Elevated monocyte distribution width in trauma: An early cellular biomarker of organ dysfunction

Introduction Traumatic injury elicits an inflammatory response such as the one occurring during systemic infection. Monocyte distribution width (MDW) has been found to distinguish sepsis in a pool of patients with suspected infection. We hypothesized that an elevated MDW in trauma patients would be associated with the development of multiple organ dysfunction syndrome (MODS) and an increased mortality. Materials and Methods Observational study in a dedicated trauma Intensive Care Unit (ICU) in Madrid during 2019-2020. Patients were classified according to their first MDW value on admission, as greater or lesser than 21 U. Clinical data was obtained and univariate and multivariate analysis were realized, as well as a test performance analysis. Results 354 patients were studied, with a median age of 46 years, 78% male. Half presented with severe trauma ISS > 15, mostly with a blunt mechanism of injury. A MDW ≥ 21 U on admission was found in 17% of cases. These patients were more likely to present with hemodynamic instability and MODS. They had a higher length of stay (3.8 vs 2 days) and higher mortality (21 vs 5%) compared to the low MDW group. These findings remained statistically significant in the multivariate analysis, with an OR 4.6 (IC 95% 1.7-12) for MODS and 3.1 (IC 95% 1.2-8.3) for mortality. Conclusions In trauma patients, a MDW ≥ 21 U on admission was independently associated with a greater risk of MODS, a higher mortality and a higher length of stay. This biomarker could be useful in predicting severity in the initial evaluation of trauma patients.