The predictive acccuracy for mortality of peripheral hematological markers ratios in mechanically ventilated COVID-19 patients

Abstract

Background. Hematologic markers ratios have been proposed as indicators to assist in the diagnosis and risk stratification of infectious diseases. The objective of the study was to explore the predictive value of neutrophils and monocytes to lymphocytes ratios (NLR and MLR, respectively) and to determine their cut-off values for the early severity stratification in mechanically ventilated critically ill SARS-CoV-2 infected patients. Material and methods. This study was retrospectively conducted on 193 patients admitted with COVID-19 in a specialized center in Jordan. Data were retrieved from the electronic medical record system over 9 months, between April – December 2020. Patients aged below 18 years, with a hospital length of stay less than 7 days, and whose studied variables were totally or partially missed were excluded from our study. An Independent and One-Sample T-Tests were used for parametric comparative data while non-parametric comparative variables were analysed using Chi Square Test. A receiver operating characteristic (ROC) was plotted to investigate the area under each curve (AUROC) of the tested prognosticator. Results. The mean age of the entire study group was 58.37±9.96 years, and the survivor group was insignificantly older than the non-survivor group (58.55±9.95 years versus 58.09±10.05 years, respectively). The 28-day intensive care unit mortality was detected in 94 patients (48.70%) during a mean of 12.40±4.79 days. NLR and MLR were significantly lower in the survivor group compared to the non-survivor cohort (2.22±0.99 and 0.25±0.10 versus 5.16±2.08 and 0.89±0.19, respectively, p <0.05). Conclusions. In this study, the higher values of MLR and NLR in patients with COVID-19, particularly in those with mechanical ventilation, could be used as predictors for risk stratification of patients with COVID-19.