A nurse is reviewing laboratory results for a client receiving warfarin therapy for a deep vein thrombosis. The INR is 1.4 and the prothrombin time (PT) is 16 seconds. Which action should the nurse take?
- A.Hold the next warfarin dose and notify the provider of supratherapeutic levels
- B.Administer the scheduled warfarin dose and notify the provider of subtherapeutic levels
- C.Administer vitamin K to reverse the warfarin effect
- D.No action needed; these values are within therapeutic range for DVT
Show answer & rationale
Correct answer
B. Administer the scheduled warfarin dose and notify the provider of subtherapeutic levels
Rationale
B is correct: Therapeutic INR for DVT treatment is 2.0-3.0. An INR of 1.4 is subtherapeutic, meaning the patient is inadequately anticoagulated and remains at risk for thrombus extension. The nurse should administer the scheduled dose and notify the provider so the dose may be adjusted. A is incorrect: Holding the dose would further delay achieving therapeutic anticoagulation. INR 1.4 is below, not above, the therapeutic range. C is incorrect: Vitamin K reverses warfarin and is used for supratherapeutic INR with bleeding risk; it would worsen an already subtherapeutic level. D is incorrect: 1.4 is not therapeutic for DVT; the target range is 2.0-3.0.
Key concepts