A 66-year-old man comes to the emergency department due to abdominal pain and nausea. He has had no vomiting or bloody stools. Yesterday he underwent a screening colonoscopy, which revealed scattered diverticulosis and 2 polyps that were then removed. The patient's other medical conditions include hypertension and gastroesophageal reflux disease.
Temperature is 38.1 C (100.6 F), blood pressure is 110/70 mm Hg, and pulse is 98/min. Mucous membranes are moist. The abdomen is tender in the periumbilical and left lower quadrants with no rebound tenderness.
Laboratory results are as follows:
Upright abdominal radiographs show no free air under the diaphragm.
Which of the following is the best next step in management of this patient?

Question

A 66-year-old man comes to the emergency department due to abdominal pain and nausea.  He has had no vomiting or bloody stools.  Yesterday he underwent a screening colonoscopy, which revealed scattered diverticulosis and 2 polyps that were then removed.  The patient's other medical conditions include hypertension and gastroesophageal reflux disease.
Temperature is 38.1 C (100.6 F), blood pressure is 110/70 mm Hg, and pulse is 98/min.  Mucous membranes are moist.  The abdomen is tender in the periumbilical and left lower quadrants with no rebound tenderness.
Laboratory results are as follows:
 Upright abdominal radiographs show no free air under the diaphragm.
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

This patient's abdominal pain following colonoscopy with biopsies is concerning for perforation at the polypectomy site. Perforation can occur due to direct mechanical trauma from the colonoscope, barotrauma from the colonoscopy pressure, or electrocautery injury during polypectomy. Screening colonoscopy has <0.1% risk of perforation, but interventions (eg, dilatation) can increase the rate up to 18%. Perforations can be retroperitoneal if involving the ascending or descending colon or the splenic and hepatic flexures, or intraperitoneal if the transverse or sigmoid colon is involved. Patients with perforations typically have abdominal pain or distension and may also have fever and chest or scapular pain. Peritoneal signs (eg, rebound tenderness, decreased bowel sounds, abdominal wall rigidity) eventually develop. Immediate abdominal x-ray (plain and upright or lateral decubitus) and upright chest x-ray should be obtained to look for free air. Patients in whom there is a high clinical suspicion for perforation but with negative x-rays should undergo abdominal and pelvic CT scan with water-soluble contrast (eg, Gastrografin). CT scan with contrast is more sensitive than plain films for detecting extraluminal air and subtle perforation. Management involves broad-spectrum antibiotics and surgical consultation. (Choice B) Noncontrast CT scan may miss subtle perforations and is not recommended. (Choice C) Sigmoidoscopy is contraindicated in the setting of a perforation as insufflating air during the procedure would significantly worsen the perforation and peritonitis. (Choices D and E) This patient has fever and acute abdominal pain. He requires immediate investigation for possible causes (eg, perforation, abscess) and intravenous broad-spectrum antibiotics; reassurance or oral antibiotics will delay necessary therapy and likely worsen his clinical outcome. Educational objective: Perforation from routine endoscopic procedures is uncommon and typically occurs from mechanical trauma, barotrauma, electrocautery, or therapeutic interventions. Immediate abdominal (upright or lateral decubitus) and upright chest radiographs can confirm a perforation. Patients with high clinical suspicion for perforation and negative x-rays should undergo CT scan with a water-soluble contrast agent, which can detect subtle perforation. __________

A 66-Year-Old Man Comes to the Emergency Department Due to Abdominal