A peritoneal dialysis system includes a base peritoneal dialysis system and a peritoneal dialysis fluid exchange system that operates independently of the base system. The base system includes a first cassette including a first patient line configured to be connected to a patient, and a PD cycler. The PD cycler receives the first cassette, and includes a pump that cooperates with the first cassette to deliver dialysate to and drain dialysate from a peritoneal cavity of the patient via the first patient line. The peritoneal dialysis fluid exchange system includes a second cassette including a second patient line configured to be connected to the patient and a fluid exchange device that receives the second cassette. The fluid exchange device includes a data exchange interface operable to transfer patient treatment data from the peritoneal dialysis fluid exchange system to the base peritoneal dialysis system.