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

Medical Aspects of Chemical WarfareDiagnosis of Incapacitating Agent SyndromesThere seems little likelihood that agents otherthan anticholinergics, still the only drugs known tobe effective and reasonably safe, would be useful onthe battlefield. Several reports suggest that BZ-likeagents have already been used, in Croatia and possiblyelsewhere. It is improbable, however, that suchagents would be used by nations (or groups such asAl Qaeda) whose predominant goal is the destructionof life. Nevertheless, elusive maladies are invariablyreported after any major conflict. The probable overestimationof the number of injuries from Agent Orangeexposure in the Vietnam War and the so-called “GulfWar syndrome” are 20th century examples of thisphenomenon. 135 Medical officers must therefore be ableto distinguish chemical intoxication from illnesses ofnonchemical origin.Impaired performance on the battlefield is much morelikely to result from stress, illicit drug use, lack of motivation,or psychiatric illness than from a chemical agent.Intoxication produced by belladonnoid agents, by contrast,should be easy to recognize if the physician maintainsthe proper index of suspicion. Medical studentswere long taught the medical adage “dry as a bone, redas a beet, hot as a hare, and mad as a hatter” as a meansof remembering the features of belladonna poisoning.As discussed, glycolate anticholinergics can varytremendously in their potency and duration of action.Signs and symptoms may last as few as 2 hours or aslong as several weeks. Differential diagnosis may bemore difficult with glycolates that produce few or noperipheral antimuscarinic features, especially at thelow end of the incapacitating dose range. Even thepupils may not be greatly enlarged. Familiarity withthe behaviors typical of delirium, such as phantomdrinking or smoking, picking or groping behavior,nonsensical speech, random disrobing, and the inabilityto follow simple instructions should greatly assistin making the diagnosis in such cases.Limited or covert use of other agents (those notsuitable for large-scale dissemination) makes it importantto recognize the effects of LSD and otherpsychedelics. Because LSD is a stimulant and usuallyprevents sleep, medical officers should not expect tosee drowsiness or sedation. Staring, enigmatic smiling,and unusual preoccupation with ordinary objectsare not uncommon. Responses to commands may besuperficially normal. Laughter may supervene, but somay insubordinate and oppositional behavior. Thereare no practical diagnostic tests for psychedelic drugs(although a sensitive fluorometric method for quantitativedetection of LSD is known, and refrigeratedblood samples could be useful in making a definitivediagnosis at a later time). 44Marijuana intoxication is common in areas wherethe drug is indigenous, and the presence of reddenedconjunctivae, along with the lack of concern and relaxedjoviality that marijuana produces, should makethe diagnosis obvious. There is little likelihood thatpurified tetrahydrocannabinols (the active componentof cannabis) would be used in a general military setting.Blood and urine can be tested if definitive proofof cannabis use is needed, but such tests are not alwaysfeasible or available.An important, sometimes overlooked cause ofbizarre symptoms and behavior is anxiety, which canmanifest as dizziness, tachycardia, sweating, headache,and even loss of sensation or ability to move parts ofthe body. Observation and reassurance may diminishthese symptoms, providing a clue to the diagnosis.Comparable syndromes such as “soldier’s heart,” “DaCosta’s syndrome,” “shell shock,” “combat neurosis,”“combat fatigue,” and “traumatic neurosis” are termsthat arose during past wars to refer to incapacitationof psychiatric origin. 135Another important differential diagnosis is heatexhaustion, and more importantly, heat stroke. Theseconditions can also impair performance and maymimic glycolate intoxication. Individuals with heatstroke will not be sweating and may have warm,flushed, skin. They have very high temperatures (106°For higher) and may be delirious, unconscious, or haveseizures. Heat stroke is a medical emergency. Thesepatients must have their body temperature reducedquickly and be monitored closely to prevent failureof critical organ systems.Whether covertly or overtly delivered, the differentialdiagnosis of incapacitation is basically thesame as used in typical emergency room overdosecases. Standard textbooks and manuals provide adequateguidelines, as in Table 12-1. The possibilitythat secret research might produce a highly potent,unfamiliar variant of a known psychoactive drug cannot,however, be ruled out. Blood or urine analysiswould probably be needed to demonstrate the drug’spresence and identify its chemical structure. Medicalofficers in the field would probably not have accessto the instruments required for precise analysis, buttheir probability of facing completely unfamiliarchemical substances is low. Exhibit 12-1 is a summaryof signs, symptoms, field detection, decontaminationmethods, and medical management of BZ andfentanyl derivatives.428