Synopsis
Separate sterile chemical aspiration pneumonitis from bacterial aspiration pneumonia, stabilise acute lung injury, treat infection proportionately, and reduce recurrence through swallowing, oral-care and person-centred feeding decisions.
- Aspiration pneumonitis is an acute chemical injury, often after witnessed large-volume gastric aspiration in a person with reduced consciousness; aspiration pneumonia is infection after aspiration of bacteria-rich secretions.
- The distinction is temporal and clinical, not established by procalcitonin: pneumonitis can improve over 24–48 hours with support, whereas persistent or later fever and deterioration suggest secondary infection.
- Assess swallowing impairment, consciousness, neurological disease, frailty, reflux, dentition, sedative medicines, feeding dependence and the patient's baseline communication and goals.
- Chest radiography can miss aspiration pneumonia; CT is appropriate when the film is inconclusive and the diagnosis or a complication remains important.
- Do not give prophylactic antibiotics after uncomplicated chemical aspiration. Treat established aspiration pneumonia using local microbiology guidance; co-amoxiclav is a reasonable common initial choice.
- Routine extra anaerobic cover is not recommended; include it when putrid sputum, severe dental disease, lung abscess or empyema makes anaerobic infection credible.
- BTS suggests five total days when aspiration pneumonia is improving clinically, with IV-to-oral switch only when swallowing and absorption are safe.
- Prevent recurrence with speech and language therapy assessment, twice-daily tooth/tongue/palate brushing, medication review, positioning and individualised feeding decisions; tubes do not eliminate aspiration.
Key red flags
Abrupt cough, wheeze, hypoxaemia and bilateral or dependent infiltrates within hours of a witnessed large gastric aspiration, usually during reduced consciousness, anaesthesia or vomiting.
Stridor, unilateral absent air entry, visible particulate material, escalating oxygen need, shock or reduced consciousness requires immediate airway and critical-care help.
Putrid sputum, persistent sepsis, cavitation or pleural fluid suggests anaerobic infection, lung abscess or empyema and changes both duration and source control.
Investigation priorities
Distinguish abrupt chemical aspiration from infective microaspiration and identify recurrence risks.
Management branches
Abrupt respiratory deterioration during vomiting, feeding, anaesthesia or reduced consciousness.
- Call for airway help, position safely, suction visible oral or tracheal material, provide target-based oxygen and support ventilation; bronchoscopy is considered for persistent large particulate obstruction, not routine lavage.
- Assess severity with observations and gas exchange, obtain imaging when stable, and treat bronchospasm or shock through the appropriate acute pathway.
- Withhold prophylactic antibiotics when the presentation is uncomplicated chemical pneumonitis; reassess closely over 24–48 hours for improvement or emerging bacterial infection.