Ischemic colitis associated with acute carbon monoxide poisoning - a case report

Carbon monoxide (CO) poisoning is common, but it has rarely been reported to cause ischemic colitis. In this case, a 34-year-old female with depression presented to an emergency department after a period of unconsciousness, with urinary and bowel incontinence, following exposure to car exhaust. Her carboxyhemoglobin level was 23%. She had metabolic acidosis. She was transferred to our facility for hyperbaric oxygen treatment, where she had intractable nausea/vomiting with abdominal pain and bright-red bleeding per rectum. She exhibited lower abdominal tenderness and hypoactive bowel sounds. Vital signs were: temperature 36.8 degrees C; blood pressure 137/86mmHg; heart rate 114 beats/minute; respiratory rate 28 breaths/minute. The patient's electrocardiogram showed sinus tachycardia with T-wave inversions in leads I, aVL and V3-V6. The troponin I level peaked at 3.7ng/ml. Echocardiogram showed a reduced ejection fraction of 30%-35%, with akinesis in the posterior lateral and distal anterior distributions. Computed tomography of the abdomen revealed diffuse colonic mural thickening, supporting mesenteric ischemia. Sigmoidoscopy showed edematous friable pale mucosa from rectum to distal sigmoid colon. Hyperbaric oxygen was deferred based on the patient's status. Over three days, the initial hematochezia progressed to melena and then resolved. Adenosine cardiac stress MRI was normal. She was transferred to the psychiatry service and discharged four days later. Four years later, she has no gastrointestinal, cardiac or cognitive problems.