Modern intensive care unit interventions such as low-tidal volume mechanical ventilation may result in short-term improvements in acute respiratory distress syndrome (ARDS) survival, but less is known about the epidemiology of long-term survival. Chen Wang et al conducted a study to quantify the gap between in-hospital and 1-year ARDS mortality rates, and to identify risk factors and causes of death at one year among patients with ARDS.
Patients were selected from an ongoing prospective, multi-unit acute lung injury (ALI) biomarker study (VALID) at a single institution (Vanderbilt University Medical Center, Nashville, TN, USA). Those who met the American European Consensus Committee criteria for ALI/ARDs were included. A sensitivity analysis was also performed to include patients who met the Berlin criteria for ARDS. All were followed until death or for at least 1 year after study enrollment. Logistic regression was used to analyze associations between risk factors and death.
The analysis included 646 patients with ALI/ARDS ; 153 patients died during hospitalization (24%) and 263 died during the year after discharge (41%). In the sensitivity analysis using the Berlin criteria, similar rates of hospital and 1-year mortality were observed. Survivors at one year were younger, had less comorbidity, and were more likely to be admitted via the emergency department. Age and severe comorbidities were independent risk factors for death at 1 year, whereas trauma and living at home before hospitalization were strong predictors of decreased mortality. The most common underlying cause of death in the hospital and after discharge was malignancy.
While the short-term mortality rate has declined in the era of lung-protective ventilation and modern intensive care, 1-year mortality was substantially higher for patients with ARDS in this study. The study cohort was derived from a single institution, though the patient mix was heterogeneous with few exclusions. The effect of specific interventions for ARDS, as well as intensive care unit interventions in general, was not assessed in this study. Based on the results of this work and others, ARDS mortality may be related to premorbid conditions more than to the development of ARDS itself.
Samuel M. Galvagno Jr., DO, PhD, is editor of Concise Critical Care Appraisal. An assistant professor at the University of Maryland, R Adams Cowley Shock Trauma Center, he is board certified in anesthesiology, critical care medicine, and public health.