Patient Overview and Types of Dialysis

  • Two patients referenced concerning acute renal failure.

Hemodialysis

  • Definition: A method of dialysis where blood is filtered outside of the body.
  • Function of Nephrons:
    • Nephrons are the functional units of the kidneys.
    • Approximately 80% nephron failure means significant kidney dysfunction.
Importance of Kidneys
  • Major Functions of the Kidneys:
    • Filter and remove waste from the blood.
    • Produce urine.
    • Regulate blood pressure.
    • Maintain fluid and electrolyte balance.
    • Produce hormones (like erythropoietin).
  • Consequences of Kidney Failure: If kidneys cannot perform these functions, dialysis becomes mandatory for survival.
Process and Setting of Hemodialysis
  • Schedule: Typically done three times a week, each session lasting 3-4 hours.
  • Location: Conducted in outpatient dialysis centers or hospitals.
  • Access Method:
    • Patients often use a custom access point like a fistula or a graft.
Indications for Hemodialysis
  • Symptoms of kidney failure include:
    • Edema (swelling)
    • Difficulty breathing
    • Fatigue

Fistula

  • Definition: A surgically created connection between an artery and a vein.
  • Characteristics:
    • High-pressure vessel ideal for dialysis access.
    • Causes an integral 'thrill' or vibration felt upon palpation.
  • Assessment:
    • Nurses should check for thrill (palpable vibration) and bruit (audible sound through stethoscope) before dialysis to ensure it’s patent:
      • Thrill: A disturbance of blood flow felt as a vibration.
      • Bruit: An abnormal sound indicating proper blood flow.
  • If these aren't present, it may signal clotting, necessitating further medical intervention.

Graft

  • Definition: An artificial tube connecting an artery and a vein used when blood vessels are inadequate for a fistula.
  • Material and Use: Made from synthetic material; serves the same purpose as a fistula but may not encourage natural blood vessel growth.

Special Patient Care Considerations

  • With Fistula and Grafts:
    • Avoid taking blood pressure or drawing blood from the arm with the fistula or graft to prevent complications.
  • Patient's Comfort: Some patients express discomfort or experience complications, and these must be monitored.
  • Body’s Adaptation: Body may develop collateral circulation (new blood vessels) around the site post-surgery.

Hemodialysis Catheter

  • Temporary access for hemodialysis, usually inserted in the right side of the chest.
  • Comparison: Heavier and sturdier than standard central lines to handle high-pressure blood flows.
  • Purpose: Facilitates dialysis while longer-term access is created (e.g. fistula or graft).
Side Effects and Complications of Hemodialysis
  • Most common side effect: Hypotension (low blood pressure).
  • Additional possible side effects include:
    • Muscle cramping
    • Electrolyte imbalances
    • Infection risks due to catheter use.

Peritoneal Dialysis

  • Definition: A dialysis method involving the peritoneal cavity utilizing the peritoneum as a membrane to filter blood.
  • Ideal Candidates: Patients unable to visit dialysis centers for traditional hemodialysis.
  • Procedure: Large bags of dialysis solution are hung and fluid is exchanged, with the waste filtered through the peritoneum.
  • Duration: Average session takes about 12 hours.
Drainage Assessment
  • Hospital staff should assess the drainage bag:
    • Signs of Concern: Large amounts of blood or cloudy drainage may indicate infection (peritonitis).
Infection and Peritonitis
  • Common infection risk: Peritonitis (inflammation of the peritoneum), often requires discontinuation of peritoneal dialysis.

Dialysis Types According to Renal Failure

Chronic Renal Failure
  • Treatment Options:
    • Hemodialysis
    • Kidney transplant
  • Patients decide on dialysis type based on lifestyle compatibility.
Acute Renal Failure
  • Types of Dialysis Used:
    • Continuous Renal Replacement Therapy (CRRT):
      • Continuous process, typically run in ICU settings for hemodynamically unstable patients.
      • Smaller amounts of fluid processed continuously to avoid strain on patient’s cardiovascular status.
    • SLED (Sustained Low-Efficiency Dialysis):
      • Intermittent but not continuous, done over longer periods (8-12 hours) to allow breaks for patients.

Lab Tests for Renal Patient Monitoring

  1. Basic Metabolic Panel (BMP):
    • Tests electrolytes, BUN, creatinine, glucose.
  2. Comprehensive Metabolic Panel (CMP):
    • BMP + albumin and liver function tests.
    • More comprehensive insights into patient health, particularly with liver risk.
  • These tests are routinely performed for ongoing monitoring or before dialysis sessions.