Evidence map›Paper›PMID 42758722›Full record

ArticlePloS one2026

Serum Na-Cl value from routine blood tests reflects CO2 retention in amyotrophic lateral sclerosis.

Isamu Yamakawa, Ryota Tamura, Hiroyuki Yabata, Takahito Tsukamoto, Shuhei Kobashi, Yoshitaka Tamaki, Nobuhiro Ogawa, Akihiro Kitamura, Makoto Urushitani

Abstract read
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Article in PloS one, 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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5 · Who and what money

Authors and funding

9 authors.

Isamu YamakawaDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.ORCID https://orcid.org/0009-0005-0968-5880
Ryota TamuraDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Hiroyuki YabataDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Takahito TsukamotoDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Shuhei KobashiDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Yoshitaka TamakiDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Nobuhiro OgawaDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Akihiro KitamuraDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Makoto UrushitaniDepartment of Neurology, Shiga University of Medical Science, Otsu, Shiga, Japan.ORCID https://orcid.org/0000-0003-2773-9836

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRespiratory failure is the leading cause of death in amyotrophic lateral sclerosis (ALS). Early detection of CO2 retention is crucial for assessing respiratory failure severity and guiding noninvasive positive pressure ventilation (NPPV) management. However, arterial blood gas analysis is invasive and uncomfortable for routine monitoring.

objectiveWe investigated whether the serum sodium-chloride difference (Na-Cl value), calculated from routine blood tests, could serve as a screening marker for CO2 retention in ALS patients.

methodsThis retrospective study included 88 ALS patients with 116 paired samples of arterial blood gas and serum electrolyte data. We analyzed correlations between Na-Cl value and blood gas parameters (HCO3-, PCO2), performed receiver operating characteristic (ROC) analysis for detecting CO2 retention (PCO2 ≥ 45 mmHg), and examined relationships with respiratory function (%FVC).

resultsNa-Cl value showed strong correlation with HCO3- (r = 0.78, p < 0.001) and PCO2 (r = 0.71, p < 0.001). Na-Cl ≥ 37 mEq/L demonstrated sensitivity of 85.11% and specificity of 69.57% for detecting PCO2 ≥ 45 mmHg, with negative predictive value of 87.27% (AUC = 0.842). Na-Cl ≥ 39 mEq/L achieved specificity of 92.75%. Patients with %FVC < 50% had significantly higher Na-Cl, PCO2, and HCO3- values.

conclusionsSerum Na-Cl value serves as a simple, noninvasive screening marker for CO2 retention in ALS. Na-Cl ≥ 37 mEq/L warrants blood gas analysis, while Na-Cl ≥ 39 mEq/L provides specificity >90%. This marker can be calculated from routine blood tests without additional cost, making it suitable for frequent monitoring and reducing the risk of missing intervention timing.

Indexed as

Amyotrophic Lateral SclerosisCarbon DioxideChloridesSodiumAdultAgedBiomarkersBlood Gas AnalysisFemaleHumansMaleMiddle AgedRespiratory InsufficiencyRetrospective StudiesROC CurveBiomarkersCarbon DioxideChloridesSodium

Identifiers

PMID42758722
PMCPMC13588376

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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.