Agreement Between Methods Assessing Changes in Plasma Volume During Fluid Therapy—A Post Hoc Analysis of a Randomized Trial
(2026) In Acta Anaesthesiologica Scandinavica 70(6).- Abstract
Volume status of a patient is
difficult to assess clinically. Methods to measure plasma volume as well
as changes in plasma volume in connection with fluid therapy are
therefore valuable for research purposes and could potentially be used
bedside to guide fluid therapy in individual patients. The objective of
the present study was to evaluate hematocrit as a marker of changes in
plasma volume and an anthropometric formula to estimate absolute plasma
volume against the reference method, plasma volume measurements using
radiolabeled albumin. A total of 64 postoperative patients received 10
mL/kg of albumin. The plasma volumes were measured with the reference
method (radiolabeled albumin)... (More)Volume status of a patient is
(Less)
difficult to assess clinically. Methods to measure plasma volume as well
as changes in plasma volume in connection with fluid therapy are
therefore valuable for research purposes and could potentially be used
bedside to guide fluid therapy in individual patients. The objective of
the present study was to evaluate hematocrit as a marker of changes in
plasma volume and an anthropometric formula to estimate absolute plasma
volume against the reference method, plasma volume measurements using
radiolabeled albumin. A total of 64 postoperative patients received 10
mL/kg of albumin. The plasma volumes were measured with the reference
method (radiolabeled albumin) at baseline, after 30 and 180 min. Plasma
volumes were compared with plasma volumes derived from either the
baseline measurements and subsequent changes in hematocrit (calibrated
method) or from an anthropometric formula and subsequent hematocrit
changes (anthropometric method). Bland–Altman plots were used to test
agreements between methods. The mean difference in plasma volume between
the anthropometric and the reference method at baseline was −0.1 mL/kg
(95% CI –2.1 to 1.8) with lower and upper LOA of −18.0 and 17.0 mL/kg.
The agreement remained essentially unchanged after fluid therapy (mean
difference −0.1 mL/kg (95% CI –1.8 to 1.5) with LOAs of −18.0 and 17.0
mL/kg). The mean difference between the calibrated and reference methods
was −0.1 mL/kg (95% CI –0.9 to 0.7) with LOAs of −9.4 and 9.2 mL/kg.
The anthropometric formula yields low precision in predicting plasma
volumes in postsurgical patients. Changes in hematocrit during fluid
therapy cannot replace the reference method to assess changes in plasma
volume in the individual patient because of the imprecision. Editorial
Comment: Clinical appreciation of plasma volume is relevant for
assessing treatment where intravenous fluid resuscitation is involved.
This analysis, using a reference method for plasma volume assessment,
and comparing to simpler methods to estimate the same, demonstrates that
there are important limitations with some simpler and readily
acceptable methods to perform this estimation.olume
status of a patient is difficult to assess clinically. Methods to
measure plasma volume as well as changes in plasma volume in connection
with fluid therapy are therefore valuable for research purposes and
could potentially be used bedside to guide fluid therapy in individual
patients. The objective of the present study was to evaluate hematocrit
as a marker of changes in plasma volume and an anthropometric formula to
estimate absolute plasma volume against the reference method, plasma
volume measurements using radiolabeled albumin. A total of 64
postoperative patients received 10 mL/kg of albumin. The plas in. A total of 64 postoperative patients received 10 mL/kg of albumin. The plasma volumes were measured with the reference method (radiolabeled albumin) at baseline, after 30 and 180 min. Plasma volumes were compared with plasma volumes derived from either the baseline measurements and subsequent changes in hematocrit (calibrated method) or from an anthropometric formula and subsequent hematocrit changes (anthropometric method). Bland–Altman plots were used to test agreements between methods. The mean difference in plasma volume between the anthropometric and the reference method at baseline was −0.1 mL/kg (95% CI –2.1 to 1.8) with lower and upper LOA of −18.0 and 17.0 mL/kg. The agreement remained essentially unchanged after fluid therapy (mean difference −0.1 mL/kg (95% CI –1.8 to 1.5) with LOAs of −18.0 and 17.0 mL/kg). The mean difference between the calibrated and reference methods was −0.1 mL/kg (95% CI –0.9 to 0.7) with LOAs of −9.4 and 9.2 mL/kg. The anthropometric formula yields low precision in predicting plasma volumes in postsurgical patients. Changes in hematocrit during fluid therapy cannot replace the reference method to assess changes in plasma volume in the individual patient because of the imprecision. Editorial Comment: Clinical appreciation of plasma volume is relevant for assessing treatment where intravenous fluid resuscitation is involved. This analysis, using a reference method for plasma volume assessment, and comparing to simpler methods to estimate the same, demonstrates that there are important limitations with some simpler and readily acceptable methods to perform this estimation.
- author
- Grubb, David LU ; Statkevicius, Svajunas LU ; Bonnevier, Johan LU ; Bark, Björn LU and Bentzer, Peter LU
- organization
- publishing date
- 2026-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- fluid therapy, hematocrit, plasma volume
- in
- Acta Anaesthesiologica Scandinavica
- volume
- 70
- issue
- 6
- article number
- e70271
- publisher
- Blackwell Munksgaard
- external identifiers
-
- pmid:42242672
- scopus:105041047206
- ISSN
- 0001-5172
- DOI
- 10.1111/aas.70271
- language
- English
- LU publication?
