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Difficulty: HardGastrointestinal and Abdominal Surgery

An 81-year-old woman is brought to the emergency department by her daughter due to the sudden onset of severe abdominal pain that began 5 hours ago. The patient has a medical history of hypertension, type 2 diabetes mellitus, and paroxysmal atrial fibrillation. She routinely takes metoprolol, lisinopril, and apixaban, but she discontinued apixaban three weeks ago prior to a dental extraction. Her daughter reports that the patient initially complained of generalized, agonizing pain and was writhing in agony, but over the last hour, she has become increasingly lethargic and now lies completely motionless on the stretcher. Her temperature is 38.4°C (101.1°F), blood pressure is 84/52 mm Hg, pulse is 128/min and irregularly irregular, and respirations are 24/min. Physical examination reveals a moderately distended abdomen. There is diffuse, severe pain on light palpation with board-like rigidity and involuntary guarding. Bowel sounds are absent. Laboratory studies show a leukocyte count of 21,500/mm³ and a serum lactate level of 6.4 mmol/L. Which of the following is the most appropriate next step in management?

  1. Urgent exploratory laparotomyAnswer
  2. B
    Multiphasic computed tomography of the abdomen
  3. C
    Intravenous administration of unfractionated heparin
  4. D
    Endovascular catheter-directed thrombolysis
  5. E
    Diagnostic laparoscopy

Answer

Urgent exploratory laparotomy is the appropriate intervention.
The correct answer is urgent exploratory laparotomy. This patient's presentation is highly suspicious for acute mesenteric ischemia (AMI) caused by an arterial embolus, given her history of atrial fibrillation, recent discontinuation of apixaban, and sudden onset of severe abdominal pain. While early AMI typically presents with 'pain out of proportion to physical exam findings' (a relatively soft abdomen), this patient's condition has progressed to transmural bowel infarction. This is evidenced by her transition to lying completely still, developing board-like rigidity, involuntary guarding (peritonitis), and profound hemodynamic instability (shock) alongside severe lactic acidosis. In any patient with an acute surgical abdomen presenting with peritonitis or hemodynamic instability, the next best step is immediate exploratory laparotomy. Surgery allows for the resection of necrotic bowel, restoration of blood flow to viable segments (via embolectomy or bypass), and definitive source control. Delaying surgery for any reason in this clinical scenario severely increases mortality.

Step-by-Step Solution

1
Analyze the patient's risk factors and initial presentation.
The patient has atrial fibrillation without recent anticoagulation and developed sudden, severe abdominal pain (pain out of proportion to early exam), which is the classic presentation of embolic acute mesenteric ischemia.
Identifying the likely etiology of the acute abdomen frames the expected disease progression.
2
Evaluate the current physical examination and vital signs.
The patient is now hemodynamically unstable (BP 84/52 mm Hg) and has developed peritonitis (board-like rigidity, involuntary guarding, lying motionless).
Physical exam changes differentiate early ischemia (soft abdomen) from transmural infarction (peritonitis).
3
Determine the appropriate intervention pathway based on hemodynamic status and exam findings.
Because the patient has peritonitis and is in shock, advanced imaging must be bypassed in favor of immediate surgical exploration.
Delaying surgery to obtain imaging in an unstable patient with peritonitis significantly increases mortality.

Key Concept

Patients with suspected acute mesenteric ischemia who exhibit signs of peritonitis or hemodynamic instability require emergent exploratory laparotomy without delay for advanced imaging.
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Topics

Gastrointestinal and Abdominal Surgery

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