Signs of Inhalation Injury
Suspect inhalation injury immediately in any patient with fire exposure in an enclosed space, facial burns, soot around the nose or mouth, singed nasal hairs, carbonaceous sputum, dysphonia, stridor, wheezing, or respiratory distress. 1, 2, 3
Critical Clinical Indicators
Most Specific Sign
- Carbonaceous (blackish) sputum is the most indicative finding of inhalation injury, as it represents direct evidence of smoke particle deposition in the lower airways and actual inhalation of combustion products 3, 4
High-Risk Historical Features
- Fire in an enclosed space (strongly raises suspicion) 1, 2, 3
- Exposure to vapors or inhaled smoke 1, 3
- Loss of consciousness at the scene 5
Upper Airway Signs
- Facial burns (particularly deep or extensive) 1, 2
- Soot on face, around nose, or in nares 1, 2, 3
- Singed nasal hairs or facial hair 1, 3
- Blistering or edema of the oropharynx 5
- Deep circular neck burns 1
Respiratory Signs
- Dysphonia (voice changes) 1, 2, 3
- Stridor (indicates critical airway narrowing) 1, 5
- Wheezing 1, 2, 3
- Dyspnea or difficulty breathing 1, 2, 3
- Respiratory distress 1, 5
- Use of accessory respiratory muscles 5
- Hypoventilation 5
Systemic Signs
- Altered mental status or coma (may indicate carbon monoxide or cyanide poisoning) 1, 2
- Severe hypoxia or hypercapnia 1, 2
Critical Diagnostic Pitfalls
False Reassurance from Normal Tests
- Normal oxygen saturation does NOT exclude inhalation injury and may remain falsely elevated initially despite significant airway damage 1, 3
- Normal chest X-ray does NOT exclude inhalation injury 1, 3
- Normal arterial blood gases do NOT exclude inhalation injury 1
- Normal FEV1/FVC ratio cannot exclude inhalation injury 3
- Normal bronchoscopy findings do NOT exclude inhalation injury, as bronchoscopy only assesses proximal airways 3
Progressive Nature of Injury
- Glottic edema and respiratory distress can develop rapidly and unpredictably even in patients with initially normal findings 1, 3
- Patients with face/neck burns who were exposed to smoke require close continuous monitoring due to risk of progressive airway compromise 1, 3
- Regular reassessment is critical as inhalation injury can progress over time, with symptoms potentially delayed for up to 48 hours 3, 6
Immediate Actions Required
When to Intubate Without Delay
- Severe respiratory distress 1, 2
- Severe hypoxia or hypercapnia 1, 2
- Coma or altered mental status 1, 2
- Symptoms of airway obstruction or stridor 1, 5
- Deep circular neck burn 1
- Severe burns involving the whole face 1
- Very extensive burns (TBSA ≥40%) 1
Emergency Activation
- Immediately activate EMS for any patient with signs of inhalation injury, as airway obstruction from edema can develop rapidly 1