Cardiogenic Shock

Cardiogenic shock (CS) refers to a condition in which there is insufficient oxygen delivery to organs and peripheral tissues due to the heart’s inability to adequately supply oxygen, despite adequate intravascular volume. CS is clinically defined by a combination of low systolic blood pressure (SBP; <90 mmHg), evidence of reduced cardiac output (cardiac index <2.2 L/min/m2), and elevated arteriovenous oxygen difference (>5.5 mL/dL) in patients with elevated pulmonary wedge pressure (>15 mmHg). Shock can be categorized as hypovolemic, cardiogenic, or distributive shock based on parameters such as cardiac output (CO), pulmonary wedge pressure (PCWP), systemic vascular resistance (SVR), and mixed venous oxygen saturation (MVO2). The cardiogenic profile is characterized by reduced CO, increased PCWP and SVR, and reduced MVO2. The SCAI shock severity classification aims to simplify the classification of CS into five distinct stages or phases that reflect the worsening severity of shock. These stages have predictive value for in-hospital and long-term mortality. It is crucial to promptly identify the cause of CS to initiate specific pharmacological or mechanical therapies that are necessary for stabilizing and treating the patient. Management of CS should address both the underlying etiology and the hemodynamic insult simultaneously to prevent further deterioration and progressive tissue hypoxia. To this end, there should be a shift in focus from solely addressing hemodynamic parameters to also prioritizing prevention and appropriate treatment of metabolic imbalances resulting from hemo-metabolic shock. Various cardiogenic shock algorithms have been published in clinical practice as a guide for managing this acutely ill and diverse patient population.