Low Blood Pressure During Dialysis May Lead to Clots

Blood clots at access points 2x more likely in dialysis patients with low blood pressure

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) It's been known that low blood pressure while undergoing kidney dialysis is linked to some nasty side effects. Now the risk of blood clots has been added to that expanding list.

Patients with low blood pressure who are receiving dialysis are at an increased risk for blood clotting at the site of where the patient's blood vessels are connected to the machine, known as the point of vascular access

"Take extra steps to manage your blood pressure before dialysis."

Dr. Tara Chang, lead study author and a Stanford University School of Medicine nephrologist, said an analysis showed the adverse consequence, emphasizing that without the vascular access, such patients would die.

Low blood pressure during dialysis has previously been linked to stroke, seizure, heart damage and death. Short term gastrointestinal, muscular and neurologic symptoms also may be present. Low blood pressure occurs in about 25 percent of all dialysis sessions.

Dialysis extends the lives of kidney failure patients by having their blood cleansed through an artificial kidney machine three or more times per week. The most common vascular access point is the fistula, which is surgically created from a patient's own blood vessels. The tubes that carry the blood to and from the machine are connected at this access point.

The access points don't last forever, and clotting is the primary access point complication that could lead to it closing.

Dr. Chang noted that many patients go through multiple access points on each arm, and sometimes the legs if needed after repeated failures in the arms. She said that when a patient runs out of access points, it becomes an emergency situation. This makes it especially critical to extend the life of access points.

The study drew results from the Hemodialysis study, which is a National Institutes of Health-sponsored randomized clinical trial that collected data from 1,846 patients on hemodialysis from 1995 to 2000. Investigators discovered that patients with the most frequent low blood pressure episodes during dialysis were twice as likely to have a clotted fistula than those with fewer episodes.

The research was published in the Journal of the American Society of Nephrology.

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Review Date: 
July 29, 2011
Last Updated:
July 31, 2011