title: Treatment of circulatory shock. Use of sympathomimetic and related vasoactive agents.
abstract: Reduction of effective blood flow represents the primary disturbance accounting for circulatory shock. Four categories of circulatory shock are identified: cardiogenic, hypovolemic, distributive, and obstructive. The pharmacology and clinical implications for treatment of shock with vasoactive drugs are reviewed in this context. Except for epinephrine, when it is used for treatment of anaphylactic shock, there is no specific indication for the routine use of alpha- or beta-adrenergic receptor agonists. These agents may increase blood pressure or cardiac output, but nutritive flow is not necessarily improved. Comparable limitations are observed with alpha-adrenergic receptor blocking agents. However, selective effects on the myocardium and on the resistance, exchange, and capacitance vessels may be advantageous as an interim and complementary measure. Since vasoactive drugs frequently intensify the fundamental defect accounting for perfusion failure, their selective rather than routine employment is mandatory.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D001776:Blood Circulation Time; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume; D002302:Cardiac Output / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D012769:Shock / Q000145:classification / Q000188:drug therapy* / Q000209:etiology; D012770:Shock, Cardiogenic / Q000188:drug therapy; D013566:Sympathomimetics / Q000494:pharmacology / Q000627:therapeutic use*; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D013566:Sympathomimetics; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents