Medical Aspects of Chemical Warfare (2008) - The Black Vault

Medical Aspects of Chemical WarfareNerve AgentsAlthough lethal chemicals such as sarin or VX arenot usually considered incapacitating drugs, cholinesteraseinhibition can produce severe incapacitationthrough neuropsychological effects alone, independentof such easily recognized bodily effects as miosis,respiratory distress, muscular weakness, autonomicdisturbances, and general malaise. Sarin and VX arerelatively reversible; some of the other cholinesteraseinhibitors are much longer acting.A chemical worker at Edgewood Arsenal, accidentallyexposed to GD (soman), provided an exampleof the effects of a persistent anticholinesterase agent.After receiving emergency treatment, he spent severalweeks under close observation with the usual supportivemeasures and repeated doses of atropine and othertherapeutic agents. 30 In addition to the usual life-threateningeffects on respiration, cardiovascular activity,and muscle strength, all of which were reversed withatropine and 2-pralidoxime chloride, his performanceof standards continued to be impaired even after hisphysical signs and symptoms had largely subsided.This case of accidental poisoning presented a uniqueopportunity to follow the time course of GD’s centralnervous system effects. Through daily psychologicaltesting the medical staff could measure the quantitativeaspects of cognitive impairment produced by cholinergicexcess in the brain. Of considerable interest wasthe greater reversal of the patient’s cognitive deficits bysmall doses of scopolamine than by doses of atropineequivalent in peripheral potency. Scopolamine wasalso more effective in reducing the frequency and severityof nightmares, a common central effect of nerveagents. Recovery was gradual and took several weeks,as GD-inactivated cholinesterase was slowly replacedby newly generated, functionally normal enzyme. 30In a study of Australian gardeners, mental defectsdeveloped in the absence of significant peripheralphysiological changes. These workers had been exposeddaily to seemingly unremarkable concentrationsof organophosphate pesticides. Although acute effectsdid not occur, the frequent, sometimes prolonged exposureto the chemicals produced cumulative effects onmental function. Hallucinations occurred and changesin cognitive efficiency became increasingly apparent,even though the men appeared otherwise normal. 31Irritants, Nausea-Producing Agents, and ToxinsIrritants and nauseants, including lacrimators suchas CN (the original tear gas), CS (successor of CN), andDM (a nauseant) are incapacitating and generally safewhen properly used. 32 These agents have the followingtwo qualities: (1) Their duration of action is short,because adaptation to the irritant effects usually occursafter 30 minutes or less of continuous exposure, withrapid recovery when the atmosphere clears; and (2)highly motivated individuals can sometimes “fightthrough” their effects.VesicantsThe vesicating agents, which include such substancesas mustard, produce severe incapacitationby burning the skin and respiratory tract. 33 Vesicantshave been internationally condemned, and althoughsome nations have used them in past decades, theprobability of their use solely as an incapacitant intoday’s conflicts is low because they have no impacton mental function.Indole-Based Psychedelics“Psychedelic,” a term coined by Humphry Osmondin collaboration with Aldous Huxley in 1957, means“mind-manifesting” and refers to the alleged expansionof awareness that early users thought to be aunique feature of LSD and related compounds. 34 Itsability to bring forth repressed memories, fears, andfantasies supposedly made LSD a useful adjunct totraditional psychoanalysis, although few practicingpsychiatrists felt comfortable using it in their practice,for the effects could be explosive and difficult to controlin a doctor’s office. The unmanageable flood of ideas,images, and emotions that LSD unleashes accountsfor many of its disorganizing effects. A person underthe influence of incapacitating doses of LSD wouldfind it impossible to carry out complex tasks becauseof the sensory overload of frightening or perplexingthoughts, accompanied by a kaleidoscope of rapidlychanging perceptions and emotions. 35,36Although many psychedelic drugs have beenextracted from plants, or synthesized in the laboratory,LSD was undoubtedly the best known of theseindole-based psychedelic drugs. It gained attentionfrom diverse subcultures and scientists starting inthe mid-1940s (long before it was tested systematicallyat the Edgewood Arsenal for possible militaryusefulness). 37 Chemical Corps testing of LSD as apossible incapacitating agent began in the mid 1950s. 38When administered to volunteers, LSD producedvirtually complete incapacitation. For unexplainedreasons, the drug was less effective when given by theoral route than when inhaled. 39 As previously reportedby civilian investigators, LSD produces bizarre andunpredictable but often well-coordinated behaviors.Individuals given larger doses usually cannot carry416