Methemoglobin and inflammatory markers in the context of mortality in COVID-19 disease

Context: Today, the world is in search of potential biomarkers for assessing the severity and prognosis of coronavirus disease-2019 (COVID-19) disease with its different clinical presentations. Aim: The aim of this study was to assess the roles of C-reactive protein (CRP), lactate dehydrogenase (LDH), procalcitonin (PCT), and methemoglobin (Met-Hb) in the clinical outcome of COVID-19 patients. Settings and Design: This observational cross-sectional study was conducted in COVID-19 cases admitted in the intensive care unit (ICU) of a tertiary care hospital from June 2021 to October 2021. Subjects and Methods: For all selected patients, estimation of CRP, LDH, PCT, and Met-Hb levels was done on the 2nd–3rd days of hospital admission, and definitive outcomes were included sequentially. Results: Out of 495 ICU admissions, 69 patients were evaluated in the end. Out of which, 27 patients died during the hospital stay. The mean Met-Hb, LDH, PCT, and CRP levels in nonsurvivors were significantly high. In multivariate bivariate regression analysis, age (odds ratio [OR]–1.06; 95% confidence interval [CI]: 1.01–1.13; P = 0.021), LDH (OR–1.006; 95% CI: 1.001–1.010; P = 0.013), and CRP (OR–1.03; 95% CI: 1.002–1.6; P = 0.047) were independently associated with nonsurvival of the patients. The receiver operating characteristic curve showed a cutoff value of 684 U/L for LDH which predicted mortality due to COVID-19 disease with 66.7% sensitivity and 70.4% specificity. For CRP, a cutoff value of 28.3 mg/L predicted mortality with 73.8% sensitivity and 59.3% specificity. Conclusions: In conclusion, higher levels of LDH and CRP were related to mortality due to COVID-19 disease. Slightly raised values of Met-Hb in nonsurvivors suggest nonresponding hypoxia. The research in this context may open new options in the treatment of COVID-19 disease.