Metabolic aspects of shock

Abstract

The study of metabolism in shock involves elements of complexity inherent in the evolution of the syndrome in different successive stages — from initial circulatory disequilibrium between vascular capacity and blood content, to a phase of blood redistribution which varies from one organ to another because of vasoconstrictor reactions which are more intense in the kidneys and liver and less so in the brain and heart, and finally to a period of general decline in vasomotor reactions. The metabolic changes appear to depend not only on tissue anoxia but also on endocrine (pituitary and adrenal) and autonomic nervous (adrenergic) reactions which may appear independently of one another, producing different effects in the various organs according to the stage of shock reached and the aetiological factors involved. These variable conditions may largely explain the discrepancies between results already obtained in the experimental field and particularly in clinical practice, where circulatory disorders are often complicated by toxic and infectious factors of various kinds. For these reasons it is impossible to make a comprehensive and uniform assessment of the many contributions that have been made towards an understanding of this syndrome, since the results reported are difficult to compare with each other and are concerned with isolated phases in particular metabolic sectors, limited to a few organs or to the blood and taken from different animal species under various conditions of environment and nutrition.