Aspiration pneumonia and pneumonitis
Background
- Difficult to predict which patients with pneumonitis will go on to develop pneumonia, aspiration alone does not cause pneumonia
- 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 pneumonia due to pulmonary defense mechanism injury
- Aspiration pneumonia
- 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 pneumonia in elderly, majority of nursing home-acquired pneumonia
- Microbiology
- Community acquired: Pneumococcus, staph, H flu, enterobacter
- Hospital acquired: Pseudomonas, gram-negatives
Risk factors
- Advanced age
- Altered level of consciousness
- Anatomic abnormality of upper airway
- Dementia
- Esophageal disorders
- Gastroesophageal reflux
- Neuromuscular disease
- Poor oral hygiene
- Prior history of aspiration
- Prolonged supine position
- Retained gastric material
- Tube feedings
Clinical Features
- Aspiration pneumonia
- Fever
- Dyspnea
- Productive cough
- Tachypnea
- [[Tachycardia
- Altered mental status
- Aspiration pneumonitis
- Cough
- Bronchospasm
- Tachypnea
- Bloody sputum
- Low-grade fever
- Respiratory distress
Differential Diagnosis
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
- Abdominal distension
- Anemia
- CO Poisoning
- Salicylate toxicity
- Diabetic ketoacidosis (DKA)
- Diaphragm injury
- Electrolyte abnormalities
- Epiglottitis
- Flail chest
- Hypotension
- Metabolic acidosis
- Pneumonia
- Pneumothorax/hemothorax
- Renal Failure
- Sepsis
- Toxic ingestion
- Other Associated with ↓ Respiratory Effort
Pediatric-specific
- Aspirated foreign body
- Respiratory distress syndrome
- Meconium aspiration syndrome
- Bronchiolitis (peds)
- Pertussis
- Bronchopulmonary dysplasia
- Croup
- Bacterial tracheitis
- Tracheomalacia
- Congenital heart disease
- Vascular ring
- Neonatal abstinence syndrome
- Inborn errors of metabolism
- Brief resolved unexplained event
- Normal neonatal periodic breathing (misinterpreted by caregivers as abnormal)
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
Evaluation
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
- CT
- Increased sensitivity, specificity, and overall accuracy compared to CXR
- Reasonable to obtain even if CXR negative if clinical suspicion is high
- Aspiration is a risk factor for pulmonary abscess formation
Management
- Aspiration pneumonitis
- Suction upper airway if aspiration is witnessed
- Antibiotics
- Only recommended if symptoms persist >48hr
- Aspiration pneumonia
- Community-acquired
- Health care-associated or periodontal disease or alcoholism
- Ceftriaxone + clindamycin OR
- Piperacillin-tazobactam + clindamycin OR
- Ampicillin-sulbactam + clindamycin OR
- Cefepime + clindamycin OR
- Levofloxacin + clindamycin
Disposition
- Admit all patients with aspiration pneumonia
- For aspiration pneumonitis, consider discharge if:
- Otherwise healthy and non-toxic
- Give outpatient antibiotics if symptomatic for >48hrs
- For aspiration pneumonitis, consider admission for:
- Chronically ill or immunocompromised
- Nursing home patient
See Also
References
This article is issued from
Wikem.
The text is licensed under Creative
Commons - Attribution - Sharealike.
Additional terms may apply for the media files.