Impact of Acute Lung Injury and Acute Respiratory Distress Syndrome After Traumatic Brain Injury in the United States

BACKGROUND: Traumatic brain injury (TBI) is a major cause of disability, morbidity, and mortality. The effect of the acute respiratory distress syndrome and acute lung injury (ARDS/ALI) on in-hospital mortality after TBI remains controversial. OBJECTIVE: To determine the epidemiology of ARDS/ALI, the prevalence of risk factors, and impact on in-hospital mortality after TBI in the United States. METHODS: Retrospective cohort study of admissions of adult patients >18 years with a diagnosis of TBI and ARDS/ALI from 1988 to 2008 identified through the Nationwide Inpatient Sample. RESULTS: During the 20-year study period, the prevalence of ARDS/ALI increased from 2% (95% confidence interval [CI], 2.1%–2.4%) in 1988 to 22% (95% CI, 21%–22%) in 2008 (P < .001). ARDS/ALI was more common in younger age; males; white race; later year of admission; in conjunction with comorbidities such as congestive heart failure, hypertension, chronic obstructive pulmonary disease, chronic renal and liver failure, sepsis, multiorgan dysfunction; and nonrural, medium/large hospitals, located in the Midwest, South, and West continental US location. Mortality after TBI decreased from 13% (95% CI, 12%–14%) in 1988 to 9% (95% CI, 9%–10%) in 2008 (P < .001). ARDS/ALI-related mortality after TBI decreased from 33% (95% CI, 33%–34%) in 1988 to 28% (95% CI, 28%–29%) in 2008 (P < .001). Predictors of in-hospital mortality after TBI were older age, male sex, white race, cancer, chronic kidney disease, hypertension, chronic liver disease, congestive heart failure, ARDS/ALI, and organ dysfunctions. CONCLUSION: Our analysis demonstrates that ARDS/ALI is common after TBI. Despite an overall reduction of in-hospital mortality, ARDS/ALI carries a higher risk of in-hospital death after TBI. ABBREVIATIONS: AECC, American-European Consensus Conference ALI, acute lung injury ARDS, acute respiratory distress syndrome CXR, chest x-ray GEE, generalized estimated equation ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification NIS, Nationwide Inpatient Sample PAOP, pulmonary artery occlusion pressures PPV, positive predictive value TBI, traumatic brain injury