Lewisite respiratory system

Little is known about lewisite s stability in the environment, but it can react with water in a manner whereby its volatility and most of its blistering potency are lost. As a potent blister agent, it has irritant effects on the eyes and respiratory system, and has similar toxicities to the other blister agents mentioned above (except that it exhibits less bone marrow suppression). Similar to its dichloroarsine cousins and phosgene oxime, but unlike the mustard vesicants, it can cause pain at the time of initial contact. There is often no erythema around the vesicles as with other mustard agents. 

Lewisite (L) is a vesicant from the arseitical (vesicant) chemical family. Lewisite causes many of the same types of damage to skin, eyes, and the respiratory system as do the mustard agents. The chemical name is dichloro-(2-chlorovinyl) arsine. It has not knowingly been used on the battlefield, and human exposure data is limited. The major difference between lewisite and mustard is that lewisite causes pain... 

An antidote is available for lewisite exposure. BAL (British-Anti-Lewisite dimercaprol) was developed by the British during World War II. The antidote is produced in oil diluent for intramuscular administration to counter the systemic effects of lewisite. There is no effect, however, on the skin lesions (eyes, skin, and respiratory system) from the antidote. Mustard agents (H), (HD), (HS), and (HT), like nerve agents, would be classihed as Class 6.1 poisons by the DOT and would have NFPA 704 designations of health 4, flammability 1, reactivity 1, and special... 

While the toxicity of Lewisite is roughly the same as mustard, the action of Lewisite on the skin causes an immediate burning sensation, and its odor is readily apparent. Severe damage to the eyes occurs almost immediately after exposure, while Lewisite vapors irritate the mucosa of the nasal and upper respiratory system. Lewisite is subsequently absorbed into the body, and distributed as a systemic poison to various organs. 

Dermal or intravenous exposure to lewisite leads to local skin edema and pulmonary edema due to increased capillary permeability. The increased capillary permeability results in blood plasma loss and resultant physiological responses collectively referred to as lewisite shock . Lewisite shock may be likened to shock observed in severe bum cases. It has been hypothesized that functional changes in the lungs, kidneys, respiratory tract, cardiovascular, and lymphatic systems may be the result of a disturbance of osmotic equilibrium (Goldman and Dacre, 1989). 

Lewisite is a local and pulmonary irritant, a vesicant, and a systemic poison. When ingested with food, it produces severe gastrointestinal irritation. The eyes, respiratory tract, and skin are the most likely sites of exposure when lewisite is used as a chemical warfare agent. The agent is lipophilic... 

The second exception is that while an antidote is available for systemic effects of Lewisite exposure, there are no antidotes for nitrogen mustard or sulfur mustard toxicity, with one minor caveat if given within minutes after exposure, intravenous sodium thiosulfate may prevent death due to sulfur mustard exposure (25). Otherwise, the medical management for skin, ocular, and respiratory exposure is only supportive. One guideline physicians can follow is to keep skin, eye, and airway lesions free from infection. 

Lewisite (also known as Agent L), is no longer considered a state-of-the-art CW agent. Lewisite is a significant threat to unprotected personnel and causes prompt incapacitation from eye injuries and respiratory irritation, coupled with long-term incapacitation from skin bums, pulmonary injury, and systemic illness. Its decomposition products are toxic, making decontamination difficult. Munitions containing lewisite may contain toxic stabilizers. Lewisite is effective as vapor, aerosol, or liquid (Sidell et al., 1997). 

Dimercaprol chelates arsenic and other heavy metals. It may have some benefit for ocular, dermal or respiratory effects of lewisite, but is mainly used to attenuate the onset of systemic effects. 

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