How much peritoneal dialysis is usually needed for optimal outcomes?

Depends: The more renal function you have left determines how much pd therapy you need. When a patient starts pd, if they still make lots of urine and the clearance rate is still reasonable, then you probably need less pd exchanges. However if you don't make urine and have poor renal function, then you will need much more pd exchanges.

Peritoneal Dialysis: There really is no optimal formula for effective peritoneal dialysis. There are so many factors such as age, diet, length of time on dialysis, social factors and the like. Thus, a peritoneal dialysis program must be individualized for every patient. Talk with your doctor further about this issue.