Ultrasound Assessment for Extravascular Lung Water in Patients Undergoing Hemodialysis: Time Course for Resolution.
Chest. 2009 Feb 2;
Authors: Noble VE, Murray AF, Capp R, Sylvia-Reardon MH, Steele DJ, Liteplo A
Background Sonographic B-lines, also known as lung comets, have been shown to correlate with the presence of extravascular lung water. Absent in normal lungs, these sonographic findings become prominent as interstitia and alveoli fill with fluid. Characterization of the dynamics of B-lines, specifically their rate of disappearance as volume is removed, has not been previously described. In this study, we describe the dynamics of B-line resolution in patients undergoing hemodialysis. Methods Patients undergoing hemodialysis underwent three chest ultrasound examinations; before, at the midpoint, and after dialysis. We followed a previously described chest ultrasound protocol that counts the number of B-lines visualized in 28 lung zones. Baseline demographics, assessment of ejection fraction, time elapsed, net volume of fluid removed, and subjective degree of shortness of breath were recorded for each patient. Results 40/45 patients completed full dialysis runs and had all three lung scans performed. 6/40 patients had zero or one B-line predialysis and none of these 6 patients gained B-lines during dialysis. 34/40 patients had statistically significant reductions in the number of B-lines from predialysis to the midpoint scan and from predialysis to post-dialysis with a p-value < 0.001. There was no association between subjective dyspnea scores and number of B-lines removed. Conclusions B-line resolution appears to occur real-time as fluid is removed from the body and this change was statistically significant. This data supports thoracic ultrasound as a useful method for evaluating real-time changes in extravascular lung water and in assessing a patient's physiologic response to the removal of fluid.
PMID: 19188552 [PubMed - as supplied by publisher]