Definition and Causes
Cyanide is a rapidly acting and deadly chemical. Smelling of bitter almonds or entirely odorless, cyanide may take the form
of a colorless gas, a liquid, or a crystal powder. Cyanide, like
(CO), binds to hemoglobin in red blood cells and blocks their capacity to carry oxygen to cells and tissues.
Many plants, foods, and microbes produce harmless cyanides, and for decades cyanides have been used safely in manufacturing.
Cigarette smoke contains traces of cyanide. Cyanide has also been used as an agent of chemical warfare and domestic terrorism.
But from day to day cyanide poisoning most often affects firefighters and other victims of fire involving smoke inhalation,
as the combustion of plastics, textiles, and other synthetic materials produces a highly toxic mix of cyanide and carbon monoxide.
Inhaling even small amounts of fire smoke can be fatal. Serious neurological effects may be delayed days or weeks after acute
poisoning. Chronic exposure may cause persistent headaches, dizziness, nausea, and permanent neurological damage. Smoke inhalation
may be further complicated by airborne particles and by burns to the throat and lungs.
Hyperbaric Oxygen Approval Status
page in the Undersea and Hyperbaric Medical Society resource library to learn more about cyanide poisoning, the rationale
for hyperbaric oxygen therapy, and key clinical evidence, outcomes, and success factors.
Treatment with Hyperbaric Oxygen Therapy
Hyperbaric oxygen therapy (HBOT) is indicated for the emergency treatment of carbon monoxide poisoning complicated by cyanide
poisoning after smoke inhalation. Hyperbaric oxygen is also an adjunctive therapy for pure cyanide poisoning in patients who
do not respond to cyanide antidotes. HBOT dissolves additional oxygen in the blood plasma and has been shown to work effectively
alone and in combination with hydroxocobalamin (Cyanokit) and other cyanide antidote kits.
The emergency treatment of smoke inhalation offers perhaps the single best reason for the healthcare community to demand
24/7 access to hyperbaric chambers across the US. Cyanide, carbon monoxide, inhaled particulates, and thermal injuries
together require speedy action to save the lives of firefighters and other fire victims. The clinical evidence for HBOT
may not be as strong for nonfire cyanide poisoning as for nonfire carbon monoxide poisoning, but the benefits of oxygen
are well established. As
puts it: “Oxygen and sodium thiosulfate are the most widely accepted cyanide antidotes…. The mechanism of action of oxygen
as a cyanide antidote is unclear, but it potentiates the effect of other antidotes. When used in the setting of smoke
inhalation, it is also therapeutic for CO poisoning. Thus, high concentrations of oxygen should be promptly delivered.”
Ongoing surveillance projects and prospective trials may bolster the clinical case for HBOT in the routine treatment of
HyperbaricLink recommends the following websites for anyone seeking authoritative information, patient advocacy, and community
support for cyanide poisoning.
The AAPCC is a nonprofit organization representing 57 poison centers staffed by pharmacists, physicians, nurses, and toxicology
specialists who provide free, private, expert medical advice 24/7/365.
A leading authority on fire, electrical, and building safety, the NFPA provides free PDF downloads with excellent carbon
monoxide safety tips and CO detector guidelines.
The DHS website includes the short but mighty alarming
Chemical Attack Fact Sheet: Warfare Agents, Industrial Chemicals, and Toxins
Start with the following resources to explore current research activities and the peer-reviewed medical literature on
hyperbaric oxygen therapy for cyanide poisoning.
ClinicalTrials.gov keeps the official list of human clinical trials currently enrolling, in progress, and recently completed.
One may reasonably question the size and legitimacy of any study not listed here.
Search ClinicalTrials.gov for current studies of hyperbaric oxygen therapy and cyanide poisoning
A specialized Google search engine, Google Scholar indexes scholarly articles, patents, and legal opinions and journals.
Google Scholar may generate excessive search results, but entries provide easy access to full-text journal articles.
Search Google Scholar for "cyanide poisoning" and "hyperbaric oxygen"
A service of WebMD, Medscape offers specialists, primary care physicians, and other health professionals robust and integrated
medical information and educational tools. The website devotes several well-referenced paragraphs to hyperbaric oxygen therapy
Emergency Department Care
for smoke inhalation.
The CDC is dedicated to protecting health and promoting quality of life through the prevention and control of disease, injury,
and disability. Its programs reduce the health and economic consequences of the leading causes of death and disability. NIOSH
offers a free
Pocket Guide to Chemical Hazards
with key information about cyanides and other chemical hazards in the work environment.
US National Library of Medicine
National Institutes of Health
PubMed keeps the official list of scientific papers published in reputable peer-reviewed medical journals. One may reasonably question the importance and
legitimacy of any study not listed here.
Search PubMed.gov for journal articles relating to hyperbaric oxygen therapy and cyanide poisoning
- Carbon monoxide (CO) poisoning
- Chemical terrorism
- Chemical warfare
- Cyanide antidote kit (CAK)
- Cyanogen chloride (CNCl) (CK)
- Emergency medical services (EMS)
- Emergency medical technician (EMT)
- Hydrogen cyanide (HCN) (AC)
- Hydroxocobalamin (Cyanokit)
- Potassium cyanide (KCN)
- Smoke inhalation
- Sodium cyanide (NaCN)
- Sodium thiosulfate
- Vitamin B12
"A Bitter Pill"
by Joy Bergmann
2 November 2000