Resuscitation of vital activity after cold arrest of respiration by physiological methods without rewarming the body

Abstract

The arrest of respiration during deep hypothermia means death, though at a low temperature the heart may rhythmically contract for 30-40 minutes more. The attempts of rewarming only shorten the time before the heart arrest. Calcium ions (Ca2+) are believed to accumulate in the nervous cells in cold. An excess of these ions inhibits the metabolism. Moreover it stimulates the cell proteases, which destroy the cell membranes. The aim of the study was to make the the attempts to develop the methods of stimulating the respiration and heart without rewarming the body. The work was carried out on wite rats 250-320g in weight. We introduced disodium salt of ethylenediaminetetraacetic acid into the animals. The second method of blocking the mechanisms of the cold death was artificial respiration. Ethylenediaminetetraacetic acid reacts with calcium ions, decreases their quantity in the blood, and, consequently, in a complex manner in the cell protoplasm. Artificial respiration not only increases the flow of oxygen into an organism but also decreases the lowest temperature threshold of the cold death of an organism. A decrease in the surviving threshold by 1.5-1.8 degrees C is very important from the point of view of reanimation of an organism since to preserve life in the critical period of reanimation each 0.5 degrees C are important. Prolongation of minimal frequency of heart contractions and maintaining a minimal arterial blood pressure in an overcooled organism given the body temperature of 11-12.5 degrees C is a special problem of great interest associated with many physiological and biological parameters.