Evidence map›Paper›PMID 42157204›Full record

ArticleBMC surgery2026

Hidden blood loss estimation using perioperative hemoglobin drop: agreement with the Sehat formula.

Nikolai Ramadanov, Maximilian Heinz, Robert Prill, Dakota Fuchs, Roland Becker

Abstract read
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Article in BMC surgery, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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1citing papers in PubMed
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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Nikolai RamadanovCenter of Orthopaedics and Traumatology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg/Havel, Germany. nikolai.ramadanov@gmail.com.
Maximilian HeinzCenter of Orthopaedics and Traumatology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg/Havel, Germany.
Robert PrillCenter of Orthopaedics and Traumatology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg/Havel, Germany.
Dakota FuchsCenter of Orthopaedics and Traumatology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg/Havel, Germany.
Roland BeckerCenter of Orthopaedics and Traumatology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg/Havel, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPerioperative hemoglobin drop is widely used as a surrogate marker for blood loss and transfusion risk across surgical disciplines. However, its agreement with dilution-based estimates of hidden blood loss remains insufficiently validated. As both approaches represent indirect estimators rather than a reference standard, this study evaluates agreement rather than validation.

methodsThis retrospective registry-based study included 828 patients undergoing elective primary total hip arthroplasty between 2016 and 2023. Hemoglobin drop was defined as the difference between preoperative hemoglobin and the lowest postoperative value within 48 h. Hidden blood loss was calculated using the Gross-Sehat method with blood volume estimation according to Nadler. Agreement between hemoglobin drop and hidden blood loss was assessed using Bland-Altman analysis and intraclass correlation coefficients. Discriminative performance for identifying patients with high hidden blood loss (upper quartile) was evaluated using receiver operating characteristic analysis.

resultsMean perioperative hemoglobin drop was 33.5 ± 12.3 g/L. Mean hidden blood loss was 854.9 mL, accounting for the majority of total blood loss. Agreement between hemoglobin drop and hidden blood loss was limited, with wide limits of agreement on Bland-Altman analysis. Although a positive association was observed, substantial interindividual variability persisted, particularly at higher blood loss levels. Hemoglobin drop demonstrated only moderate discriminative performance for identifying patients with high hidden blood loss.

conclusionPerioperative hemoglobin drop shows only moderate agreement with dilution-based estimates of hidden blood loss and cannot reliably replace formal blood loss calculations at the individual patient level. These findings have implications for perioperative blood management and caution against reliance on hemoglobin change alone for blood loss assessment. LEVEL OF EVIDENCE (LOE): Level III - retrospective cohort study / registry-based observational study.

Indexed as

Arthroplasty, Replacement, HipBlood Loss, SurgicalHemoglobinsAgedBiomarkersFemaleHumansMaleMiddle AgedRegistriesRetrospective StudiesBiomarkersHemoglobinsHemoglobin dropHidden blood lossPatient blood managementPerioperative bleedingTotal hip arthroplasty

Identifiers

PMID42157204
PMCPMC13188665

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.