Detecting and Treating Lung Congestion with Kidney Failure.

Fluid overload is a common complication in patients with CKD, particularly patients with kidney failure, a population with a very high risk for pulmonary edema. Lung ultrasound is now a well-validated technique that allows for reliable estimates of lung water in clinical practice. Several studies in patients with kidney failure documented a high prevalence of asymptomatic lung congestion of moderate to severe degree in this population, and this alteration was only weakly related with fluid excess as measured by bioimpedance spectroscopy. Furthermore, in these studies, lung congestion correlated in a dose-dependent fashion with death risk. In the Lung Water by Ultra-Sound Guided Treatment to Prevent Death and Cardiovascular Complications in High Risk Kidney Failure Patients with Cardiomyopathy (LUST) trial, a treatment strategy guided by lung ultrasound safely relieved lung congestion but failed to significantly reduce the risk for a combined end point including death, nonfatal myocardial infarction, and decompensated heart failure. However, in line with three trials in patients with heart failure, a post hoc analysis of the LUST trial showed that the use of lung ultrasound reduces the risk for repeated episodes of acute heart failure and repeated cardiovascular events. Given the high cardiovascular risk of pulmonary edema in patients with predialysis CKD, defining the epidemiology of lung congestion in this population is a public health priority. Specific trials in this population and additional trials in patients with kidney failure will establish whether targeting lung congestion at an asymptomatic phase may improve the severe cardiovascular prognosis of both patients predialysis and patients on dialysis.