Congestive heart failure (CHF) and pulmonary hypertension are well-known complications of high-flow hemodialysis access. Although ‘high flow’ is subjective, since every patient has a threshold of access flow that will induce such failure (as well as distal extremity ischemia), Fistula First uses a minimal threshold of 2 L/min flow to refer the patient for cardiac evaluation.

This is an often-overlooked cause of left ventricular hypertrophy (LVH) and congestive heart failure — and any hemodialysis patient with a history of CHF or progressive LVH, should absolutely have access flow measured. When unrecognized, many of these patients with recurring CHF will die from their access-induced heart disease, since the cause was not recognized, and only gets worse.

The advent of accurate non-invasive measurement by ultrasound saline dilution has made it possible to measure access flow, which has permitted a number of studies that confirms the correlation between cardiac output and access flow. Access flow is usually approximately 20 percent of cardiac output. As access flow increases, so does cardiac output.

The only reason that this problem is not seen in many patients is because only a small proportion of patients have access flow approaching or greater than 2 L/min. Certainly, any patient developing LVH or CHF after starting HD should have the access flow measured. One of the reasons I strongly urge use of access flow surveillance, is because it provides so much information. Spergel LM, MD, FACS

References:

1 http://www.fistulafirst.org/Professionals/FrequentlyAskedQuestions.aspx#Q5

2 Spergel LM, “Transonic Flow Surveillance - The Cornerstone of My Vascular Access Management Program (VAMP)” or Clinical Applications of the Transonic Flow Monitor in the Hemodialysis Facility. (Transonic Focus Note # HD58)