CORRELATION OF B-LINES ON LUNG ULTRASOUND AND NT PRO BNP TO DIFFERENTIATE BETWEEN ACUTE HEART FAILURE FROM OTHER NON CARDIOGENIC CAUSES OF DYSPNEA A PROSPECTIVE DIAGNOSTIC STUDY

Background: Dyspnea can be a manifestation of a variety of clinical conditions like acute heart failure (AHF), chronic obstructive pulmonary disease (COPD), pneumonia, pulmonary embolism and asthma. Dyspnea can prove to be life threatening and therefore it is immensely important to initiate the treatment at the earliest. It is not uncommon for patients to present as combination of various causes of breathing difficulty. In fact it is often almost impossible to discriminate between cardiogenic and non cardiogenic causes of dyspnea on initial presentation. A diagnostic aid which can be used atthis very minute of presentation can prove to be boon for emergency physicians to accurately recognize the cause and initiate the treatment. We correlated the presence of B lines on lung USG and NT proBNP in cardiogenic pulmonary edema. 

Methods: A diagnostic prospective study was done on patients of age more than 18 years presenting with acute dyspnea to the emergency department after obtaining informed consent. Lung ultrasound was done to look for B- lines and NT-Pro BNP samples were sent along with the other investigations. More than 3 B-lines in the anterior surface of the chest present bilaterally were taken as positive. NT pro BNP values above 900pg/ml were considered significantly positive. Final diagnosis made by Cardiologist/Intensivist/Pulmonologist was recorded. Results: 65 patients presenting with symptoms of breathlessness were studied. 49 patients had presence of B-lines on the lung USG constituting about 75.4% of the patients. Based on history, clinical examination,initial diagnosis of cardiogenic dyspnea was made in 50.8% of 49 patients with B profile. Out of the 49 patients with positive B lines, 40 patients were finally diagnosed with cardiac failure by cardiologists/ intensivists with a sensitivity of B- lines to diagnose cardiac failure is 90.91%, specificity is 57.14%, Positive predictive value is 81.63% and Negative Predictive value is 75%. The data analysis showed that out of 49 subjects who had B profile of the lung, 44 patients had positive NT pro BNP values above 900pg/ml. However, A-profile of the lung was present in all the patients with NT proBNP values more