USING LUNG ULTRASOUND OBTAINED BY AN INTERNIST TO ASSESS LEFT ATRIAL PRESSURE IN HOSPITALIZED PATIENTS

Background: Lung ultrasound (LUS) is emerging as a useful diagnostic tool for several lung pathologies including pulmonary edema. The number of sonographic B-lines on LUS has been used as a test to detect pulmonary congestion in patients with chronic heart failure. However, its ability to detect elevated left-sided filling pressures relative to accepted noninvasive measure of elevated left-sided filling pressures and other more commonly used tools such as brain-naturetic peptide (BNP) is not well defined. We sought to evaluate the association of LUS findings (number of sonographic B-lines on lung ultrasound) and BNP to E/e’ on transthoracic echocardiogram (TTE).

Methods: This was a prospective convenience sample of 90 patients admitted to an academic medical center in New York from 2014-2015. Patients 18 years or older, admitted to the hospital with an order for an inpatient TTE were approached for enrollment. Patients who required the intensive care unit, or carried a current diagnosis of pulmonary fibrosis or pneumonia were excluded. All included patients had a LUS performed by two internal medicine physicians trained in LUS within 24 hours of TTE. LUS were assessed by the number of B-lines present on eight 6-second video clips. TTE parameters including E/e’ and BNP level were extracted by chart review. Spearman correlation was used to examine relationships between E/e’, LUS and BNP.

Results: Of the 90 included patients, 56 had a recorded value for E/e’ (62%) and 68 had a recorded BNP (75%). The mean number of B lines was 9 (SE: 1.27) and mean BNP was 785 (SE: 119.96) ; 42% of patients with a recorded E/e’ value had an E/e’ > 14. LUS findings significantly correlated with E/e’ (0.52, p<0.0001)), and BNP significantly correlated with E/e’ (0.50, p< 0.001).

Conclusions: Among a population of hospitalized patients who received a LUS by an internist, our findings suggest a moderate correlation between LUS findings and E/e’ comparable to that of BNP. Our findings also suggest LUS may provide an alternative to TTE or BNP for assessing elevated left-sided filling pressures. Given its ease of acquisition, noninvasiveness and the immediate availability of results, further research is needed to better define the role of LUS in the management of hospitalized patients.