Inhalation Burns and Smoke Inhalation Injury

Inhalation injury is the leading cause of death in fire victims. More people die from breathing in smoke, toxic combustion gases, and superheated air than from skin burns alone. In patients with both skin burns and inhalation injury, the fatality rate is dramatically higher than for either injury in isolation.

Inhalation injury is also more complex than it appears from outside. The lungs and airways may appear to be functioning immediately after exposure while tissue damage continues to develop over hours. Symptoms can be absent immediately after exposure and then progress rapidly to life-threatening respiratory failure. Any person who has been in a building fire, a vehicle fire, or an enclosed space fire must be medically assessed regardless of how they appear immediately after rescue.

Three Types of Inhalation Injury

Inhalation injury encompasses three distinct mechanisms, which can occur separately or together:

Type	Cause	Effect	Timeline
Upper airway thermal burn	Inhalation of superheated air or steam	Burns to mouth, throat, larynx, and upper trachea; oedema (swelling) can obstruct airway	Swelling develops within 30 minutes to several hours
Lower airway and lung injury	Inhalation of toxic combustion products (aldehydes, hydrogen cyanide, carbon monoxide, fine particles)	Damage to bronchi and alveoli; disrupts oxygen transfer	Can worsen over 24–72 hours
Systemic toxicity	Absorption of carbon monoxide, hydrogen cyanide, and other toxins into bloodstream	CO displaces oxygen in blood; cyanide impairs cellular respiration	Immediate; may cause rapid collapse

Signs of Inhalation Injury

Immediate Signs

Sign	Significance
Singeing of facial hair, eyebrows, or nasal hair	Indicates extreme heat near the face; high probability of airway involvement
Burns to lips, mouth, or tongue	Direct airway exposure
Soot in the mouth, nose, or throat	Combustion products inhaled
Hoarse voice	Swelling in the larynx — airway compromise is developing
Stridor (high-pitched sound on breathing in)	Narrowing airway — critical warning sign
Coughing with carbonaceous sputum (black)	Inhaled combustion products
Rapid or laboured breathing	Respiratory compromise
Confusion, agitation, or drowsiness	Possible carbon monoxide poisoning or hypoxia

Delayed Signs (Hours After Exposure)

Sign	Significance
Progressive worsening of breathing	Oedema developing in airways
Increasing hoarseness	Worsening airway swelling
Coughing increasing	Airway irritation and inflammation
Reduced oxygen saturation (if measured)	Lung function compromised
Deteriorating consciousness	Progressing toxicity or hypoxia

⚠️ A person with facial burns, singed nasal hair, or hoarse voice after fire exposure may appear to be breathing adequately. This presentation can deteriorate rapidly over 1–4 hours as airway swelling develops. All such patients require immediate emergency hospital care — even if they are walking and talking.

First Aid Response

For a Conscious Person with Smoke Inhalation

1. Move to fresh air — the priority is removing the person from further exposure.
2. Call 999 — all significant smoke inhalation requires emergency medical response.
3. Sit upright — upright positioning is better for breathing than lying flat; semi-recumbent if the person cannot sit unsupported.
4. Loosen clothing around the neck and chest.
5. Do not give food or water — if the airway is injured, swallowing may worsen or complicate intubation at hospital.
6. Monitor breathing continuously — any worsening, stridor, or increased distress requires immediate updating of emergency services.

For an Unconscious Person with Suspected Inhalation Injury

1. Confirm breathing — look, listen, feel.
2. If not breathing: begin CPR immediately.
3. If breathing: recovery position; monitor breathing continuously.
4. Airway management — tilt the head back to open the airway; if there is suspected spinal injury, use jaw thrust without head tilt if possible.
5. Call 999 if not already done.

Carbon Monoxide Inhalation (See Also CO Poisoning Article)

Inhalation injury frequently co-occurs with CO poisoning:

• CO poisoning symptoms: headache, nausea, confusion, loss of consciousness
• CO poisoning causes cherry-red skin in some cases (unreliable sign)
• Treatment at hospital: high-flow oxygen; possible hyperbaric oxygen
• CO poisoning can occur without visible signs of inhalation burn

What Not to Do

Action	Why Not
Give food or water to someone with airway burns	May complicate emergency airway management
Lay the person flat if conscious	Reduces lung capacity; upright or semi-recumbent is better
Assume they are fine because they appear okay	Delayed deterioration is a feature of inhalation injury
Leave them unmonitored	Respiratory status can deteriorate quickly

Hospital Treatment of Inhalation Injury

At hospital, inhalation injury is managed with:

• High-flow oxygen via mask (100% O₂)
• Early intubation (breathing tube) if airway swelling is anticipated — it is easier to intubate before the airway swells than after
• Bronchoscopy to assess lower airway damage
• Nebulised medications to reduce bronchospasm
• Hyperbaric oxygen therapy for severe CO poisoning

Early intubation is performed proactively in cases with clear signs of upper airway involvement — the window for safe intubation is limited if swelling develops. This is why transfer to hospital rapidly is critical even when the patient appears stable.

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Quick Reference

Sign	Action
Singed nasal hair / facial burns	Emergency — call 999; potential inhalation injury
Hoarse voice after fire exposure	Emergency — airway swelling developing
Stridor (high-pitched breathing sound)	Critical — airway critically narrowed; call 999 immediately
Confusion after fire	CO poisoning or hypoxia — fresh air + 999
Appears okay but was in building fire	Still requires medical assessment — delayed deterioration
Unconscious + smoke inhalation	Recovery position; CPR if not breathing; call 999
Do not	Give food/water; leave unmonitored; assume stable