Dialysis is a treatment for kidney failure. Often, it is the only thing that keeps the patient alive until a kidney becomes available for transplant. Generally, dialysis is started when the patient's renal function drops around 10 percent. Before that time, the patient should receive counseling so that he can learn about different modalities of dialysis and choose one that best fits his lifestyle.
Hemodialysis
Hemodialysis involves accessing a vein or artery, usually in the arm. Blood flows into a machine called a dialyzer that cleans the blood before returning it back to the patient's body. The patient is usually hooked up to the dialysis machine three or four times a week. Dialysis sessions may run between two and four hours, depending on the size of the person and how well she tolerates dialysis.
Vascular Access
Vascular access is essential to the success of hemodialysis. This term refers to how the the patient's veins and arteries are accessed to clean the blood. Since repeated needle sticks would eventually destroy veins, a fistula is created or a graft is surgically implanted before starting dialysis.
A surgeon creates a fistula by joining a vein and an artery in the patient's arm. The resulting structure grows much stronger and can be repeatedly accessed. A graft involves implanting a catheter under the skin in the arm. This graft can be stuck repeatedly by needles during hemodialysis.
Unlike fistulas, grafts are vulnerable to clotting and infection. For this reason, the National Kidney Foundation launched a special program called "Fistulas First" to educate patients as to the benefits of fistulas. Although fistulas must be created several months before dialysis begins, they are the preferred form of vascular access for hemodialysis.
Home Hemo
As of 2010, home hemo is becoming a popular form of hemodialysis. The patient is provided with a dialysis machine and is taught how to use it. Since the machine is in the patient's home, the patient can dialyze more frequently.
Home hemo is particularly attractive because dialysis has fewer side effects if done slower and more frequently. This is possible in a home setting. Some patients dialyze every night. in addition to enjoying being freed from the dialysis center, patients often feel substantially better and have better laboratory results.
Peritoneal Dialysis
Peritoneal dialysis provides an alternative to hemodialysis. The lining of the abdominal wall includes the peritoneal membrane or peritoneum. Instead of filtering blood from a vein or artery, a catheter is implanted in the patient's belly on one side of the peritoneal membrane. This catheter is used to introduce a dialysis solution. Waste products in the bloodstream pass through the peritoneum into the dialysis solution. After waiting a predetermined amount of time called the in-dwelling period, the patient removes the fluid from the belly.
Adding and removing the dialysis fluid is called performing an exchange. Exchanges can be performed manually several times a day according to a protocol called continuous ambulatory peritoneal dialysis. Alternatively, they can be performed at night while the patient is sleeping. Instead of performing the exchange manually, the patient hooks herself up to a machine called a cycler that circulates the dialysis fluid in and out of her belly. This protocol is called continuous cycler-assisted peritoneal dialysis.
Considerations
Regardless whether the patient elects hemodialysis or peritoneal dialysis, the procedure will be more successful if the patient tries to get enough exercise and watches his diet.
Prior to starting dialysis, most patients meet with a dietitian who advises them about what types of substances can be removed from the blood and how they should tailor their diet accordingly. Much of this advice is directly responsive to the patient's individual labs so different patients have different dietary restrictions. Heeding dietary advice is very important for dialysis patients because excess amounts of some minerals such as potassium can easily be fatal.
