Lung congestion as a risk factor in end-stage renal disease

Lung congestion is emerging as a pervasive, insidious problem in end-stage renal disease (ESRD) patients on dialysis.

Chest ultrasound (US), a novel, easy-to-perform, cheap technique, which is currently applied for objective monitoring of pulmonary congestion in patients with heart failure in Europe, allows reliable quantification of lung water in clinical practice. Before hemodialysis (HD), about 60% of ESRD patients displayed moderate-severe lung congestion and this alteration is frequently asymptomatic. Lung congestion is reduced but not abolished by ultrafiltration dialysis, and about one third to one fourth of patients still have excessive lung water after dialysis. Lung congestion is also prevalent in patients on peritoneal dialysis (PD), and in apparently asymptomatic HD and PD patients this alteration is strongly associated with poor physical performance. Lung water in HD patients correlates in an inverse fashion with echocardiographic parameters of systolic and diastolic function, but it is only weakly related with hydration status measured by bioimpedance analysis. Moderate-severe lung congestion is a strong predictor of death and cardiovascular events and provides prognostic information independent of NYHA class, and traditional and nontraditional risk factors in ESRD patients on HD.

Systematic application of chest US in ESRD patients shows that hidden or clinically manifest lung congestion is exceedingly frequent in this population. This alteration largely reflects left ventricular disorders superimposed on volume overload. The clinical usefulness of systematic application of chest US in ESRD remains to be tested in a formal clinical trial.