Aspiration pneumonia occurs due to what?

• A. Aspiration of gastric contents causing chemical pneumonitis
• B. Bacterial infection of alveoli
• C. Viral infection of bronchial tree
• D. Fungal infection of lungs

Answer: (A)

Aspiration pneumonia happens when gastric contents are inhaled into the lungs, causing chemical pneumonitis from the acidic stomach fluid. That chemical irritation injures the airway and alveolar membranes, triggering inflammation and edema which can impair gas exchange. A bacterial infection of the alveoli can occur later if bacteria colonize the damaged tissue, but the initial problem is the chemical injury from the aspirated material, not a primary infection by bacteria, viruses, or fungi. In pregnancy, risk factors include vomiting or reflux during labor and conditions that blunt airway protection; recognizing the chemical nature of the injury helps guide management and the decision to use antibiotics only if a bacterial infection is suspected.