- 0May 2, '06 by snippywhat is your institutions practice when it comes to clave changes on central lines? I know the basics (every 72 hrs, TPN/IL, blood transfusions). There is much debate going on about this at my institution and there's not a lot of "evidenced based" information. The powers that be are looking to changing them anytime blood is aspirated into it. This does not seem conducive to infection control so anyone's general policy would be greatly appreciated.