Difficult to predict which patients with<unk> is will go on to develop<unk> ,<unk>  alone does not cause<unk> 
Witnessed<unk>  key to distinguishing between the two<unk> <unk> is
Inflammatory chemical injury of tracheobronchial tree and pulmonary parenchyma
Due to inhalation of regurgitated sterile gastric contents
Must aspirate at least 20-30mL of gastric contents with pH <2.5
Can lead to<unk><unk>  due to pulmonary defense mechanism injury<unk><unk> 
Alveolar space infection secondary to inhalation of pathogenic material from oropharynx
Result of a complex interplay of the aspirated material, aspirated volume, pH, patient physiology and pulmonary defense mechanisms
Increased in patients with periodontal disease, chronic colonization of upper airways, or taking PPI/H2-blockers
Accounts for up to 20% of community-acquired<unk>  in elderly, majority of nursing home-acquired<unk> 
Microbiology
Community acquired: Pneumococcus, staph, H flu, enterobacter
Hospital acquired: Pseudomonas, gram-negatives
Inflammatory chemical injury of tracheobronchial tree and pulmonary parenchyma
Due to inhalation of regurgitated sterile gastric contents
Must aspirate at least 20-30mL of gastric contents with pH <2.5
Can lead to<unk><unk>  due to pulmonary defense mechanism injury
Alveolar space infection secondary to inhalation of pathogenic material from oropharynx
Result of a complex interplay of the aspirated material, aspirated volume, pH, patient physiology and pulmonary defense mechanisms
Increased in patients with periodontal disease, chronic colonization of upper airways, or taking PPI/H2-blockers
Accounts for up to 20% of community-acquired<unk>  in elderly, majority of nursing home-acquired<unk> 
Microbiology
Community acquired: Pneumococcus, staph, H flu, enterobacter
Hospital acquired: Pseudomonas, gram-negatives
Community acquired: Pneumococcus, staph, H flu, enterobacter
Hospital acquired: Pseudomonas, gram-negatives
Aspiration pneumonia and pneumonitis
Pulmonary
High altitude pharyngitis and bronchitis
Airway obstruction
Immersion pulmonary edema
Anaphylaxis
Multisystem inflammatory syndrome in children
Angioedema