Abstract
OBJECTIVES: The neutrophil-lymphocyte ratio is an inexpensive and simple inflammatory marker. A higher ratio, indicative of an acute hyperinflammatory response or diminished overall physiologic health status, has been associated with poor prognoses. This study aimed to evaluate the prognostic potential of admission neutrophil-lymphocyte ratio in patients admitted to the medical ICU with coronavirus disease 2019. DESIGN: Retrospective review of prospectively collected data. SETTING: Medical ICU from a large medical center. PATIENTS: 2,071 consecutive patients admitted to the medical ICU with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 between March 15, 2020, and December 30, 2020, were grouped by neutrophil-lymphocyte ratio above or below the median (7.45) at the time of hospital admission. INTERVENTIONS: Complete blood count with differential at the time of hospital admission. MEASUREMENTS AND MAIN RESULTS: A neutrophil-lymphocyte ratio above 7.45 at the time of hospital admission was associated with increased need for mechanical ventilation (45.8% vs 38.0%, p < 0.0001), vasopressor therapy (55.6% vs 48.2%, p = 0.001), and decreased survival through 180 days (54.8% vs 67.0%, p < 0.0001). Patients with a high neutrophil-lymphocyte ratio exhibited a 1.32 (95% CI, 1.14-1.54) times greater risk of mortality than those with a low neutrophil-lymphocyte ratio. CONCLUSIONS: The neutrophil-lymphocyte ratio at the time of hospital admission is an independent risk factor for morbidity and mortality. This prognostic indicator may assist clinicians appropriately identify patients at heightened risk for a severe disease course and tailor treatment accordingly.