Mechanical & Non-Infectious

The contract between this chapter and the reader.

1. 1. Classify the non-infectious complications of peritoneal dialysis.
2. 2. Recognise raised intra-abdominal pressure as the common mechanism behind leaks, hernias, oedema, and hydrothorax.
3. 3. Diagnose a dialysate leak and locate it — external, abdominal wall, genital, or pleural.
4. 4. Manage abdominal-wall and inguinal hernias, including the emergency of incarceration.
5. 5. Diagnose pleuroperitoneal leak (hydrothorax) and interpret pleural-fluid glucose.
6. 6. Manage genital and abdominal-wall oedema.
7. 7. Distinguish infusion pain from drain pain and treat each.
8. 8. Evaluate blood-stained effluent and separate benign from serious causes.

A sixty-second reading. Each bullet stands alone.

• Many non-infectious complications share one mechanism: raised intra-abdominal pressure.
• The shared management lever is reducing that pressure — lower fill volume, supine automated PD, and temporary rest.
• Dialysate leaks may be external at the catheter, into the abdominal wall, into the genitalia through a patent processus vaginalis, or into the pleural space.
• CT peritoneography with contrast added to the dialysate localises a leak.
• Hernias — umbilical, inguinal, incisional, pericatheter — are common; large fill volumes and the upright posture raise the risk.
• A tender, irreducible hernia is incarceration — a surgical emergency.
• Hydrothorax is usually right-sided; a pleural effusion whose glucose exceeds serum confirms a pleuroperitoneal leak.
• Hydrothorax is managed by stopping PD, draining, and pursuing repair — pleurodesis or surgery — or temporary haemodialysis.
• Infusion pain comes from cold, acidic, or hypertonic fluid and the inflow jet; warming, slower fills, and neutral-pH solutions help.
• Drain pain comes from the catheter tip irritating the pelvis at end-drain; tidal PD and a coiled catheter help.
• Blood-stained effluent is often benign and self-limiting — for example with menstruation — but serious causes must be excluded.
• Definitive treatment of leaks, hernias, and oedema is surgical repair of the defect, with PD modified around it.

The medical core. An expert should agree the non-infectious complications are fully covered here.

Why it matters at the bedside

Two litres of fluid in the abdomen raises the pressure inside it, and that pressure has to go somewhere. Recognise raised intra-abdominal pressure as the thread running through leaks, hernias, genital oedema, and hydrothorax, and a scattered list of complications becomes one problem with one main lever.

The unifying mechanism

• Instilled dialysate raises intra-abdominal pressure, and pressure rises further when the patient is upright, when fill volumes are large, and when the abdominal wall is weak. The same pressure drives fluid through weak points — producing leaks, widening hernias, tracking into the genitalia, and crossing the diaphragm.
• The corollary is practical: the first shared move for almost all of these is to lower the pressure — reduce the fill volume, dialyse supine on a cycler, or rest the abdomen — while planning definitive repair of the defect.

Dialysate leaks

• An early pericatheter leak follows use before healing (Chapter 4). Later leaks track into the abdominal wall, causing subcutaneous swelling and apparent weight gain, or through a patent processus vaginalis into the genitalia.
• Localise the leak with CT peritoneography — contrast added to the dwell shows where fluid escapes — then reduce intra-abdominal pressure and repair the defect surgically.

Hernias

• Umbilical, inguinal, incisional, and pericatheter hernias are common, favoured by large fills, the upright posture, a weak or stretched wall, obesity, and multiparity. Most are diagnosed clinically, with ultrasound or CT for the equivocal.
• A reducible hernia is repaired electively, with low-volume supine PD around the operation. A tender, irreducible hernia is incarceration — with the risk of strangulation — and is a surgical emergency.

Genital and abdominal-wall oedema

• Scrotal, labial, or abdominal-wall swelling in a PD patient signals a leak through a patent processus or a wall defect, not simple fluid overload. Diuretics will not fix it; image to confirm, reduce pressure, and close the defect surgically.

Hydrothorax

• A pleuroperitoneal communication lets dialysate cross the diaphragm, usually on the right, presenting as breathlessness with a pleural effusion. The bedside discriminator is pleural-fluid glucose markedly higher than serum, reflecting the glucose-rich dialysate; scintigraphy or CT peritoneography confirms it.
• Management is to stop PD, drain the effusion, and pursue definitive repair — chemical pleurodesis or surgical (often thoracoscopic) closure — or move to temporary haemodialysis; some communications seal with PD rest alone.

Catheter flow dysfunction

• Non-infectious inflow and outflow problems — constipation, tip migration, omental wrap, kinking, and fibrin — are diagnosed and managed as in Chapter 4; classify inflow versus outflow versus both, and image with a plain abdominal X-ray.

Pain

• Infusion pain occurs during the fill, from cold, acidic, or hypertonic fluid and the jet effect of inflow; warm the fluid, slow the fill, and use a neutral-pH solution.
• Drain pain occurs at the end of drainage, when the catheter tip irritates the pelvic peritoneum; tidal PD that leaves a reservoir, a coiled catheter, or repositioning helps.
• Back pain reflects the lordosis and load of a full abdomen; reduce the fill, dialyse supine, and strengthen the core.

Blood-stained and other effluents

• Blood-stained effluent is frequently benign — retrograde menstruation or ovulation in women, or minor catheter trauma — and self-limiting, but a serious source must be excluded before reassurance. Chylous effluent and the late, ominous picture of encapsulating peritoneal sclerosis (Chapter 8) are rarer non-infectious causes of an abnormal bag.

Five fully-built tables.

Table A — The non-infectious complications

Table B — Leaks: types and management

Table C — Hernias

Table D — Infusion pain versus drain pain

Table E — Diagnostic tests

Visualise & Map

Numbered rules. These numbers are the cross-reference handle for the cases and flowcharts.

Clinical Reasoning

Four cases. Each stops you at a decision before it answers it.

Exhaustive. Every rule in the chapter is here.

Safety & Evidence

Panel A — Red flags

Panel B — NEVER DO

Anti-patterns clinicians fall into. Each becomes a Level 22 distractor.

The grade reflects strength of evidence, not importance.

Apply & Test

Copy-paste chart notes that map to the real decisions in this chapter.

Template 1 — Non-infectious complication assessment

• Complication: leak / hernia / oedema / hydrothorax / pain / bloody effluent.
• Intra-abdominal-pressure factors: fill volume ___; posture; wall integrity.
• Localising tests: CT peritoneography ___; pleural-fluid glucose ___; ultrasound ___.
• Emergency features: tender/irreducible hernia? dyspnoea? — escalate if yes.
• Plan: reduce pressure (low-volume supine / rest); definitive repair ___.

Template 2 — Perioperative PD plan

• Procedure and date: ___.
• PD modification: low-volume supine / temporary rest / bridge HD from ___.
• Resumption plan: graded volumes from ___.
• Escalation triggers: leak recurrence, pain, poor drainage.

Pre-rounds compression. Rules only.

Active recall. At least one card per objective.

Micro-teaching for rounds. Two scenarios, five steps each.

Eight items, each anchored in this chapter. At least one per objective.