Therapeutic Ranges

  1. I have consulted a few different books. Each one of them is giving me different ranges for therapeutic values for labs.

    The ones I am specifically interested in though are PT, PTT, aPTT and INR.

    I can't seem to find a concrete answer for the therapeutic ranges on those that are consistant in at least two books.


    Thank you!!!!!!!
  2. Visit Cherybaby profile page

    About Cherybaby

    Joined: Aug '02; Posts: 634; Likes: 979
    Specialty: 10 year(s) of experience in Derm/Wound Care/OP Surgery/LTC


  3. by   SuesquatchRN
    Are you asking for your classes? If so, I would ask your instructor what ranges s/he will be looking for on exams. ranges can vary for many reasons, so find out specifically what you need to know to pass.
  4. by   Cherybaby
    No. I'm 8 years out of school already and about to take my boards in three weeks time. I Have been using saunders, springhouse and barrons and none of their values are concurrent with one another!

    What does everyone generally study for ranges? Just a general idea.

  5. by   SuesquatchRN
    Oh, I see.

    I used Saunders. But really, you'll get values on the exam that will be so whacked that it'll be obvious.
  6. by   Cherybaby
    "So whacked..."

    I like that! Is that a medical term?

    Thanks, Doll.

  7. by   SuesquatchRN
    Quote from Cherybaby
    "So whacked..."

    I like that! Is that a medical term?
    Yeah, it's up there with, "Well, that ain't right!"

    And you're welcome. Good luck!
  8. by   Daytonite
    Cherybaby. . .I am looking at my copy of Memory Notebook of Nursing: Pharmacology & Diagnostics by Tom Gaglione, JoAnn Zerwekh, Jo Carol Claborn and C. J. Miller (Nursing Education Consultants) on page 113 and this is the information that they give (these educators have developed these tools for NCLEX review classes):
    • PTT 60-70 seconds
    • APPT 30-45 seconds
    • Anticoagulant therapy should be 1.5 to 2.5 time the control in seconds
    With regard to the INR, they say on page 116 that the difference between the INR and the PT is that the INR is the calculated standard and the PT is a lab value
    • Normal PT range is 10-13 seconds
    • For anticoagulation the PT needs to be 1.5 to 2 times the control in seconds (INR range 2.0 to 3.0)
    • If PT is greater than 2.5 times the control value, OR INR is greater than 4.0, the person will have bleeding tendencies.
    Hope that helps.

    The people who write the questions for the NCLEX are very well aware of these differences in normal values. The questions are reviewed by a number of people before they are approved to be put on the test. They won't try to trip you up with a question that requires you to pick one normal value from a choice of values that all fall within what you could easily determine to be within a normal range. The wrong answers will stick out like sore thumbs. They will, more likely, be looking for you to know the principles behind the testing and it's significance.