Title: SPONTANEOUS INTRAMURAL SMALL BOWEL HEMATOMA ASSOCIATED WITH WARFARIN NONADHERENCE IN AN ELDERLY PATIENT
Abstract: To the Editor: A 91-year-old woman was sent to the emergency department (ED) because of severe abdominal pain. She had a 10-year history of hypertension and atrial fibrillation under medical control. Warfarin 5 mg/d had been prescribed for atrial fibrillation, but she had increased the dosage to 5 mg twice a day for 3 days before ED admission without notifying her physician because she perceived that that would provide better symptom control. She denied any trauma history. Severe abdominal pain developed 6 hours after taking the second dose on the third day. Physical examination at the ED revealed diffuse abdominal tenderness with mild rebound pain. Vital signs were within the normal ranges. Coagulation tests revealed prolonged prothrombin time (PT; 27.7 seconds (normal range 8–12 seconds)) with an international normalized ratio of 2.86 and activated partial thromboplastin time (aPTT) of 56.6 seconds (normal range 23.3–39.3 seconds). Other blood tests were in the normal range. What is the final diagnosis? Emergent computed tomography (CT) of the abdomen and pelvis (Figure 1) showed circumferential small bowel wall thickening with intramural hyperdensity and luminal narrowing in the right lower abdomen. Cul-de-sac fluid collection with a CT attenuation value of 30 suggested hemoperitoneum. During the first day of hospitalization, warfarin was discontinued, and vitamin K 1 mg and two units of fresh-frozen plasma were administered under PT and aPTT guidance. Bowel rest and hydration were also given. After conservative treatment, abdominal pain gradually subsided, coagulation tests returned to normal limits within 2 days, and she was discharged in stable condition. The patient was doing well at follow-up 6 months after discharge. Transverse reformatted computed tomography (CT) image of the abdomen showing circumferential small bowel wall thickening with intramural hyperdensity and luminal narrowing in the right lower abdomen (arrows). Cul-de-sac fluid collection with a CT attenuation value of 30 suggesting hemoperitoneum (arrowhead). Oral anticoagulants are widely used in many indications, such as pulmonary embolism, deep vein thrombosis, prosthetic valves, and persistent atrial fibrillation.1,2 The most serious complication associated with the use of warfarin is bleeding due to excess anticoagulation, occurring approximately 7.6 per 100 patient-years.2 Bleeding is usually subcutaneous or intramuscular. Lesions in the large intestine are now less frequently reported than in the past.3 Spontaneous intramural small bowel hematoma has become increasingly recognized as a complication of anticoagulant therapy, hemophilia, idiopathic thrombocytopenic purpura, leukemia, lymphoma, myeloma, chemotherapy, and vasculitis.4 Warfarin toxicity is the most common cause of spontaneous intramural small bowel hematoma.5 We report a case of spontaneous intramural small bowel hematoma associated with warfarin nonadherence in a very old patient. A general surgeon was consulted, and medical treatment was recommended. Most intramural hematomas are single and most commonly involve the jejunum, followed by the ileum and the duodenum.6 The characteristics of this condition are different from those seen in traumatic small bowel hematoma, which most commonly affects the duodenum.6 Because of her very old age and insufficient renal function, the patient's decision to ingest a double dose of warfarin may have increased her susceptibility to hemorrhagic complications. The clinical manifestations of warfarin toxicity vary from vague abdominal pain, nausea, vomiting, acute abdomen, to intestinal obstruction and gastrointestinal bleeding.4,5 Despite the diagnostic viability of ultrasonography, CT is the diagnostic examination of choice and has been proven to be extremely sensitive, showing alterations suggestive of the presence of hematoma in almost 100% of cases.4 The mainstay of management is medical treatment and discontinuing the anticoagulant drugs, bowel rest, correction of PT with intravenous vitamin K with fresh-frozen plasma, and correction of anemia if present.5,6 Surgical intervention is indicated only if there is significant intramural hemorrhage, bowel perforation, ischemia, or peritonitis.4–6 Efforts to measure the quality of medication use in elderly patients have traditionally focused on inappropriate medications and doses, although a more-comprehensive approach to measuring the quality of medication use in elderly patients has been recommended.7 The most important determinant of risk for adverse drug reaction–related hospital admission in older patients is the number of drugs being taken. When considering only severe adverse drug reactions, risk is also related to age and frailty.8 In a previous study, poor adherence of elderly patients was responsible for 31% of overanticoagulation cases.9 These admissions could potentially be avoided with better anticoagulation control. Long-term warfarin use requires close monitoring of the coagulation profile to prevent this complication. Physician and patient awareness of the risk of bleeding when using warfarin is especially important for elderly patients. Clearer advice to older patients on the risk of nonadherence is important in such case. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Concept and design: Min-Po Ho, Wing-Keung Cheung. Acquisition of subjects and data: Kuang-Chau Tsai, Min-Po Ho, Wing-Keung Cheung. Analysis and interpretation of data: Min-Po Ho and Kao-Lun Wang. Preparation of manuscript: Min-Po Ho, Wing-Keung Cheung. Critical review and approval: All authors. Sponsor's Role: None.