A nurse is caring for a client who has a prescription for warfarin. Which of the following laboratory tests should the nurse monitor?
Explanation & Rationale
Rationale: A. Triiodothyronine: Triiodothyronine (T3) measures thyroid function and is not related to anticoagulation therapy. It is important for evaluating thyroid disorders but has no role in monitoring the effects of warfarin. B. Arterial blood gases: Arterial blood gases (ABGs) assess oxygenation, ventilation, and acid-base balance, not anticoagulation status. ABGs are not used to monitor warfarin therapy. C. Serum potassium: Serum potassium levels are crucial for cardiac and muscle function but are not affected directly by warfarin use. Potassium monitoring is more critical with diuretics or certain cardiac medications, not anticoagulants like warfarin. D. Prothrombin time: Prothrombin time (PT) measures how long it takes blood to clot and is directly affected by warfarin therapy. Monitoring PT (and the related INR) ensures that the warfarin dose maintains therapeutic anticoagulation without causing excessive bleeding.