Chapter 50: Peritoneal Dialysis
A 60-year-old woman with ESRD on APD for 5 years develops worsening orthopnea, edema, and progressive weight gain over the last 2 months. She has been adherent to a low-sodium diet and limits her daily fluid intake to 1 L. She is anuric. Her current dialysis regimen is 4 × 2 L exchanges on the cycler over 10 hours with a last fill of 2 L. She uses all 2.5% dextrose dialysate. A recent PET test performed in the clinic shows that she has high peritoneal transport.
Which of the following changes to her PD regimen would be most appropriate?
A. Change all dialysate to 1.5% dextrose.
B. Change her regimen to CAPD.
C. Change her last fill to 7.5% icodextrin.
D. Eliminate her last fill.
The answer is C. This patient has developed worsening volume overload while on CCPD. We are told that she is compliant with sodium and fluid restriction, so we can rule out these reversible causes of volume overload. She has high peritoneal transport, and her dialysis regimen needs to be adjusted. Changing to less concentrated dialysate (ie, 1.5% dextrose) will result in decreased ultrafiltration. Changing to CAPD will also likely result in decreased daily ultrafiltration due to the increased dwell time with the manual exchanges. In the setting of high peritoneal transport and increased dwell time, the osmotic pressure gradient will dissipate and fluid will likely be reabsorbed before the next exchange. Eliminating her last fill may result in improved daily ultrafiltration because we are eliminating her longest dwell; however, this would not be the best option because she is anuric (no residual renal function) and would be at risk for under dialysis without a daytime dwell. The best answer would be to employ icodextrin during the long daytime dwell. The icodextrin will result in sustained ultrafiltration during the long dwell, despite the high peritoneal transport, due to the maintenance of an oncotic pressure gradient.
A 50-year-old man on CAPD presents with abdominal pain and cloudy PD fluid. Examination of the catheter exit site and overlying tunnel is unremarkable. After sending appropriate fluid studies, antibiotic therapy is initiated with intraperitoneal vancomycin and gentamicin. The fluid cell count returns at 300/mm3 with 70% neutrophils and the culture grows MRSA. Gentamicin is discontinued and therapy is continued with IP vancomycin. After 5 days the patient still reports severe abdominal pain. Repeat fluid cell count is 500/mm3 and culture remains positive for MRSA.
What is the most appropriate next step in management?
A. Continue vancomycin and add back gentamicin.