When kidneys can no longer filter waste and excess fluid from the blood, dialysis becomes necessary. This condition, known as kidney failure, means the body struggles to maintain a healthy balance of fluids, electrolytes, and minerals. Dialysis performs these functions, preventing harmful substance buildup and regulating blood pressure. It is not a cure for kidney disease, but it allows individuals to live longer and maintain a better quality of life.
Understanding Dialysis Options
Dialysis offers two primary methods for filtering the blood: hemodialysis and peritoneal dialysis. Each uses different mechanisms to remove waste and balance fluid. The choice between them often depends on individual health, lifestyle, and preferences.
Hemodialysis involves circulating blood outside the body through an artificial kidney, known as a dialyzer. The machine filters waste and excess fluid, returning cleaned blood. It can be performed in a dialysis center, typically three times a week for about 4 hours, or at home with training. Home hemodialysis offers flexibility, with options for shorter daily sessions (5-7 times a week for 2-4 hours) or longer nocturnal sessions (3-6 times a week while sleeping).
Peritoneal dialysis uses the body’s own peritoneal membrane, the lining of the abdomen, as a natural filter. A sterile dialysis solution, dialysate, is introduced into the abdominal cavity through a catheter. Waste and extra fluid from blood vessels lining the peritoneum pass into this solution. After a “dwell time,” the used solution is drained and replaced with fresh dialysate.
It is typically performed daily at home, offering continuous filtration and often more dietary freedom than hemodialysis. Two main types exist: Continuous Ambulatory Peritoneal Dialysis (CAPD), a manual method with several daily exchanges, and Automated Peritoneal Dialysis (APD), which uses a machine, often overnight.
Preparing for Treatment
Before beginning regular dialysis treatments, individuals undergo preparatory steps for safe access to their bloodstream or abdominal cavity. For hemodialysis, vascular access creation is a surgical procedure. The preferred method is an arteriovenous (AV) fistula, which connects an artery directly to a vein, typically in the arm. This connection causes the vein to enlarge and strengthen over several weeks to months, making it suitable for repeated needle insertions.
If an AV fistula is not feasible, an AV graft may be created. This uses a synthetic tube to connect an artery and a vein, ready for use in about 2 to 3 weeks. In urgent situations, a temporary central venous catheter can be placed in a large vein (neck, chest, or leg), allowing immediate dialysis access while a permanent access matures. For peritoneal dialysis, a soft, flexible catheter is surgically placed into the abdomen, usually below the belly button. This catheter serves as the conduit for dialysate and typically requires 10 to 14 days to heal before treatment.
During a Dialysis Session
The experience during a dialysis session varies between hemodialysis and peritoneal dialysis. For in-center hemodialysis, patients typically visit a clinic three times a week. Two needles are inserted into the vascular access: one draws blood to the dialyzer (artificial kidney), and another returns filtered blood.
During the 3 to 5-hour session, the machine monitors blood pressure and the filtering process. While connected, patients usually sit or recline, and can read, watch TV, or sleep. Some may experience lingering fatigue, muscle cramps, or dizziness, particularly in early sessions, due to rapid fluid and waste removal.
Peritoneal dialysis sessions, or “exchanges,” are performed by the patient, often at home. Each exchange involves three steps: fill, dwell, and drain. First, dialysate flows into the abdominal cavity through the catheter.
The solution remains in the abdomen for a prescribed “dwell time,” typically 4 to 6 hours for CAPD, during which waste and excess fluid move into the dialysate. Finally, the used solution is drained from the abdomen.
Each manual exchange takes 30 to 40 minutes, with 3 to 5 exchanges typically performed daily. For automated peritoneal dialysis (APD), a machine handles exchanges, often overnight, for 8 to 12 hours.
Life Beyond the Treatment Chair
Living with dialysis requires adjustments to daily life and ongoing health management beyond treatment sessions. Many on dialysis experience side effects between sessions, such as lingering fatigue, muscle cramps, or itching. These symptoms often relate to toxin and fluid accumulation that dialysis cannot fully clear, or to shifts in body chemistry. Managing these side effects involves careful adherence to medication schedules and dietary guidelines.
Dietary considerations are a key part of living with dialysis. Patients face restrictions on fluid intake, and limits on potassium, phosphorus, and sodium to prevent buildups between treatments. A dietitian works with patients to create a meal plan balancing nutritional needs with these restrictions. Medication management is also important, as patients often take multiple prescriptions to manage blood pressure, anemia, bone health, and other conditions. Adjusting to a chronic condition like kidney failure and dialysis can involve emotional and psychological challenges, making support from healthcare teams, family, and support groups a valuable part of the journey.