Screening performance of Ultrasonographic Blines in Detection of Lung Contusion following Blunt Trauma; a Diagnostic Accuracy Study

Introduction: Chest ultrasonography is routinely used in evaluation of chest trauma for diagnosis of pulmonary injury. This study aimed to evaluate the accuracy of BLines for diagnosing lung contusion in patients with blunt trauma of the chest. Methods: Trauma patients who met the inclusion criteria were enrolled in the study and underwent ultrasonography by trained emergency medicine residents. Ultrasound results were recorded in terms of number of Blines and the existence of peripheral parenchymal lesion (PPL). After ultrasound, the patient underwent chest xray and chest CT scan (as reference test) and screening performance of Blines and PPL were evaluated.Results: 147 patients underwent chest ultrasound. The mean age of the patients was 40.74 ± 18.6 (78.9% male). Blines˃3 had 94.0% (95% CI: 83.4598.75) sensitivity and 57.7% (95% CI: 47.367.7) specificity, Blines˃6 had 90.0% (95% CI: 78.296.7) sensitivity and 93.81% (95% CI: 87.097.7) specificity, and PPL had 34.0% (95% CI: 21.248.8) sensitivity and 100% (95% CI: 96.3100.0) specificity. Composite findings of Blines˃6 + PPL had 92.0% (95% CI: 80.897. 8) sensitivity and 93.8% (95% CI: 87.097.7) specificity in the diagnosis of lung contusion.Conclusion: PPL and BLines˃6 had the highest accuracy in detecting lung contusion. BLine˃6 had high sensitivity and specificity and was easy to perform; thus, it seems that BLine˃6 could be considered as an alternative screening tool in detection of lung contusion.