Neutrophil-to-Lymphocyte Ratio: A Promising Predictor of Mortality in Patients With Acute Respiratory Distress Syndrome. A Retrospective Analysis of a Single Hospital Center

Abstract

ObjectivesTo examine how the neutrophil-to-lymphocyte ratio (NLR) affects both short-term and long-term mortality in individuals with acute respiratory distress syndrome (ARDS). DesignA retrospective study SettingCritical care unit ParticipantsA total of 785 patients with ARDS were included. InterventionsThere were three groups in the NLR study. To calculate the hazard ratio (HR) between the NLR and mortality (30-day, 90-day and 1-year mortality), a Cox proportional hazards regression model was utilised. Measurements and Main ResultsOf the 785 patients, 329 were women (41.9%) and 456 were men (58.1%), with a mean age of 63.4 ± 16.7 years and mean NLR of 14.2 ± 9.8. In the unadjusted model, the second (6.0–11.3) and third (>11.3) NLR groups had HR (95% CI) values of 1.12 (0.83, 1.52) and 2.39 (1.87, 3.04), respectively, for 30-day all-cause mortality compared with the first (<6.0) NLR group. This association remained significant after adjusting for potential confounding variables (HR = 1.54, 95% CI: 1.18–2.02), with a statistically significant trend (P = 0.0004) in the third (>11.3) NLR group. There was a similar effect on both 90-day and 1-year all-cause mortality. The R (95% CI) in a two-piecewise linear regression was 1.25 (1.06–1.48; P < 0.0001) on the left side of the inflection point (NLR 17.1). ConclusionsIn this retrospective single-centre study, the NLR was a potential predictor of both short-term and long-term mortality in patients with ARDS and may help with risk stratification.