Examkin

Question

Difficulty: MediumInterpreting Imaging Results

A 75-year-old man is brought to the emergency department from a skilled nursing facility due to a 2-day history of progressive abdominal distension, colicky abdominal pain, and obstipation. His medical history is significant for Parkinson disease, chronic constipation, and hypertension. His temperature is 37.1°C (98.8°F), blood pressure is 138/86 mmHg, heart rate is 92/min, and respiratory rate is 18/min. Physical examination reveals a markedly distended, tympanitic abdomen with mild, diffuse tenderness. There is no guarding, rigidity, or rebound tenderness. Laboratory studies show a leukocyte count of 9,500/mm³. An upright plain abdominal radiograph is obtained and demonstrates a massive, ahaustral, dilated loop of large bowel forming a U-shape that originates from the pelvis and extends toward the right upper quadrant. There is a noticeable absence of rectal gas. Based on the interpretation of these imaging findings, which of the following is the most appropriate next step in management?

  1. A
    Computed tomography of the abdomen and pelvis with intravenous contrast
  2. B
    Emergent exploratory laparotomy
  3. Flexible sigmoidoscopyAnswer
  4. D
    Intravenous administration of neostigmine
  5. E
    Nasogastric tube placement and serial abdominal examinations

Answer

Flexible sigmoidoscopy
The correct answer is flexible sigmoidoscopy. The patient's clinical history (elderly, Parkinson disease, chronic constipation) and the classic radiographic description of a massive, ahaustral, U-shaped dilated loop of large bowel originating from the pelvis confirm the diagnosis of sigmoid volvulus. Because the patient's vital signs are stable, the leukocyte count is normal, and there are no physical signs of peritonitis (such as guarding or rigidity), the bowel is likely viable. The most appropriate first-line management for uncomplicated sigmoid volvulus is endoscopic detorsion and decompression via flexible sigmoidoscopy. This approach often successfully relieves the obstruction and allows for elective definitive surgery (sigmoid resection) during the same admission, which carries a significantly lower mortality risk than an emergent operation.

Step-by-Step Solution

1
Analyze the patient's clinical presentation.
The patient is an elderly man with risk factors (Parkinson disease, chronic constipation) presenting with progressive abdominal distension, obstipation, and stable vital signs without peritonitis.
To determine the severity and acuity of the bowel obstruction, which dictates whether emergent surgery is necessary.
2
Interpret the specific radiographic findings.
The upright abdominal radiograph shows a massive, ahaustral, U-shaped dilated loop of large bowel originating from the pelvis. This perfectly describes the classic "coffee bean" sign.
To establish the specific etiology of the large bowel obstruction.
3
Correlate the imaging interpretation with the patient's clinical status to determine management.
The imaging confirms a sigmoid volvulus. Because the patient is hemodynamically stable without peritonitis or bowel ischemia, non-operative endoscopic decompression is indicated.
To select the safest and most effective initial therapeutic intervention, avoiding surgical morbidity while directly treating the underlying cause.

Key Concept

The classic radiographic appearance of a sigmoid volvulus is a massive, U-shaped dilated bowel loop originating from the pelvis. In a stable patient without signs of peritonitis or bowel ischemia, the initial treatment of choice is endoscopic detorsion using flexible sigmoidoscopy.
Rate this question

Topics

Interpreting Imaging Results

More questions from this topic