Eight-point lung ultrasonography protocol for assessing hypervolemia in chronic hemodialysis patients: A pilot study

Hypervolemia (HV) and arterial stiffness present an important problem for chronic hemodialysis (HD) patients. The most promising methods for evaluating excess fluid are bioelectrical impedance analysis (BIA) and lung ultrasonography with B-line assessment (LUS). The latter is traditionally performed in 28 anatomical locations on the front side of the chest. The study aimed to investigate whether a shorter LUS procedure in 8 locations correlates with other markers of HV and arterial stiffness.

We performed a single dialysis center observational study in adult chronic HD patients. Patients had to be without active malignancy, infection, chronic atrial fibrillation, carotid stenosis, severe aortic stenosis, or peripheral artery disease. We performed predialysis blood pressure measurements, LUS on 8 predefined locations, BIA, carotid-femoral pulse wave velocity (cfPWV) assessment, and laboratory values of the N-terminal prohormone of brain natriuretic peptide.

19 patients were included, 7 male (36.8%). The median age of the patients was 71 years (IQR (60 - 74)), the median dialysis vintage was 51 months (IQR (27 - 87)). We found a statistically significant positive correlation between LUS and overhydration measured by BIA (r_s= 0.697; p < 0.001), LUS and intracellular water measured by BIA (r_s= 0.478; p = 0.038), and between LUS and extracellular water measured by BIA (r_s= 0.462; p = 0.046). Furthermore, we also found a statistically significant negative correlation between LUS and cfPWV (r_s= -0.539; p = 0.026).

LUS in 8 locations is associated with markers of HV in HD patients, correlating positively with BIA measurements. Its correlation with cfPWV should be further investigated.