CAUSTICS (caustica) — means which during the drawing on skin and mucous membranes cause death of cells of the surface layer of fabric with an escharosis which is accurately outlined by a line of demarcation. These changes are connected with sedimentation of proteins and formation of acid or alkaline albuminates that leads to an irreversible gelifikation (consolidation) of a surface layer of cytoplasm of cells. Eventually the scab disappears, and the defect which arose on its place is replaced with granulyatsionny fabric (see).
P.'s action by the village is based on physical. - the chemical transformations happening in the center of cauterization (see) it is also similar to effect of astringents (see), in comparison with to-rymi P. villages have bigger ability to get into thickness of fabrics, and the changes caused by them differ in irreversible character. At P.'s contact by the village with skin, mucous membranes and intercellular lymphs there is a denaturation of proteins (see the Denaturation). Extent of consolidation of surface layers of skin and mucous membranes depends on P.'s concentration of page and exposure. In low concentrations of P. of page can have the irritating or knitting effect.
As a result of consolidation of fabrics under the influence of P. of page secretion of glands and transudation of intercellular lymphs decreases, migration of uniform elements of blood through walls of the narrowed vessels in this connection the local antiinflammatory effect develops decreases. Besides, P. pages suppress life activity of microorganisms on site of cauterization.
On mucous membranes of P. of page have more expressed effect, than on skin and therefore are used in smaller concentration. In the presence on the surface of fabrics of pus, blood or slime P.'s efficiency of page sharply decreases in this connection in such cases before P.'s use by the village it is necessary to carry out the corresponding processing of fabrics.
As P. villages in medical practice use various chemical connections: caustic alkalis, to - you, compounds of metals, etc.
Caustic (strong) alkalis — caustic potassium (see) and caustic soda (see) — soften fabrics with formation of a kashitseobrazny flabby and viscous scab (a kollikvatsionny necrosis), and also saponify fats and dissolve a keratin of epidermis.
The smoking and pure nitric acid (see), lactic acid (see), pure concentrated sulphuric acid (see), trichloroacetic acid and other acids have the cauterizing effect by dehydration of superficial elements with formation of a dense scab (a coagulative necrosis).
At dissociation of salts of heavy metals acids which also possess the cauterizing action are formed, and their efficiency as P. of page is directly proportional to ability to dissociation.
From compounds of metals as P. villages use soluble drugs of aluminum (see), napr, Burov's liquid, simple and exsiccated alum; drugs of silver (see), e.g. silver nitrate; drugs of zinc (see), e.g. zinc chloride; drugs of copper (see), e.g. copper sulfate. As P. the page can apply also potassium permanganate (see). The cauterizing activity of compounds of metals is proportional to extent of their dissociation. It increases among: Pb, Al, Zn, Cu, Ag, Hg.
Items of page use locally for destruction patol. educations: hypertrophied sites of a mucous membrane, vulgar and bottom warts, sharp-pointed condylomas, excess granulations, etc. In modern medical practice of P. of page apply rather seldom since for the specified purposes highly effective physical methods of treatment, e.g. electrolysis (see), diathermocoagulation (see), cryotherapy (see) and thermocoagulation are implemented (see).
Bibliography: Mashkovsky M. D. Pharmaceuticals, p.1 — 2, M., 1977.
D. N. Samoylov.