Dialysis: answers to commonly asked questions

What is dialysis?

Dialysis is a procedure that supports kidneys when they have failed. It is considered life sustaining therapy. When kidneys fail, toxins can build up in the body that cannot be cleared with medications alone. Kidney failure can lead to complications such as hyperkalemia (high potassium), acidosis (acid build up in the body), and volume overload (fluid building up in the body that cannot be excreted in the form of urine). Dialysis comes in various forms and can help manage these complications as well as prolong life.

Who needs dialysis?

Patients may require dialysis to manage complications of progressive chronic kidney disease that can no longer be managed by medications and diet. A patient could require dialysis in the acute setting temporarily if the kidneys have a chance of recovering. Dialysis is most often provided chronically long-term, which would then be lifelong. Here, we discuss dialysis specifically for patients who have end stage renal disease (ESRD). There are 5 stages of kidney disease. The 5th stage most often precedes kidney failure when kidneys no longer work to manage electrolytes, blood pressure, acid base status and volume. The 5th stage is when complications of kidney disease can become more apparent and difficult to medically manage. When complications can no longer be managed medically, we say the patient has ESRD and would need to start life sustaining dialysis. Some symptoms of ESRD include swelling in hands and feet due to volume overload, shortness of breath, loss of appetite and fatigue from toxin build up, acid accumulation in the body, high blood pressure, anemia, kidney-related bone disease and tremors. These symptoms would be managed by initiating dialysis. The kidney stage alone does not dictate when to initiate dialysis. The nephrologist, a board-certified physician trained in managing kidneys, reviews blood tests, blood pressure, the patient’s volume status and the patient informs their doctor of how they feel. Dialysis initiation is a conversation between a nephrologist and the patient. Prior to starting dialysis, the patient will typically have frequent office visits and discussions with their nephrologist to review labs and if needed, determine the best type of dialysis, as well as when and how to start.

What options currently exist to do dialysis and how does dialysis work?

There are generally two types of dialysis that can be performed in those with end stage kidney disease: hemodialysis and peritoneal dialysis.

Hemodialysis requires access to the bloodstream to clear toxins and remove fluid if needed. Access to the bloodstream comes in the form of a dialysis fistula or dialysis graft, usually placed by a vascular surgeon in the patient’s arm. Surgery is required for either method and involves communication and planning amongst the patient, nephrologist and vascular surgeon. A fistula connects the patient’s own artery and vein to each other to allow for needles to be inserted for dialysis. A dialysis graft connects the patient’s vein and artery but requires foreign material for the connection to take place. Once a patient has a functional fistula or graft, typically 6-16 weeks after fistula surgery and sooner for a graft, 2 needles are inserted into the arm access to perform dialysis. Blood is pumped out from one needle so that it may reach the dialysis filter in the dialysis machine to clean blood of toxins, correct electrolyte imbalances and pull out fluid if a patient is volume overloaded. The cleaned blood then goes back into the patient’s body through the other needle. If a patient needs dialysis suddenly, or because a fistula or graft are not ready for use, a dialysis catheter is placed. The dialysis catheter is usually placed in a large vein in the neck or chest. Dialysis catheters are considered temporary as they can lead to infection, often clot, and lead to lower blood flows causing ineffective dialysis sessions. Fistulas or grafts are preferred for patients on chronic dialysis for end stage renal disease.

One type of hemodialysis is in-center hemodialysis. Patients receive 3-4 hour pre-scheduled dialysis sessions, typically three times per week. Dialysis is performed through a fistula, graft or dialysis catheter at a specialized center called a dialysis unit. Dialysis technicians, social workers, dieticians, dialysis nurses and nephrologists all work together to take care of patients while they are receiving dialysis at the dialysis unit.

Home hemodialysis is performed just as in-center hemodialysis, but the patient must learn to connect the dialysis machine to needles in the fistula or graft at home. This involves a period of training with a dialysis nurse at a dialysis center. The number of nights and number of hours can vary person to person as everyone’s needs for effective dialysis can vary. Patients on home hemodialysis must still come to monthly appointments at a dialysis center for monitoring of their dialysis efficacy and bloodwork. Sometimes, more frequent appointments are required if the patient needs help or dialysis is ineffective.

Peritoneal dialysis (PD) is another method of doing dialysis at home, but it does not require access to the bloodstream. Instead, a plastic tube called a peritoneal catheter is usually placed in the abdominal cavity to perform peritoneal dialysis. In some cases, peritoneal dialysis is initiated immediately or urgently after the catheter is placed in a hospital setting. Other times, the peritoneal dialysis catheter placement is scheduled with a surgeon or interventional radiologist. Instead of performing dialysis through a filter outside the body as with hemodialysis, the lining inside the patient’s abdomen acts as a natural filter. Once a peritoneal dialysis catheter is ready for use, PD training can be initiated. This usually lasts 5-7 days until the patient has learned and demonstrated competency. After training is complete, PD is performed at home: Sterile fluid is put through the catheter into the abdominal cavity. It remains in the cavity for a period of time and is then drained back out. This process of dwelling and draining allows for toxins to be filtered and fluid to be removed from the patient’s body. PD can be performed with the help of a machine overnight or without a machine, with manual exchanges during the day while awake. The overnight PD machine allows patients to connect prior to bed, and the machine does the work of draining and dwelling the fluid. The best choice of overnight, daytime manual exchanges or combination of both is determined by a conversation amongst the nephrologist, dialysis nurse and the patient. Patients on PD must come to a dialysis unit for regular follow up monthly just like patients who perform home hemodialysis.

Conclusion

It is important to have regular kidney health monitoring by your primary care doctor. If kidney related abnormalities are noted by the patient or their physician, they should be addressed early and consideration for consultation with a nephrologist may be warranted. If a patient is already seeing a nephrologist, the patient will be updated on their kidney function at each visit. If a patient has late stage chronic kidney disease and/or nearing end stage renal disease, the nephrologist will educate the patient and ensure the patient is aware of the best choice for them if they should need dialysis through open communication. Primary care doctors and nephrologists can work together to promote kidney health in the community.