Examkin

Question

Difficulty: MediumDiagnostic Workup and Test Sequencing

A 78-year-old woman is brought to the emergency department by her family due to the sudden onset of severe, relentless abdominal pain that began 2 hours ago. She also reports one episode of non-bloody emesis. Her past medical history is significant for hypertension, type 2 diabetes mellitus, and atrial fibrillation. She was prescribed apixaban but admits she stopped taking it two weeks ago due to financial difficulties. Current vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 145/85 mm Hg, pulse of 118/min and irregularly irregular, and respiratory rate of 22/min. Physical examination reveals a soft, non-distended abdomen. There is mild, diffuse tenderness to palpation, but no guarding, rebound tenderness, or rigidity. Bowel sounds are diminished. Stool guaiac test is negative. Given the most likely diagnosis, which of the following studies represent the most appropriate initial concurrent diagnostic workup for this patient? (Select all that apply)

  1. Computed tomography angiography of the abdomen and pelvisAnswer
  2. Serum lactate concentrationAnswer
  3. C
    Conventional catheter-directed mesenteric angiography
  4. D
    Magnetic resonance angiography of the abdomen
  5. E
    Colonoscopy

Answer

The correct initial concurrent diagnostic workup includes computed tomography angiography of the abdomen and pelvis AND serum lactate concentration.
The clinical presentation of sudden, severe abdominal pain out of proportion to physical examination findings in a patient with unanticoagulated atrial fibrillation is highly suspicious for acute mesenteric ischemia (AMI) due to an arterial embolus. The most appropriate initial concurrent diagnostic workup includes computed tomography angiography (CTA) of the abdomen and pelvis and a serum lactate concentration. CTA is the non-invasive gold standard for diagnosing AMI, providing rapid and highly sensitive visualization of the mesenteric vasculature to identify occlusions. Concurrently, a serum lactate concentration should be drawn; while it may be normal early in the disease course, an elevated lactate indicates tissue hypoperfusion and bowel infarction, which helps risk-stratify the patient and dictates the urgency of surgical intervention.

Step-by-Step Solution

1
Identify the most likely diagnosis based on the clinical presentation.
The patient has sudden, severe abdominal pain out of proportion to physical exam findings, combined with unanticoagulated atrial fibrillation, highly suggesting acute mesenteric ischemia (arterial embolism).
Recognizing the high pre-test probability of a life-threatening vascular emergency determines the urgency and type of diagnostic testing.
2
Select the most appropriate initial imaging modality.
Computed tomography angiography (CTA) of the abdomen and pelvis.
CTA is rapid, highly sensitive, and non-invasive, making it the preferred first-line imaging test to identify mesenteric vessel occlusion.
3
Select the most appropriate concurrent laboratory study to assess disease severity.
Serum lactate concentration.
An elevated serum lactate indicates tissue hypoxia and potential bowel necrosis, which helps guide the urgency of surgical consultation, although a normal level early on does not rule out ischemia.

Key Concept

In patients with suspected acute mesenteric ischemia, the most appropriate initial concurrent diagnostic workup is a computed tomography angiography (CTA) of the abdomen and pelvis alongside a serum lactate concentration.
Rate this question

Topics

Diagnostic Workup and Test Sequencing

More questions from this topic