This study examined dynamics for blood gas, parameters of acid-base equilibration, water-and-electrolyte balance, glucose, hemocoagulation, and blood rheology at surgery for aortic arch and thoracoabdominal aneurysm during profound hypothermia and circulatory arrest. Frequency for development of homeostatic disorders was related to the temperature (r = -0.71; P < 0.05), and to the duration of circulatory arrest period (r - 0.77; P <0.05). Also, it established the dependencies from duration of cooling time (r = 0.59; P < 0.05), and from warming time when temperature has attained more than 28±C (r = -0.65; P < 0.05). It was shown that long hypoxia and reperfusion disorder stipulated the decrease of utilization for main metabolites, the increase of oxygen failure in tissues, the increase of the permeability of cells membranes, and the increase of blood viscosity and disseminated intravascular coagulation (DIC), which are the main reasons for homeostasis disorders during the same surgery. In the period from the start to the end of the second extracorporeal circulation, there exists the heaviest probability for hypoxic failure in tissues and thrombohemorrhagic complications. For aortic aneurysm surgery with circulatory arrest and profound hypothermia, the adequacy for the correction of homeostatic disorders is expressed only in complex therapy of hypoxical and thrombohemorrhagic complications that enable one to execute simultaneous reduction of the tissue's oxygen deficit and failures of hemocoagulation and blood rheology.

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