Vesical pressure

Fig. 16.2. Estimation of high bladder filling pressure by modified VCU. Increasing vesical pressure (Pves) i h bladder filling leads to decreasing flow and cessation of infusion flow if Pves...

Fig. 16.3. Estimation of poor bladder compliance by modified VCU (V bladder filling volume PyEs vesical pressure)...

Fig. 16.4. Estimation of the safe storage period (the bladder volume at which vesical pressure remains well below 40 cm H2O, the safe storage pressure) by modified VCU (Pves vesical pressure V bladder filling volume)...

Fig. 16.5. Leak-point pressure estimation by modified VCU (Pves vesical pressure, Pu l urethral closure pressure...

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g. 

Chloroethyl methyl sulfide is a vesicant and must be handled with care. It boils at 140° under atmospheric pressure. 

L-l is a vesicant (blister agent) also, it acts as a systemic poison, causing pulmonary edema, diarrhea, restlessness, weakness, subnormal temperature, and low blood pressure. In order of severity and appearance of symptoms, it is a blister agent, a toxic lung irritant, absorbed in tissues, and a systemic poison. When inhaled in high concentrations, it may be fatal in as short a time as 10 min. L-1 is not detoxified by the body. Common routes of entry into the body include ocular, percutaneous, and inhalation. 

Crude sulfur vesicants are relatively stable and stability increases with purity Distilled materials show very little decomposition on storage. Solvents such as carbon tetrachloride and chlorobenzene have been added to enhance stability of crude material. Agents can be stored in glass or steel containers, although pressure may develop in steel containers. Sulfur vesicants rapidly corrode brass and cast iron, and permeate into ordinary rubber. 

Skin Immediate stinging pain increasing in severity with time. Erythema (skin reddening) appears within 30 minutes after exposure accompanied by pain with itching and irritation for 24 hours. Blisters appear within 12 hours after exposure with more pain that diminishes after 2-3 days. Skin burns are much deeper than with HD. Tender skin, mucous membrane, and perspiration-covered skin are more sensitive to the effects of L. This, however, is counteracted by L s hydrolysis by moisture, producing less vesicant and higher vapor pressure product. 

Mustard gas (H)—also known as yellow cross, yperite, sulfur mustard, Schwefellost, bis(2-chloroethyl) sulfide, and dichlor-diethylsulfide—is a chemical-warfare agent with both vesicant and systemic effects. H is colorless and almost odorless and is an oily liquid at 14-215°C with a molecular weight of 159.08. Except in extremely cold weather, the low vapor pressure (0.072 mm Hg at 20°C) and low volatility of H are sufficient to make contaminated surfaces a source of danger to anyone nearby. H is slightly soluble... 

Tolerance to CS may develop from repeated exposures at low concent rations,20 but it is reduced by hyperventilation, as well as by increased environmental temperature and humidity.2 Whole-body exposure to CS solutions may result in a transient increase in blood pressure, but not to the extent observed with CR.3 20 CS is a hapten and may cause allergic contact dermatitis, with erythema, edema, and vesication, which is less severe than the effects of CN. ... 

Not only is the acute toxicity of CR extremely low, with an estimated human LCt5Q over 100,000 mg mln/m, but the overt signs of exposure are even more transitory than those of CS. Eye Irritation passes In 15-30 min, and skin Irritation in 15-20 min. Erythema, which develops only on contaminated skin, passes In about an hour and does not lead to vesication or to contact sensitization. The abrupt Increase in blood pressure, which has been observed after whole-body drenches of CR In solution, subsides rapidly. Although available results show no long-term health effects of exposure to CR, there are no available data on the mutagenicity and carcinogenicity of this compound, and the data on teratology are limited. 

Conte et al. (1991) proposed a method for simultaneous recording of vesical and the external urethral sphincter pressure in urethane-anesthetized rats. 

Lewisite [dichloro(2-chlorovinyl)arsine] is an organic arsenical known for its vesicant properties (Rosenblatt et al., 1975). It has a molecular weight of 207.32, vapor pressure of 0.58 mm HG at 25°C, a liquid density of 1,89 g/cm at 25°C, freezing point of -18°C, boiling point of 190°C, and is negligibly soluble in water (DA, 1974). The chemical structure of lewisite is shown below. Lewisite may occur as a trans-isomer and as a cis-isomer. In aqueous solutions, the cis-isomer undergoes photoconversion to the trans-isomer (Clark, 1989). hi the presence of moisture, lewisite is rapidly converted to the more stable but highly toxic lewisite oxide (2-chlorovinylarsenous acid) (Cameron et al., 1946). 

Agent HT is generally a mixture of 60% HD and 40% bis(2-chloroethylthioethyl)ether (T), although this ratio may vary. Agent HL is a mixture of sulfur mustard (HD) and lewisite (L) that was developed for cold weather or high-altitude use due to its lower freezing point. Sesqui mustard (Q) is l,2-bis(2-chloroethylthio) ethane and is considered a more potent vesicant than HD but its very low vapor pressure limits its effectiveness as a warfare agent,... 

Methyldichloroarsine was apparently used by the Germans in 1917. Methyldichloroarsine is a colorless liquid of powerful burning odor, which boils at 132°C. It is somewhat soluble in water and is soluble in organic solvents. The specific gravity is 1.838 at 20°C. The vapor pressure at 25° was found to be 10.83 mm Hg. Not only is the material toxic but it has remarkable vesicant properties, comparing favorably with mustard gas in this respect (Bennett and Ddl, 1994). 

High pressure has been applied successfully to Diels-Alder reactions of furans, which are notoriously troublesome due to low activation barriers and low or even negative AC values. For example, attempts to synthesize the potent vesicant cantharidin (232) via reaction of furan (228) with dimethylmaleic anhydride (234) date back to 1928. The failure of this approach has been attributed to a thermodynamic preference for cycloreversion over cycloaddition. More than SO years later the problem was solved by employing high pressures and either a modified dienophile (229) or diene paitner (233). Interestingly, product (235) reverts to reactants (233) and (234) in solution at atmospheric pressure and room temperature (Scheme S4). 

Vesic, A. S., Cratering by Explosives as an Earth Pressure Problem, 6th Inti. Conf. on Soil Mechanics and Foundation Engineering, Montreal, Canada, 1965. 

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