Dialysis lung imaging reveals congestion, prognosis
medwireNews: Lung ultrasound (US) can be used to identify asymptomatic pulmonary congestion among end-stage renal disease (ESRD) patients on hemodialysis, study findings show.
Moreover, the researchers significantly improved prediction of the likelihood of cardiac events and death in a group of 392 hemodialysis patients when they included ultrasound B-line (BL) scores for water alongside conventional chronic kidney disease markers.
"Overall, our data show that the application of lung US may help to refine prognosis and that it adds meaningful specificity to prediction models based on classic and kidney failure related risk factors in dialysis patients," write Carmine Zoccali (Ospedali Riuniti, Reggio Calabria) and co-authors.
Lung US revealed that just 10% of patients had no lung congestion (BL-US score <5), with 41% showing mild (BL-US score 5-15) and 45% moderate-to-severe (BL-US score 15-60) disease. Very severe congestion (BL-US score >60) was detected in 14% of patients.
Overall, 55% of patients had cardiovascular disease and 30% of patients had New York Heart Association (NHYA) class III-IV severe heart failure. But 71% of patients with moderate-to-severe lung congestion showed no or only mild symptoms of heart failure, the researchers note.
Multivariate analysis showed that BL-US scores significantly correlated with NYHA class and hemoglobin level, after adjusting for confounders such as age, gender, cardiovascular disease, and diabetes.
Compared with patients with no or mild congestion, those with very severe congestion were 4.2 times more likely to die during a median of 21 months of follow up, after adjusting for NYHA class and other risk factors.
Patients with very severe congestion were also 3.2 times more likely to experience electrocardiogram-proven myocardial infarction, angina or arrhythmia, heart failure, pulmonary embolism, or sudden death suspected from cardiac causes.
Indeed, a 10-unit increase in BL-US was associated with a 6% increase for mortality and cardiac events, the researchers report in the Journal of the American Society of Nephrology.
There was also a significantly correlation between rising BL-US score and likelihood of admission to hospital, at 19 hospitalizations per 100 person-years for patients with score below 15 versus 50 hospitalizations per 100 person-years for those with scores above 60.
When lung US was added to classic risk factor scores for chronic kidney disease patients, including hypoalbuminemia, hyperphosphatemia, and inflammation, there was a 6% increase in the explained variation in death rate and 5% increase for rate of cardiovascular events.
Zoccali et al therefore recommend that the diagnostic benefits of BL-US be further investigated for patients undergoing hemodialysis.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lynda Williams, Senior medwireNews Reporter