- How often do you flush PD catheters when they are not being used? We flush weekly for four weeks post insertion and then generally leave them alone until we use them. This is normally six weeks, but could be longer. Not sure this is good practice. 2. Do you train your families to do the flushes once the catheter is healed but not being used? 3. If the catheter is not in use for some time, when do you have it removed?