Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Sep 20, 2023; 13(4): 248-258
Published online Sep 20, 2023. doi: 10.5662/wjm.v13.i4.248
Association of carbon monoxide poisonings and carboxyhemoglobin levels with COVID-19 and clinical severity
Abuzer Coskun, Burak Demirci, Kenan Ahmet Turkdogan
Abuzer Coskun, Burak Demirci, Emergency Medicine Clinic, Istanbul Bagcilar Training and Research Hospital, Istanbul 34200, Turkey
Kenan Ahmet Turkdogan, Emergency Medicine Department, Istanbul Çam and Sakura City Hospital, Istanbul 34494, Turkey
Author contributions: Coskun A and Demirci B contributed to study design, concept, writing the manuscript, and revising the final form; Coskun A and Turkdogan KA contributed to data collection and manuscript revision; All authors contributed to writing and discussion management; All authors contributed to data management and manuscript revision, data collection, interpretation of data, and revising the manuscript; Coskun A contributed to data collection and revision; Turkdogan KA contributed to data collection; Demirci B contributed to critical revision; Turkdogan KA contributed to statistical analysis; Coskun A suggested the idea, as a chair of the department provided general support and substantial contribution to concept and design, and acquisition of data; All authors read and approved the final manuscript.
Institutional review board statement: All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the last Declaration of Helsinki (2013), and the protocol was approved by the Ethics Committee of Project identification (Decision No: 136).
Conflict-of-interest statement: The authors report there are no competing interests to declare.
Data sharing statement: Informed Consent Form belonging to the research titled "Clinical Relation of Carboxyhemoglobin Levels in Carbon Monoxide Poisonings with COVID-19", which I conducted, was uploaded to the approved system on April 22, 2022.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Abuzer Coskun, MD, Associate Professor, Emergency Medicine Clinic, Istanbul Bagcilar Training and Research Hospital, No. 2, Dr. Sadik Ahmet Street, Istanbul 34200, Turkey. dr.acoskun44@hotmail.com
Received: April 10, 2023
Peer-review started: April 10, 2023
First decision: June 1, 2023
Revised: June 8, 2023
Accepted: July 25, 2023
Article in press: July 25, 2023
Published online: September 20, 2023
Processing time: 163 Days and 4.4 Hours
ARTICLE HIGHLIGHTS
Research background

There is a need for new techniques to assess risk in patients with both coronavirus disease 2019 (COVID-19) and carbon monoxide (CO) poisoning, and techniques to aid rapid diagnosis.

Research motivation

The impact of emergency room patients with COVID-19 and CO poisoning on clinical status, morbidity and morbidity is worth investigating.

Research objectives

We aim to determine whether patients with COVID-19 and CO poisoning, as the primary outcome, are definite risk factors for short-term emergency hospitalization and whether there is long-term morbidity and mortality during hospitalization as a secondary outcome.

Research methods

This single-center retrospective study was conducted between January 2018 and December 2021, and included 479 CO poisoning patients. The patients were divided according to the pandemic period and the pre-pandemic period. In addition, the pandemic period was classified according to the presence of COVID-19 and its clinical severity. Patients' demographic, clinical, arterial blood gas, COVID-19 polymerase chain reaction, and other laboratory data were extracted from the hospital information system.

Research results

The mean age of the 479 patients was 54.93 ± 11.51 years, and 187 (39%) were female. 226 (47%) patients were included in the pandemic group and 143 (30%) of them had a history of COVID-19. The mean potential of hydrogen (pH) in arterial blood gas of all patients was 7.28 ± 0.15, was 7.35 ± 0.10 in the pre-pandemic group, and was 7.05 ± 0.16 in the severe group during the pandemic period (P < 0.001). Carboxyhemoglobin (COHb) was 23.98% ± 4.19% in the outpatients and 45.26% ± 3.19% in the mortality group (P < 0.001). Partial arterial oxygen pressure (PaO2) was 89.63 ± 7.62 mmHg in the pre-pandemic group, and 79.50 ± 7.18 mmHg in the severe group during the pandemic (P < 0.001). While 35 (7%) of all cases died, 30 (85.7%) of those that died were in the pandemic group (P < 0.001). In the univariate linear analysis, the relationship between COHb, troponin, lactate, partial arterial pressure of carbon dioxide, bicarbonate, calcium, glucose, age, pH, PaO2, potassium, sodium, and base excess levels was statistically significant with the pre-pandemic and pandemic groups. In the receiver operating characteristic curve analysis, changes in COHb, lactate, and troponin due to CO poisoning were determined. Based on this analysis, the optimum cut-off values (sensitivity and specificity), the area under the curve, and the 95% confidence interval for COHb, lactate, and troponin were found to be above 45% in predicting the evolution of the pre-pandemic and pandemic groups (P < 0.001).

Research conclusions

In cases with a history of COVID-19, CO poisoning was observed with more severe clinical and laboratory findings and more frequent mortality. We believe this will have critical implications for the diagnosis and treatment of COVID-19 in the future, as CO levels may be abnormal compared to healthy subjects and can be higher in mechanically ventilated patients.

Research perspectives

CO poisoning in the pre-pandemic period appears to be milder than in the pandemic period. However, it was determined that mortality due to CO poisoning during the pandemic period was much higher in COVID-19 patients with a moderate and severe clinical course.