Synopsis
Detect evolving inhalational airway injury and occult carbon monoxide or cyanide toxicity, give immediate oxygen and secure specialist toxicology and airway care.
- Smoke injury can combine upper-airway thermal damage, lower-airway chemical injury, carbon monoxide poisoning, cyanide toxicity, bronchospasm, trauma and cutaneous burns.
- An enclosed fire, loss of consciousness, neurological symptoms or several co-exposed household members should raise concern even when the patient looks pink and pulse oximetry seems normal.
- Standard pulse oximetry cannot distinguish oxyhaemoglobin from carboxyhaemoglobin reliably, while PaO2 measures dissolved oxygen and may remain normal in serious carbon monoxide poisoning.
- Give the highest available inspired oxygen concentration promptly; do not wait for the carboxyhaemoglobin result and do not use a conventional saturation target during active carbon monoxide treatment.
- Carboxyhaemoglobin falls after removal and oxygen, and its value correlates imperfectly with tissue injury; symptoms, exposure, cardiac findings, acidosis and vulnerability guide severity.
- Hoarseness, stridor, drooling, soot in the mouth, facial burns and progressive swelling warrant early expert intubation because oedema and fluid resuscitation can make a later airway much harder.
- Severe lactic acidosis, cardiovascular collapse or coma after an enclosed-space fire suggests possible cyanide toxicity; seek immediate TOXBASE advice and do not wait for a cyanide assay.
- ECG changes and troponin elevation can reveal carbon-monoxide myocardial injury, particularly in older people or those with coronary disease, and change monitoring intensity.
- Pregnancy lowers the threshold for specialist discussion because fetal carboxyhaemoglobin can rise higher and clear more slowly than maternal levels.
- Routine antibiotics and corticosteroids do not prevent smoke-inhalation complications; treat established infection or a specific airway indication instead.
Key red flags
Voice change, stridor, dysphagia, drooling, tongue or oropharyngeal swelling, facial or neck burns and increasing work of breathing predict a narrowing airway. Absence of external burns does not guarantee safety.
Cough, wheeze, carbonaceous sputum, hypoxaemia, coarse breath sounds and rising secretion burden may evolve after an initially normal examination. Bronchial casts and acute lung injury can cause later deterioration.
Headache, dizziness, nausea, weakness, confusion, ataxia, syncope, seizures, coma, chest pain or arrhythmia after combustion exposure are non-specific but important. Clustered symptoms in co-occupants strongly support a shared source.
Ischaemic chest discomfort, hypotension, dysrhythmia, ECG change or troponin rise suggests myocardial injury from hypoxic stress. Symptoms can be subtle in older adults and those with diabetes.
Rapid collapse, coma, seizures, severe hypotension and marked lactic acidosis after an enclosed fire, particularly with soot or very high smoke burden, warrant immediate toxicology-guided antidote consideration.
Pregnant people, fetuses, infants, older adults, and patients with anaemia or cardiopulmonary disease may have severe effects at lower measured carboxyhaemoglobin and deserve cautious specialist assessment.
Investigation priorities
Define likely toxicants, dose and risk to others.
Management branches
Hoarseness, stridor, oral burns, swelling, respiratory fatigue or a high-risk enclosed fire.
- Move to a monitored resuscitation area, give high-concentration oxygen, remove contaminated clothing when relevant and call senior anaesthesia, critical care and the burns service early.
- Assess mouth, voice, neck, breathing effort and associated facial trauma repeatedly; do not rely on one normal laryngoscopic view or chest radiograph.
- Intubate early using the local difficult-airway plan when progression is likely, with smaller tubes, videolaryngoscopy, fibreoptic or front-of-neck rescue equipment selected by experts.
- After securing the airway, use lung-protective ventilation, humidification and secretion clearance; arrange bronchoscopy when distal injury or casts are clinically important.
The airway is stable and immediate resuscitation is complete.
- Observe high-risk exposures for evolving airway, pulmonary, neurological and cardiac features with duration based on symptoms, investigations and toxicology advice.