Shock States and Hemodynamic Management - NREMT Paramedic Level

1. Calculate MAP for $SBP=90$ and $DBP=50$ using $MAP \approx \frac{SBP+2(DBP)}{3}$.

   $63\ \text{mmHg}$. Formula weights diastolic phase to approximate cycle-averaged pressure for perfusion assessment.

2. What is the preferred initial crystalloid strategy for septic shock after IV access is obtained?

   Rapid isotonic crystalloid bolus; reassess frequently for fluid responsiveness. Fluid resuscitation aims to restore intravascular volume in sepsis-induced capillary leak and vasodilation.

3. What bedside finding most strongly suggests obstructive shock from tension pneumothorax?

   Severe respiratory distress with unilateral absent breath sounds and hypotension. Mediastinal shift from pressure buildup compresses structures, impairing venous return and ventilation.

4. Identify the classic hemodynamic profile of hypovolemic shock (preload, SVR, CO).

   Preload low, SVR high, CO low. Hypovolemia reduces venous return, triggering compensatory vasoconstriction and decreased output.

5. Calculate shock index for $HR=120$ and $SBP=100$; what value do you obtain?

   $1.2$. Elevated index above 0.9 suggests occult shock by reflecting compensatory tachycardia relative to pressure.

6. What is the formula for shock index used to screen for occult shock?

   $Shock\ Index = \frac{HR}{SBP}$. Shock index helps detect early hypoperfusion by quantifying the ratio of heart rate to systolic pressure.

7. What is the primary immediate goal of hemodynamic management in any shock state?

   Restore adequate perfusion and oxygen delivery to vital organs. Management targets reversal of hypoperfusion to prevent irreversible cellular damage and organ failure.

8. What is the key prehospital management priority for massive pulmonary embolism shock?

   Support oxygenation/ventilation and perfusion; rapid transport for definitive therapy. Prehospital care stabilizes hemodynamics while expediting access to anticoagulation or thrombolysis.

9. Identify the classic hemodynamic profile of obstructive shock (preload, SVR, CO).

   Preload variable, SVR high, CO low due to impaired filling/outflow. Obstruction impedes cardiac filling or ejection, prompting compensatory responses with reduced output.

10. What is the formula for mean arterial pressure (MAP) used in shock assessment?

    $MAP \approx \frac{SBP + 2(DBP)}{3}$. MAP estimates average arterial pressure throughout the cardiac cycle, crucial for assessing perfusion in shock.

11. Identify the shock type: hypotension with JVD and muffled heart sounds after chest trauma.

    Obstructive shock from cardiac tamponade. Trauma causes pericardial filling, impairing output with signs of low flow and venous backup.

12. What triad is classically associated with cardiac tamponade causing obstructive shock?

    Beck triad: hypotension, JVD, muffled heart sounds. Pericardial effusion restricts diastolic filling, reducing stroke volume and causing venous congestion.

13. Identify the shock type: hypotension with bradycardia and warm dry skin after spinal injury.

    Neurogenic shock. Spinal injury disrupts sympathetic outflow, causing vasodilation without compensatory tachycardia.

14. Which vasopressor is first-line for septic shock with persistent hypotension after fluids?

    Norepinephrine. Norepinephrine provides alpha-adrenergic support to counteract vasodilation in refractory septic hypotension.

15. Which inotrope is commonly used for cardiogenic shock with low cardiac output and congestion?

    Dobutamine. Dobutamine enhances myocardial contractility to improve output in pump failure with fluid overload.

16. Which vasopressor is preferred for anaphylactic shock with airway or hypotension involvement?

    Epinephrine. Epinephrine counters histamine-mediated vasodilation and bronchospasm in anaphylaxis.

17. What is the most reliable early sign of shock in many adult patients before hypotension occurs?

    Tachycardia with cool, clammy skin and delayed capillary refill. Compensatory sympathetic activation causes these signs as early indicators of hypoperfusion.

18. Identify the classic hemodynamic profile of cardiogenic shock (preload, SVR, CO).

    Preload high, SVR high, CO low. Cardiac pump failure increases filling pressures with compensatory resistance but inadequate output.

19. What is the immediate definitive prehospital intervention for tension pneumothorax shock?

    Needle decompression (followed by chest tube in-hospital). Decompression relieves intrathoracic pressure, restoring venous return and cardiac output.

20. Identify the shock type: warm flushed skin, hypotension, bounding pulses early, fever suspected.

    Septic (distributive) shock. Sepsis induces systemic vasodilation and hyperdynamic state with inflammatory signs like fever.

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