Before administering Warfarin, which lab value should the nurse check?

Checking the PT, or prothrombin time, is crucial before administering Warfarin because it directly assesses the client's coagulation status. Warfarin is an anticoagulant medication that works by inhibiting vitamin K-dependent clotting factors, which can lead to an increased bleeding risk if the dosage is not properly adjusted. PT is used to monitor the effectiveness of Warfarin therapy and to determine the appropriate dose to maintain a therapeutic range.

A typical therapeutic range for PT, expressed as INR (International Normalized Ratio), is between 2.0 and 3.0 for most indications of anticoagulation. By checking the PT prior to administration, the nurse can ensure that the patient's coagulation levels are within a safe range, helping to prevent potential bleeding complications.

Other lab values listed, such as serum sodium, serum potassium, and serum BUN, do not provide specific information related to the anticoagulation effects of Warfarin and are not direct indicators of the necessity for Warfarin administration. Knowing the PT allows the healthcare provider to make informed decisions about the treatment regimen.