Initially synthesized by humans as a weapon for chemical warfare, sarin (also known as O-isopropyl methylphosphonofluoridate) is a colorless and clear liquid that belongs to a group of highly toxic and life-threatening nerve agents [1] [2]. Similar to organophosphates, sarin behaves as an inhibitor of acetylcholinesterase (Ach); thus it produces symptoms by promoting cholinergic effects at both muscarinic (M) and nicotinic (N) receptors of the parasympathetic part of the autonomic nervous system [2] [3] [4] [5]. Sarin poisoning has been described in very few reports, mainly during the terrorist attacks in Japan during the 90's [1] [3] [6]. In addition to direct contact with its liquid form, individuals can inhale sarin as a gas and it is equally potent in both forms [2]. The clinical presentation depends on the route of exposure - dermal absorption may delay first signs for up to 18 hours, with local sweating and glandular hypersecretion, together with weakness and fasciculations being the main symptoms [2] [4]. On the other hand, instantaneous development of life-threatening symptoms such as airway obstruction, weakness and failure of respiratory muscles leading to anoxia, and convulsions is seen in the case of inhalation [2] [4]. Additional findings include miosis, hypothermia, muscle twitching, tremors, ataxia, visual deficits, cardiac abnormalities (including cardiac arrest) and coma [1] [3] [7].

• Intravenous Administration

  Intravenous administration of atropine sulfate to mildly ill victims was adverse. We believe that it was because eye symptoms were mainly due to local reaction of sarin. [nointervention.com]

  In more severe cases, intravenous administration must be used. Diazepam should be administered in repeated i.m. or i.v. doses (10–15 mg or 0.2 mg/kg for children). [academic.oup.com]

• Shivering

  “The team found people fainting, and people with froth coming from the mouth, and shivers in their bodies…many died while they were asleep.” [independent.co.uk]

• Bronchorrhea

  Intubation may be necessary in cases of respiratory distress due to laryngospasm, bronchospasm, bronchorrhea, or seizures. Immediate aggressive use of atropine may eliminate the need for intubation. [openanesthesia.org]

• Abdominal Cramps

  Symptoms like bronchoconstriction, nausea and vomiting, abdominal cramps and diarrhoea may also diminish. Atropine will also reduce the parasympathetic overstimulation and the consequent risk of bradyarrhythmias induced by ACh accumulation. [academic.oup.com]

  Symptoms include: Dilated pupils Headache Sense of pressure Salivation Runny nose or congestion Nausea Vomiting Tightness in chest Anxiety Mental confusion Nightmares Weakness Tremors or twitches Involuntary defecation or urination Abdominal cramps Diarrhea [thoughtco.com]

  Atropine also blocks other effects of poisoning, such as nausea, vomiting, abdominal cramping, low heart rate, and sweating. Atropine, however, does not prevent or reverse paralysis. [emedicinehealth.com]

• Foaming at the Mouth

  According to the Syrian Observatory for Human Rights (SOHR), victims were having difficulty breathing, foaming at the mouth, seizures, bleeding from the nose and mouth, fainting, and some progressed to losing consciousness and dying. [gcnlive.com]

  Excessive acetylcholine corroborates what has been reported and seen in the videos taken just after the attack, including uncontrolled salivation that will cause "foaming at the mouth," vomiting, tearing, involuntary defecation and urination, tiny pinpoint [tonic.vice.com]

  “For example, if it’s a secretion in the mouth, it will make the person foam at the mouth,” he said. If it’s tear ducts, it will make you cry. if its muscles in the leg, it will make the muscles twitch.” [pbs.org]

  Symptoms included bleeding from the nose and mouth, coma, convulsions, difficulty breathing, extreme sensitivity to light, flulike symptoms, foaming at the mouth, fevers, loss of consciousness, loss of memory, loss of vision, nausea, vomiting, paralysis [wired.com]

  Those on the periphery of that zone were the ones being rushed to hospitals, gasping for breath and foaming at the mouth, in the hopes of being saved. [foxnews.com]

• Psychiatric Symptoms

  The results suggested delayed effects on psychomotor performance, the higher and visual nervous system and the vestibulo-cerebellar system with psychiatric symptoms resulting from PTSD. [ncbi.nlm.nih.gov]

Except for terrorist attack-related incidents, the diagnosis of sarin poisoning has virtually never been made in general practice. Nevertheless, nerve agents such as sarin must be considered in the differential diagnosis of sudden and life-threatening respiratory and gastrointestinal tract complaints in a cluster of patients who were in the same surroundings shortly before symptoms occurred. For this reason, history taking that reveals many individuals affected by the same symptoms might be crucial in raising suspicion. Physicians must perform a quick physical examination during which cholinergic effects of sarin poisoning must be observed - miosis, sweating, hypothermia, muscle weakness, spasms, etc. In addition, some studies have identified leukocytosis, elevated serum creatine kinase levels, hyperglycemia, hypokalemia, and hypotriglyceridemia in the laboratory workup [3].

