Would you recommend transition to hemodialysis for a patient with calciphylaxis, hyperphosphatemia, and ESKD on peritoneal dialysis?

Changing from PD to HD is a tough decision but I would do it for calcemic uremic arteriopathy CUA (calciphylaxis) for two reasons, increase clearance and guarantee IV delivery of sodium thiosulfate (STS). Peritoneal STS has been described

Mataic & Bastani, PMID 16771254

But I think CUA is life-threate...

I do. I would recommend frequent hemodialysis as it would give the best phosphorus clearance. Intensive PD would be a less ideal option but a consideration in conversation with the patient.