Neurogenic Shock

Hemodynamic Pattern Explanation

The American College of Cardiology and other guideline societies describe neurogenic shock as a form of distributive shock caused by loss of sympathetic tone, characterized by bradycardia, decreased cardiac output, low CVP, and increased SvO2 1
Bradycardia occurs due to unopposed parasympathetic tone following loss of sympathetic innervation, typically from spinal cord injury above T6 2, 1
Decreased cardiac output results from both the bradycardia and loss of sympathetic-mediated cardiac contractility 1
Low CVP reflects pathological vasodilation and venous pooling from loss of vascular sympathetic tone, leading to decreased venous return 1

The European Society of Cardiology notes that cardiogenic shock would show tachycardia rather than bradycardia, elevated CVP, and elevated systemic vascular resistance as compensatory vasoconstriction 3, 1
Distributive shock, including neurogenic shock, demonstrates decreased SVR as the primary pathophysiologic mechanism 2, 1
Normal or decreased CVP is observed in distributive shock, contrasting with the elevated CVP of cardiogenic shock 1

The International Trauma Care society states that neurogenic shock typically occurs following high spinal cord injuries, severe head trauma affecting autonomic centers, or spinal anesthesia complications 2

The Surviving Sepsis Campaign guidelines warn against confusing late-stage septic shock with cardiogenic shock, as septic shock can develop myocardial depression but remains distributive with decreased SVR and often elevated SvO2 1