Chapter_051 FA24

Chapter Overview

• Acute Kidney Injury and Chronic Kidney Disease

  • Focus on the implications of kidney failure on individuals

  • Treatment approaches and patient quality of life considerations

Kidney (Renal) Failure

• Definition: Impairment of kidney functions leading to difficulty in metabolic waste and water excretion

• Impact: Affects all body systems, requiring complex treatments and dietary management

• Lifestyle Effects: Notable impacts on occupation, family dynamics, and self-perception

Dialysis Overview

• Definition of Dialysis: Movement of fluids/molecules across a semipermeable membrane to address kidney failure

• Purpose: Corrects fluid and electrolyte imbalances, and removes waste products—can also treat drug overdoses.

Methods of Dialysis

• Two primary methods:

  • Peritoneal Dialysis (PD)

  • Hemodialysis (HD)

• Initiated when conservative treatment is ineffective; typically when GFR is < 15 mL/min/1.73 m².

• Decision to start dialysis is made by a nephrologist based on uremic symptoms.

Dialysis Candidacy

• End-Stage Renal Disease (ESRD): Treatment with dialysis due to:

  • Limited organ donation availability

  • Patient ineligibility for transplantation

  • Patient preference against transplantation

• Age: Not a determining factor for eligibility.

General Principles of Dialysis

Diffusion

• Process where solutes move from areas of high to low concentration

Osmosis

• Fluid movement from areas of low solute concentration to high.

• Utilization of glucose in dialysate to create osmotic gradients that draw fluids from the blood.

Ultrafiltration

• Removal of water and fluids driven by osmotic or pressure gradients across the membrane.

  • PD and HD: Utilize different mechanisms for fluid movement (glucose for PD, pressure for HD).

Peritoneal Dialysis (PD) Technique

• Access Method: Catheter placement via the anterior abdominal wall, typically surgically.

• Key Techniques: Aseptic methods crucial to avoid peritonitis post-catheter insertion.

• Dialysis Cycle: Three phases in manual PD—Inflow, Dwell, Drain, repeated as exchanges based on peritoneal cavity size; usually involves dextrose as an osmotic agent.

Hemodialysis (HD)

• Requires vascular access—mainly arteriovenous (AV) fistulas or grafts

• Access Types:

  • AV fistulas: Preferred, created in forearm; needs maturation.

  • AV grafts: Made from synthetic materials, for patients where fistulas are unsuitable.

  • Temporary vascular access: Catheters for immediate access, highest infection risk.

Hemodialysis Procedure

• Pre-Treatment Assessment: Check patient's fluid status, assess vascular access, and monitor vital signs.

• Dialyzer Function: Semipermeable membranes perform ultrafiltration, diffusion, and osmosis.

• Post-Treatment Management: Ensure proper flushing to clear the system of air and return all blood.

Complications of Dialysis

Hemodialysis Complications

• Potential for hypotension, muscle cramps, and blood loss.

• Infectious risks, particularly hepatitis; necessitates strict infection control measures.

Peritoneal Dialysis Complications

• Risks include infections (exit site and peritonitis), hernias, pulmonary complications, and protein loss from body.

Continual Renal Replacement Therapy (CRRT)

• Alternative method for treating patients with acute kidney injury requiring hemodynamic stability.

• Various forms including:

  • Continuous venovenous hemofiltration (CVVH)

  • Slow continuous ultrafiltration (SCUF)

  • Continuous venovenous hemodialysis (CVVHD)

• Advantages over traditional HD include reduced hemodynamic instability.

Innovations in Dialysis

• Development of miniaturized wearable artificial kidneys to enhance patient control and independence.

Nutritional Considerations

• Patients undergoing peritoneal dialysis need increased dietary protein and caloric intake due to losses during the dialysis process.