Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study

Mehmet Yildiz; Ahmed Cihad Genç; Ahmed Bilal Genç; Deniz Çekiç; Selçuk Yaylacı

doi:10.70058/cjm.1928830

Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study

Abstract

Objective: To evaluate the association between second-dose vaccination status, clinical characteristics, treatment modalities, and laboratory parameters with intensive care unit (ICU) mortality among patients with COVID-19 who had received at least one dose of vaccination.

Methods: This single-center retrospective cohort study included 100 consecutive adults with RT-PCR-confirmed COVID-19 admitted to the COVID-19 ICU between March 11, 2021, and August 23, 2021, who had received at least one vaccine dose. Demographic, clinical, treatment-related, and laboratory data were obtained from medical records and hospital information systems. The primary outcome was ICU mortality. Variables associated with mortality were evaluated using univariate and multivariable logistic regression analyses, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

Results: Among the 100 patients included in the study, 49% died during ICU follow-up. The rate of receiving a second vaccine dose was significantly higher among survivors (78.4% vs. 61.2%, p=0.048). Invasive mechanical ventilation (IMV) was markedly more frequent in non-survivors (95.9% vs. 3.9%, p<0.001), whereas dexmedetomidine use was significantly more common among survivors (66.7% vs. 6.1%, p<0.001). Non-survivors had significantly higher ferritin, troponin, and myoglobin levels and lower platelet counts (all p<0.05). In univariate logistic regression analysis, dexmedetomidine use was associated with lower odds of mortality (OR: 0.03, 95% CI: 0.008–0.120, p<0.001), whereas IMV was strongly associated with increased mortality (OR: 24.46, 95% CI: 6.28–95.27, p<0.001). Higher log-transformed troponin (OR: 1.49, 95% CI: 1.15–1.92, p=0.002) and ferritin levels (OR: 1.67, 95% CI: 1.16–2.38, p=0.006) were associated with increased mortality. In multivariable analysis, dexmedetomidine use remained independently associated with lower mortality (OR: 0.03, 95% CI: 0.007–0.14, p<0.001), while higher ferritin levels remained independently associated with increased mortality risk (OR: 1.83, 95% CI: 1.09–3.07, p=0.022).

Conclusion: Among vaccinated COVID-19 patients admitted to the ICU, mortality was associated with IMV requirement and elevated inflammatory and cardiac biomarkers. Dexmedetomidine use and ferritin levels remained independently associated with mortality after adjustment. These findings suggest that integrating clinical characteristics and routinely available laboratory parameters into patient assessment may improve risk stratification in critically ill COVID-19 patients.

Keywords

Ethical Statement

This study was approved by the Ethics Committee of Giresun University Medical Research Ethics Committee (Approval number: 24.12.2025/12, Date: December 24, 2025). The study was conducted in accordance with the principles of the Declaration of Helsinki. Due to the retrospective nature of the study, the requirement for informed consent was waived.

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Details

Primary Language

English

Subjects

Intensive Care

Journal Section

Research Article

Authors

Mehmet Yildiz ^*
0000-0003-0706-0906
Türkiye

Ahmed Cihad Genç
0000-0002-7725-707X
Türkiye

Ahmed Bilal Genç
0000-0002-1607-6355
Türkiye

Deniz Çekiç
0000-0002-7114-9334
Türkiye

Selçuk Yaylacı
0000-0002-6768-7973
Türkiye

Early Pub Date

May 29, 2026

Publication Date

May 31, 2026

Submission Date

April 12, 2026

Acceptance Date

May 27, 2026

Published in Issue

Year 2026 Volume: 3 Number: 2

DOI

https://doi.org/10.70058/cjm.1928830

IZ

https://izlik.org/JA27EJ69HR

Cite

RIS / Bibtex

APA

Yildiz, M., Genç, A. C., Genç, A. B., Çekiç, D., & Yaylacı, S. (2026). Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study. Cerasus Journal of Medicine, 3(2), 147-156. https://doi.org/10.70058/cjm.1928830

AMA

1.Yildiz M, Genç AC, Genç AB, Çekiç D, Yaylacı S. Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study. Cerasus J Med. 2026;3(2):147-156. doi:10.70058/cjm.1928830

Chicago

Yildiz, Mehmet, Ahmed Cihad Genç, Ahmed Bilal Genç, Deniz Çekiç, and Selçuk Yaylacı. 2026. “Association of Vaccination Status, Clinical and Laboratory Parameters With Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study”. Cerasus Journal of Medicine 3 (2): 147-56. https://doi.org/10.70058/cjm.1928830.

EndNote

Yildiz M, Genç AC, Genç AB, Çekiç D, Yaylacı S (May 1, 2026) Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study. Cerasus Journal of Medicine 3 2 147–156.

IEEE

[1]M. Yildiz, A. C. Genç, A. B. Genç, D. Çekiç, and S. Yaylacı, “Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study”, Cerasus J Med, vol. 3, no. 2, pp. 147–156, May 2026, doi: 10.70058/cjm.1928830.

ISNAD

Yildiz, Mehmet - Genç, Ahmed Cihad - Genç, Ahmed Bilal - Çekiç, Deniz - Yaylacı, Selçuk. “Association of Vaccination Status, Clinical and Laboratory Parameters With Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study”. Cerasus Journal of Medicine 3/2 (May 1, 2026): 147-156. https://doi.org/10.70058/cjm.1928830.

JAMA

1.Yildiz M, Genç AC, Genç AB, Çekiç D, Yaylacı S. Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study. Cerasus J Med. 2026;3:147–156.

MLA

Yildiz, Mehmet, et al. “Association of Vaccination Status, Clinical and Laboratory Parameters With Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study”. Cerasus Journal of Medicine, vol. 3, no. 2, May 2026, pp. 147-56, doi:10.70058/cjm.1928830.

Vancouver

1.Mehmet Yildiz, Ahmed Cihad Genç, Ahmed Bilal Genç, Deniz Çekiç, Selçuk Yaylacı. Association of Vaccination Status, Clinical and Laboratory Parameters with Mortality in COVID-19 Patients Admitted to the Intensive Care Unit: A Single-Center Retrospective Study. Cerasus J Med. 2026 May 1;3(2):147-56. doi:10.70058/cjm.1928830