The epidemiology of posttraumatic adult respiratory distress syndrome

Although adult respiratory distress syndrome is an important early complication of blunt trauma, the epidemiology and risk factors for its development remain poorly defined. The aims of this study were to determine the prevalence and demographics of this complication in a prospective cohort series of patients admitted to the hospital following injury. We also assessed the contribution of the severity and pattern of the injury to the risk of this complication developing. By identifying factors associated with the highest risk of the development of adult respiratory distress syndrome, we aimed to produce guidelines to facilitate earlier detection.

We prospectively studied 7192 patients admitted to a single university hospital, over an eight-year period, for treatment of a traumatic injury. With the exception of patients who had sustained a hip fracture or who had been discharged within seventy-two hours after admission, all patients who required hospital admission following trauma, were older than thirteen years of age, and were a resident within the catchment area were included in the analysis. The prevalence and demographics of posttraumatic adult respiratory distress syndrome were identified for patients who had sustained musculoskeletal, thoracic, abdominal, and head injuries, either in isolation or in combination. The relative risks of this condition developing were calculated according to the injury pattern. Multiple logistic regression analysis was performed to identify the most highly significant predictors of the development of adult respiratory distress syndrome.

Adult respiratory distress syndrome developed in thirty-six (0.5%) of the patients. The prevalence was significantly higher among younger patients (p = 0.002), and 83% of the cases followed high-energy trauma. The prevalence of adult respiratory distress syndrome after isolated thoracic, head, abdominal, or extremity injury was <1%. Patients with injuries to two anatomical regions had a higher prevalence (up to 2.9%), and those with injuries to three anatomical regions had an even higher prevalence (up to 10.2%). Multiple logistic regression analysis showed the Injury Severity Score, the presence of a femoral fracture, the combination of abdominal and extremity injuries, and observations of compromised physiological function on admission each to be an independent predictor of the later development of adult respiratory distress syndrome.

The prevalence of adult respiratory distress syndrome increases with injury severity and combinations of injuries to more than one anatomical region. We have been able to quantify the importance and relative risks associated with these injuries. The implications of our findings with regard to facilitating early detection of this complication are discussed.