Aspiration pneumonia and pneumonitis
Background
- Difficult to predict which pts with pneumonitis will go on to develop PNA
- Aspiration pneumonitis
- 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 aspiration PNA d/t pulmonary defense mechanism injury
- Due to inhalation of regurgitated sterile gastric contents
- Inflammatory chemical injury of tracheobronchial tree and pulmonary parenchyma
- Aspiration pneumonia
- Alveolar space infection d/t inhalation of pathogenic material from oropharynx
- Increased in pts w/ periodontal dz, chronic colonization of upper airways, PPI/H2 meds
- Accounts for up to 20% of CAP in elderly, majority of nursing home-acquired PNA
- Microbiology
- Community acquired: Pneumococcus, staph, H flu, enterobacter
- Hospital acquired: Pseudomonas, gram-negatives
- Alveolar space infection d/t inhalation of pathogenic material from oropharynx
Clinical Features
- Aspiration pneumonitis
- Cough, tachypnea, bloody sputum, respiratory distress
- Aspiration PNA
- Fever, dyspnea, productive cough, Tachypnea, tachycardia, AMS
Differential Diagnosis
Acute dyspnea
Emergent
- Pulmonary
- Airway obstruction
- Anaphylaxis
- Angioedema
- Aspiration
- Asthma
- Cor pulmonale
- Inhalation exposure
- Noncardiogenic pulmonary edema
- Pneumonia
- Pneumocystis Pneumonia (PCP)
- Pulmonary embolism
- Pulmonary hypertension
- Tension pneumothorax
- Idiopathic pulmonary fibrosis acute exacerbation
- Cystic fibrosis exacerbation
- Cardiac
- Other Associated with Normal/↑ Respiratory Effort
- Other Associated with ↓ Respiratory Effort
Non-Emergent
- ALS
- Ascites
- Uncorrected ASD
- Congenital heart disease
- COPD exacerbation
- Fever
- Hyperventilation
- Interstitial lung disease
- Neoplasm
- Obesity
- Panic attack
- Pleural effusion
- Polymyositis
- Porphyria
- Pregnancy
- Rib fracture
- Spontaneous pneumothorax
- Thyroid Disease
- URI
Diagnosis
Work-Up
- CXR
- Unilateral focal or patchy consolidations in dependent lung segments
- Right lower lobe is most common area; bilateral patterns can also be seen
- Lower lobe infiltrate when aspiration occurs in upright position
- Upper lobe infiltrate when aspiration occurs in recumbent position
Management
- Aspiration pneumonitis
- Suction upper airway if aspiration is witnessed
- Abx
- Only recommended if symptoms persist >48hr
- Levo/moxifloxacin or clindamycin or amoxicillin-clavulanate
- Only recommended if symptoms persist >48hr
- Aspiration pneumonia
- Community-acquired
- Moxifloxacin or clinda or amoxicillin-clavulanate
- Health care-associated or periodontal disease or alcoholism
- Ceftriaxone + clindamycin OR
- Piperacillin-tazobactam + clindamycin OR
- Ampicillin-sulbactam + clindamycin OR
- Cefepime + clindamycin OR
- Levofloxacin + clindamycin
- Community-acquired
Disposition
- Healthy person
- Observe for 1hr; if asymptomatic discharge
- If mild-moderate symptoms develop and persist >48hr treat with antibiotics
- Chronically ill or nursing home pt
- Consider ED obs unit versus short admission for observation +/- prophylactic abx
- Admit all pts w/ aspiration PNA