- yes
- id
- 7e513bcc-1b97-4d9b-b3c3-dc073e689d00
- date added to LUP
- 2026-07-03 14:49:14
- date last changed
- 2026-07-04 03:00:03
@article{7e513bcc-1b97-4d9b-b3c3-dc073e689d00,
abstract = {{<p>Volume status of a patient is <br>
difficult to assess clinically. Methods to measure plasma volume as well<br>
as changes in plasma volume in connection with fluid therapy are <br>
therefore valuable for research purposes and could potentially be used <br>
bedside to guide fluid therapy in individual patients. The objective of <br>
the present study was to evaluate hematocrit as a marker of changes in <br>
plasma volume and an anthropometric formula to estimate absolute plasma <br>
volume against the reference method, plasma volume measurements using <br>
radiolabeled albumin. A total of 64 postoperative patients received 10 <br>
mL/kg of albumin. The plasma volumes were measured with the reference <br>
method (radiolabeled albumin) at baseline, after 30 and 180 min. Plasma <br>
volumes were compared with plasma volumes derived from either the <br>
baseline measurements and subsequent changes in hematocrit (calibrated <br>
method) or from an anthropometric formula and subsequent hematocrit <br>
changes (anthropometric method). Bland–Altman plots were used to test <br>
agreements between methods. The mean difference in plasma volume between<br>
the anthropometric and the reference method at baseline was −0.1 mL/kg <br>
(95% CI –2.1 to 1.8) with lower and upper LOA of −18.0 and 17.0 mL/kg. <br>
The agreement remained essentially unchanged after fluid therapy (mean <br>
difference −0.1 mL/kg (95% CI –1.8 to 1.5) with LOAs of −18.0 and 17.0 <br>
mL/kg). The mean difference between the calibrated and reference methods<br>
was −0.1 mL/kg (95% CI –0.9 to 0.7) with LOAs of −9.4 and 9.2 mL/kg. <br>
The anthropometric formula yields low precision in predicting plasma <br>
volumes in postsurgical patients. Changes in hematocrit during fluid <br>
therapy cannot replace the reference method to assess changes in plasma <br>
volume in the individual patient because of the imprecision. Editorial <br>
Comment: Clinical appreciation of plasma volume is relevant for <br>
assessing treatment where intravenous fluid resuscitation is involved. <br>
This analysis, using a reference method for plasma volume assessment, <br>
and comparing to simpler methods to estimate the same, demonstrates that<br>
there are important limitations with some simpler and readily <br>
acceptable methods to perform this estimation.olume<br>
status of a patient is difficult to assess clinically. Methods to <br>
measure plasma volume as well as changes in plasma volume in connection <br>
with fluid therapy are therefore valuable for research purposes and <br>
could potentially be used bedside to guide fluid therapy in individual <br>
patients. The objective of the present study was to evaluate hematocrit <br>
as a marker of changes in plasma volume and an anthropometric formula to<br>
estimate absolute plasma volume against the reference method, plasma <br>
volume measurements using radiolabeled albumin. A total of 64 <br>
postoperative patients received 10 mL/kg of albumin. The plas in. A total of 64 postoperative patients received 10 mL/kg of albumin. The plasma volumes were measured with the reference method (radiolabeled albumin) at baseline, after 30 and 180 min. Plasma volumes were compared with plasma volumes derived from either the baseline measurements and subsequent changes in hematocrit (calibrated method) or from an anthropometric formula and subsequent hematocrit changes (anthropometric method). Bland–Altman plots were used to test agreements between methods. The mean difference in plasma volume between the anthropometric and the reference method at baseline was −0.1 mL/kg (95% CI –2.1 to 1.8) with lower and upper LOA of −18.0 and 17.0 mL/kg. The agreement remained essentially unchanged after fluid therapy (mean difference −0.1 mL/kg (95% CI –1.8 to 1.5) with LOAs of −18.0 and 17.0 mL/kg). The mean difference between the calibrated and reference methods was −0.1 mL/kg (95% CI –0.9 to 0.7) with LOAs of −9.4 and 9.2 mL/kg. The anthropometric formula yields low precision in predicting plasma volumes in postsurgical patients. Changes in hematocrit during fluid therapy cannot replace the reference method to assess changes in plasma volume in the individual patient because of the imprecision. Editorial Comment: Clinical appreciation of plasma volume is relevant for assessing treatment where intravenous fluid resuscitation is involved. This analysis, using a reference method for plasma volume assessment, and comparing to simpler methods to estimate the same, demonstrates that there are important limitations with some simpler and readily acceptable methods to perform this estimation.</p>}},
author = {{Grubb, David and Statkevicius, Svajunas and Bonnevier, Johan and Bark, Björn and Bentzer, Peter}},
issn = {{0001-5172}},
keywords = {{fluid therapy; hematocrit; plasma volume}},
language = {{eng}},
number = {{6}},
publisher = {{Blackwell Munksgaard}},
series = {{Acta Anaesthesiologica Scandinavica}},
title = {{Agreement Between Methods Assessing Changes in Plasma Volume During Fluid Therapy—A Post Hoc Analysis of a Randomized Trial}},
url = {{http://dx.doi.org/10.1111/aas.70271}},
doi = {{10.1111/aas.70271}},
volume = {{70}},
year = {{2026}},
}