[Shock. A review (author's transl)]

Shock is defined as a secondary condition constituting a complication to a primary disease of which more than 100 are recorded in the literature. Shock is characterized by prolonged circulatory inadequacy leading to insufficient tissue perfusion and cell death. According to etiology shock is classified into three main groups: hypovolemic, vasogenic and cardiogenic shock. Taking hypovolemic shock as a model the pathgenesis of shock is presented. Hypovolemia acts on the baroreceptors giving rise to a sympatho-adrenal response resulting in increased vasoconstriction, which again leads to viscerocutaneous ischemia. This phase is known as the ischemic anoxic or centralized shock phase. Without treatment this phase develops into the second socalled stagnant anoxic or paralytic shock phase. "Irreversible shock" is discussed. The pathogenesis of vasogenic and cardiogenic shock is mentioned and compared with hypovolemic shock. It is emphasized that the sympatho-adrenal response is the central and common feature in every shock development. Special reference is made to septic shock with its outstanding circulatory conditions (arteriovenous shunting). Lacticacidemia and metabolic acidosis are described as the most important metabolic alterations in shock. With reference to pathenesis the main clinical symptoms of shock are presented: increased heart rate, initially pale later hyperemic, congested and terminally cyanotic mucosae, increased capillary filling time, cold skin and low body temperature. All these signs are related to the sympatho-adrenal response. It is pointed out that the patient in shock is depressed. Inevitably the primary disease will modify the shock symptoms. Hyperemia with edema, hemorrhages and thrombosis in organs and tissues are morphological manifestations of shock. Later microscopically detectable degenerative and necrotic alterations develop, and there are signs of intravascular coagulation (hyaline thrombi and spheres). Due to the rather nonspecific macroscopic alterations a post mortem shock diagnosis necessitates for completion histology and/or a clinical shock diagnosis. Some of the most important shock-provoking primary diseases dealt with in veterinary practice are mentioned along with their possible shock pathogenesis. Referring to the shock pathogenesis the therapy is discussed. The first and indispensable therapeutical measure in treating shock per se is increasing the circulating blood volume, Balanced electrolyte solutions are preferred. Examples of composition, doses (up to 80--200 ml/kg body weight) and infusion rate (initially 15--30 ml/kg body weight during the first 10--20 min., then quantum satis) are given.