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Difficulty: Very hardGastrointestinal and Abdominal Surgery

An 8282-year-old woman is evaluated in the emergency department due to a 4848-hour history of worsening abdominal distension, failure to pass flatus, and multiple episodes of dark green emesis. She resides in a skilled nursing facility and has a medical history significant for Alzheimer dementia, coronary artery disease, and an open appendectomy performed three decades ago. On presentation, she appears lethargic and moans during the examination. Temperature is 38.6∘C38.6^\circ\text{C} (101.5∘F101.5^\circ\text{F}), pulse is 124/min124/\text{min}, blood pressure is 88/54 mm Hg88/54\text{ mm Hg}, and respirations are 24/min24/\text{min}. Physical examination reveals a markedly distended abdomen that is rigid, with diffuse rebound tenderness and absent bowel sounds.

Laboratory results:
Leukocyte count: 18,200/mm318,200/\text{mm}^3 with 15%15\% bands
Serum lactate: 5.4 mmol/L5.4\text{ mmol/L}
Creatinine: 1.8 mg/dL1.8\text{ mg/dL}

An upright chest radiograph reveals no free air under the diaphragm. A supine abdominal radiograph demonstrates multiple dilated loops of small bowel with prominent air-fluid levels and a paucity of colonic gas. After initiating aggressive intravenous fluid resuscitation, the patient's blood pressure remains 90/56 mm Hg90/56\text{ mm Hg}.

Which of the following is the most appropriate next step in management?

  1. Emergent open abdominal explorationAnswer
  2. B
    Computed tomography of the abdomen and pelvis with intravenous contrast
  3. C
    Nasogastric tube insertion and serial physical examinations
  4. D
    Diagnostic laparoscopy with potential adhesiolysis
  5. E
    Administration of intravenous broad-spectrum antibiotics and admission to the intensive care unit

Answer

The most appropriate next step is emergent open abdominal exploration (laparotomy).
The correct answer emphasizes immediate surgical intervention. This patient presents with the classic triad of small bowel obstruction (SBO): bilious emesis, marked abdominal distension, and obstipation, supported by plain radiography. Furthermore, she exhibits overt signs of bowel strangulation and ischemia, including severe lactic acidosis, marked leukocytosis, fever, and a rigid abdomen with rebound tenderness (peritonitis). Because she is hemodynamically unstable (hypotensive despite initial fluid resuscitation) and has a definitive clinical mandate for surgery (peritonitis), she must be taken immediately to the operating room for an emergent open laparotomy. Delaying surgery for advanced imaging is contraindicated.

Step-by-Step Solution

1
Diagnose the primary pathology based on the clinical presentation and initial radiographs.
The patient has a complete small bowel obstruction, indicated by bilious vomiting, obstipation, abdominal distension, and dilated small bowel loops with air-fluid levels on X-ray.
Recognizing the mechanical obstruction is the first step in the surgical triage pathway.
2
Identify clinical and laboratory markers of complicated (strangulated) disease.
The patient has severe lactic acidosis (5.4 mmol/L5.4\text{ mmol/L}), fever, marked leukocytosis with left shift, and a rigid abdomen with diffuse rebound tenderness.
These findings differentiate a simple obstruction (which can be managed conservatively) from a strangulated obstruction with necrotic bowel (which requires surgery).
3
Assess the patient's hemodynamic stability.
The patient is in shock (blood pressure 90/56 mm Hg90/56\text{ mm Hg} despite fluid resuscitation).
Hemodynamic instability dictates the safety of transporting the patient for advanced imaging versus immediate operative intervention.
4
Synthesize findings to determine the next therapeutic step.
A diagnosis of strangulated small bowel obstruction with peritonitis and shock mandates immediate transport to the operating room for an open laparotomy.
Advanced imaging (CT scan) is contraindicated in unstable patients with a clear indication for surgical exploration.

Key Concept

Patients presenting with a small bowel obstruction complicated by peritonitis, ischemia (lactic acidosis, fever), and hemodynamic instability require immediate open exploratory laparotomy without delay for CT imaging.
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Topics

Gastrointestinal and Abdominal Surgery

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