Ultrasonography in chest trauma
Ultrasound can be performed to rapidly detect and treat findings of fluid collection in the intraperitoneal, pericardial and intrathoracic region of the body. A haemothorax may also be diagnosed in this manner.9 The lung point sign has been found to have a high specificity (100%) and an absence of lung sliding is diagnostic for pneumothorax.
A systematic review by Staub et al.9 reviewed nineteen studies, 17 of which assessed pneumothorax and 5 assessed haemothorax. The reference standard was chest tomography, alone or in parallel with chest radiography and observation of the chest tube. It should be noted that the overall methodological quality of the studies were low.
The diagnostic accuracy of chest ultrasonography had an area under the curve (AUC) of 0.979 for pneumothorax. The absence of lung sliding and comet-tail artefacts was the most reported sonographic sign of pneumothorax, with a sensitivity of 0.81 (95% CI 0.71–0.88), specificity of 0.98 (95% CI 0.97–0.99), LR+ of 67.9 (95% CI 26.3–148) and LR– of 0.18 (95% CI 0.11–0.29).
An echo-poor or anechoic area in the pleural space was the only sonographic sign for haemothorax, with a sensitivity of 0.60 (95% CI 0.31–0.86), specificity of 0.98 (95% CI 0.94–0.99), LR+ of 37.5 (95% CI, 5.26–207.5), LR– of 0.40 (95% CI, 0.17–0.72) and AUC of 0.953.9