Tag Archives: international normalised ratio (INR)

Introduction Warfarin is an anticoagulant commonly used in atrial fibrillation, venous thromboembolism, prosthetic cardiac valve replacement and postoperative atrial fibrillation.1 Warfarin is usually discontinued prior to cardiac surgery and subsequently re-initiated postoperatively to achieve the target therapeutic international normalised ratio (INR).2 At the cardiac surgery unit of St. Paul’s Hospital, it has been observed that the warfarin dosage needed to achieve therapeutic anticoagulation is often lower post-cardiac surgery, compared with the patient’s warfarin dose prior to cardiac surgery. Serious complications, such as postoper