THE EPIDEMIOLOGY OF POST TRAUMATIC ACUTE RESPIRATORY DISTRESS SYNDROME

Abstract

Acute Respiratory Distress Syndrome (ARDS) is a rare but important complication of trauma, with a mortality of around 50%, and considerable morbidity amongst survivors. The treatment options currently available are supportive only. Although trauma is known to be an important risk factor, previous studies have been intensive care-based and the epidemiology of ARDS amongst trauma patients remains unknown.

We prospectively studied 7387 consecutive admissions to a single University Hospital, providing all trauma care to a well defined population, over an eight year period. Inclusion criteria were admission following trauma, age over thirteen and residence within the catchment area. Fifty five percent of all patients studied were male, the average age was fifty years and 97% of injuries were due to blunt trauma.

Thirty-eight (0.5%) patients developed ARDS following trauma, giving an incidence of 0.8 per 100 000 population per annum. The mortality rate was 26%. The incidence of ARDS after isolated thoracic, head, abdominal or extremity injury was less than one percent. The incidence was significantly higher amongst younger patients with a median age of 29 for those developing the condition. High energy trauma was also associated with an increased incidence, with 84% cases arising following a road traffic accident or a fall from a height. The highest incidence was observed amongst patients with multiple injuries. Patients with injuries to two anatomical regions had a higher incidence (up to 2.9%) than those with isolated injuries, and those with injuries to three anatomical regions had a higher incidence still (up to 8.2%). The combination of abdominal and extremity injury was shown on logistic regression to be especially significant.

The epidemiology of ARDS following trauma has not previously been defined. The incidence is highest following high energy trauma, in younger patients and in polytraumatised patients.

We have identified risk factors for the development of this rare but serious complication of trauma. Vigilant monitoring of those patients who are at increased risk will allow appropriate supportive measures to be instituted at an early stage.