Many people who have been burned in fires have also inhaled smoke. Sometimes people inhale smoke without sustaining skin burns.
Inhaling small amounts of smoke usually causes no serious, lasting effects. However, if the smoke contains certain poisonous chemicals or is unusually dense or if inhalation is prolonged, serious problems can develop. Even common household materials such as plastics and fabrics can produce poisonous chemicals (toxic products of combustion) when they burn.
Smoke inhalation can cause problems in several ways:
Carbon monoxide is a gas produced in many fires. When inhaled, carbon monoxide prevents the blood from carrying oxygen so tissues do not get enough oxygen (see also Carbon Monoxide Poisoning).
Many household and industrial substances release cyanide when burned and cause cyanide poisoning.
Inhalation of chemicals released in the smoke, such as hydrogen chloride, phosgene, sulfur dioxide, toxic aldehyde chemicals, and ammonia, can cause swelling and damage to the windpipe (trachea) and even the lungs. Eventually, the small airways leading to the lungs narrow, further obstructing airflow.
Hot smoke usually burns only the mouth and throat rather than the lungs because smoke cools quickly. However, an exception is steam, which carries much more heat energy than smoke and thus can also burn the airways in the lungs.
Symptoms of carbon monoxide poisoning include headache, nausea, drowsiness, confusion, and coma.
Damage to the windpipe, breathing passages, or lungs can cause cough, wheezing and/or shortness of breath. These symptoms can occur right away or take up to 24 hours to develop.
Burns of the mouth and throat cause swelling that can make it difficult to breathe air in. People may have soot in the mouth or nose, singed nasal hairs, or burns around the mouth.
Sometimes a doctor's examination is all that is needed for people who have few or no symptoms and had only brief exposure to smoke.
People with symptoms usually need some testing, such as blood tests to measure oxygen and carbon monoxide levels and a chest x-ray. To assess the extent of injury due to smoke inhalation in people with significant symptoms, doctors may pass a flexible viewing tube (bronchoscope) into the trachea.
People who have inhaled smoke are given oxygen through a face mask. If a tracheal burn is suspected, a breathing tube is inserted through the nose or mouth in case the trachea later swells and obstructs airflow. If people begin to wheeze, drugs that open small airways, such as albuterol, may be given, usually as a mist that is combined with oxygen and inhaled through a face mask. If lung damage causes shortness of breath that persists despite use of a face mask and albuterol, a ventilator (breathing machine) may be necessary.