What Is Shock?
Shock is inadequate tissue perfusion resulting in insufficient oxygen delivery to meet cellular demands. It is not defined by low blood pressure alone. The NREMT tests your understanding of the pathophysiology of shock, your ability to recognize it early, and your knowledge of appropriate prehospital management for each type.
Types of Shock
Hypovolemic shock results from fluid loss (hemorrhage, dehydration, burns). Distributive shock results from widespread vasodilation (anaphylaxis, sepsis, neurogenic). Cardiogenic shock results from pump failure (heart attack, heart failure, dysrhythmias). Obstructive shock results from mechanical obstruction of blood flow (tension pneumothorax, cardiac tamponade, pulmonary embolism). Each type has distinct assessment findings and treatment priorities.
Compensated vs. Decompensated Shock
In compensated shock, the body maintains blood pressure through increased heart rate, vasoconstriction, and increased respiratory rate. Signs include tachycardia, pale and cool skin, delayed capillary refill, anxiety, and thirst. Blood pressure may be normal. In decompensated shock, compensatory mechanisms fail and blood pressure drops. Signs include hypotension, severely altered mental status, weak or absent pulses, and mottled or cyanotic skin. The transition from compensated to decompensated shock can be sudden.
Prehospital Management
Management priorities for shock include: control any external bleeding, maintain the airway and provide high-flow oxygen, keep the patient warm (prevent hypothermia), position the patient appropriately (supine with legs elevated for hypovolemic shock, sitting up for cardiogenic shock with pulmonary edema), and transport rapidly to an appropriate facility. Do not delay transport for interventions that can be performed en route.
Exam Focus Areas
The NREMT frequently presents scenarios where you must identify the type of shock based on the mechanism and assessment findings. Know the key differentiators: hypovolemic shock has a clear source of fluid loss, anaphylactic shock has allergen exposure with urticaria and bronchospasm, neurogenic shock has a spinal cord mechanism with warm and dry skin below the injury, and cardiogenic shock has a cardiac history with jugular vein distension and crackles.