113.A 63-year-old man is brought to the ED by EMS complaining of severe
abdominal pain that began suddenly 6 hours ago. His BP is 145/75 mm Hg
and HR is 105 beats per minute and irregular. On examination, you note mild
abdominal distention and diffuse abdominal tenderness without guarding.
Stool is heme positive. Laboratory results reveal WBC 12,500/μL, hematocrit
48%, and lactate 4.2 U/L. ECG shows atrial fibrillation at a rate of 110. A CT
scan is shown below. Which of the following is the most likely diagnosis?
Abdominal and Pelvic Pain 99a. Abdominal aortic aneurysm
b. Mesenteric ischemia
c. Diverticulitis
d. SBO
e. Crohn disease