A 68-year-old man is admitted to the coronary care unit with an acute myocardial infarction. His postinfarction course is marked by congestive hea failure and intermittent hypotension. On the fouh day in hospital, he develops severe midabdominal pain. On physical examination, blood pressure is 90/60 mm Hg and pulse is 110 beats per minute and regular; the abdomen is soft with mild generalized tenderness and distention. Bowel sounds are hypoactive; stool Hematest is positive. Which of the following is the most appropriate next step in this patient's management?
In the absence of peritoneal signs, angiography is the diagnostic test of choice for acute mesenteric ischemia. Patients with peritoneal signs should undergo emergent laparotomy. Acute mesenteric ischemia may be difficult to diagnose. The condition should be suspected in patients with either systemic manifestations of aeriosclerotic vascular disease or low cardiac-output states associated with a sudden development of abdominal pain that is out of propoion to the physical findings. Because of the risk of progression to small-bowel infarction, acute mesenteric ischemia is an emergency and timely diagnosis is essential. Although patients may have lactic acidosis or leukocytosis, these are late findings. Abdominal films are generally unhelpful and may show a nonspecific ileus pattern. Since the pathology involves the small bowel, a barium enema is not indicated. Upper gastrointestinal series and ultrasonography are also of limited value. CT scanning is a good initial test, but should still be followed by angiography in a patient with clinically suspected acute mesenteric ischemia, even in the absence of findings on the CT scan. In addition to establishing the diagnosis in this stable patient, angiography may also assist with operative planning and elucidation of the etiology of the acute mesenteric ischemia. The cause may be embolic occlusion or thrombosis of the superior mesenteric aery, primary mesenteric venous occlusion, or nonocclusive mesenteric ischemia secondary to low-cardiac output states. A moality of 50% to 75% is repoed. The majority of affected patients are at high operative risk, but early diagnosis followed by revascularization or resectional surgery or both are the only hope for survival. Celiotomy must be performed once the diagnosis of aerial occlusion or bowel infarction has been made. Initial treatment of nonocclusive mesenteric ischemia includes measures to increase cardiac output and blood pressure. Laparotomy should be performed if peritoneal signs develop
Barium enema
Upper gastrointestinal series
Angiography
Ultrasonography
Preoperative assessment and monitoring in anaesthesia