GFR calculations for waived i-STAT creatinine testing

A while back I had asked for input on switching to the i-STAT for creatinine testing at an off campus clinic location due to COLA no longer being accepted by TJC.  We more than like are going to make the switch, but the most difficult challenge will be with the GFR results.  Currently we use the StatSensor creatinine meter and this gives the GFR results on the screen of the meter with the creatinine results.  I don't think that having the employees look up GFR results on a website and somehow manually documenting this is going to be an option.  With that being said, we use RALS and Meditech expanse.  Does anyone use these and have one or the other calculate the GFR when results are transmitted across?  I would love to get some input on how others have this set up.  I believe we will have to do this in Meditech, but does anyone know if RALS can calculate the results for GFR?  Thank you for any input!  You may also email me at aholland@catawbavalleymc.org if you would prefer to respond by email.