Hematological parameters- as mortality predictors in COVID-19 patients

Abstract

Introduction: In-hospital mortality of SARS-CoV-2 infection could range from 4% to 11%, particularly in the elderly. The overall mortality rate in intensive care unit (ICU) is about 25%, but the factors predicting mortality are not well established.

Aims: To identify the hematological parameters associated with high mortality risk and outcomes within a group of ICU patients with COVID-19.

Methods: A retrospective analysis was conducted on 59 patients admitted to ICU with COVID-19. The overall mortality rate was 50.8%, higher for males (59.5%). The evaluated parameters were: the white blood cell count (WBC), neutrophil count (NEU), lymphocyte count (LYM), neutrophil (NEU)-to-lymphocyte (LYM) ratio (NLR), derived NLR ratio (d-NLR) and platelet-to-lymphocyte ratio (PLR).

Results: The mean ICU length of stay was 10.2 ±7.9 days for patients who died compared to 17.8 ± 13.3 days for patients who survived (p=0.007). The mean age and the median were higher in deceased cases (66 years and 70 years, respectively) compared to patients who survived (mean 59.2 years). Results indicated that men had a shorter survival rate (9.6 days) than women (13.4 days), p < 0.05. The significant differences between the deceased compared to survivors were observed for NLR (18.7 versus 8.6), d-NLR (9.3 vs 5.6), PLR (274.1 vs 212.5) and fibrinogen (458.8 vs 470.8 mg/dL).

Conclusion: Routine hematological parameters, like NLR, d-NLR and PLR, which are not usually reported by the laboratories, may provide to clinicians an accurate estimation of mortality risk for ICU patients together with some factors such as male gender and older age.