Two new smoke inhalation treatment algorithms developed by European experts have been published in the current issue of the European Journal of Emergency Medicine (EJEM).1 The algorithms outline the most appropriate clinical response to suspected cyanide poisoning caused by smoke inhalation, in both pre-hospital and in-hospital settings, and have been met with praise from leading UK emergency medicine specialists.
Prof Tim Coats, Professor in Emergency Medicine at the University of Leicester, and the University Hospitals of Leicester NHS Trust commented: ‘These treatment algorithms give very useful advice for UK Emergency Departments and should become the standard of care that patients receive after being rescued from house fires, as currently we are a long way behind our European counterparts in the treatment of cyanide poisoning from smoke inhalation.’
The algorithms1 were drawn up by European Society of Emergency Medicine (EuSEM) members, and were outlined at the EuSEM annual conference in 2011. EuSEM members were motivated to produce these guidelines by the fact only local and national guidelines on the treatment of cyanide poisoning from smoke inhalation previously existed. These algorithms have been produced in the hope that they will improve recognition of cyanide poisoning from smoke inhalation, and enhance survival rates across Europe.
Although the deadly effects of cyanide in house fire smoke are relatively under recognised in the UK, this threat is better established elsewhere. In France for example, cyanide poisoning in house fire victims is treated with cyanide antidotes with much greater regularity.2
The presence of cyanide in house fire smoke is well established, as it is given off when a variety of household materials incompletely combust. These include plastic, wool, wood, and foam in sofas and mattresses.3 With a role in 52% of deaths, smoke inhalation is the single greatest cause of mortality in house fires.4 For this reason, it is hoped that the new European algorithms will encourage UK clinicians to consider cyanide poisoning as part of the clinical picture for smoke inhalation patients.
One of the challenges associated with treatment of cyanide poisoning is the difficulty in confirming the condition in a clinically relevant timescale. Inhaled smoke, containing hydrogen cyanide and carbon monoxide working in synergy1, can kill very rapidly, yet confirmation of cyanide poisoning is a process which currently takes days. This is why empiric treatment, with hydroxocobalamin – the only cyanide antidote which is licensed to be used without a confirmed diagnosis – is so central to the treatment algorithms.
‘It is important that we embrace empiric treatment of cyanide poisoning from smoke inhalation in the UK. The College of Emergency Medicine (CEM) recommends hydroxocobalamin should be stocked by all emergency departments, and it is in this area, where there can be no certain diagnosis, that the drug is most suitable,’ explained Prof Coats.
Symptoms of cyanide poisoning from smoke inhalation include giddiness, confusion, headache, vertigo, and dizziness; nausea and vomiting; palpitations, and hyperventilation. Later symptoms include seizures, bradycardia, hypotension, coma, respiratory and cardiac arrest. The EuSEM group has condensed this wide range of symptoms into guidance that one should suspect cyanide poisoning if the patient has:
- History of exposure to an enclosed-space fire
- Any alteration in level of consciousness
- Any cardiovascular changes (particularly inexplicable hypotension)
- Elevated plasma lactate.
The algorithms also advise on how to classify severity of poisoning, using Glasgow Coma Scale (GCS) as a surrogate marker in the field, and plasma lactate levels in-hospital.
Dr Kurt Anseeuw, EuSEM board member and co-author of the new algorithms believes that these guidelines will support the best possible treatment of smoke inhalation: ‘These algorithms are a great leap forward for feasibility and safety of empiric treatment for cyanide poisoning from fire smoke inhalation; a reality which should not be ignored when there is a licensed treatment available, and the road block presented by diagnosis of the condition in a clinically relevant timeframe can be negotiated by empiric treatment.’
Despite the CEM guidance, an audit recently published in the Emergency Medicine Journal conducted by the official central poisoning advice body, the National Poisons Information Service (NPIS), revealed that 80% of hospitals do not stock Cyanokit.5 While stocking levels are improving, this is something which will need to continue so that UK physicians can follow the lead of their European counterparts.
About Cyanokit® (hydroxocobalamin):
Hydroxocobalamin is an analogue of vitamin B12. It is licensed for treatment of known or suspected cyanide poisoning.
1)Anseeuw K, Delvau N, Burillo-Putze G, De Iaco F, Geldner G, Holmström P, Lambert Y, Sabbe M. (2013) Cyanide poisoning by fire smoke inhalation: an European expert consensus. Eur J Emerg Med. 20(1):2-9, February 2013.
2)Borron SW, Baud FJ, Barriot P, Imbert M, Bismuth C. Prospective study of hydroxocobalamin for acute cyanide poisoning in smoke inhalation. Ann Emerg Med. 2007;49(6):794-801.
3)Wakefield JC. (2010) A Toxicological Review of the Products of Combustion. HPA Chemical Hazards and Poisons Division 004.
4)Department for Communities and Local Government. (2011). Fire Statistics: Great Britain, 2010-2011; 19.
5)Thanacoody RH, Aldridge G, Laing W, Dargan PI, Nash S, Thompson JP, Vale A, Bateman N, Thomas S. (2012) National audit of antidote stocking in acute hospitals in the UK. Emerg Med J. Published online. doi:10.1136/emermed-2012-201224