Rapid triage of victims suspected of a chemical attack: A one-page sheet allowing identifying the toxidrome. The doctors without borders (MSF) experience

Abstract

Over the past five years, events in the Middle East have increased the awareness about the possible use of chemical weapons and their surrogates, the so-called “toxic industrialized compounds”. The major issue is to identify on a clinical basis the likelihood of exposure to chemicals ranging from riots agents to lethal agents in order – to advice protection of rescuers and care givers at the scene – to provide adapted treatment to casualties, and; – to address the need for antidote supply. Systematic review of the literature on acute chemical accidents resulting in casualties to identify easily collected clinical signs and symptoms resulting. This review provided a limited list of signs to be collected in a small subset of frankly symptomatic patients. The signs and symptoms were classified according to the corresponding organ(s) involved by chemical injury. All signs shoud be clinically collected using current physical examination. There are presently three versions of the sheet: French, English, and Arabic. Owing to the political context and analytical difficulties, we never attempted at determining the agent having caused signs and symptoms. The one-page questionnaire was used in 5 settings, including – a chemical incident related to the opening of a chemical plan in Lumumbashi in 2011; – the repeated use of anticholinesterasic agents towards civilians in Syria from April 2013 up to that the attack launched the 21st of August 2013; – repeated chlorine attack towards civilians in Syria since March 2014; – an attack using a vesicant agent towards civilians in August 2015 in Syria, and; – the acute onset of paraplegia in Mali on Summer 2015. In each setting, the analysis of the quoted items on the sheet allowed to suggest the class of the toxicant within a few hours after exposure. In the case of exposure to chlorine and to the vesicant agent, two collections of signs over a period of a few hours were needed to draw definitive conclusion. The lowest number of casualties in an exposure was three after exposure to vesicant agents. The definitive diagnosis was in accord with the initial presumption regarding the class of toxicant. Early identification allowed to advise adapted protection of caregivers at the site as well as define the need for antidote supply and the nature of the antidote. Conversely, in one setting (Mali 2015) a toxic origin was ruled out as not fitting any known toxicant while an infectious disease was identified as the likely cause of the outbreak. In case of incident, a one-page sheet of the list of signs and symptoms allowed to define a toxidrome specific of a class of toxicant, helped in protecting rescuers and care givers and refined the needs for supportive and antidotal treatment. Repeated collection of signs may be required in agents acting over hours. A close collaboration with a skilled toxicologist is needed when facing incident involving hazardous materials. At the scene only chemical incident was identified. However, repetition of bombing in the same area resulted in a more accurate and rapid medical response. A one-page sheet easily filled out at the scene in the context of chemical incident allowed defining the toxidrome and consequently protection of rescuers, needs for supportive and antidotal supply. Owing to the rapidity of action of a number of toxicant a single or repeated examination over a few hours is needed to define the toxidrome and therefore the class of toxicant.