A Case of Inadequate Ultrafiltration on Peritoneal Dialysis: A Quiz

A 35-year-old female patient with end-stage kidney failure secondary to focal segmental glomerulosclerosis was initiated on continuous cyclic peritoneal dialysis (CCPD). The PD regimen comprised 5 L of 2.5% tonicity dextrose and 5 L of 1.5% dextrose, administered in 5 cycles of 2 L over 10 hours followed by a long dwell of 2 L icodextrin. Three years after PD initiation, she developed refractory Streptococcus agalactiae peritonitis requiring catheter removal and conversion to hemodialysis. Subsequently she decided to return to PD; hence 5 months later, a PD catheter was reinserted. After her return to PD, she had recurrent episodes of fluid overload. She had become anuric by her second year on PD. Her daily ultrafiltration before the episode of peritonitis was 1.5-2 L. After return to PD, the daily ultrafiltration decreased to 700-900 mL despite increasing dialysate tonicity on the cycler to all 2.5% dextrose. Ultrafiltration was mainly from the cycler, as she was retaining 200-300 mL on icodextrin long dwell. Subsequently she received a mix of 4.25% and 2.5% dextrose, but ultrafiltration remained inadequate and she was eventually admitted a month later for fluid overload and hypertensive urgency requiring hemodialysis for volume control. •What is the approach to a patient on peritoneal dialysis who presents with fluid overload? •How is the modified peritoneal equilibration test performed and what information may it provide? •What is the most likely diagnosis in this case and what would be the appropriate treatment?