Pulmonary agent

Hydroxocobalamin (vitamin another antidote, is a potential alternative to sodium nitrite treatment. It works by binding with cyanide to form nontoxic cyano-cobalamin (vitamin Bj ). Although effective and relatively safe in experimental models, the concentration available in the United States requires large infusion volumes and has a short shelf life due to light instability, and reports of anaphylactoid reactions have limited its use (8,13,21). Further studies using higher concentrations available in European formulations may eventually lead to its use as an outpatient alterative to sodium nitrite treatment in the United States (7,32). Other alternatives currently used or undergoing clinical trials in Europe include cobalt salts, limited by their toxicity, aldehydes, and aminophenol derivatives. These alternative treatments are not currently available in the United States (7). 

In addition to antidotal therapy, administration of 100% oxygen can help with cyanide detoxification, possibly by affecting the binding of cyanide to cytochrome oxidase (13). Hyperbaric therapy may be considered, but only after standard treatment has failed, or if the patient has concurrent carbon monoxide poisoning (13). 

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Blood/pulmonary agents, which interfere with metabolic functions such as hydrogen cyanide (AC) or phosgene (CG). 

Pulmonary agents have been stockpiled by most countries that have pursued a chemical weapons program, and have been used a number of times on the battlefield. Although this class of agents is considered obsolete on the modern battlefield, several of these agents are still considered a significant threat as potential improvised weapons that could be utilized in urban warfare. 

Pulmonary agents are primarily an inhalation hazard. However, at high concentration, agents and decomposition products may exhibit some corrosive properties on the skin. 

As a class, pulmonary agents do not have good warning properties. However, halogens and some alkylating agents will produce eye and skin irritation at low levels. 

Most pulmonary agents are either volatile liquids or gases. These agents are typically colorless. Odors, if present, vary from mildly pleasant to harsh and irritating. Some agents, especially in high concentration, may cause eye irritation and tearing. 

Pulmonary agents have been absorbed into porous powders (e.g., pumice) and disseminated as dust clouds. The agents are slowly released by the dust particles thereby greatly increasing the persistency of the agents. 

Some pulmonary agents are stored and shipped as concentrated solutions to facilitate handling and stabilize the agents. Odors will vary depending on the characteristics of the solvent(s) used and concentration of pulmonary agent in the solution. 

During World War I, pulmonary agents were sometimes mixed with various metal chlorides to produce a visible cloud. Agents were also sometimes mixed with arsenical vesicants (Agent Index C04) to increase their lethality. 

Due to the volatile nature of most pulmonary agents, there is minimal extended risk except in an enclosed or confined space. Vapors have a density greater than air and tend to collect in low places. Solids that are dispersed as aerosols have little or no vapor pressure. Once the aerosols settle, there is minimal extended hazard from the agents unless the dust is resuspended. 

Pulmonary agents have limited solubility in water and many decompose rapidly in contact with moisture (e.g., high humidity) or with water. 

Animals exposed to volatile pulmonary agents do not require decontamination. If low volatility agent aerosols have been released, animals can be decontaminated with shampoo/soap and water (see Section 10.5.3). If the animals eyes have been exposed to the agent, they should be irrigated with water or saline solution for a minimum of 30 minutes. 

Many of these agents are incompatible with acids, bases, reducing agents, and other flammable materials. Some agents, such as chloropicrin (C10-A006) and chlorine trifluoride (C10-A015), are incompatible with oxidizers. Most pulmonary agents react with water to... 

Most pulmonary agents produce corrosive decomposition products that may include hydrogen chloride (HC1), hydrogen bromide (HBr), hydrogen fluoride (HF), and/or hydrogen cyanide (HCN). Agents with metal halide additives will also form potentially toxic metallic oxides. 

No specific biologic marker/test is available for pulmonary agents as a class however, exposure to bromine might be indicated by detection of elevated bromide levels in serum (reference level is 50-100 mg/L), or if chlorine or bromine is released and they are detected in environmental samples. The case can be confirmed if laboratory testing is not performed because either a predominant amount of clinical and nonspecific laboratory evidence is present or an absolute certainty of the etiology of the agent is known. 

An asymptomatic casualty with known or potential exposure to pulmonary agents. Observe closely and retriage every 2 hours for at least 6 hours before discharge. 

There is no antidote for exposure to these agents. Enforce rest as even minimal physical exertion may shorten the clinical latent period. Asymptomatic individuals suspected of exposure to pulmonary agents should be monitored for possible complications caused by... 

Pulmonary agents pose little risk of direct residual contamination. Wash the remains with soap and water. Pay particular attention to areas where agent may get trapped, such as hair, scalp, pubic areas, fingernails, folds of skin, and wounds. Once the remains have been thoroughly decontaminated, no further protective action is necessary. Body fluids removed during the embalming process do not pose any additional risks and should be contained and handled according to established procedures. Use standard burial procedures. 

The pulmonary agent phosgene was used extensively as a chemical weapon in WW I. Nowadays, it is an important intermediate for industrial production of insecticides, isocyanates, plastics, aniline dyes and resins, with an estimated yearly production of almost 1 billion pounds. Reliable diagnosis of exposure to phosgene, other than observation of the developing edema by means of chest roentgenology, is not available. 

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