How it works
Peritoneal dialysis (PD) uses the peritoneum as a semipermeable membrane. Dialysate is instilled via a Tenckhoff catheter; solutes diffuse across the membrane and water is removed by osmosis using glucose (or icodextrin) in the fluid. The dwell fluid is then drained and exchanged.
Modalities
- CAPD (continuous ambulatory PD) — manual exchanges several times a day
- APD (automated PD) — a machine performs exchanges overnight
Advantages
- Home-based, offering independence and flexibility
- Better preservation of residual renal function
- Avoids the need for vascular access
Complications
- Peritonitis — the key complication: cloudy effluent and abdominal pain, usually skin organisms (coagulase-negative staphylococci, Staph aureus); treat with intraperitoneal antibiotics
- Exit-site and tunnel infections
- Membrane failure over time; encapsulating peritoneal sclerosis (a serious late complication)
- Hernias and fluid leaks from raised intra-abdominal pressure
- Metabolic: glucose absorption → weight gain, hyperglycaemia, hyperlipidaemia
MRCP-specific traps
- Cloudy PD fluid + abdominal pain = PD peritonitis — treat with intraperitoneal antibiotics.
- Long-term PD risks encapsulating peritoneal sclerosis and membrane failure.
- Glucose in the dialysate contributes to weight gain and hyperglycaemia.
Summary
Peritoneal dialysis uses the peritoneum as a membrane, with solute diffusion and glucose-driven ultrafiltration via a Tenckhoff catheter (CAPD or APD). It is home-based and preserves residual function. Peritonitis (cloudy effluent, skin organisms) is the defining complication; long-term risks include membrane failure and encapsulating peritoneal sclerosis.
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