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Difficulty: HardGastrointestinal and Abdominal Surgery

An otherwise healthy 62-year-old male is evaluated in the emergency department for a 6-hour history of acute, intense, colicky abdominal pain accompanied by several episodes of bilious vomiting. His past medical history is notable only for an open appendectomy performed 15 years ago for a ruptured appendix. On current evaluation, his temperature is 37.1°C (98.8°F), blood pressure is 135/85 mm Hg, pulse is 92/min, and respiratory rate is 16/min. The abdominal examination is significant for pronounced distention and high-pitched, hyperactive bowel sounds. Palpation elicits moderate, diffuse tenderness, though there is no evidence of guarding, rigidity, or rebound tenderness. Initial laboratory investigations reveal a leukocyte count of 9,500/mm³ and a serum lactate concentration of 1.1 mmol/L (Normal: 0.5 - 1.5 mmol/L). An abdominal and pelvic computed tomography scan with intravenous contrast reveals a distinct transition point in the distal jejunum with substantial upstream small bowel dilation. Additionally, a C-shaped, fluid-distended segment of small bowel is noted, and the corresponding mesenteric vasculature is seen tapering toward a central focal point. Which of the following is the most appropriate next step in the management of this patient?

  1. Emergent surgical explorationAnswer
  2. B
    Placement of a nasogastric tube and administration of intravenous fluids
  3. C
    Administration of an oral water-soluble contrast agent
  4. D
    Initiation of intravenous broad-spectrum antimicrobial therapy and clinical observation
  5. E
    Computed tomography angiography of the mesenteric arteries

Answer

Emergent surgical exploration is the most appropriate next step in management.
The correct management is emergent surgical exploration. This patient presents with an adhesive small bowel obstruction complicated by a closed-loop obstruction, which is indicated by the CT findings of a C-shaped, fluid-distended bowel segment and a 'whirl sign' (mesenteric vasculature tapering to a central point). In a closed-loop obstruction, a segment of bowel is blocked at two adjacent points, leading to a rapid and exponential increase in luminal pressure within the isolated segment. This quickly compromises venous outflow and arterial inflow, creating an extremely high risk for rapid progression to bowel ischemia, necrosis, and perforation. Therefore, a closed-loop obstruction is an absolute indication for immediate operative intervention, regardless of the patient's current hemodynamic stability, normal serum lactate levels, or the absence of frank peritonitis.

Step-by-Step Solution

1
Evaluate the clinical presentation
The patient exhibits classic symptoms of a small bowel obstruction (colicky pain, bilious vomiting, distention) with a history of prior abdominal surgery (adhesions).
Establishing the primary clinical syndrome is necessary to direct further diagnostic and therapeutic algorithms.
2
Analyze the radiologic findings
The contrast-enhanced CT scan demonstrates a transition point with proximal dilation, alongside a C-shaped fluid loop and a 'whirl sign' (mesenteric twisting).
These specific imaging characteristics are pathognomonic for a closed-loop obstruction.
3
Determine the appropriate triage and management
The correct action is immediate surgical exploration.
A closed-loop obstruction carries an exceedingly high risk of rapid progression to bowel strangulation and infarction. It mandates emergent operative intervention, even in a patient who currently lacks systemic toxicity, peritonitis, or lactic acidosis.

Key Concept

Management of closed-loop small bowel obstruction
Estimated Time:1m 30s
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Topics

Gastrointestinal and Abdominal Surgery

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