These are lower-toxicity pesticides used variously for home and garden pest control, veterinary treatments, agricultural pest control, and even treatment of head lice. [poison.org]

How sarin exposure is treated Treatment consists of removing sarin from the body as soon as possible and providing supportive medical care in a hospital setting. Antidotes are available for sarin. [emergency.cdc.gov]

We examined clinical and laboratory findings of 264 people who sought treatment and the results of health examinations on 155 residents done 3 weeks after the poisoning. [ncbi.nlm.nih.gov]

Treatment: Treatment of victims exposed to nerve gas is similar to the treatment of those poisoned by organophosphate insecticides. Atropine sulfate: Victims with symptoms require immediate treatment with atropine. [emedicinehealth.com]

Treatment Termination of the exposure including removing all soiled clothing. Gently cleanse with soap and water to hydrolyze organophosphate solutions. Airway control and adequate oxygenation. [openanesthesia.org]

Mustards Prognosis Victims with significant respiratory tract burns usually require admission to the hospital’s intensive care unit. [emedicinehealth.com]

This prognosis is based on decades of research on rats and mice, and the fate of veterans of the 1990-1991 Gulf War who were exposed to low-levels of sarin gas and who continue to suffer serious health effects 26 years later. [blogs.scientificamerican.com]

Once the patient survives for a few hours, the prognosis is equally as good as that of unexposed people. Psychologic complications cannot be disregarded; almost 60% of victims suffered from PTSD that persisted longer than 6 months. [nointervention.com]

The diagnosis is difficult to attain and is based on clinical criteria and epidemiologic information. [symptoma.com]

The epidemiological pattern of occurrence such as the mass influx of patients in a short time suggests exposure to sarin, a nerve agent in Syria’s arsenal. [undispatch.com]

Biden: Syrian gov't responsible for "heinous use" of chem. weapons Syrian state news agency: Kerry lying about chemical weapons attack "The reported symptoms of the patients, in addition to the epidemiological pattern of the events -- characterized by [cbsnews.com]

Jernigan, Daniel B., et al., and the National Anthrax Epidemiologic Investigation Team, Oct. 2002, "Investigation of bioterrorism-related anthrax, United States, 2001: Epidemiologic findings," Emerging Infectious Diseases, 8:1019-1028. [johnstonsarchive.net]

A chart of signs and symptoms is available from the North Carolina Statewide Program for Infection Control and Epidemiology. [emedicinehealth.com]

This review summarizes the biochemistry and pathophysiology of anticholinesterase poisoning, the relevant clinical manifestations and the currently available therapeutic strategies. [academic.oup.com]

Preventing Sarin Poisoning An option pursued by chemists and medical professionals is a vaccine–an approach is to release scavenger molecules into the blood stream. [decodedscience.org]

CONCLUSIONS: Rescuers should protect themselves with appropriate clothing, gloves, and a mask to prevent a secondary disaster for at least 24 hours after a similar accident. [ncbi.nlm.nih.gov]

However, do not administer antidotes preventatively; there is no benefit to doing so. [emedicine.medscape.com]

Diazapam can also be used to prevent seizures and convulsions. [encyclopedia.com]

All nerve agents cause their toxic effects by preventing the proper operation of an enzyme that acts as the body’s “off switch” for glands and muscles. Without an “off switch,” the glands and muscles are constantly being stimulated. [emergency.cdc.gov]

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4. Miyaki K, Nishiwaki Y, Maekawa K, et al. Effects of sarin on the nervous system of subway workers seven years after the Tokyo subway sarin attack. J Occup Health. 2005;47(4):299-304.
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6. Shewale SV, Anstadt MP, Horenziak M, et al. Sarin causes autonomic imbalance and cardiomyopathy: an important issue for military and civilian health. J Cardiovasc Pharmacol. 2012;60(1):76-87.
7. Tokuda Y, Kikuchi M, Takahashi O, Stein GH. Prehospital management of sarin nerve gas terrorism in urban settings: 10 years of progress after the Tokyo subway sarin attack. Resuscitation. 2006;68(2):193-202.