Role of chest ultrasonography in differentiating between acute cardiogenic pulmonary edema and acute respiratory distress syndrome

Abstract

Sometimes it is difficult to differentiate between acute cardiogenic pulmonary edema (APE) and acute respiratory distress syndrome (ARDS) on clinical basis only. Chest ultrasonography (CUS) may be helpful in providing ultrasonographic pleuropulmonary signs, which aids in such differentiation. The aim of this study was to evaluate the role of CUS in differentiating between ARDS and APE through the characterization of comparative peculiar ultrasonographic pleuropulmonary signs. On admission, CUS was performed in Ain Shams University Hospital and Al-Abbassia Chest Hospital ICUs on 28 consecutive patients who presented with ARDS (15 cases) or APE (13 cases). CUS examination focused on the detection of the following pleuropulmonary signs in both ARDS and APE: alveolar–interstitial syndrome (AIS), pleural line abnormalities, absent or reduced lung sliding, consolidation, and pleural effusion. AIS was found in 100% of patients with ARDS and in 100% of patients with APE. Pleural line abnormalities were observed in 100% of patients with ARDS and in 0% of patients with APE (P=0.001). Absent or reduced lung sliding was observed in 100% of patients with ARDS and in 0% of patients with APE (P=0.001). Consolidations were present in 93.3% of patients with ARDS in 7.5% of patients with APE (P=0.001). Pleural effusion was present in 40% of patients with ARDS and in 76.9% of patients with APE (P=0.049). All pleuropulmonary signs, except the presence of AIS, presented a statistically significant difference in presentation between ARDS and APE, resulting peculiar ultrasonographic pleuropulmonary signs of ARDS. CUS represents a useful tool for differentiating ARDS from APE in ICU patients. In fact, the presence of absent or reduced lung sliding, pleural line abnormalities, and lung consolidations on a background of AIS seems diagnostic of ARDS.