Dialysis access: Issues related to conversion from peritoneal dialysis to hemodialysis and vice versa

Hemodialysis (HD) and peritoneal dialysis (PD) represent two complementary modalities of renal replacement therapy (RRT) for end-stage renal disease patients. Conversion between the two modalities is frequent and more likely to happen from PD to HD. Every year, 10% of PD patients convert to HD, suggesting the need for recommendations on how to proceed with the creation of a vascular access in these patients. Criteria for selecting patients who would likely fail PD, and therefore take advantage of a backup access, are undefined. Creating backup fistulas at the time of PD treatment start to allow emergency access for HD has proved to be inefficient, but it may be considered in patients with progressive difficulty in achieving adequate depuration and/or peritoneal ultrafiltra-tion. A big challenge is represented by patients switching from PD to HD for unexpected infectious complications. Those patients need to start HD with a central venous catheter (CVC), but an alternative approach might be using an early cannulation graft, provided that infection has been cleared by the circulation. An early cannulation graft might also be used to considerably shorten the time spent using a CVC. In patients who need a conversion from HD to PD, urgent-start PD is now an accepted and well-established approach.