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Estimating the plasma volume by infusing albumin: a retrospective feasibility study
Robert G Hahn1, Joachim H Zdolsek2
1Anesthesia and Intensive Care, Karolinska Institutet at Danderyds Hospital (KIDS), 152 86, Danderyd, Stockholm, Sweden. robert.hahn@ki.se.
Intensive Care Medicine Experimental
|March 20, 2025
Summary
Estimating plasma volume (PV) using albumin and hemoglobin changes is most accurate at the end of or 10 minutes after a 30-minute albumin infusion. A 0.3 L correction accounts for capillary leakage.
Area of Science:
- Physiology
- Medical Technology
Background:
- Plasma volume (PV) estimation using albumin infusion is feasible.
- Optimal timing for blood sampling and accounting for capillary leakage remain unclear.
Purpose of the Study:
- To determine the optimal timing for blood sampling to estimate plasma volume (PV) during albumin infusion.
- To evaluate the impact of capillary leakage correction on PV estimation accuracy.
Main Methods:
- Retrospective analysis of plasma albumin and hemoglobin data from 41 volunteers and 45 patients during 30-minute 20% albumin infusions.
- Application of manual and kinetic corrections for capillary leakage.
- Comparison with anthropometric equations derived via tracer methods.
Main Results:
- Strongest linearity (r=0.75) between albumin-derived and anthropometric PV was observed at the end of or 10 minutes after infusion.
- Prediction error was 0.31 ± 0.56 L, with lower standard deviation for smaller PVs.
- Capillary leakage correction improved linearity and accuracy but not precision.
Conclusions:
- Plasma albumin and hemoglobin changes accurately indicate PV at the end of or 10 minutes post-infusion.
- A 0.3 L subtraction effectively corrects for capillary leakage.
- Further evaluation using isotopes is suggested.
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