Therapeutic Phlebotomy via Vascular Access Devices

I am a nurse extern working in an infusion center. We have a few patients who need therapeutic phlebotomies, however, they do not have good peripheral veins. I was just looking for any information in regards to using a mediport, PICC line, or central line for the therapeutic phlebotomy. Does your medical facility have a protocol in place? Do you know of any research in which would help us get one in place?