From Big Medical Encyclopedia

THERMAL SHOCK — the morbid condition caused by the general overheating of an organism as a result of influence of external thermal factors.

Disturbance is the main reason for overheating of an organism thermal controls (see), arising under the influence of excess receipt of heat from the environment. At the same time any conditions complicating a thermolysis (high humidity and an immovability of air) or increasing heat production (physical tension, suralimentation) are the factors promoting overheating (see. Overheating of an organism ). Degree and speed of overheating at different persons. fluctuate over a wide range and depend on external factors and on specific features of an organism. A bowl are exposed to overheating of the person easier. having cardiovascular diseases, exchange disturbances (obesity), endocrine frustration (hyperthyroidism), vascular and vegetative dystonias. Overheating of an organism easily occurs at newborns and children till 1 year (see. Baby ).

T. at. can develop: 1) at working in hot workshops (founders, welders, steelmakers, etc.) at long stay in the room with high temperature and hard physical activity; on building sites, at the earth and mining operations which are carried out in hot days and in places with big humidity, 2) during the marches of the military divisions made in summer days with the full calculation, long transitions, especially in the conditions of a subtropical and tropical belt; 3) in vrekhmya long tourist campaigns in the absence of a sufficient training at their participants, etc.

Overheating is possible as a result of direct exposure to sunlight on the head — a so-called heliosis. On a clinical and morphological picture thermal and solar blows are so close that a number of researchers considers inexpedient to divide them. Overheating of a body is followed by the strengthened sweating with considerable loss by an organism of water and salts that conducts to a pachemia, increase in its viscosity, difficulty of blood circulation and air hunger. Leading links of a pathogeny of T. at. disorders of water and electrolytic balance because of disturbance of sweating and activity of the hypothalamic center of thermal control are.

T. at. quite often is followed by development collapse (cm.). Disturbances of blood circulation are promoted by toxic action on a myocardium of surplus in blood of the potassium which is released from erythrocytes. At T. at. also regulation of breath and function of kidneys, different types of exchange suffer (proteinaceous, carbohydrate, fatty). If symptoms of T. at. develop quickly, disturbances of water content and electrolytes can reach insignificant degrees.

In the central nervous system at T. at. note a hyperemia and hypostasis of covers and tissue of a brain, multiple hemorrhages; histologically — perivascular and pericellular hypostasis, proliferation of a glia. As a rule, observe a plethora of internals, punctulate hemorrhages under a pleura, an epicardium and an endocardium, in a mucous membrane of a stomach, intestines, quite often a fluid lungs, dystrophic changes of a myocardium.

T. at. usually arises during the maximum influence of heat and only in rare instances during escaping of a zone of overheating. The beginning is usually acute, a current — bystry; in some cases massive nevrol. the symptomatology reminds a picture of a stroke (see). On weight and a current it is accepted to distinguish three forms of a thermal shock: easy, moderately severe and heavy.

At an easy form the adynamia, a headache, nausea are noted; breath and pulse are speeded up, skin wet, pupils are expanded, body temperature normal or subfebril-ny. If injured to take out from a zone of overheating, to quickly give help, then symptoms of a hyperthermia completely disappear.

The moderately severe thermal shock is characterized by more expressed symptoms: a sharp adynamia, an intensive headache with nausea and vomiting, an oglushennost, uncertainty of movements, periodically short-term loss of consciousness (faints). Pulse and breath are speeded up, skin is hyperemic, wet, sweating is strengthened, body temperature is increased to 39 — 40 °. At the termination of thermal influence and under influence to lay down. actions body temperature decreases and functions of an organism are normalized.

Severe form of T. at. usually develops suddenly, sometimes even apoplektiformno. The symptomatology is various. Into the forefront act nevrol. symptoms: change of consciousness from easy degrees to a coma, a spasm of clonic and tonic character, periodic psychomotor excitement, often nonsense, hallucinations. The shallow breathing which is speeded up, wrong. Pulse is speeded up to 120 — 140 blows in 1 min., small, threadlike, cardiac sounds deaf. The person is hyperemic in the beginning, further becomes pale cyanochroic. Skin is dry, hot or becomes covered by a clammy sweat; body temperature rises to 41 — 42 ° above; the diuresis is reduced. On an ECG — signs of diffusion damage of a myocardium. The pachemia with increase in it residual nitrogen, urea and reduction of chlorides is observed. The lethality at this form reaches 20 — 30%.

The help at T. at. it has to appear quickly, only then she is effective. The victim needs to be removed urgently from a zone of overheating to the place protected from the sun and open for wind, to exempt from outerwear, to undress to a belt. Measures to cooling shall be taken: wetting of the person a cold water, pat up to a breast a wet towel, on the head and a neck — a bubble with a cold water, frequent «opakhivaniye» of the victim. In all cases inhalation of oxygen and oxygen mixes, especially Carbogenum is shown (see. Oxygen therapy ). For compensation of losses of water and chlorides appoint subcutaneously or intravenously physiological solution of sodium chloride, drop enemas, intravenously — solution of glucose, during the falling of cordial activity — an injection of camphor, caffeine, strophanthin, at disorder of breath — lobeline. For strengthening of a thermolysis give a cold water, tea, coffee. At excitement enter aminazine, Dimedrol, at spasms — anticonvulsant drugs and tranquilizers (Seduxenum, aminazine, phenobarbital, etc.). At increase in intracranial pressure owing to hypostasis of covers and tissue of a brain the unloading spinal puncture is shown (see).

As effects of T. at. epileptic seizures, hydrocephaly, paresis, in other cases — mental disturbances with a delirium, hallucinations, etc. can be observed, to-rye can demand the corresponding treatment. For the purpose of treatment of the asthenic state which is most often found in such cases vitamins, iron preparations, calcium, glutaminic to - that, Aminalonum, nootropil are recommended.

A significant role in the prevention of T. at. play preventive actions. Their character is defined in each separate case by a specific situation. E.g., long transitions to the hot period are recommended to be carried out to more cool one o'clock in the afternoon, in light porous free clothes, to arrange to a thicket halts in the shady, well aired places. The particularly important becomes observance of rules of the drinking mode (see), thanks to Krom it is possible to korrigirovat directionally a water salt metabolism in an organism. Instead of water it is possible to use the cold acidified or sweetened tea, rice or cherry water, grain kvass. Broader use of carbohydrates, dairy products with restriction of the products containing acid radicals is recommended (porridges, etc.). High temperature of the environment forces to postpone the main meal to evening hours, with consumption for breakfast — 35%, for lunch — 25%, for dinner of 40% of a daily diet.

In hot workshops install devices for cooling of air by spraying of water, recommend drink of the added some salt soda water, widely apply hydrotherapeutic procedures (souls, douches, etc.), establish periodic breaks in work, limit reception of proteinaceous and greasy food.

Importance in prevention of T. at. the preliminary training has, with the help a cut it is possible to achieve increase in adaptation to action of thermal factors.

Bibliography: Kassirsky I. A. and Plotnikov N. N. Diseases of tropical countries, M., 1959; Mild F. G. Military hygiene, M., 1959; The Multivolume guide to pathological physiology, under the editorship of N. N. Sirotinin, t, 2, page 398, M., 1966; Some questions of a patobiokhimiya and a histopathology of overheating, under the editorship of G. M. Starikov, etc., Smolensk, 1970; Panisyak V. I. and Kozlov N. B. About treatment of a thermal shock in experimental conditions, the Stalemate. fiziol. and ekspe-Rome. ter., t. 4, No. 6, page 57, 1960; The Guide to occupational health, under the editorship of F<» G. Krot-kova, t. 3, page 342, M., 1961; At m and d the island and 3. And. and d river. Sketches of cardiology of hot climate, Tashkent, 1975; II and sh N and N. T. t-ti and Levitskayaa. V. Klinika of thermal defeats, Klin, medical, t. 38, No. 12, page 87, 1960.

G. A. Akimov. M. S. Sheiman.