Complete Blood Count and Derived Indices: Evolution Pattern and Prognostic Value in Adult Burned Patients

Certain parameters of complete blood count (CBC) such as red cell distribution width (RDW) and mean platelet volume, as well as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and RDW-to-platelet ratio (RPR) have been associated with inflammatory status and outcome in diverse medical conditions. The aim of this study was to describe the evolution pattern of these parameters in adult burned patients. Adult burned patients admitted to the National Burn Center in Uruguay between May 2017 and February 2018 (discovery cohort) and between March 2018 and August 2019 (validation cohort) were included. Patients' characteristics and outcomes were recorded, as well as CBC parameters on days 1, 3, 5, and 7 after thermal injury. Eighty-eight patients were included in the discovery cohort. Total body surface area burned was 14 [7-23]% and mortality was 15%. Nonsurvivors presented higher RDW and mean platelet volume (P < .01). NLR decreased after admission in all patients (P < .01), but was higher in nonsurvivors (P < .01). Deceased patients also presented higher RPR on days 3, 5, and 7 (P < .001). On the contrary, PLR was reduced in nonsurvivors (P < .05). There was a significant correlation between NLR on admission and burn extension and severity. Kaplan-Meier analysis revealed that NLR, PLR, and RPR could identify patients with increased mortality. These findings were confirmed in the validation cohort (n = 95). Basic CBC parameters and derived indices could be useful as biomarkers to determine prognosis in adults with thermal injuries.