By Laura Troidle, PA

In 2006, 353,836 patients with chronic kidney disease (CKD) started kidney replacement therapy (dialysis) (2008 USRDS report). In starting the dialysis process patients are confronted with a variety of issues related to their health. One choice patients must consider is the type of dialysis to perform.

Since dialysis was first offered to all patients with end-stage renal disease (ESRD), two main types of kidney replacement therapies have emerged. Patients choose either in-center hemodialysis (HD) or out-patient peritoneal dialysis (PD). Now there are many other therapies that are variants of these two main types to consider, each with its own advantages and disadvantages. For patients confronted with selecting a particular therapy, it is important to keep in mind the aspects of each therapy and how it may impact the patient’s overall quality of life. And, it is important to physically prepare for the type of dialysis desired.

Dialysis Types Overview Hemodialysis
The most common type of dialysis in the United States is HD. Greater than 90 percent of the ESRD patients in the United States are maintained on HD. HD is typically performed at a HD center with other patients. Treatments are initiated by placing two needles into an arteriovenous fistula (also known as a shunt). Tubing is then connected to each needle and the patient’s blood is continuously filtered through a dialysis machine with excess water and waste products removed and “clean” blood continuously returned back to the patient. These treatments last for 3.5 to 5 hours.

Traditional HD has expanded its menu for ESRD patients. Patients may now choose incenter nocturnal HD for longer treatment times (typically eight hours overnight at an in-center HD unit) as well as home HD where the patient provides his/her own HD therapy at home under his/her own assistance. Patients maintained on long (eight hours) in-center nocturnal HD have been shown to have a significantly lower mortality than patients maintained on conventional HD (of three to four hours). And, the patients maintained on eight-hour treatments have better control of dietary parameters, including phosphorus, as well as better blood pressure control and possibly better quality of life. However, no head to head studies have confirmed these findings yet.

Home HD therapy allows the patient to independently perform the HD treatment at home under his/her own care. These treatments are generally performed up to six nights per week for two to three hours each treatment. Supervision by another trained adult is necessary in the event of an emergency at home. Home HD treatments are gaining popularity in the United States. Many studies show significant advantages of daily treatments over intermittent, thrice weekly treatments.

Considerations
Patients opting for HD need to consider placement of the fistula early on in the course of their CKD. The Kidney Dialysis Outcomes and Quality Initiative (KDOQI) suggest patients be referred to a vascular access center during CKD stage 3 or 4. The fistula is usually placed in the non-dominant arm. Thus, patients need to avoid venous puncture or intravenous procedures in the non-dominant arm once the patient is identified as at risk for needing dialysis. The fistula takes about 90 days on average to develop adequately for use of HD treatment.

Unfortunately, for some patients it is necessary to have a central venous catheter when starting HD. Some patients have an acute change in their kidney function that requires an immediate need for HD. Other patients do not arrive at ESRD prepared with a fistula for a variety of reasons and need urgent access. Thus, a central venous catheter is necessary to achieve urgent access in these patients. That said, it is preferable to plan on a fistula early on in the course of CKD to avoid a situation where the patient needs a catheter to start dialysis. And, patients using a central venous catheter to initiate HD should have plans for fistula placement immediately after starting HD with a catheter.

It is critical patients understand the importance of starting HD with a functioning fistula at the first HD treatment. Outcome studies have provided strong evidence that patients starting HD without a functioning fistula have a significantly higher rate of complications including death in the first year of HD than do patients starting HD with a fistula. HD with a central venous catheter is associated with many different complications. The most common complication is infection with bacteria in the blood stream (sepsis). These infections carry a high mortality rate and threaten patients with serious complications such as heart valve infections (endocarditis), spinal abscesses and infections in other parts of the body, such as joints, which are difficult to treat. In other patients catheter use can cause blockages in the blood vessels which can lead to disfiguring facial, neck and arm swelling, and ultimate catheter malfunction. Thus, it is most prudent for patients approaching dialysis to plan on getting a fistula placed prior to starting HD.

As far as deciding on conventional in-center, longer (eight hour) in-center or home HD therapy it is also necessary to consider how the therapies will impact your quality of life. Patients need to consider whether assisted therapy at an in-center unit is preferable over doing the therapy at home with family members or friends. Patients should also consider the social impact of each therapy. Some patients prefer to be at an HD center because of the desire to be with other patients and staff. Some patients desire a more private setting at home at his/her own convenience. It is important to keep in mind patients performing HD at home need to have another adult nearby in the event of an emergency.

Peritoneal Dialysis
Continuous PD (CPD) is an alternative to HD therapy. In contrast to HD, this therapy requires a peritoneal catheter placed into the patient’s peritoneum for access. Access is not via the blood stream. A dextrose (sugar) based solution is then infused by the patient via the peritoneal catheter. After a few hours the fluid is drained from the patient, carrying excess water and waste products with it. Patients must perform this around the clock therapy each day. For convenience, continuous cycling peritoneal dialysis uses an instrument called the automated cycler. The cycler is pre-programmed to provide the necessary dialysis each night as the patient sleeps.

Patients choosing to undergo PD therapy are trained in an out-patient setting by a nurse. Patients are allowed to perform treatments at home once a training period is completed. PD supplies are delivered directly to a patient’s home by the dialysis company. Patients are required to have a clinic appointment with their doctor every six weeks or as needed.

Considerations
Patients opting for CPD should consider the need to perform this technique on a daily basis. Once a peritoneal catheter is placed, the catheter can be used immediately. However, most clinicians prefer waiting two weeks for the catheter exit site to heal. Patients and their support systems need to be committed to doing CPD in order for this therapy to be effective. Patients in whom the procedure is burdensome will have difficulty performing CPD therapy daily.

Some complications involving PD include infection of the abdominal cavity (peritonitis), mechanical problems such as leaking or poor draining, and abdominal/pelvic hernias. Most of these complications, including infections, may be treated on an out-patient basis. Allowing for the catheter exit site to heal for several weeks after placement prior to starting PD does reduce the risk of these complications.

Conclusion
Patients with CKD facing the need to start dialysis are faced with many issues including choosing the type of dialysis to perform. No one type of dialysis is superior. Individual patient characteristics may lead to a preference of a particular type of dialysis. However, it is necessary for patients to be ready to start a particular type of dialysis with a functional access be it a fistula for HD or a peritoneal catheter for PD for the best outcome. Knowledge and preparation are the cornerstones for a smooth transition to dialysis therapy.

Laura Troidle, PA, is a graduate of the Yale University Physician Associate Program. She’s worked for the for the Metabolism Associates in New Haven, Conn., since 1991. She’s a member of the American Association of Nephrology PAs, International Society of Peritoneal Dialysis and has published extensively on a variety of dialysis related (HD and PD) topics.

This article originally appeared in the March 2009 issue of Kidney Beginnings: The Magazine.

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