A 65-year-old man is brought to the emergency department by his wife due to severe upper-abdominal pain. The pain began suddenly 4 hours ago while he was watching television; it radiates to the back and is exacerbated by any movement. The patient has had gastroesophageal reflux disease for many years and has been taking over-the-counter antacids for symptom control. He also has hypertension, which is controlled with a thiazide diuretic. He walks 5 miles daily. The patient has been consuming large amounts of milk and other dairy products to relieve "burning" symptoms in his stomach. His temperature is 37.8 C (100 F), blood pressure is 110/62 mm Hg, pulse is 110/min, and respirations are 22/min. He lies flat and motionless on the bed. His mucous membranes are dry. Abdominal examination shows marked tenderness on superficial palpation. The patient does not allow any further palpation of the abdomen. Electrocardiogram shows sinus tachycardia.
Which of the following is the best initial test for this patient?

Question

A 65-year-old man is brought to the emergency department by his wife due to severe upper-abdominal pain.  The pain began suddenly 4 hours ago while he was watching television; it radiates to the back and is exacerbated by any movement.  The patient has had gastroesophageal reflux disease for many years and has been taking over-the-counter antacids for symptom control.  He also has hypertension, which is controlled with a thiazide diuretic.  He walks 5 miles daily.  The patient has been consuming large amounts of milk and other dairy products to relieve "burning" symptoms in his stomach.  His temperature is 37.8 C (100 F), blood pressure is 110/62 mm Hg, pulse is 110/min, and respirations are 22/min.  He lies flat and motionless on the bed.  His mucous membranes are dry.  Abdominal examination shows marked tenderness on superficial palpation.  The patient does not allow any further palpation of the abdomen.  Electrocardiogram shows sinus tachycardia. 
Which of the following is the best initial test for this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bf49_ade3_8f63_894b03f5a9bb_MD0005_00 This patient's acute abdominal pain with significant tenderness and guarding is highly suggestive of bowel perforation with peritonitis. A perforated peptic ulcer is the most common etiology, and is especially likely in this patient who has a history of "burning" abdominal sensations. In contrast to patients with renal colic, who tend to writhe in pain, patients with peritonitis tend to lie flat and motionless to limit peritoneum irritation. Rupture of a hollow organ allows air into the abdomen (pneumoperitoneum); this air can often be detected by an upright chest x-ray. It is important to keep the patient in an upright position so that air within the peritoneal cavity can be visualized beneath the diaphragm. Pneumoperitoneum identification in a supine patient can be much more difficult. Given this patient's presentation, the presence of pneumoperitoneum on the chest x-ray would likely be diagnostic. If the findings of the chest x-ray are unclear, an abdominal CT scan may be useful (Choice C). (Choice A) An abdominal ultrasound is most helpful in evaluating the acute abdomen when there is concern for gallbladder disease or a ruptured abdominal aortic aneurysm. However, neither is likely in this patient. A ruptured abdominal aortic aneurysm is usually accompanied by profound hypotension. Gallbladder disease can cause acute epigastric pain, but it generally causes recurrent episodes of right upper-quadrant pain. (Choice D) Diagnostic peritoneal lavage is occasionally used to detect hemoperitoneum in patients with blunt abdominal trauma. It would not be useful in the initial evaluation of acute abdominal pain. (Choice E) Lipase is a useful marker for pancreatic disease, especially acute pancreatitis. Lactic acid is a marker for impaired tissue perfusion (seen in acute bowel infarction). Both tests may be informative, but chest and abdominal x-rays should be completed first as they may prompt emergency surgical intervention. This patient's history is more suggestive of peptic ulcer disease with perforation. Educational objective: Peritonitis from hollow viscus perforation should be suspected in patients experiencing sudden-onset abdominal pain with significant tenderness and guarding. Patients with peritonitis tend to lie still to minimize peritoneum irritation. An upright chest x-ray showing pneumoperitoneum can identify perforation. References: Detection of pneumoperitoneum on chest radiographs: comparison of upright lateral and posteroanterior projections. (http://www.ncbi.nlm.nih.gov/pubmed/7785629)

A 65-Year-Old Man Is Brought to the Emergency Department by His