{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,9]],"date-time":"2025-12-09T09:47:01Z","timestamp":1765273621022,"version":"3.46.0"},"reference-count":35,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,12,9]],"date-time":"2025-12-09T00:00:00Z","timestamp":1765238400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Chronic obstructive pulmonary disease (COPD) is a recognized risk factor for poor outcomes in SARS-CoV-2 infection, yet its specific impact on critically ill patients remains unclear. We aimed to compare the clinical and laboratory profiles of ICU SARS-CoV-2 pneumonia patients with or without pre-existing COPD and identify factors associated with mortality among those with COPD. In this retrospective study, adult intensive care unit (ICU) admissions for SARS-CoV-2 pneumonia (n = 1536) were divided into a COPD group (n = 253) and a non-pulmonary-disease (NPD) group (n = 1283). Demographics and clinical characteristics, severity of disease, length of stay, laboratory values, and survival outcomes were compared. COPD patients were older, had higher Acute Physiology and Chronic Health Evaluation score, and had a greater prevalence of comorbidities (p &lt; 0.05). They required invasive mechanical ventilation (IMV) more frequently, had experienced higher mortality, and had shorter hospital stays (p &lt; 0.05). Ferritin levels were lower in COPD patients (p &lt; 0.001). Multivariate regression analysis also identified that length of hospital stay, IMV, elevated procalcitonin, and neutrophil-to-lymphocyte ratio (NLR) were associated with COPD patients\u2019 mortality (p &lt; 0.05). COPD is associated with an increased disease burden and mortality rate in critically ill SARS-CoV-2 patients. High NLR levels and IMV are significantly associated with mortality in these patients.<\/jats:p>","DOI":"10.3390\/v17121594","type":"journal-article","created":{"date-parts":[[2025,12,9]],"date-time":"2025-12-09T09:02:50Z","timestamp":1765270970000},"page":"1594","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of SARS-CoV-2 Pneumonia on Chronic Obstructive Pulmonary Disease: A Comparative Study in ICU Patients"],"prefix":"10.3390","volume":"17","author":[{"given":"Duygu Kayar","family":"Calili","sequence":"first","affiliation":[{"name":"Department of Anesthesiology and Reanimation-Intensive Care, Faculty of Medicine, Ankara Y\u0131ld\u0131r\u0131m Beyaz\u0131t University, Ankara Bilkent City Hospital, Ankara 06800, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nihal","family":"Yuzbasioglu","sequence":"additional","affiliation":[{"name":"Department of Intensive Care, Ad\u0131yaman Training and Research Hospital, Ad\u0131yaman 02100, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Melih Gaffar","family":"Gozukara","sequence":"additional","affiliation":[{"name":"Department of Public Health, Faculty of Medicine, Ankara Y\u0131ld\u0131r\u0131m Beyaz\u0131t University, Ankara 06800, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Demet","family":"Bolukbasi","sequence":"additional","affiliation":[{"name":"Department of Intensive Care, Ankara Bilkent City Hospital, Ankara 06800, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0405-0107","authenticated-orcid":false,"given":"Isil Ozkocak","family":"Turan","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation-Intensive Care, University of Health Sciences, Ankara Bilkent City Hospital, Ankara 06800, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Seval","family":"Izdes","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation-Intensive Care, Faculty of Medicine, Ankara Y\u0131ld\u0131r\u0131m Beyaz\u0131t University, Ankara Bilkent City Hospital, Ankara 06800, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1111\/all.14657","article-title":"Risk factors for severe and critically ill COVID-19 patients: A review","volume":"76","author":"Gao","year":"2021","journal-title":"Allergy"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Tummala, A., Ramesh, V., Balakrishna, N., Koyyada, R., Singh, A.D., Patnam, S., Satish Kumar, M., Varahala, S., Manda, S.V., and Narreddy, S. 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