The clinical benefit of a follow-up thoracic computed tomography scan regarding parenchymal lung injury and acute respiratory distress syndrome in polytraumatized patients

Purpose To evaluate the increase of parenchymal lung injury (PLI) volume between the initial and a follow-up computed tomography (CT) scan and to ascertain which of the 2 scans was more appropriate to predict acute respiratory distress syndrome (ARDS). Material and methods From 2011 to 2015, polytraumatized patients (≥18 years; ISS ≥ 16) directly admitted to our level I trauma center were included in our prospective study if a follow-up CT scan was possible 24 to 48 hours after the trauma. The PLI volume was measured using volumetric analysis. Statistical calculations were performed to identify patients at risk for ARDS. Results One hundred thirty patients (mean age, 41.3 years; mean ISS, 31.9) met the inclusion criteria. Median relative PLI volume was higher in the follow-up than in the initial CTs (9.65% vs 4.84%; P = .001). The ARDS developed in 42 patients (32.3%). Their initial PLI volume was higher compared with those without ARDS (11.23% vs 2.14%; P < .0001). The ARDS incidence increased with increasing initial PLI volume. Receiver operating characteristic statistics identified initial (area under the curve = 0.753) and follow-up relative PLI volume as a predictor for ARDS (area under the curve = 0.725). Conclusions The CT scans performed directly after admission are sufficient to define patients at risk for ARDS. Therefore, solely the incidence of PLI does not justify a routine follow-up CT scan.