Associations between pulmonary congestion on chest ultrasound and survival in hemodialysis patients

Background Volume overload in hemodialysis patients is an independent risk factor for cardiovascular event-related mortality. The number of B-lines observed using lung ultrasound is correlated with the severity of pulmonary congestion. The aim of this study was to evaluate the association between the number of B-lines and mortality among hemodialysis patients. Methods A total of 61 patients receiving maintenance hemodialysis were enrolled in this study. Clinical data including age, sex, duration of hemodialysis therapy, presence of diabetes mellitus and/or hypertension and/or dyslipidemia complications, the results of biological examinations, and outcome were collected from the patients' clinical records. We performed echographic examinations at three time points (just after the start, during the middle, and just before the end of hemodialysis therapy). A univariate Cox proportional hazard model was used to identify predictors of the overall outcomes. Furthermore, we divided patients into two groups according to the median number of the B-lines at the end of dialysis and compared the mortality between the two groups. Results The mean follow-up period was 507 +/- 385 days. During the follow-up period, 24 deaths were recorded. Predictive variables for mortality included age; serum level of albumin, creatinine, and N-terminal pro-brain natriuretic peptide; and body weight (P < 0.001, P < 0.0001, P < 0.001, P = 0.014, and P = 0.019, respectively). The number of B-lines at the start, middle, and end of dialysis therapy was correlated with mortality (hazard ratio (95% confidence interval) 1.20 (1.09-1.32), P = 0.0002; 1.17 (1.07-1.28), P = 0.0008; and 1.23 (1.12-1.37), P = 0.0001; respectively). The mortality was statistically higher in the group with 5 or more B-lines than in the group with less than 5 B-lines (P = 0.013). Conclusions The number of B-lines at the start, middle, and end of hemodialysis therapy may be correlated with mortality among hemodialysis patients.