I'm taking the NCLEX RN in a little over a week (yikes!) and I have a question about aPTT and PTT values, and how they appear on the NCLEX. Mosby's Diagnostic Manual explains that they are essentially the same test, but the aPTT is a newer version.
It gives there values as follows:
aPTT: 30 - 40 seconds
PTT: 60 -70 seconds
..and the therapeutic range for heparin monitoring as 1.5 to 2.5 x the normal, for both values.
Here's the problem: some sources continue to only use the term PTT (not aPTT) but have "updated" the value to something around 30 - 40 (which actually is the aPTT). Others, do distinguish between the two. Kaplan, for example, only mentions the "PTT" and lists the range of normal as: lower range of normal = 20-25, upper range of normal = 32-39, which I'm guessing are the new values of the aPTT. My only concern is how the NLCEX treats these two values. Does it distinguish between the two? Or will it only ask questions regarding the "PTT" and have corresponding correct values of 30 - 40?
I could conceive of a problem where a question is asking about whether or not to give the next heparin dose based on a provided PTT and not knowing if the numbers were safe because of the difference between the two sets of values. Thanks!
Jan 28, '13
I see this question never got answered. I am taking the NCLEX tomorrow and am wondering the same thing. I've noticed many review books using "PTT" to refer to aPTT ranges. Does anyone have an answer on this as to whether the NCLEX itself distinguishes between aPTT and PTT and their respective values?