A patient is admitted to the hospital for routine elective surgery. Included in the list of current medications is warfarin (Coumadin) at a high dose. Concerned about the possible effects of the drug, particularly in a patient scheduled for surgery, the nurse anticipates which of the following actions?
A. Draw a blood sample for prothrombin (PT) and international normalized ratio (INR) level.
B. Administer vitamin K.
C. Draw a blood sample for type and crossmatch and request blood from the blood bank.
D. Cancel the surgery after the patient reports stopping the Coumadin one week previously.
Correct Answer: A. Draw a blood sample for prothrombin (PT) and international normalized ratio (INR) level.
The effect of Coumadin is to inhibit clotting. The next step is to check the PT and INR to determine the patient’s anticoagulation status and risk of bleeding. Patients receiving treatment with warfarin should have close monitoring to ensure the safety and efficacy of the medication. Periodic blood testing is the recommendation to assess the patient’s prothrombin time (PT) and the international normalized ratio (INR).
Option B: Vitamin K is an antidote to Coumadin and may be used in a patient who is at imminent risk of dangerous bleeding. When managing warfarin toxicity, the initial step would be to discontinue warfarin and then administer vitamin K (phytonadione). The vitamin K may administration can be either via the oral, intravenous, or subcutaneous route. However, the initial administration of oral vitamin K is often preferable in patients without major bleeding or extremely elevated INR.
Option C: Preparation for transfusion, as described in option C, is only indicated in the case of significant blood loss. A reduction in INR should occur within 24 hours of administration. After that, the recommendation is for intravenous vitamin K administration if necessary. Subcutaneous vitamin K is often not recommended for warfarin toxicity or reversal due to erratic and unpredictable absorption. Administering agents like prothrombin complex concentrate (PCC), fresh frozen plasma (FFP), and activated Factor VII may be considered for cases of significant bleeding.
Option D: If lab results indicate an anticoagulation level that would place the patient at risk of excessive bleeding, the surgeon may choose to delay surgery and discontinue the medication. Patients also require close monitoring for signs and symptoms of active bleeding throughout their treatment. Close monitoring for signs and symptoms of bleeding, such as dark tarry stools, nosebleeds, and hematomas, is necessary. The patient’s hemoglobin and hematocrit level should undergo an assessment before initiating warfarin and approximately every six months while on therapy.