For vesicant exposures

While decontamination and supportive therapy are the mainstays of treatment, antidotes to counteract HD vapor, aerosol, or liquid exposures do not exist (Yu et al, 2003). Adult decontamination may include bleach solutions however, this method can cause greater toxicity in children. Soap and water are the preferred agents to use for decontamination in children. Supportive care consists of the management of pulmonary and skin manifestations such as the use of cough suppressants and/or topical silver sulfadiazine for bums (Yu et al, 2003 Sidell et al, 1997 Azizi and Amid, 1990). Pediatric dosage and treatment recommendations for vesicant exposures are displayed in Table 61.5. 

Because terrorists are unlikely to announce they are about to release a vesicant agent, there are no effective preventive measures for vesicant exposure. Recognition of the exposure and rapid, effective decontamination of victims is essential to prevent secondary exposure and additional cases. 

Medical Management There is no known antidote for mustard exposure, and the process of cellular destruction is irreversible. It is essential to remove the mustard agent as quickly as possible. Vesicants rapidly penetrate the skin causing both localized cellular damage and systemic damage. The deadly nature of such agents effect is that a person... 

The skin and eyes are especially sensitive to the toxic effects of sulfur mustard. When applied to human skin, about 80% of the dose evaporates and 20% is absorbed (Vogt et al., 1984). About 12% of the amount absorbed remains at the site and the remainder is distributed systemically (Renshaw, 1946). Doses up to 50 pg/ cm cause erythema, edema, and sometimes small vesicles. Doses of 50-150 pg/cm cause bullous-type vesicles, and larger doses cause necrosis and ulceration with peripheral vesication. Droplets of liquid sulfur mustard containing as little as 0.0025 mg may cause erythema (Ward et al., 1966). Eczematous sensitization reactions were reported in several early studies and may occur at concentrations below those causing direct primary irritation (Rosenblatt et al., 1975). In humans, the LCtso (estimated concentration x exposure period lethal to 50% of exposed individuals) for skin exposures is 10,000 mg-min/m (DA, 1974) (for masked personnel however, the amount of body surface area exposed was not reported). The ICt 50 (estimated concentration x exposure period incapacitating to 50% of exposed individuals) for skin exposures is 2000 mg-min/m at 70-80°F in a humid enviromnent and 1000 mg-min/m at 90°F in a dry enviromnent (DA, 1974, 1992). The ICtso for contact with the eyes is 200 mg-min/m (DA, 1974, 1992). The LDl for skin exposure is 64 mg/kg and the LD50 is estimated to be about 100 mg/kg (DA, 1974,1992). 

Mershon, M.M., Mitcheltree, L.W., Petrali, J.P., Braue, E.H., Wade, J.V. (1990). Hairless guinea pig bioassay model for vesicant vapor exposures. Fundam. Appl. Toxicol. 15 622-30. 

Pediatric exposures to vesicants can be quite toxic however, in contrast to nerve agent exposures, HD causes significantly greater morbidity than mortality. While mustard did not cause many deaths in WWI, death from HD exposure is usually due to massive pulmonary damage complicated by infection (bronchopneumonia) and sepsis. Children often show a quicker onset and greater severity of toxicity. Skin and eye toxicity occurs in the form of blisters or irritation that can result in blindness for the most severe cases. Except for lewisite, vesicant exposures must be managed with supportive care and rapid decontamination. 

On short exposures (t.e., le.ss than 5 minutes), ethyidichlorarsine is not a particularly efficient irritant for the human skin. On exposures greater than 5 minutes, however, positive bums appear which increiv. in severity with lengtii of exposure. On the basis of rapidity of action, extent of rubefaction, swelling and edema, and time of healing, ethyidichlorarsine is about t vo-tliird.s as effective as mustard gas, but for vesication it is only about o ie-sixth as effective. 

Treatment follows decontamination of the patient, after donning protective gear. The various agents may vary in their ability to generate local and systemic pathology however, the general treatment principles remain the same for all vesicants except for the availability of British Antilewisite (BAL) for dichloroarsine exposure. 

LD50S for skin exposure to liquid Sulfur Vesicants are as low as 7 gm per individual. 

Achieving a deeper understanding of OS is important for the elucidation of all acute inflammatory disorders. The OS component of vesicant exposure has not been a focal point of research, by... 

Unfortunately, vesicant exposure creates a huge problem because microscopic cellular damage occurs within very few minutes of exposure, but at a minimum, outward physical signs of that damage does not normally occur for at least 2 or 3 h after exposure, though usually longer. While phosgene oxime produces immediate pain on skin contact and Lewisite produces pain usually within 1 min after skin contact, sulfur mustard produces absolutely no pain on contact with the skin. As much as people do not like pain, pain is an extremely important protective mechanism for... 

As described below, urinary metabolites have been identified for vesicants, nerve agents, 3-quinuclidinyl benzilate (BZ), hydrogen cyanide and the RCAs, CS, CR and capsaicin. Protein adducts have been identified for vesicants, nerve agents and phosgene, and DNA adducts for sulphur and nitrogen mustards. With the rapid advances being made in proteomics and metabo-nomics, new biological markers of exposure will undoubtedly be identified in the near future. 

Ion Mobility Spectrometry (IMS) technology is used to detect nerve, vesicant, and blood agents. The Chemical Agent Monitor (CAM) uses ion mobility spectrometry to provide a portable, hand-held point detection instrument for monitoring nerve or vesicant agent vapors. Minimum levels detectable are about 100 times the acceptable exposure limit (AEL) for the nerve agents and about 50 times the AEL for vesicants. This insensitivity to low concentrations limits the utility of this instrument to check the efficacy of decontamination efforts or in occupational exposure measurements. 

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