New Clue May Explain Residual Renal Function Loss in HD Patients
Small study implicates a fall in renal perfusion during hemodialysis.
CHICAGO—Decreased renal perfusion during hemodialysis (HD) could explain the loss of residual renal function (RRF) observed in HD patients, according to new study findings presented at the American Society of Nephrology's 2016 Kidney Week meeting.
“An acute drop in renal perfusion is observed during HD and is related to demonstrable organ injury in another vulnerable vascular bed,” investigators concluded in a poster presentation. “Cumulative exposure to circulatory stress may be a key pathophysiological factor in the loss of RRF observed in HD patients. Longitudinal studies are needed to examine whether amelioration of circulatory stress during HD helps to preserve RRF.”
In a study of 12 HD patients with a urine output less than 500 mL per 24 hours, a team led by Christopher W. McIntyre, MD, of the University of Western Ontario in London, tested whether intradialytic circulatory stress results in significant ischemic challenge to the remnant kidneys. The patients underwent renal imaging before, during, and after a dialysis session. Investigators used a novel dynamic-contrast imaging algorithm in conjunction with a latest-generation 256-slice computed tomography scanner to evaluate renal perfusion. They used echocardiography at baseline and prior to the end of dialysis to detect myocardial stunning, as a reference organ system for ischemic response to HD-induced circulatory stress, Dr McIntyre and his colleagues explained.
Baseline renal perfusion was markedly reduced (48.2 mL/min/100g) compared with normal control values. HD resulted in significant reduction in renal perfusion to 25.9 mL/min/100g at peak stress (3 hours), the researchers reported. Of the 11 patients in whom perfusion fell, 10 also exhibited myocardial stunning (more than 2 segments with greater than 20% reduction in longitudinal strain). The investigators did not observe stunning in the 1 patient whose renal perfusion did not fall.
- Marants R, et al. Renal perfusion falls during hemodialysis: An explanation for the loss of residual renal function in dialysis patients. Poster presented at the 2016 Kidney Week meeting in Chicago, Nov. 15-20. Poster TH-PO997