The Relationship Between Carboxyhemoglobin Level and Red Cell Distribution Width and Inflammatory Indices in Cases of Carbon Monoxide Poisoning
Abstract
Aim: Carbon monoxide (CO) poisoning is an important cause of morbidity and mortality among emergency department admissions. Although carboxyhemoglobin (COHb) level is a widely used marker, it may not always reflect clinical severity and biological response. This study aimed to evaluate the relationship between COHb levels, red cell distribution width (RDW), and hemogram-derived inflammatory indices in patients presenting with CO poisoning.
Material and Methods: This retrospective, descriptive, and cross-sectional study included 216 patients diagnosed with CO poisoning between January 1, 2020, and December 31, 2024. Demographic data, complete blood count parameters, biochemical parameters, and arterial blood gas results were recorded. The relationships between COHb and RDW, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), multiple inflammation indices (MII-1, MII-2, MII-3), pan-immune-inflammation value (PIV), and lactate were analyzed using Spearman correlation analysis.
Results: In patients who were followed without hospitalization, COHb levels showed significant positive correlations with NLR, PLR, SII, MII-1, MII-2, MII-3, and lactate. In patients receiving hyperbaric oxygen therapy, COHb was positively correlated with NLR, SII, PIV, and lactate. In patients who did not receive hyperbaric oxygen therapy, a significant negative correlation was observed between COHb and RDW. No significant inflammatory associations were found in ward or intensive care patients.
Conclusion: Inflammatory indices derived from routine hemogram parameters, when evaluated together with COHb and lactate, may contribute to understanding the early systemic inflammatory and metabolic response in CO poisoning. RDW appears to show variability depending on clinical subgroups.
Keywords
- Carbon monoxide poisoning
- carboxyhemoglobin
- inflammation
- neutrophil-to-lymphocyte ratio
- systemic immune-inflammation index
Ethical Statement
References
- Hampson NB, Weaver LK. Carbon monoxide poisoning: a new incidence for an old disease. Undersea Hyperb Med. 2007;34(3):163-8.
- Rose JJ, Wang L, Xu Q, McTiernan CF, Shiva S, Tejero J, et al. Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy. Am J Respir Crit Care Med. 2017;195(5):596-606. doi: 10.1164/rccm.201606-1275CI. Erratum in: Am J Respir Crit Care Med. 2017;196(3):398-9. doi:10.1164/rccm.1963erratum.
- Ernst A, Zibrak JD. Carbon monoxide poisoning. N Engl J Med. 1998;339(22):1603-8. doi:10.1056/NEJM199811263392206.
- Lippi G, Henry BM, Mattiuzzi C. Red blood cell distribution width (RDW) reflects disease severity in patients with carbon monoxide poisoning: systematic literature review and meta-analysis. Scand J Clin Lab Invest. 2024;84(2):79-83. doi:10.1080/00365513.2024.2332998.
- Fois AG, Paliogiannis P, Scano V, Cau S, Babudieri S, Perra R, et al. The systemic inflammation index on admission predicts in-hospital mortality in COVID-19 patients. J Clin Med. 2020;25(23):5725. doi:10.3390/molecules25235725.
- Li J, Qi HN, Gong P, Wang YY, Xiao QM, Wang P, et al. Prognostic value of systemic immune-inflammation index and monocyte-to-HDL-cholesterol ratio in early cardio-cerebral complications in elderly patients with acute severe carbon monoxide poisoning. Drug Chem Toxicol. 2024;47(4):381-5. doi:10.1080/01480545.2024.2301938.
- Gulen M, Zengin S, Satar S, Sabak M, Yildirim C. Diagnostic role of plasma biomarkers in early myocardial injury due to carbon monoxide poisoning. Intern Emerg Med. 2025;1-10. doi:10.1007/s11739-025-04188-8.
- Chenoweth JA, Albertson TE, Greer MR. Carbon monoxide poisoning. Crit Care Clin. 2021;37(3):657-72. doi:10.1016/j.ccc.2021.03.010.
Details
Primary Language
English
Subjects
Clinical Sciences (Other)
Journal Section
Research Article
Publication Date
September 22, 2026
Submission Date
March 30, 2026
Acceptance Date
July 29, 2026
Published in Issue
Year 2026 Volume: 16 Number: 3