Evidence map›Paper›PMID 41514359›Full record

ArticleJournal of intensive care2026

Thermal intervention improves pulse oximetry accuracy in critically ill patients with low perfusion: a quasi-experimental study.

Natalie Karlsson, Felicia Olsson Lindstrand, Lotta Johansson, Carl Sjödin

Abstract read
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Article in Journal of intensive care, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Natalie KarlssonDepartment of Thoracic Anaesthesiology and Intensive Care, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden.
Felicia Olsson LindstrandDepartment of Anaesthesiology and Intensive Care, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden.
Lotta JohanssonDepartment of Anaesthesiology and Intensive Care, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden.
Carl SjödinDepartment of Anaesthesiology and Intensive Care, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden. carl.sjodin@gu.se.

Funding

Regional Executive Board, Region Västra Götaland, Sweden. VGFOUGSB-997222
6 · The paper itself

Abstract

backgroundPulse oximetry is essential for continuous oxygen monitoring in intensive care, yet its accuracy declines in patients with low peripheral perfusion, risking both unrecognised hypoxaemia and inappropriate oxygen therapy. The perfusion index (PFI) reflects peripheral blood flow and is often reduced in critically ill patients with impaired microcirculation. Simple bedside strategies to restore PFI and improve SpO₂ accuracy remain underexplored.

methodsIn this prospective quasi-experimental study, 46 adult ICU patients with arterial catheters and baseline PFI < 1.0 underwent localised peripheral warming using a wrist-forearm heating pad for 15 min. The warming pad maintained a surface temperature of 54 °C, with directly measured skin-interface temperatures of 41-42 °C. SpO₂, PFI, and arterial oxygen saturation (SaO₂) were measured immediately before and after the intervention. The primary outcome was the change in PFI; the secondary outcome was the improvement in SpO₂ accuracy (SpO₂-SaO₂ bias).

resultsThermal intervention increased PFI from a median (IQR) of 0.56 (0.34-0.78) to 3.59 (2.45-4.77) (p < 0.001; Hedges' g = 2.43). The pre-intervention SpO₂-SaO₂ bias was 4.09% (95% limits of agreement 0.61-7.56%), which decreased to 0.00% (- 1.22-1.23%) after warming. Improvements were consistent across subgroups and unrelated to cardiac index, vasoactive use, or skin pigmentation.

conclusionsA brief, localised thermal intervention markedly improves peripheral perfusion and restores pulse-oximetry accuracy to within the clinically acceptable ± 2% range in critically ill patients with low PFI. However, ceiling effects at SpO₂ values near 100% and the pre-post design limit the strength of causal inference. This simple, non-invasive technique can be readily integrated into ICU practice to enhance the reliability of oxygen monitoring and reduce the risk of undetected hypoxaemia or hyperoxaemia.

Indexed as

Intensive careMicrocirculationOxygen monitoringPatient safetyPerfusion indexPulse oximetry

Identifiers

PMID41514359
PMCPMC12849173

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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.