# Peritoneal Dialysis Technique > Peritoneal dialysis technique for Dialysis Technology: CAPD exchanges, Tenckhoff catheter, glucose solutions, weekly Kt/V 1.7, peritonitis diagnosis. - Canonical URL: https://prepelephant.com/topics/allied/dialysis-technology/peritoneal-dialysis-technique - Exam / course: Allied Health · Subject: Dialysis Technology - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Peritoneal Dialysis Technique", PrepElephant, https://prepelephant.com/topics/allied/dialysis-technology/peritoneal-dialysis-technique ## Direct answer Peritoneal dialysis uses the patient's own peritoneum (about 1-2 square metres of visceral and parietal membrane with its capillary network) as the dialysis membrane: dialysate is instilled through a Tenckhoff catheter into the abdominal cavity, dwells while glucose osmotically pulls water and solutes cross the capillary endothelium, and is drained and discarded. Continuous ambulatory PD (CAPD) is manual — typically four 2-litre exchanges a day — while automated PD cyclers run overnight. Adequacy is judged by a weekly Kt/V of at least 1.7, and the modality's defining emergency is peritonitis: cloudy effluent with an absolute neutrophil count above 100 per microlitre, treated with intraperitoneal antibiotics. ## What you must remember - **Physiology:** diffusion across the peritoneal capillary bed plus osmotic ultrafiltration from glucose (1.5, 2.5 and 4.25 per cent dextrose strengths; icodextrin for the long dwell in high transporters). - **Access:** the Tenckhoff catheter — a silicone tube with a Dacron cuff, tunnelled, exiting below the umbilicus; deep cuff on the preperitoneal fascia, exit site dressed and inspected daily. - **CAPD prescription:** typically 2 litres per exchange, 4 exchanges daily (adjust for size and transport type), each cycle of fill (5-10 min), dwell (4-6 hours), drain (15-20 min). - **Adequacy:** weekly Kt/V at least 1.7 (higher than the haemodialysis per-session figure because it is summed across the week) plus clinical wellbeing and fluid balance. - **Peritonitis — the examinable triad:** cloudy effluent, abdominal pain, fever; diagnosis needs effluent white cell count over 100/microlitre with more than 50 per cent neutrophils; empirical intraperitoneal therapy commonly covers gram-positives (vancomycin or first-generation cephalosporin) and gram-negatives (ceftazidime or aminoglycoside) per ISPD guidance. - **Other complications:** exit-site and tunnel infection, catheter malfunction (migration, omental wrap), hernias, leaks, hyperglycaemia and weight gain, protein loss (5-15 g/day), and ultrafiltration failure in long-term patients. - **Contraindications:** extensive abdominal adhesions, recent abdominal surgery with drains, abdominal wall infection, severe respiratory compromise, and inability to perform aseptic technique. - **Assessment tool:** the peritoneal equilibration test (PET) classifies the membrane from low to high transporter and tailors dwell times and solution strength. ## Teaching a first CAPD exchange Teach the exchange as a ritual, because the ritual is the prophylaxis. Hands washed to the elbow, mask on, a clean dedicated area, the minicap disconnected under no-touch technique: the patient drains until the abdomen is empty (time it — a slowing drain reports catheter malfunction before it becomes an emergency), weighs or eyeballs the effluent for cloudiness, then fills with 2 litres of 1.5 per cent dextrose warmed to body temperature, and caps. The whole cycle buys four to six hours of clearance and a few hundred millilitres of osmotic ultrafiltration, and repeats four times daily — which is precisely why PD offers steady biochemistry without needles, machines or a hospital chair. The emergency drill deserves equal rehearsal. Cloudy effluent, even without fever, is peritonitis until the cell count says otherwise: send the effluent immediately, start empirical intraperitoneal antibiotics (fast-exchange loading dose per unit protocol), and culture — in Indian units Staphylococcus aureus remains the leading organism, with culture-negative cases common after antibiotic exposure. Meanwhile examine the exit site (purulence means tunnel involvement and a harder course), confirm the drain, and remember that refractory peritonitis, fungal peritonitis or refractory tunnel infection is the standard answer to "when is the catheter removed?" ## How the exam frames it Allied and Dialysis Technology papers alternate between numbers and emergencies. The numbers: 2 litres × 4 exchanges, weekly Kt/V 1.7, glucose strengths 1.5/2.5/4.25 per cent, effluent cell count above 100 with over half neutrophils. The emergencies: cloudy effluent (first step — cell count and empirical IP antibiotics, never "wait for culture"), and ultrafiltration failure (think PET re-testing, icodextrin for the long dwell, and glucose absorption in high transporters). A favourite comparison asks why PD suits diabetics less well metabolically (glucose load, weight gain) yet suits children and remote patients better (needle-free, home-based, fewer hospital visits) — and a viva may end on India-specific reality: PD penetration remains low despite lower infrastructure costs, limited by patient confidence, technique-loss and reimbursement structure. ## Frequently asked questions ### What defines peritonitis in a CAPD patient? Cloudy effluent with an absolute neutrophil count above 100 per microlitre (over 50 per cent neutrophils), with or without abdominal pain and fever. ### What is the standard CAPD prescription? About four exchanges of 2 litres daily with dwell times of 4-6 hours, individualised by size, residual function and peritoneal transport type. ### How is peritoneal dialysis adequacy measured? By a weekly Kt/V of at least 1.7, together with fluid balance, nutrition and biochemical targets — a lower per-treatment bar than HD because clearance accrues continuously. ### Which glucose strength is used for ultrafiltration in high transporters? A long dwell with icodextrin (glucose polymer) or 4.25 per cent dextrose when glucose is absorbed too fast; the PET guides the choice. ### Name absolute contraindications to peritoneal dialysis. Extensive peritoneal adhesions, uncorrected abdominal wall defects or infection, recent abdominal surgery with drains, and inability to perform aseptic exchanges.