A 60 yo F presents to the ED w cough and dyspnea. History is limited due to the patient's respiratory distress, but you are able to determine that she does have underlying lung disease and is on home O2.  Vital signs are significant for a RR of 36 and SPO2 is 84% on 6L NC. A CT chest is obtained and shown below. What's the diagnosis?  (scroll down for answer) 

Answer: Bullous Emphysema 

• Bullous Emphysema= subset of COPD
• Bulla = an air filled space of > 1 cm in diameter within the lung which has developed because of emphysematous destruction of the lung parenchyma
• Male predominance (~ 90%)
• Two most common causes are smoking, alpha-1 antitrypsin deficiency
• Higher occurrence of exacerbations and higher rates of hospitalizion compared to COPD patients
• Patients with history of bullous emphysema should aviod flying, especially during exacerbations, due to increased risk of spontaneous pneumothorax!