AMLS Shock and Hemodynamic Instability 3

Question 1

What is the pathophysiologic mechanism underlying cardiogenic shock?

Accepted Answer

Pump failure reduces cardiac output causing tissue hypoperfusion

Answer

Cardiogenic shock results from the heart's inability to maintain adequate cardiac output, leading to tissue hypoperfusion despite normal or elevated filling pressures.

Question 2

Which clinical finding indicates a positive response to a fluid challenge in a hypotensive patient?

Accepted Answer

Increase in pulse pressure and improvement in mental status

Answer

A positive fluid response is indicated by improved perfusion markers such as increased pulse pressure, improved mentation, and decreased heart rate.

Question 3

A patient in decompensated shock has cold, mottled extremities and a capillary refill of 5 seconds. What organ is most immediately at risk?

Accepted Answer

Kidneys (acute tubular necrosis)

Answer

Prolonged hypoperfusion in shock preferentially damages the kidneys, causing acute tubular necrosis and acute kidney injury.

Question 4

What is the significance of a serum lactate greater than 4 mmol/L in a shock patient?

Accepted Answer

Indicates severe tissue hypoperfusion and high mortality risk

Answer

A lactate >4 mmol/L reflects severe anaerobic metabolism from tissue hypoperfusion and is associated with significantly increased mortality.

Question 5

Which intervention is definitive for obstructive shock caused by tension pneumothorax?

Accepted Answer

Needle decompression followed by chest tube thoracostomy

Answer

Needle decompression (2nd ICS MCL or 4th/5th ICS AAL) releases trapped air, converting tension pneumothorax to simple pneumothorax, followed by chest tube.

AMLS - Advanced Medical Life Support Practice Test

AMLS - Advanced Medical Life Support Practice Test

AMLS Shock and Hemodynamic Instability 3