Case Presentation: A 56 year-old female teacher presents with 1-week history of shortness of breath. She noted progressive shortness of breath on minimal exertion over the past week. She denied associated pedal edema, orthopnea, epistaxis or chest pain. She noted associated cough with white frothy sputum and subjective chills. She denied rashes, exposure to sick contacts, recent travel or change in medications. No prior similar complaints in the past. On exam, the patient was in moderate respiratory distress requiring 6 liters of oxygen via nasal cannula (none at baseline), RR=25, HR=90. Lungs showed reduced air entry and wheezes over bilateral lower lung fields. Heart sounds were normal with no murmurs. JVP was not elevated. No pedal edema was noted on exam. Skin was pale with no rashes.
Labs were notable for WBC=12,000/uL, Hb=9.5g/dL, BNP=20ng/L, D-dimer was negative. A chest x-ray was done and the report noted bilateral infiltrates with possible pneumonia. She was started on IV antibiotics for suspected pneumonia and was admitted to intermediate medical floor. The patient continued to be dyspneic and hypoxic after 48 hours of treatment. On further questioning the patient, she noted history of Osler-Weber-Randu (OWR) . A CT chest was ordered to rule-out pulmonary hemorrhage in setting of low hemoglobin and history of OWR. The CT was notable for 2-3 pulmonary arterio-venous malformations (AVMs) that were actively bleeding. The patient’s AVMs was embolized by Interventional Radiology and her oxygen requirements improved following the procedure and required 1 unit of blood transfusion to control the bleeding.

Discussion: Osler-Weber-Rendu also known as Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disease that is characterized by abnormal blood vessel formation. It commonly involves the skin, mucous membranes, central nervous system, liver, lungs and spleen. It is diagnosed by having 3 out of the 4 Curacao criteria: Epistaxis ,telangiectasias, visceral lesions or family history (a first-degree relative with HHT). Pulmonary AVMs occur in 15-30% of cases and are asymptomatic in nature. However, clinical suspicion can be life-saving in the setting of shortness of breath or increasing oxygen requirements in at risk, hospitalized patients. A good history and physical exam aided in the diagnosis of actively bleeding pulmonary AVMs in our patient.

Conclusions: Pulmonary AVMs should be in the differential of shortness of breath or refractive hypoxic respiratory failure in hospitalized patients with existing or suspected history of OWR. Pulmonary AVMs are usually asymptomatic but can be have serious complications including hypoxemia, hemorrhage, right-to-left shunting, secondary polycythemia and increased incidence of infection as a result of septic emboli. Anchoring on the initial diagnosis such as pneumonia can lead to preventable diagnostic and treatment errors. A high index of suspicion along with a good history and physical exam can aid in reaching the correct diagnosis.