View source for WBR1112

 {{WBRQuestion
|QuestionAuthor= {{M.P}}
|ExamType=USMLE Step 3
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|MainCategory=Emergency Room
|MainCategory=Emergency Room
|SubCategory=Gastrointestinal
|Prompt=A 53 year old male is brought to the emergency department with complaints of sudden onset of severe abdominal pain for the past three hours.  The pain is generalized and is increasing in severity since then.  He also had two episodes of non-bloody vomiting on the way to the emergency department.  On further review of his history, he reveals that he was having recurrent episodes of abdominal pain for the past three months, especially after meals that persisted for one to two hours.  He denies any blood or mucus in stools or any recent travel outside the country.  His past history is significant for mitral valvular disease and is on ACE inhibitors and thiazide diuretics for that.  He is a chronic smoker, but consumes alcohol occasionally.  His family history is insignificant.  On examination the patient is conscious and his vitals are pulse: 102/min, BP: 90/60 mmHg and temperature: 38 degree Celsius.  Abdominal examination reveals generalized tenderness with rebound tenderness and guarding.  Other system examinations are normal except for a murmur at the mitral area.  The patient is kept on NPO and started on intravenous fluids and broad spectrum antibiotics.  Which of the following would be the most appropriate next step in the management of this patient?
|Explanation=[[Acute mesenteric ischemia]] refers to the sudden onset of intestinal hypoperfusion, most commonly due to acute embolic or thrombotic occlusion of the [[superior mesenteric artery]] (SMA).  The diagnosis of AMI depends upon a high clinical suspicion, especially in patients who develop severe and persisting abdominal pain that is disproportionate to their abdominal finding and with known risk factors such as [[atrial fibrillation]], [[congestive heart failure]], [[valvular heart disease]], [[peripheral vascular disease]], or a history of [[hypercoagulability]].  Rapid diagnosis is essential to prevent the catastrophic events associated with intestinal infarction.  Laboratory studies are nonspecific and hence in any patient with acute abdominal pain and metabolic acidosis, [[intestinal ischemia]] is suspected until proven otherwise.  Surgery should not be delayed in patients suspected of having intestinal infarction or perforation and hence an urgent abdominal X-ray should be done to plan the management.  An abdominal X-ray also serves as an important investigation tool to rule out other causes of acute abdomen. 
|AnswerA=Abdominal X-ray

|AnswerAExp=An abdominal [[X-ray]] is the best next step in the management of this patient as it helps to rule out other causes of acute abdomen and also find out any perforation. 
|AnswerB=USG abdomen

|AnswerBExp=[[Ultrasound]] is not routinely used in patients with intestinal ischemia as though they can identify stenoses or occlusions in the celiac or superior mesenteric arteries, it is technically limited by the presence of air-filled loops of distended bowel.
|AnswerC=Laprotomy

|AnswerCExp=Laprotomy should not be delayed in this patient as he is suspected of having intestinal perforation.  A quick diagnosis of perforation is made with abdominal X-ray before surgery is done.
|AnswerD=Mesenteric arteriography

|AnswerDExp=[[Arteriography]] is still recommended if the diagnosis of acute mesenteric ischemia remains in question even after performing a multidetector CT angiography and magnetic resonance (MR) angiography in stable patients.
|AnswerE=CT angiography

|AnswerEExp=Multidetector computed tomographic (CT) [[angiography]] are chosen above magnetic resonance (MR) angiography because of its low cost to diagnose acute mesenteric ischemia and is used in hemodynamically stable patients with acute intestinal ischemia pain.
|RightAnswer=A
|WBRKeyword=[[Intestinal ischemia]], [[mesenteric ischemia]], [[acute mesenteric ischemia]]
|Approved=Yes
}}