Makindo Medical Notes.com

Related Subjects: |Respiratory Failure |Non invasive ventilation (NIV) |Haemodialysis |Cautions Renal Dialysis and Transplant Patients |Continuous Ambulatory Peritoneal Dialysis (CAPD)

Continuous Ambulatory Peritoneal Dialysis (CAPD)

Continuous Ambulatory Peritoneal Dialysis (CAPD) is a form of dialysis used to treat patients with kidney failure. It involves the use of the peritoneum in the abdomen as a membrane through which fluids and dissolved substances are exchanged with the blood. Here is an overview of the CAPD process, indications, and considerations.

Indications for CAPD

• Chronic kidney disease (CKD) stages 4 and 5, especially when haemodialysis is not suitable.
• Patients who prefer a home-based dialysis treatment.
• Individuals who have difficulty with vascular access for haemodialysis.
• Preference for a more flexible dialysis schedule.

The CAPD Process

• Access to the Peritoneal Cavity:
  • A permanent catheter (Tenckhoff catheter) is surgically placed in the lower abdomen.
• Dialysis Solution:
  • A sterile dialysate solution is infused into the peritoneal cavity through the catheter.
  • The solution typically contains glucose, which helps draw waste products and excess fluids from the blood into the peritoneal cavity.
• Exchange Process:
  • The dialysate remains in the peritoneal cavity for a specified dwell time (usually 4-6 hours).
  • During this time, waste products and excess fluids pass from the blood vessels in the peritoneum into the dialysate.
  • After the dwell time, the used dialysate, now containing waste products and excess fluids, is drained out and replaced with fresh solution.
• Frequency and Duration:
  • Typically involves four exchanges per day.
  • Each exchange takes about 30-40 minutes.

Complications and Management

• Peritonitis:
  • Infection of the peritoneal cavity, often caused by contamination during an exchange.
  • Symptoms include abdominal pain, cloudy dialysate, fever, and nausea.
  • Management includes antibiotics and proper aseptic technique during exchanges.
• Catheter-Related Issues:
  • Catheter blockage or displacement can occur.
  • Management involves ensuring proper catheter care and sometimes surgical intervention.
• Fluid Overload:
  • Occurs if the fluid removal is insufficient.
  • Management includes adjusting the dialysate concentration or volume.
• Electrolyte Imbalances:
  • Can occur due to improper dialysate composition or fluid management.
  • Regular monitoring and adjustments to the dialysis prescription are essential.

Advantages and Disadvantages of CAPD

• Advantages:
  • Flexible schedule, allowing for greater independence.
  • Can be performed at home or at work, providing convenience.
  • No need for vascular access, reducing the risk of related complications.
• Disadvantages:
  • Risk of peritonitis and other infections.
  • Requires patient training and strict adherence to aseptic technique.
  • May be less effective than haemodialysis for some patients.

Summary

Continuous Ambulatory Peritoneal Dialysis (CAPD) is an effective treatment for kidney failure that allows for more flexible and independent management compared to haemodialysis. It involves using the peritoneum as a filter to remove waste products and excess fluids from the blood. While it offers several advantages, it also requires careful management and adherence to aseptic techniques to prevent complications such as peritonitis.

Additional Notes

The Peritoneal membrane is used to dialyse the patient. The membrane acts as exchange filter. A Tenckhoff catheter tunnelled into the peritoneal cavity through the anterior abdominal wall. Dialysate fluid introduced and later drained and this cycle is repeated. Can be done at home by patient/carer. Either continuous with 3-5 changes per day or overnight using an automated device. Not used problems with abdominal adhesions or active abdominal sepsis or lack of ability or help to perform the technique. Complications include Bacterial peritonitis both Gram-positive and negative, Fluid overload - use a hypertonic bag, Constipation, Pleural effusion. Leakage into the scrotal sac, Sclerosing peritonitis.