A nurse is caring for a patient who is taking warfarin (Coumadin). Which of the following laboratory values should the nurse monitor regularly?

The nurse should monitor the INR regularly for a patient who is taking warfarin (Coumadin), which is an anticoagulant that inhibits the synthesis of vitamin K-dependent clotting factors in the liver. The INR is a standardized measure of the prothrombin time (PT), which reflects the time it takes for blood to clot.The INR should be between2 and 3for most patients on warfarin therapy, unless otherwise specified by the provider.

Choice A is wrong becausehemoglobinis the protein in red blood cells that carries oxygen.

It is not affected by warfarin therapy and does not indicate the risk of bleeding or clotting.

Choice B is wrong becausehematocritis the percentage of blood volume that is occupied by red blood cells.

It is also not affected by warfarin therapy and does not indicate the risk of bleeding or clotting.

Choice C is wrong becauseplatelet countis the number of platelets in the blood.

Platelets are cell fragments that help with blood clotting by forming a plug at the site of injury.

Warfarin does not affect platelet production or function, but rather inhibits the clotting factors that are needed to stabilize the platelet plug.

Choice D is wrong becauseprothrombin time (PT)is the time it takes for blood to clot in the presence of a specific reagent.

It is affected by warfarin therapy, but it is not standardized and may vary depending on the reagent and the laboratory.

This statement indicates a need for further teaching because taking an antacid can interfere with the absorption of warfarin and affect its effectiveness. The client should not self-medicate with any over-the-counter drugs without consulting their healthcare provider first.

Choice A is wrong because reporting black tarry stools and abdominal pain to the healthcare provider immediately is the appropriate action.These symptoms may indicate gastrointestinal bleeding, which is a serious adverse effect of warfarin.

Choice B is wrong because stopping the medication if these symptoms persist is not advisable.Warfarin should not be discontinued abruptly without medical supervision, as this can increase the risk of thrombosis.

Choice D is wrong because increasing the intake of green leafy vegetables is not harmful.

Green leafy vegetables are rich in vitamin K, which is the antidote for warfarin overdose.However, the client should maintain a consistent intake of vitamin K and avoid sudden changes in their diet.