Prognostic marker for mortality of COVID-19 patients in the intensive care unit: the delta neutrophil index

Abstract

Aim: The Delta Neutrophil Index (DNI) shows the ratio of immature granulocytes in the circulation and increases in conditions of infection and inflammation. The aim of this study was to investigate the suitability of using DNI as a prognostic marker of mortality in COVID-19 patients in the Intensive Care Unit (ICU). Material and Method: This retrospective study included 316 patients followed up in the ICU with a diagnosis of COVID-19. A record was made for each patient of demographic data, laboratory values, clinical results and mortality status. All the data of the patients were evaluated and compared between the two groups of surviving and non-surviving patients. Results: Mortality developed in 181 (57.27%) patients. The Glasgow Coma Scale score was lower and the APACHE II and SOFA scores were higher in the mortality group than in the surviving group (p<0.001 for all). The creatinine, procalcitonin, white blood cell, neutrophil count, neutrophil-lymphocyte ratio, lactate, interleukin -6 and C-reactive protein values were statistically significantly higher in the mortality group. In the comparison of DNI between the groups, a statistically significant difference was only determined on day 3 (p=0.026). For the DNI examined on day 3, the AUC value was 0.574 and the cutoff value was 1.35% for the prediction of mortality. Conclusion: DNI, which is low cost and simple to use, can be considered safe for use in the prediction of mortality of ICU patients diagnosed with COVID-19. The monitoring of increasing or decreasing trends by keeping regular records can be considered important for the clinical course.