Shock Recognition and Management - NREMT AEMT Level

1. What does narrowing pulse pressure most strongly suggest in early hypovolemic shock?

   Compensatory vasoconstriction with falling stroke volume. Rising diastolic pressure from vasoconstriction narrows the gap with systolic pressure as cardiac output declines.

2. Calculate MAP for BP $90/60$ using $MAP = \frac{SBP + 2(DBP)}{3}$.

   $70$ mmHg. Applying the MAP formula to these values yields 70 mmHg, a threshold for adequate perfusion in many organs.

3. Which reassessment finding most strongly indicates your shock treatment is improving perfusion?

   Improving mental status and stronger peripheral pulses. These signs reflect restored cerebral and peripheral perfusion, indicating effective resuscitation efforts.

4. What is the most common overall cause of shock in trauma patients?

   Hemorrhage (hypovolemic shock). Traumatic blood loss rapidly depletes intravascular volume, leading to hypovolemic shock if uncontrolled.

5. Which oxygen strategy is appropriate for a patient with suspected shock and hypoxia risk?

   High-concentration oxygen to maintain adequate oxygenation/ventilation. High-flow oxygen supports oxygen delivery in shock states where hypoxia exacerbates cellular dysfunction.

6. What is the formula for mean arterial pressure (MAP) used to assess perfusion?

   $MAP = \frac{SBP + 2(DBP)}{3}$. MAP estimates average arterial pressure driving organ perfusion, weighted toward diastolic phase duration.

7. What is the definition of shock in prehospital care?

   Inadequate tissue perfusion causing cellular hypoxia and dysfunction. Shock occurs when perfusion fails to deliver adequate oxygen and nutrients, leading to cellular injury and potential organ failure in emergency settings.

8. Which shock category is caused by pump failure leading to low cardiac output?

   Cardiogenic shock. Myocardial dysfunction decreases ejection fraction and cardiac output, failing to maintain systemic perfusion despite adequate preload.

9. Identify the earliest skin finding commonly associated with compensated shock.

   Cool, pale, diaphoretic skin. Sympathetic activation causes peripheral vasoconstriction, resulting in these skin changes to preserve core perfusion.

10. What key history finding most strongly supports anaphylactic shock?

    Recent allergen exposure with urticaria or airway swelling. IgE-mediated reaction to allergens triggers massive histamine release, causing vasodilation and capillary leak.

11. In cardiogenic shock with pulmonary edema, which fluid strategy is most appropriate?

    Avoid large boluses; use cautious small bolus only if clearly indicated. Excess fluid can worsen pulmonary edema in low-output states, so titration prevents overload while supporting perfusion if needed.

12. What is the classic triad of obstructive shock from cardiac tamponade?

    Beck triad: hypotension, JVD, muffled heart sounds. These signs indicate pericardial effusion compressing the heart, reducing diastolic filling and cardiac output.

13. Which shock category is caused by pathologic vasodilation and relative hypovolemia?

    Distributive shock. Vasodilation from sepsis or anaphylaxis increases vascular capacity, causing relative hypovolemia and hypotension.

14. What is the typical early compensatory vital sign change in shock?

    Tachycardia. The sympathetic response increases heart rate to compensate for reduced stroke volume or preload in early shock stages.

15. What is the most reliable early indicator of shock in an adult with normal baseline BP?

    Altered mental status (anxiety, restlessness, confusion). Brain hypoperfusion manifests as these symptoms before hypotension in compensated shock, making it a sensitive indicator.

16. What is the preferred initial IV fluid for most shock states in prehospital care?

    Isotonic crystalloid (normal saline or lactated Ringer solution). These fluids expand intravascular volume effectively without causing osmotic shifts in most hypotensive patients.

17. Which shock category is caused by obstruction to cardiac filling or outflow?

    Obstructive shock. Conditions like tamponade or tension pneumothorax impede venous return or ventricular ejection, reducing cardiac output.

18. Which shock type often presents with warm, flushed skin early rather than cool and clammy?

    Distributive shock (especially early septic shock). Vasodilation in distributive shock increases skin blood flow initially, contrasting with vasoconstriction in other types.

19. Which shock category is caused by loss of circulating blood volume?

    Hypovolemic shock. Absolute volume loss from hemorrhage or dehydration reduces preload and cardiac output, impairing tissue perfusion.

20. What is the initial priority sequence for managing shock in the field?

    Airway, breathing, circulation, rapid transport while treating cause. Following ABC priorities stabilizes oxygenation and circulation while addressing underlying causes en route to definitive care.

21. What is the adult initial crystalloid bolus commonly used for suspected hypovolemic shock?

    Approximately $1$ L isotonic crystalloid, then reassess. A 1 L bolus restores preload in hypovolemia, with reassessment to avoid overload or confirm need for more.

22. What finding best differentiates neurogenic shock from other shock types?

    Hypotension with bradycardia after spinal cord injury. Loss of sympathetic tone in neurogenic shock causes unopposed parasympathetic activity, leading to bradycardia despite hypotension.

23. Which physiologic endpoint best defines adequate perfusion at the cellular level?

    Sufficient oxygen delivery to meet metabolic demand (aerobic metabolism). Adequate perfusion ensures cells receive enough oxygen for aerobic processes, preventing anaerobic metabolism and acidosis.

24. Which lung finding most supports tension pneumothorax as a cause of obstructive shock?

    Absent breath sounds on one side. Unilateral lung collapse shifts mediastinum, compressing vena cava and reducing cardiac preload in tension pneumothorax.

25. Identify the best immediate intervention for life-threatening external hemorrhage causing shock.

    Direct pressure and tourniquet as indicated. These methods rapidly control bleeding to prevent further volume loss and stabilize hemodynamics in hemorrhagic shock.

Study these flashcards