Cloudy Effluent on CAPD: Peritonitis Decisions
Mr. D is 68 and has been on continuous ambulatory peritoneal dialysis for 2 years: four 2 L exchanges daily with 2.5% dextrose. He presents with 2 days of diffuse abdominal pain, nausea, and cloudy effluent. Temperature 37.9 °C, BP 138/84, pulse 96, weight up 1.4 kg. Effluent cell count 620 WBC/µL with 85% neutrophils; Gram stain shows gram-positive cocci in clusters. Exit site is clean and dry, and he has had no previous peritonitis. Residual urine output is 300 mL/day. He asks whether he can skip tonight's exchange because of the pain.
1. What are your immediate actions, in priority order, including the antibiotic approach?
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1. Obtain the specimen for culture before antibiotics. Send effluent for cell count with differential and culture; culture in blood culture bottles markedly improves yield, and add fungal and mycobacterial cultures if there is any prior antibiotic exposure. Gram stain is helpful but not sufficient.
2. Start empiric intraperitoneal antibiotics promptly, ideally within an hour, covering both gram-positive and gram-negative organisms. Per ISPD guidance this is typically a first-generation cephalosporin or vancomycin for gram-positives plus ceftazidime or an aminoglycoside for gram-negatives; gram-positive cocci in clusters raise Staphylococcus including MRSA, so review local resistance patterns and consider vancomycin. Dose by weight and renal function per protocol and give in the dwell.
3. Continue peritoneal dialysis. Do not drain the patient dry or stop exchanges; pain control with simple analgesia, and assess for ileus, constipation, and catheter malposition.
4. Look for a source: technique review (touch contamination, hand hygiene, mask use, catheter care), exit site and tunnel inspection, review recent antibiotics and diverticular symptoms.
5. Reassess at 72 hours and day 5 and narrow therapy using sensitivities; failure to clear by day 5 defines refractory peritonitis. Escalate the 1.4 kg weight gain and residual renal function trend to the team.
2. The patient asks to skip tonight's exchange and the next day's exchanges "to let it settle." How do you respond, and what would change your plan about continuing PD at all?
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Skipping exchanges is the wrong move: it stops delivery of the intraperitoneal antibiotic into the peritoneum, allows the effluent to sit and worsen, and removes the very mechanism that clears organisms. Explain plainly that the exchanges are the treatment-each dwell carries the antibiotic-and that stopping can turn a manageable infection into a catheter removal. Offer pain control, warmth, positioning, and help with the mechanics of the exchange rather than endorsing the skip. Use teach-back to confirm he understood why.
Continuing PD is the default, but the following would prompt catheter removal and transfer to hemodialysis: refractory peritonitis (failure to clear within 5 days of appropriate antibiotics), relapsing or recurrent peritonitis, fungal peritonitis, peritonitis with refractory exit-site or tunnel infection, or a catheter not functioning properly. Catheter removal is also considered for severe or persistent symptoms with hemodynamic compromise. A mechanical catastrophe such as bowel perforation requires urgent surgical involvement and removal.
If the catheter must be removed, her residual urine output of 300 mL/day is important-she will still need dialysis, and a plan (temporary hemodialysis, access strategy, and the possibility of returning to PD later) should be discussed early rather than presented as a failure.
3. Two months later he returns with ultrafiltration of only 350 mL/day, weight gain, edema, and BP 152/94 despite 2.5% dextrose exchanges. What is your differential, and how do you reason toward a prescription change?
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Differential: adherence (missed exchanges, longer dwells, or using glucose-containing drinks), high peritoneal transport (rapid glucose absorption, loss of the osmotic gradient, so little net UF), catheter malfunction or leak, and reduced residual kidney function.
Reasoning: perform a peritoneal equilibration test with a 24-hour collection. A high transporter with poor UF despite hypertonic dwells is the classic picture and explains the clinical course; low transport points to membrane failure, and mechanical problems show as poor drainage or leakage. Also check his technique and actual exchange logs without a prosecutorial tone.
Prescription logic: in high transport, shorter dwells work better than stronger dextrose-more frequent, smaller-volume daytime exchanges, avoiding long overnight dwells, or using icodextrin (a glucose polymer) for the long dwell. In low transport, increase dwell time and volume as tolerated. In all cases add dietary sodium and fluid restriction, review antihypertensives, and check residual kidney function.
Crucially, resistant edema plus inadequate UF is a signal to assess for volume overload and plan for modality change before the patient presents in pulmonary edema-not to simply push 4.25% dextrose, which worsens glucose load and membrane injury over time.