The Value of a Simplified Lung Ultrasound Protocol in the Pre-Discharge Evaluation of Patients Hospitalized with Acute Heart Failure

Abstract

Optimal timing of hospital discharge in patient with acute heart failure (AHF) is an important factor of preventing rehospitalizations. Aim. To evaluate the value of a simplified lung ultrasound (LUS) protocol in assessing pre-discharge status of patients with AHF, correlating the US findings with the values of NT-proBNP levels. Methods. 24 patients (18 men, 6 women, mean age 68,2 years) hospitalized with acute heart failure underwent LUS examination in the afternoon of the day before hospital discharge, applying a simplified LUS protocol, using three basal examination areas on the right side (anterior, lateral and posterior) and two basal examination areas on the left side (lateral and posterior). The LUS score was represented by the sum of B lines. In the next morning the value of NT-proBNP was also determined. The correlation between LUS findings and NT-proBNP values was analyzed using Fisher`s exact test (significant if alpha<0,05). Results. 6 patients had <15 B lines, 16 patients had >15 B lines and 2 patients had pleural effusion on LUS, while 16 patients had the value of NT-proBNP >1000pg/ml at discharge. The results of LUS examination correlated significantly (p=0.0013) with the NT-proBNP values -only one patient not having increased NT-proBNP in the group with >15 B lines. Conclusions. Despite a relatively good clinical status, the majority of patients had high NT-proBNP values at the time of hospital discharge. LUS proved to be a useful tool in identifying patients with subclinical congestion reflected also by the high NT-proBNP levels. These patients may need a prolongation of hospitalization and/or a more careful follow-up to prevent early readmission.