, General Madariaga, Provincia de Buenos Aires, Argentina, siga@telpin.com.ar.
International Urology and Nephrology
|September 4, 2014
Summary
Plasma volume changes significantly impact intradialytic hemoglobin (Hb) levels. Estimating true functional Hb is crucial, especially in patients with weight gain exceeding 1 kg, to guide erythropoiesis-stimulating agent (ESA) dosing.
Area of Science:
- Nephrology
- Hematology
- Clinical Chemistry
Background:
- Intradialytic hemoglobin (Hb) fluctuations are common but not fully understood.
- True functional Hb may differ from pre-dialysis Hb measurements.
Purpose of the Study:
- To investigate the role of plasma volume variation in intradialytic Hb changes.
- To determine if functional Hb estimation is necessary for accurate erythropoiesis-stimulating agent (ESA) dosing.
Main Methods:
- A multicenter study using Krisper's formula to estimate time-averaged Hb concentration (TAC-Hb) and average Hb (Avg-Hb).
- Correlations between Hb changes (ΔHb), body weight loss (ΔBW), and relative plasma volume changes (%ΔPV) were analyzed in patients with >1 kg weight gain.
Main Results:
- TAC-Hb and Avg-Hb were comparable and higher than pre-dialysis Hb.
- A strong negative correlation (r=-0.92) was observed between ΔHb and %ΔPV, indicating plasma volume expansion dilutes Hb.
- Hb changes were independent of body weight loss but strongly correlated with plasma volume variations.
Conclusions:
- Plasma volume variations are a primary driver of intradialytic Hb changes.
- Estimating true functional Hb is recommended for patients with significant weight gain (>1 kg) to optimize treatment.
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