An obscure case of using apixaban anti-Xa levels in a morbidly obese patient who was nil per os with enterocutaneous fistula

Apixaban anti-Xa levels have been introduced to monitor apixaban activity. Presented is a fundamental use of anti-Xa monitoring in questionable absorption in enterocutaneous fistula. A 57-year-old morbidly obese male (150 kg, BMI 42.5) presented to the emergency department with deep venous thromboses and pulmonary embolisms. He also had high-output enterocutaneous fistula managed with an abdominal collection device, total parental nutrition...