NEPH 09: Dialysis

Learning Objective 1: Explain the treatment options for patients with ESRD.

Background

  • End-Stage Renal Disease (ESRD) occurs when the kidneys fail, defined as GFR < 15 mL/min/1.73 m² (Stage 5 CKD).

  • Without functional kidneys, waste products and fluid build-up must be managed through:

    1. Conservative Care: Symptom relief and comfort-focused care for those who opt against dialysis or transplant.

    2. Dialysis: Hemodialysis (HD) or peritoneal dialysis (PD) to filter blood and remove waste.

    3. Kidney Transplantation: Replacing a diseased kidney with a functional one from a donor, the preferred option for long-term outcomes.

Learning Objective 2: Describe the indications to initiate dialysis.

When to Start Dialysis?

  • Dialysis is usually initiated when symptoms of kidney failure are present or GFR drops below 5-10 mL/min/1.73 m², based on guidelines.

Indications:

  1. Clinical Symptoms:

    • Uremia (buildup of toxins causing confusion, fatigue, nausea, etc.).

    • Severe acid-base disturbances (e.g., metabolic acidosis with pH < 7.1).

    • Medically resistant electrolyte imbalances (e.g., hyperkalemia).

    • Intractable fluid overload or uncontrolled blood pressure.

    • Deteriorating nutritional status.

    • Cognitive impairment due to toxin buildup.

  2. Mnemonic for Indications:

    • Acidosis

    • Electrolyte abnormalities

    • Intoxications (e.g., salicylates, lithium poisoning).

    • Overload (fluid).

    • Uremia.

Key Evidence: IDEAL Trial

  • Found no survival benefit for early initiation of dialysis at GFR 10-15 mL/min/1.73 m² compared to waiting until GFR 5-7 mL/min/1.73 m².

Learning Objective 3: Illustrate key elements of hemodialysis (HD) and peritoneal dialysis (PD).

Hemodialysis (HD)

  • Blood is filtered outside the body using a machine and returned clean to the patient.

  • Mechanism: Removes waste (via diffusion) and excess water (via ultrafiltration).

Peritoneal Dialysis (PD)

  • Blood is filtered inside the body using the peritoneum (the lining of the abdomen).

  • Dialysis fluid is introduced, absorbs waste/toxins, and then drained.

Learning Objective 4: Distinguish advantages and disadvantages of HD and PD.

Hemodialysis Advantages

  1. Managed by trained healthcare providers.

  2. Higher efficiency for rapid toxin removal.

  3. Requires no home storage of supplies.

Hemodialysis Disadvantages

  1. Requires travel to a dialysis center.

  2. Schedule rigidity (e.g., thrice-weekly sessions).

  3. Risk of hypotension, vascular access complications, and “washed-out” feelings.

Peritoneal Dialysis Advantages

  1. Performed at home; flexible scheduling.

  2. Better preservation of residual kidney function.

  3. Fewer dietary restrictions.

  4. Minimally invasive delivery of medications (e.g., antibiotics).

Peritoneal Dialysis Disadvantages

  1. Risk of peritonitis (infection).

  2. Patient/caregiver burnout due to daily exchanges.

  3. Potential hyperglycemia and hyperlipidemia from the glucose-based fluid.

Learning Objective 5: Discuss potential complications with HD and PD.

Hemodialysis Complications

  1. Infectious: Sepsis, vascular access site infections.

  2. Mechanical: Thrombosis or stenosis of access sites.

  3. Metabolic: Electrolyte imbalances, such as hypokalemia.

  4. Other: Hypotension, cramping, dialysis disequilibrium syndrome.

Peritoneal Dialysis Complications

  1. Infectious: Peritonitis, exit-site infections.

  2. Mechanical: Hernias, catheter blockages, fluid leaks.

  3. Metabolic: Hyperlipidemia, hypokalemia, glucose intolerance.