2. Neurology
APTT, PTT, PT, INR

3. The Tests We All Must Pass
Chronological Order of the Presentation
Introduction
APTT & PTT
PT & INR
Nursing Interventions
Differences
Current Research
Summary
Questions

4. The Cold Hard Facts We all die, but first we must live
We control our bodies via a large neurological system
Depriving this neurological system of blood flow = death
Thromboli can impede blood flow
Therefore thromboli = death

5. The Selfish Gene We all want to live
Keeping blood flowing to neurological system prolongs life
Thromboli impedes blood flow
Antithrombolitic therapy prevents thromboli formation
Therefore antithrombolitic therapy prolongs life

6. Too Much of a Good Thing...
Too much antithrombolitic therapy = prolonged bleeding
Prolonged bleeding decreases blood flow to neurological system
Decreased blood flow to neurological system can cause death
Therefore too much antithrombolitic therapy can cause death

7. How to Walk the Line Develop tests to measure clotting factor
APTT & PTT
PT & INR

8. APTT & PTT APTT – Activated Partial Thromboplastin Time
PTT - Partial Thromboplastin Time
Use intrinsic factors to initiate coagulation pathways
Coagulation is timed and compared to a standard
Test used to diagnosis and monitor
70 seconds…

9. PT & INR PT – Prothrombolin time
INR – International Normalization Ratio
Firm fibrin clot formation initiated by tissue thromboplastin (factor III) and calcium
Timed test

10. PT & INR Uses the equation: INR = (PTclient)x ISI PTavg
* ISI - International Sensitivity Index *
INR = 1
INR = 2-3
INR =

11. Nursing Interventions
Both are blood tests = similar interventions
Require interventions at all stages of the test:
Pre-test
Intra-test
Post-test

12. Pre-Test Education Client Health History
Bleeding disorders
Surgeries, lab tests, diagnostic tests
Current and recent medications
Anticoagulants, acetylsalicylic acid, herbs, nutritional suppliments, and nutraceuticals

13. Intra-Test Follow directions Breath normally
Avoid unnecessary movement
Identify client
Label vials accordingly
Fill tube completely
Have sample analyzed within 4 hours

14. Post-Test Observe venipuncture site
Provide instructions regarding excessive bleeding and bruising
Educate regarding prolonged APTT or high INR
Reinforce health care provider information or instructions
Notify client’s health care provider if INR < 2 or APTT < 53 seconds

15. Where are the Differences
INR internationally recognized and understood
APTT uses kaolin, celite or elegia acid to speed up reaction time, therefore increasing the speed of the test
APTT not recommended for prophylactic low-dose heparin therapy
INR affected by more drugs
INR may be performed on samples older than 4 hours*
* A topic of current research

16. Current Research Certified Diagnostic Plasmas for INR
Are INR values optimal?
Obtaining INR and APTT values using different analyzers
INR self testing by clients

17. Summary APTT value < 70 seconds INR value 2.0-3.0
APTT and INR instrumental in anticoagulation therapies, should be monitored closely to ensure adequate dosing

18. References
Cha, C.H., Park, C.J., Kim, D.H., Kim, M.J., Cho, Y.U., Jang, S. & Chi, H.S. (2010) Direct international normalized ratio determination using multicalibrators is more responsive than the conventional method for measuring prothrombin time. International Journal of Laboratory Hematology, 32(4), pp. 392–397. doi: /j X x
Christensen, T.D., Jensen, C., Larsen T.B., Maegaard, M., Christiansen, K. & Sørensen, B. (2010) International normalized ratio (INR), coagulation factor activities and calibrated automated thrombin generation -- Influence of 24 h storage at ambient temperature. International Journal of Laboratory Hematology, 32(2), pp doi: /j X x
Peng, L., Yan, C., Wu, X. & Nie, L. (2009) Comparability of the results of PT–INR with local MNPT and APTTR with MNAPTT on different coagulation analyzers in China. International Journal of Laboratory Hematology, 31(3), pp doi: /j X x
Plesch, W. & van den Besselaar, A. M. H. P. (2009) Validation of the international normalized ratio (INR) in a new point-of-care system designed for home monitoring of oral anticoagulation therapy. International Journal of Laboratory Hematology, 31(1), pp doi: /j X x

19. References
You, J. H. S., Chan, F. W. H., Wong, R. S. M. & Cheng, G. (2005) Is INR between 2.0 and 3.0 the optimal level for Chinese patients on warfarin therapy for moderate-intensity anticoagulation? British Journal of Clinical Pharmacology, 59(5), pp doi: /j x

20. Questions? A wise person once observed:
“Nurses are like the blood of the health care system...without them it would die.”