Catheters Can Be Killers for Kidney Patients

Dialysis patients using catheters may have high risk of heart problems and death

(RxWiki News) Kidney disease patients often require dialysis. If this procedure is done with a catheter, however, it may increase the risk of death and heart problems.

For many patients with kidney failure, the blood must be filtered outside the body to eliminate waste and unwanted water—a process known as dialysis.

To carry out this process, a patient is often connected to a dialysis machine through a catheter. However, other types of vascular access may lower the likelihood of death, infection and cardiovascular events, according to new research.

"Find out the risks of dialysis with a catheter."

Pietro Ravani, MD, of the department of medicine at University of Calgary, Canada, led the study and has a special interest in outcomes of vascular access for hemodialysis.

Based on their review of 67 studies with a total of 586,337 participants, Dr. Ravani and his colleagues assessed the safety of different methods used to access blood for dialysis.

One type of vascular access is an arteriovenous fistula. As the name arteriovenous suggests, this a surgical connection of an artery to a vein; usually in the arm. This connection—called a fistula—creates an area of rapid blood flow where the blood can then be directed through a dialysis machine under higher pressure.

Two needles are inserted into the fistula—one to draw blood and one to return it. The National Kidney Foundation (NKF) has called arteriovenous fistula the best type of access for dialysis.

An arteriovenous graft is similar to a arteriovenous fistula, except that the artery and vein are surgically connected with an artificial vessel, or tiny tube. The NKF recommends this approach next after fistula.

Catheter is the third common type of access to the blood. A dialysis catheter is a soft tube that is placed in a large vein, sometimes in your neck or in a large vein under the collar bone.

A catheter has two openings inside. One is a red (arterial) opening to draw blood from your vein and out of your body into the dialysis pathway. The other is a blue (venous) opening that allows cleaned blood to return to your body.

Compared with individuals who had fistulas, catheter patients had a 38 percent higher risk of experiencing a major heart-related event, a 53 percent higher risk of dying and more than double the risk of developing fatal infections.

Compared with individuals with fistulas, those with grafts had an 18 percent increased risk of dying and a 36 percent increased risk of developing fatal infections, but they did not have an increased risk of experiencing a major heart-related event.

Investigators noted that patients in these studies did not have a similar health status—those using catheters were likely sicker than those with fistulas.

Many patients use a catheter instead of fistula or graft methods for several reasons, including avoidance of surgery and fear of needles. Attachment to the dialysis machine with a catheter does not require needles. Also, an arteriovenous fistula or graft is not possible in all patients, especially those who are sicker.

"Our findings are reflected in current clinical practice guidelines, which promote fistulas as the preferred form of bloodstream access in hemodialysis patients,” said Dr. Ravani.

The study was published February 21 in the Journal of the American Society of Nephrology. The work was supported by a grant from the University of Calgary through an unrestricted educational grant from Diaverum, a provider of kidney services.

Review Date: 
February 19, 2013