aptt values

:icon_rolli'm kind of confused about whole aptt thing.. i know that if the pt is on heparin therapy, their aptt should be 1.5-2.5x the normal value. My pt's normal value is: 33.6, so 1.5x33.6=50.4 and 2.5x33.6=84. so my pt's aptt value should be between 50.4-84 to be considered therapeutic.. right?

also, does i see a side effect of heparin is anemia.. does heparin lyse the red blood cells? i can't find a scientific reason for anemia being caused by heparin.

thanks!:bowingpur

Most places have gone away from using APTT for heparin and are now using anti factor Xa (also know as a Heparin level). As far as a level you are correct depending on what your hospital uses for normals (one of the reasons that hospitals are going away from APTT). Most of the protocols that I have seen come with a range that is calibrated to the test standard. For example if APTT = x then increase to x. Not sure about specific ranges. For a good treatise on PT PTT and INR look here:

https://allnurses.com/forums/f205/can-someone-explain-ptt-aptt-inr-138282.html

As far anemia, Heparin does not generally cause anemia. It may exacerbate GI bleed or Hematuria. That would be my concern.

David Carpenter, PA-C