What mechanism leads to pink frothy sputum?

What mechanism leads to pink frothy sputum?

• A. Alveolar edema
• B. Bacterial infection
• C. Ruptured bronchial veins from the mix of blood and airway fluids
• D. Severe bronchospasm

Answer: (C)

Pink frothy sputum occurs when edema fluid fills the air spaces and mixes with a small amount of blood entering the airway. In pulmonary edema, fluid leaks from the alveolar-capillary membranes; if bronchial veins rupture, blood enters the airway secretions. As air passes through this liquid during breathing or coughing, it creates froth and gives the sputum a pink tint from the blood. This differs from infection, which tends to produce purulent (yellow-green) sputum, or severe bronchospasm, which usually yields little to no frothy sputum.

Pink frothy sputum occurs when edema fluid fills the air spaces and mixes with a small amount of blood entering the airway. In pulmonary edema, fluid leaks from the alveolar-capillary membranes; if bronchial veins rupture, blood enters the airway secretions. As air passes through this liquid during breathing or coughing, it creates froth and gives the sputum a pink tint from the blood. This differs from infection, which tends to produce purulent (yellow-green) sputum, or severe bronchospasm, which usually yields little to no frothy sputum.