Shock

Overview

Definition

• Shock is a state of circulatory failure characterised by tissue perfusion inadequate to meet the needs of the body.

Classification (shock can be classified as PROVED?)

• cardiogenic (Pump)
• Rhythm abnormalities (some purists exclude dysrhythmia as a cause of cardiogenic shock)
• Obstructive
• hypovolemia (Volume)
• Endocrine causes (often mixed classification, but a useful subheading to make sure endocrine causes aren’t missed!)
• Distributive (due to vasodilation)
• ? = is it real? (check the BP measurement, is the arterial line in an artery, is the transducer at the correct height?)

Remember that drugs and toxic exposures can contribute to cardiogenic, rhythm, or distributive causes of shock.

Causes

Cardiogenic shock

Impaired contractility

• Myocardial ischemia and compliations
• [ ]
  • Infarction — anterior MI, reinfarction, right ventricular infarction, myocardial stunning
  • Acute mitral regurgitation due to papillary muscle rupture
  • Ventricular septal rupture
  • Left ventricular free wall rupture and tamponade
• Myocarditis
• Myocardial contusion