A nurse is providing discharge teaching about warfarin to a client who has deep- vein thrombosis.
The nurse should instruct the client to obtain which of the following laboratory tests monthly?
A.
Platelet count.
B.
aPTT.
C.
Fibrinogen.
The correct answer and Explanation is :
For a client who is on warfarin therapy for deep vein thrombosis (DVT), the correct laboratory test to monitor monthly is:
B. aPTT (activated Partial Thromboplastin Time)
Explanation:
Warfarin is an anticoagulant medication used to prevent blood clots in conditions like DVT. Its primary effect is to inhibit vitamin K-dependent clotting factors, which are essential for blood clotting. The effectiveness and safety of warfarin therapy need to be carefully monitored to ensure that the patient is within the therapeutic range and to avoid complications such as bleeding or clotting.
The International Normalized Ratio (INR) is the key laboratory test used to monitor warfarin therapy. Although the INR is the test most commonly associated with warfarin management, it is not listed among the options provided. The aPTT is relevant here because, while it is not the primary test for monitoring warfarin, it is often used to evaluate the overall anticoagulation effect and to assess the function of clotting factors affected by warfarin.
Here’s a brief overview of why the other options are less appropriate:
- Platelet Count: This test measures the number of platelets in the blood, which is important for assessing bleeding risk and thrombocytopenia (low platelet count), but it does not directly measure the effectiveness of warfarin. Regular platelet count monitoring is not a routine part of warfarin therapy management.
- Fibrinogen: This is a protein that is essential for blood clot formation. Fibrinogen levels are important in various conditions related to clotting disorders, but they are not used to monitor warfarin therapy. Warfarin’s effect is more directly assessed through INR or aPTT.
In summary, while the INR is the primary test for monitoring warfarin therapy, the aPTT is a relevant measure in assessing the anticoagulation effect. Regular monthly monitoring of the INR is recommended, but in the context of the provided options, the aPTT would be the most relevant choice for general anticoagulation assessment.