Lung ultrasound versus pulmonary auscultation in detecting pulmonary congestion in the critically ill

Abstract

BACKGROUND: In critically ill patients, auscultation might be challenging as dorsal lung fields are difficult to reach in supine-positioned patients, and the environment is often noisy. In recent years, clinicians have started to consider lung ultrasound (LUS) as a useful diagnostic tool for a variety of pulmonary pathologies, including pulmonary edema. AIM: The aim of this study was to compare LUS versus pulmonary auscultation for detecting pulmonary edema in critically ill patients. PATIENTS AND METHODS: Sixty-one patients were included in this study, all included patients underwent clinical examination, chest auscultation of anterior and lateral (axillary) chest wall and back in each hemithorax in supine position was done, followed by LUS using Bedside LUS in Emergency (BLUE) protocol. LUS score was recorded; abnormal auscultation was defined as the presence of rales or wheezes. Laboratory tests were done on admission such as pro-BNP, renal function, and blood gases. Pro-BNP was used as diagnostic tool for volume overload and was correlated with LUS and stethoscope for detecting pulmonary edema. Pneumonia was excluded with normal total leukocyte counts, C-reactive protein, and absence of fever. RESULTS: This study included 61 patients with diagnosis of pulmonary edema, all data were recorded on admission and showed that there was statistically significant good positive correlation between LUS and Pro-BNP (p < 0.05), and Pearson correlation between LUS and Pro-BNP among the studied patients is statistically significant at the 0.01 level (two-tailed). Furthermore, we found that both LUS and Pro-BNP were statistically significant higher among patients with rales (p < 0.05) only 36 (59%) patients were positive as pulmonary edema with pulmonary auscultation (presence of rales) and 25 (41%) patients were negative for pulmonary edema (NO RALES) while they were positive for pulmonary edema with LUS (high LUS score)and pro-BNP. CONCLUSION: Pulmonary auscultation has poor sensitivity for pulmonary congestion while LUS had statistically significant higher sensitivity for pulmonary edema.