As a first responder, I hope you have heard of the Subway Sarin Incident in Tokyo on March 20, 1995. There are many lessons to be learned in a case review of this terrorism incident perpetrated by members of a Japanese religious cult called Aum Shinrikyo. If you have not, look it up… it will be worth your time.
A really interesting fact from this incident is that the most common complaint of victims and first responders alike was the sensation that "everything was going black, like they are entering a tunnel." In a medical assessment, when we inspect the pupils in this event, we would find miosis.
Miosis is a term derived from the ancient Greek that means "to close the eyes". It is a medical term that denotes a constriction of the pupils to an abnormal or excessive degree, caused, in this case, by exposures to an organophosphate based chemical weapon known as Sarin Nerve Gas (GB).
Nerve agents attack the nervous system by inactivating acetylcholinesterase (AChE), producing a toxic accumulation of acetylcholine (ACh) at the muscarinic, nicotinic, and CNS synapses. This causes an end organ overstimulation, which is often referred to as a cholinergic crisis. Vapor exposure of these nerve agents provides the most rapid onset of symptoms, and since the most exposed muscarinic receptors are found in the eyes, nerve agent vapor easily crosses the cornea and produces miosis.
So if you are ever responding to such an attack or another organophosphate based toxicological event, and you start to get literal “tunnel vision”, you know why!
How about that!
No comments:
Post a Comment