Diagnostic accuracy of bedside ultrasonography in the ICU: feasibility of detecting pulmonary effusion and lung contusion in patients on respiratory support after severe blunt thoracic trauma

Background: Blunt thoracic trauma is a major concern in critically ill patients. Repeated lung diagnostic evaluations are needed in order to follow up the clinical situation and the results of the therapeutic strategies. The aim of this prospective clinical study was to evaluate the possible role of lung ultrasound (LU) compared with bedside radiography (CXR) and computed tomography (CT) used as the gold standard in the evaluation of trauma patients admitted to the intensive care unit with acute respiratory failure. Method: A total of 15 thoracic trauma patients were studied at intensive care unit (ICU) arrival (T1) and 48 h later (T2) with CT, CXR and LU. We evaluated the presence of pleural effusion (PE) and lung contusion (LC). For this purpose the lung parenchyma was divided into 12 regions so that we could compare 180 lung regions at T1 and T2, respectively. Results: Sensitivity of ultrasound was 0.94 for PE and 0.86 for LC while specificity 0.99 and 0.97, respectively. The likelihood ratio was 94 (rho(+)) and 0.06 (rho(-)) for PE and 28.6 (rho(+)) and 0.14 (rho(-)) for LC. Conclusion: Ultrasound provides a reliable noninvasive, bedside method for the assessment of chest trauma patients with acute respiratory failure in the ICU.