Correct!
2. Left-to-right shunting of blood

Pulmonary arteriovenous malformations in the context of hereditary hemorrhagic telangiectasia (HHT, also referred to as Osler-Weber-Rendu disease, or OWR) are often associated with mutations in endoglin, ACVLI/ALK1, or Smad4. Hypoxemia in patients with HHT may be the result of right-to-left shunting, and may even be present even when such patients are completely asymptomatic. Strokes may occur in patients with HHT owing to right-to-left shunting producing cerebral embolization. Orthodeoxia- a decrease in blood oxygenation in the standing position compared with the supine position- occurs in patients with pulmonary arteriovenous malformations owing to the basal predominance of the vascular lesions, which leads to increased shunting when upright and reduction in perfusion of the arteriovenous malformations when lying supine. Pulmonary arteriovenous malformations are associated with right-to-left, not left-to-right, shunting of blood.

Which of the following courses of action is the NOT an appropriate next step for the management of this patient? (Click on the correct answer to be directed to the tenth and final page)

  1. Antibiotic prophylaxis for minor procedures associated with transient bacteremia
  2. Assess for shunting with an echocardiographic bubble study
  3. Bronchoscopy with fluoroscopically-guided transbronchial biopsy of the right middle lobe lesion
  4. Catheter pulmonary angiography with embolization
  5. Fecal occult blood testing

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