Which laboratory test measures the effectiveness of warfarin?

Listeriosis is a foodborne illness that can have severe consequences during pregnancy. To minimize the risk of listeriosis, a pregnant client should avoid certain foods that are more likely to be contaminated with the bacteria Listeria. The correct statement that indicates an understanding of the teaching is:

C) "I can eat grilled chicken on a bun at lunchtime."

Grilled chicken is a safe option, and as long as it's properly cooked, it's a suitable choice during pregnancy. The other options are not recommended during pregnancy:

A) Soft cheeses, like Brie or feta, can carry a risk of Listeria contamination, so they should be avoided.

B) Seafood salad from the grocery store may not be safe as it could contain seafood that's been sitting at improper temperatures, which can increase the risk of foodborne illness.

D) Hot dogs can also be a risk as they are often not served steaming hot, which is necessary to kill any potential Listeria contamination.

PT stands for prothrombin time, which is a measure of how long it takes the blood to clot.

INR stands for international normalized ratio, which is a way of standardizing the PT results across different laboratories.

Warfarin is a blood thinner that works by inhibiting the production of vitamin K-dependent clotting factors in the liver.

Therefore, warfarin prolongs the PT and increases the INR.The PT/INR test is used to monitor the effectiveness of warfarin therapy and adjust the dose accordingly.

Choice A is wrong because PTT stands for partial thromboplastin time, which is another measure of blood clotting time, but it reflects the activity of different clotting factors than PT.PTT is used to monitor heparin therapy, not warfarin therapy.

Choice C is wrong because aPTT stands for activated partial thromboplastin time, which is a variation of PTT that uses an activator to speed up the clotting time.Like PTT, aPTT is used to monitor heparin therapy, not warfarin therapy.

Choice D is wrong because ACT stands for activated clotting time, which is a measure of the whole blood clotting time.ACT is used to monitor high-dose heparin therapy during certain procedures, such as cardiac bypass surgery or angioplasty.

The normal ranges for these tests may vary depending on the laboratory and the method used, but generally, they are:

• PT: 10 to 13 seconds

• INR: 0.8 to 1.2 (without warfarin) or 2.0 to 3.0 (with warfarin)

• PTT: 25 to 35 seconds

• aPTT: 30 to 40 seconds

• ACT: 70 to 120 seconds