What makes massive hemoptysis massive? - Classic teaching is 100 cc/h but really it's an amount of blood that is causing hemodynamic instability, airway obstruction or abnormal gas exchange. 

Why did this patient go into cardiac arrest? - Asphyxiation as the tracheobronchial tree can hold ~ 200 cc. 

Why does this patient have massive hemoptysis? - Likely secondary to the fungus ball eroding into bronchial artery.

• 90% of bleeds secondary to involvement of the high pressure bronchial arteries.
• 10% of massive hemoptysis involve pulmonary arteries which give off larger volumes but at lower pressures.

What are some etiologies for massive hemoptysis?

• The Big 3 for massive hemoptysis are:
• Infection: TB, Pneumonia, Lung Abscess, Cavitary lesion like Mycetoma
• Mass/ Neoplasm
• Bronchiectasis
• Other etiologies include PE, AVM, Connective Tissue Disease, Diffuse Alveolar Hemorrhage, Trauma

Management

• More on management and the resolution of this case to be discussed next week.
• ABC's
• Airway or Asphyxiation 
• Reverse coagulopathy, resuscitate for hemorrhage 
• Localize the bleed
• Refractory hypoxemia on mechanical ventilation is a shunt problem; some ARDS maneuvers are applicable in this situation
• Early consultation
• Pulmonary for bronchoscopy
• IR and CTA when stable for embolization
• Thoracic Surgeon
• Consider systemic TXA