Prediction of respiratory complications by quantifying lung contusion volume using chest computed tomography in patients with chest trauma

Pulmonary contusion is an important risk factor for respiratory complications in trauma patients. Hence, we aimed to determine the relationship between pulmonary contusion volume and patient outcomes and the predictability of respiratory complications. We retrospectively included 73 patients with a pulmonary contusion on chest computed tomography (CT) from 800 patients with chest trauma admitted to our facility between January 2019 and January 2020. Chest injury severity was expressed as the ratio of the normal lung volume to total lung volume by quantifying pulmonary contusion volume on chest CT. The cut-off value was 80%. Among 73 patients with pulmonary contusion (77% males, mean age: 45.3 years), 28 patients had pneumonia, and 5 had acute respiratory distress syndrome. The number of patients in the severe risk group with <80% of normal lung volume was 38, among which 23 had pneumonia. In predicting pneumonia, the area under the receiver operating characteristic curves for the ratio of the normal lung volume to total lung volume was 0.85 (95% confidence interval: 0.76–0.95, p=0.008), and the optimal threshold was 70.4%. Quantifying pulmonary contusion volume using initial CT in patients with chest trauma allows for identifying patients at high risk of delayed respiratory complications.