Dialysis Overview:  Used when the kidneys fail to filter waste products from the blood.

1. Hemodialysis:

• Process:
  • Blood is removed from the patient via a catheter or arteriovenous shunt.
  • Blood is circulated through a dialysis machine containing a semi-permeable membrane.
  • Dialysate, containing bicarbonate buffer, removes waste products such as urea, creatinine, potassium, hydrogen ions, and excess salts.
  • After filtration, cleaned blood is returned to the patient.
  • Duration:  About 3-4 hours per session, 3 times a week.
• Complications:
  • Infection: Can occur at access sites.  Prophylactic antibodies are often used to prevent infection.
  • Blood clots: May form; heparin is used as an anticoagulant.
  • Vascular damage: Repeated access can damage vessels and scar the shunt.
• Advantages:  Can be performed at hospital or at home (with training).
• Disadvantage: Symptoms if too fast, hypotension, nausea, vomiting, muscle cramps, headache, chest pain, disequilibrium syndrome (decreased level of consciousness and papilledema, possible cerebral edema)

2. Peritoneal Dialysis:

• Uses the peritoneal membrane lining the abdomen as the filter.
• Process:
  • A catheter is inserted into the peritoneal cavity.
  • Dialysate (1-3L) is infused into the cavity and remains there for a set period (~4-6hrs).
  • Waste products diffuse across the peritoneal membrane into the dialysate.
  • The dialysate is then drained out, carrying away wastes.
• Benefits:  Can be done at home or at work or while sleeping.  Slower solute exchange, more comfortable.

3. Kidney Transplantation:

• Option for end-stage renal failure.
• Provides permanent solution; the person can live with one kidney (more than enough to sustain life).
• Post-transplant: Patients require lifelong immunosuppressants to prevent rejection.

Summary:

Dialysis options are lifesaving therapies for kidney failure, with hemodialysis being most common but requiring specialized equipment and sterile technique, and peritoneal dialysis offering more independence. Proper hygiene and anticoagulation are crucial for safety, and kidney transplantation remains the best long-term solution when feasible.