Integrated Use of Bedside Lung Ultrasound and Echocardiography in Acute Respiratory Failure

BACKGROUND: It has been suggested that the complementary use of echocardiography could improve the diagnostic accuracy of lung ultrasonography (LUS) in patients with acute respiratory failure (ARF). Nevertheless, the additional diagnostic value of echocardiographic data when coupled with LUS is still debated in this setting. Th e aim of the current study was to compare the diagnostic accuracy of LUS and an integrative cardiopulmonary ultrasound approach (thoracic ultrasonography [TUS]) in patients with ARF. METHODS: We prospectively recruited patients consecutively admitted for ARF to the ICU of a university teaching hospital over a 12-month period. Inclusion criteria were age  18 years and the presence of criteria for severe ARF justifying ICU admission. We compared both LUS and TUS approaches and the fi nal diagnosis determined by a panel of experts using machine learning methods to improve the accuracy of the fi nal diagnostic classifi ers. RESULTS: One hundred thirty-six patients were included (age, 68  15 years; sex ratio, 1). A three-dimensional partial least squares and multinomial logistic regression model was developed and subsequently tested in an independent sample of patients. Overall, the diagnostic accuracy of TUS was signifi cantly greater than LUS ( P , .05, learning and test sample). Comparisons between receiver operating characteristic curves showed that TUS signifi cantly improves the diagnosis of cardiogenic edema ( P , .001, learning and test samples), pneumonia ( P , .001, learning and test samples), and pulmonary embolism ( P , .001, learning sample). CONCLUSIONS: Th is study demonstrated for the fi rst time to our knowledge a signifi cantly better performance of TUS than LUS in the diagnosis of ARF. Th e value of the TUS approach was particularly important to disambiguate cases of hemodynamic pulmonary edema and pneumonia. We suggest that the bedside use of artifi cial intelligence methods in this setting could pave the way for the development of new clinically relevant integrative diagnostic models. CHEST 2014; 146(6): 1586 1593 [ Original Research Critical Care ]