Dialysis

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Definition | Body Parts Involved | Reasons for Procedure | Complications | What to Expect | Outcome | Call Doctor If

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Definition

Dialysis is a procedure that replaces natural kidney function when kidneys fail. Most patients begin dialysis when their kidneys have lost 85% - 90% of their ability to function, and will continue dialysis for the rest of their life; this is called "end-stage renal disease" (ESRD). ESRD may be caused by a variety of conditions that can impair kidney function, including diabetes, kidney cancer, drug use, high blood pressure, or other kidney problems.

There are two types of dialysis: hemodialysis and peritoneal dialysis.

Parts of the Body Involved

Hemodialysis: Veins in the arm, leg, or neck

Peritoneal dialysis: Abdomen

Reasons for Procedure

The purpose of dialysis is to help keep the body's chemistry in balance, which the kidneys do when they are healthy. The main functions of dialysis are:

• Removing waste and excess fluid from the blood to prevent build-up
• Controlling blood pressure
• Keeping a safe level of chemicals in the body, such as potassium, sodium, and chloride

Dialysis may also be done to quickly remove toxins from the bloodstream, in cases of poisoning or drug overdose.

Risk Factors for Complications during the Procedure

Hemodialysis: Heart problems

Peritoneal dialysis:

• Adhesions or significant abdominal scar tissue
• Abdominal hernia
• Diverticulitis
• Abdominal defects

What to Expect

Prior to Procedure

Hemodialysis:

• Weight, blood pressure, and temperature are taken
• Topical anesthetic is applied to the arm for needle insertion
• Heparin (a medication that prevents blood clotting) is given

Peritoneal dialysis: Before the first treatment, the physician places a small, soft tube (approximately 24 inches long) in the abdomen, which remains there permanently. A portion of the tube remains outside the body for use in the peritoneal dialysis process. It is important to keep this access clean and dry to prevent infection.

Anesthesia - For hemodialysis, topical anesthetic

Description of the Procedure

Hemodialysis: An artificial kidney machine, called a dialyzer, filters the blood, and returns the cleaned blood to your body. You are connected to the dialyzer via tubes that are inserted through a vein in your arm, leg, or occasionally, neck. If hemodialysis is being performed as a temporary measure, then the catheter is likely to be inserted through the neck vein. If hemodialysis is going to be done regularly, then an access site called a fistula or shunt may be surgically created in one of your veins. Hemodialysis is usually done at a dialysis center or hospital, or may be done at home with assistance.

Peritoneal dialysis: Instead of using a machine, this type of dialysis uses the abdominal lining, called the peritoneal membrane, to filter blood. A cleansing solution, called a dialysate, is infused through a tube inserted into your abdomen. Long-term peritoneal dialysis may require the surgical creation of a port in the abdomen through which this dialysate can be infused. Fluid, wastes, and chemicals pass from the tiny blood vessels in the peritoneal membrane into the dialysate, which is then drained. New dialysate can then be added to repeat the process.

There are three types of peritoneal dialysis:

1. Continuous ambulatory peritoneal dialysis (CAPD): The most common type. A bag of dialysate is infused into the abdomen through a catheter, remains there for 3-6 hours, and is then drained. No machine is required, and the empty plastic bag may be hidden under clothing.
2. Continuous cyclical peritoneal dialysis (CCPD): Fluid exchanges in this procedure are done by machine, usually at night while sleeping.
3. Intermittent peritoneal dialysis (IPD): Uses the same type of machine as CCPD, but requires assistance and is usually done at a hospital or center.

After Procedure - Once blood pressure is stable, you may resume everyday activities.

How Long Will It Take? The time needed for dialysis depends on a few factors:

• How well your kidneys function
• How much fluid weight gain has occurred since the last treatment
• Amount of waste in the body
• Body size
• Dialysis method used

The approximate time and frequency of each method:

Type	Length of procedure	Frequency of procedure
Hemodialysis	2-4 hours	3 times/week
CAPD	3-6 hours, plus 30 minutes to drain	4 times/day
CCPD	9-12 hours	Every night
IPD	12 + hours	36-42 hours/week

Will It Hurt? In general, dialysis procedures do not cause pain, and you will not feel the blood exchange. There may be some temporary discomfort with the insertion of the needle or tube.

Possible Complications:

• Anemia
• Drop in blood pressure during dialysis
• Muscle cramps
• Nausea, vomiting
• Headaches
• Infection
• Feeling hot, sweaty, weak, and/or dizzy
• Peritonitis (infection of the peritoneum), which causes fever and stomach pain (peritoneal dialysis only)
• Growth problems in children
• Inflammation of the heart sac (pericarditis)
• Neurological problems
• Disruption of calcium and phosphorus balance, resulting in weakened bones

Average Hospital Stay – None. Dialysis is typically done at an outpatient dialysis center or at home.

Postoperative Care - Once the hemodialysis procedure is completed and blood pressure is stabilized, you are free to continue daily activities. There are some special considerations, though:

Dietary Guidelines Dialysis patients should follow certain dietary guidelines at all times to maintain health and optimize the dialysis process. Patients who have peritoneal dialysis may have slightly fewer dietary restrictions than hemodialysis patients, due to the more frequent peritoneal dialysis schedule. Your doctor and a dietitian will tailor the dietary guidelines to meet your specific needs. The factors you need to pay most attention to include protein, potassium, phosphorous, fluid, sodium, and total calories.

Medications Your doctor may prescribe various types of medication. These include, but are not limited to:

• Blood pressure medications
• Calcium supplements or multivitamins
• Phosphorus binders - to lower phosphorus levels in the blood
• Diuretics - to remove excess fluid
• Stool softeners or laxatives - to prevent or treat constipation, which can be caused by decreased fluid intake
• Iron supplements - to increase iron intake, which is important for production of red blood cells

Outcome

Dialysis helps maintain blood pressure, cleaning of the blood, and chemical and hormonal exchanges that are critical to survival.

Call Your Doctor If Any of the Following Occurs

• Signs of infection, including fever and chills
• Redness, swelling, increasing pain, excessive bleeding, or discharge at the catheter or tube insertion site
• Blood or cloudiness in the peritoneal dialysis fluid
• Nausea or vomiting
• Abdominal pain
• Dizziness or weakness

SOURCES:

National Diabetes Information Clearinghouse (NDIC)

National Kidney Foundation

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Last reviewed March 2001 by Medical Review Board