Evaluation of Hematological Parameters in Predicting Intensive Care Unit Admission in COVID-19 Patients

Hematological parameters like total leukocyte count (TLC), neutrophil, lymphocyte, and absolute eosinophil counts (AEC), and neutrophil-to-lymphocyte ratio (NLR) are known to predict the severity of novel coronavirus disease 2019 (COVID-19) patients. In the present study, we aimed to study the role of complete blood count parameters in triaging these patients requiring intensive care unit (ICU) admission. A retrospective study was done over a period of 2 months. Patients, who were ≥ 18 years of age with COVID-19 confirmed on SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) and whose routine hematology counts were sent within 24 h of admission, were included in the study. Cut-off values of 47.5 years for age, 11.3 × 10⁹/L for TLC, and 9.1 for NLR were predictive of disease severity among COVID-19 patients. Relative neutrophilia ≥ 70% (p < 0.007), relative lymphopenia ≤ 20% (p < 0.002), AEC ≤ 40/cumm (p < 0.001), and NLR ≥ 9.1 (p < 0.001) were significantly associated with ICU admission. Routine hematological parameters are cost-effective and fast predictive markers for severe COVID-19 patients, especially in resource-constrained health care settings to utilize limited ICU resources more effectively.