An evidence-based approach to managing the anticoagulated patient in the emergency department.

You start another busy shift with a double row of charts waiting to be seen. Your first patient is an elderly man who fell 1 hour prior to presentation. He did not lose consciousness, but he was dazed for a few minutes. He complains of a mild headache but denies any neck pain. He takes warfarin for valvular heart disease. He looks good and has no focal neurological complaints. His mental status is normal, he has a negative head CT scan, and his INR is 3.9. His family wants to take him home, which would help relieve some of the congestion in the ED, but you wonder what would be best. To observe and repeat imaging? Reverse his anticoagulation? Change his dosing regimen of warfarin? In the next room, you quickly evaluate a 51-year-old obese woman with nonspecific back and abdominal pain that started 24 hours before and has slowly progressed to become intolerable. She denies fever, chills, nausea, or vomiting. She is on the last day of a 5-day course of ciprofloxacin for a UTI. She takes warfarin for a pulmonary embolus that occurred 2 months prior. Her hematocrit is mildly decreased, and her white blood count is normal; however, the INR is 6.8. You wonder if her abdominal pain is related to the UTI, or if it could be somehow related to the prolonged INR. In fact, you wonder why her INR is so prolonged...