Is chest imaging relevant in diagnosing acute respiratory distress syndrome in polytrauma patients? A population-based cohort study

PURPOSE: The definition of acute respiratory distress syndrome (ARDS) has often been modified with Berlin criteria being the most recent. ARDS is divided into three categories based on the degree of hypoxemia using PaO(2)/FiO(2) ratio. Radiological findings are standardized with bilateral diffuse pulmonary infiltrates present on chest imaging. This study investigated whether chest imaging is relevant in diagnosing ARDS in polytrauma patients. METHODS: The 5-year prospective study included consecutive trauma patients admitted to a Level-1 Trauma Center ICU. Demographics, ISS, physiologic parameters, resuscitation parameters, and ARDS data were prospectively collected. Acute hypoxic respiratory failure (AHRF) was categorized as Berlin criteria without bilateral diffuse pulmonary infiltrates on imaging. Data are presented as median (IQR), p < 0.05 was considered significant. RESULTS: 267 patients were included. Median age was 45 (26–59) years, 199 (75%) males, ISS was 29 (22–35), 258 (97%) patients had blunt injuries. Thirty-five (13%) patients died. 192 (72%) patients developed AHRF. AHRF patients were older, more often male, had higher ISS, needed more crystalloids and blood products than patients without AHRF. They developed more pulmonary complications, stayed longer on the ventilator, in ICU and in hospital, and died more often. Fifteen (6%) patients developed ARDS. There was no difference in outcome between ARDS and AHRF patients. CONCLUSIONS: Many patients developed AHRF and only a few ARDS. Patients with similar hypoxemia without bilateral diffuse pulmonary infiltrates had comparable outcome as ARDS patients. Chest imaging did not influence the outcome. Large-scale multicenter validation of ARDS criteria is warranted to investigate whether diffuse bilateral pulmonary infiltrates on chest imaging could be omitted as a mandatory part of the definition of ARDS in polytrauma patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00068-019-01204-3) contains supplementary material, which is available to authorized users.