Common Causes of Inhalation Poisoning
Carbon monoxide and cyanide are the most common causes of severe inhalation poisoning, particularly in fire-related incidents, with other toxic gases, volatile substances, and chemical agents also presenting significant risks. 1, 2
Carbon Monoxide Poisoning
Carbon monoxide (CO) is one of the leading causes of poisoning death and results in thousands of emergency department visits annually in the United States 1. CO poisoning occurs through:
- Combustion sources in enclosed spaces (furnaces, heaters, engines) 1
- Structure fires and smoke inhalation 2
- Indoor use of charcoal briquettes 1
CO causes toxicity through multiple mechanisms:
- Binding to hemoglobin, reducing oxygen-carrying capacity 1
- Shifting the oxyhemoglobin curve to the left, further reducing tissue oxygenation 1
- Direct cellular toxicity through binding to intracellular proteins 1
- Immune-mediated injury and delayed inflammation 1
Cyanide Poisoning
Cyanide is another significant cause of inhalation poisoning, particularly in:
- Structure fires where synthetic materials burn 1, 2
- Industrial accidents involving hydrogen cyanide 1
Cyanide impairs cellular oxygen usage, with early signs including:
- Hyperventilation and tachycardia 1
- Progression to coma, cyanosis, and convulsions 1
- Severe metabolic acidosis (pH < 7.20) in serious cases 1
Other Common Inhalation Toxins
- Volatile organic compounds: Including butane, solvents from adhesives, typewriter correction fluids, and aerosol propellants 3, 4
- Hydrogen sulfide: A toxic gas often encountered in industrial settings 1
- Corrosive chemicals: Including strong acids, alkalis, and paraquat 1
- Organophosphorus compounds: Can be absorbed through respiratory tract 1, 5
- Irritant gases: Found in industrial accidents and fires 6, 7
- Smoke: A heterogeneous mixture of particulates, respiratory irritants, and systemic toxins 1, 8
Risk Factors and Circumstances
Inhalation poisoning commonly occurs in these settings:
- Residential exposures: Faulty heating systems, indoor use of combustion sources 1
- Structure fires: Combined exposure to multiple toxins 2, 8
- Industrial accidents: Release of toxic chemicals or gases 6
- Substance abuse: Deliberate inhalation of volatile substances, particularly among young people 3, 4
- Warfare or terrorism: Intentional release of injurious agents 6
Clinical Presentation
The presentation varies by toxin but often includes:
- Respiratory symptoms: Difficulty breathing, chest tightness, coughing 2
- Neurological symptoms: Confusion, headache, loss of consciousness 1, 2
- Cardiovascular effects: Tachycardia, arrhythmias, hypotension 3, 4
- Metabolic abnormalities: Acidosis, particularly with cyanide exposure 1
Prevention
Preventive measures include:
- Public education programs about CO poisoning risks 1
- Warning labels on fuels or devices that emit CO 1
- Proper ventilation when using combustion sources 1
- Carbon monoxide detectors in homes 1
- Proper protective equipment in industrial settings 1
Understanding the diverse causes of inhalation poisoning is essential for proper risk assessment, rapid diagnosis, and appropriate treatment to reduce morbidity and mortality associated with these exposures 2, 6.