Читать книгу Emergency Medical Services - Группа авторов - Страница 182

Causes of cardiogenic shock include arrhythmias, valvular heart disease, infection, cardiotoxic agents, and most commonly myocardial infarction. As a result, cardiogenic shock requires individualized treatment. Early revascularization among patients with myocardial infarction improves long‐term survival [45]. Cardiogenic shock from severe dysrhythmias should be treated with appropriate electrical or pharmacological therapy. “Pump failure” is often difficult to diagnose and to treat without invasive monitoring. Adult patients without obvious pulmonary edema may benefit from fluid challenges of approximately 200‐300 mL of crystalloid. An improvement in the patient’s condition suggests that enhancing preload would be beneficial. A worsening of the patient’s condition with a modest fluid challenge, or the presence of obvious pulmonary edema on initial evaluation, suggests that fluid therapy would not be helpful. In such settings, treatment with inotropic agents or vasopressors, such as dobutamine or norepinephrine, would be more appropriate. Intravenous infusions are often difficult to manage in the field without an infusion pump and must be monitored closely.

Less common causes of cardiogenic shock include beta‐blocker and calcium channel blocker toxicity. Such agents block sympathomimetic receptors, impairing the body’s normal compensatory responses. These patients present with profound bradycardia and shock, often refractory to sympathomimetic treatment and fluid challenges due to the receptor blockade. Additional therapies may include IV glucagon or calcium, which facilitate heart rate stimulation and vasoconstriction through alternative cellular receptors. EMS agencies carry them for the treatment of hypoglycemia and hyperkalemia, respectively.