Журнал «Медицина неотложных состояний» 8 (55) 2013

The situation in which the person finds himself at cryoinjury, is a stress i.e. a response which naturally arises with activity of extreme environmental factors on an organism [2,3,7,14]. Analysis of literary data and the gained experience testify that disturbances of life body activity which arise after cold effect, both common and widespread local, have similar prolonged character and processes which occur in late periods of course disease are closely connected with initial hours and days of disease.

Firstly in spite of low environment temperature, the body temperature does not fall and remains at normal level thanks to including the compensatory responses predetermining the thermoregulation change. This cooling period is called compensation phase. The complex change in organism which maintains a constant body temperature in the conditions of a cold occurs with the participation of neurohumoral regulatory mechanisms [8,16]. Skin thermoreceptors accept cold excitation and send impulses to hypothalamus by sensitive ways where there is a thermoregulation center and the highest departments of the central nervous system. Therefrom in the opposite direction the signals are transmitted to different organs and systems participating in support of a body temperature. On the mobile nerves impulses go to muscles where thermoregulatory tonus and tremor are developed. On sympathetic nerves excitation reaches adrenal marrow where adrenaline secretion is strengthened. Adrenaline promotes narrowing of peripheral vessels and stimulates glycogen breakdown in a liver and muscles.

In the conditions of long-term or intense cold effect there is possible the supertension and an exhaustion of thermoregulation mechanisms after that the body temperature falls and the second cooling stage occurs - a decompensation phase or hypothermia. The stress is a so strong situation that autoregulation "failure" on the background of adaptable body abilities is almost inevitable. There is so called catabolic phase or Selye "destruction" phase [9].

The organism has exhausted reserve (compensatory) abilities and a decompensation arises. The hyperventilation leads to a respiratory alkalosis and cerebral circulation depression, to disturbance of rheological blood properties and results in hypercoagulation and coagulopathy consumption (DVS-TGS-syndrome), structural proteins, fats are utilized, reducing body functionality, enzymatic systems, an information transfer are inactivated, function of cell membranes is disturbed, and as consequence there is an adrenal insufficiency, respiratory function of lungs is affected, contractive myocardium function is reduced, there are disturbances in microcirculation system in all organs that result in their dystrophy [9,12].

Washout of toxic products from ischemic tissues and mass saturation of organs and body tissues result in the significant dysfunctions of brain, heart, lungs which is displayed in the form of the DVS-syndrome of different severity level, endothelial lesion of bloodstream, especially in lungs that leads to development of respiratory and heart failure, mediatory "explosion", development of a respiratory distress-syndrome. And as a final result the multiple organ insufficiency (MOI) arises [1]. This state can be characterized as transferring of adaptable into destructive stress effect. A state when the adaptive period of cold stress transfers into destructive can be termed as a period of formation of cold shock according to Cairns C.B. (2001). This course period of cryoinjury can be characterized as formation of manifestations of "cold" shock, that is when the blockage of microcirculation and hemostasis disturbance result in depression of organs perfusion [13,17]. We consider expedient to characterize "cold" shock as acutely arising critical state of a destructive period of cold stress with progressing insufficiency of the life support system predetermined by an acute circulatory deficiency, acute respiratory insufficiency, disturbance of microcirculation and a hypoxia of tissues with pathology of all physiologic body systems.