Smoke Inhalation

What to do now

1. Get out and stay out of the smoke. Never go back into a burning building.
2. Call 911 for anyone who was trapped in smoke, has burns, or has any warning signs.
3. Move to fresh air and keep the person calm and still, ideally sitting up if breathing is difficult.
4. If they are not breathing, start CPR.
5. Cool any burns with cool running water for 20 minutes. See burn injury.
6. Tell responders how long the person was exposed and whether it was an enclosed space.

How smoke injures the body

Heat injury

Hot air and gases burn the mouth, throat and voice box. The upper airway can swell rapidly, sometimes over several hours, and block breathing. Steam can burn deeper into the airways.

Chemical injury

Smoke contains soot and irritant chemicals (such as acrolein, ammonia, hydrogen chloride and sulfur dioxide) from burning plastics, furniture and building materials. They damage the airway lining, cause swelling and mucus, trigger bronchospasm and can lead to acute respiratory distress syndrome and pneumonia days later.

Toxic gases

• Carbon monoxide binds to hemoglobin far more tightly than oxygen, so blood carries less oxygen. Standard pulse oximeters can give falsely normal readings.
• Hydrogen cyanide, from burning plastics, wool and foam, blocks cells from using oxygen.
• Together they cause most early deaths in house fires.

Symptoms

• Cough, sometimes with black or gray sputum
• Hoarseness or loss of voice
• Sore throat and difficulty swallowing
• Breathlessness, wheezing or chest tightness
• Stridor (high-pitched breathing), a sign of airway narrowing
• Soot around the nose and mouth, singed facial hair
• Red, watery, irritated eyes
• Headache, dizziness, nausea and vomiting (carbon monoxide)
• Confusion, drowsiness, seizures, collapse
• Cherry-red skin (rare and late) or blue lips

Symptoms can be delayed. Airway swelling may peak 12 to 24 hours after exposure, and lung injury may develop over 1 to 3 days.

Diagnosis

• Examination of the face, mouth, nose and throat for burns and soot
• Blood gas test with co-oximetry to measure carboxyhemoglobin (carbon monoxide level)
• Lactate level: very high levels suggest cyanide poisoning
• Chest X-ray, which is often normal at first
• Bronchoscopy to examine airway damage
• ECG and heart tests, as carbon monoxide can strain the heart

Treatment

Oxygen

100% oxygen through a tight-fitting mask is given immediately. It shortens the half-life of carbon monoxide from around 5 hours to about 1 hour.

Airway protection

Early insertion of a breathing tube may be needed before swelling makes it impossible, especially with facial burns, stridor or hoarseness.

Breathing support

• Bronchodilators for wheezing
• Humidified oxygen
• Suctioning and airway clearance
• Mechanical ventilation for severe lung injury

Antidotes

• Hydroxocobalamin for suspected cyanide poisoning
• Hyperbaric oxygen therapy may be considered for severe carbon monoxide poisoning, especially with loss of consciousness, neurological symptoms or pregnancy

Burns and other care

Treatment of skin burns, fluids, pain control and monitoring for infection.

Complications

• Airway obstruction
• Pneumonia
• Acute respiratory distress syndrome
• Respiratory failure
• Worsening asthma or COPD
• Delayed neurological effects of carbon monoxide: memory problems, mood changes and movement problems appearing days to weeks later
• Long-term airway narrowing or reactive airway disease

Wildfire smoke

Wildfire smoke contains fine particles (PM2.5) that irritate the lungs and worsen heart and lung disease, even far from the fire. To protect yourself:

• check local air quality (AirNow in the US)
• stay indoors with windows closed and use a HEPA air cleaner
• wear a well-fitted N95 or KN95 mask outdoors; cloth and surgical masks do not filter fine particles well
• keep rescue inhalers and medicines on hand

Prevention

• Install smoke alarms and carbon monoxide detectors on every level of your home and test them monthly
• Plan and practice fire escape routes
• Stay low under smoke when escaping
• Never use generators, grills or camp stoves indoors

Frequently asked questions

What are the symptoms of smoke inhalation?

Symptoms include cough, hoarseness, sore throat, breathlessness, wheezing, chest tightness, eye irritation, headache, dizziness and nausea. Soot around the mouth or nose, noisy breathing, confusion or drowsiness are signs of serious injury needing emergency care.

Can smoke inhalation symptoms be delayed?

Yes. Airway swelling can worsen over 12 to 24 hours and lung injury can develop over 1 to 3 days. Carbon monoxide can cause delayed memory and mood problems weeks later. Anyone with significant exposure should be checked even if they feel fine.

What is the treatment for smoke inhalation?

Treatment starts with 100% oxygen, protecting the airway, and medicines to open the airways. Cyanide poisoning is treated with hydroxocobalamin, and severe carbon monoxide poisoning sometimes with hyperbaric oxygen. Severe lung injury may need a ventilator.

How long does it take to recover from smoke inhalation?

Mild cases improve within days. Moderate to severe injuries can take weeks to months, and some people develop lasting cough, breathlessness or asthma-like symptoms. People with carbon monoxide poisoning need follow-up for delayed neurological effects.

Is wildfire smoke dangerous?

Yes, especially for children, older adults, pregnant women and people with heart or lung disease. Fine particles can trigger asthma attacks, heart problems and breathing difficulties. Stay indoors, use HEPA air cleaners and wear an N95 mask outdoors when air quality is poor.