PHTLS - Prehospital Trauma Life Support Prehospital Trauma Life Support Shock and Hemorrhage Control 1

Question 1

In PHTLS, which physiologic mechanism is the PRIMARY cause of death in hemorrhagic shock when the body's compensatory mechanisms fail?

Accepted Answer

Inadequate cellular oxygen delivery leading to anaerobic metabolism and organ failure

Answer

PHTLS defines shock as inadequate tissue perfusion and oxygenation. When compensatory mechanisms (vasoconstriction, tachycardia) are exhausted, cells shift to anaerobic metabolism, producing lactic acidosis, which progresses to multi-organ failure and death.

Question 2

According to PHTLS hemorrhagic shock classification, a patient presenting with heart rate of 118 bpm, mildly anxious affect, and normal blood pressure most likely falls into which class?

Accepted Answer

Class II

Answer

Class II hemorrhage (750–1500 mL blood loss, 15–30% volume) typically causes tachycardia (100–120 bpm) and anxiety while systolic BP is still maintained through compensatory vasoconstriction. BP drop is not yet measurable at this stage.

Question 3

When applying a wound packing technique for hemorrhage control in a non-compressible truncal wound, PHTLS recommends packing the wound with hemostatic gauze and then:

Accepted Answer

Holding firm, direct manual pressure for a minimum of 3 minutes

Answer

PHTLS requires at least 3 minutes of firm, uninterrupted direct manual pressure after hemostatic gauze packing to allow the agent to activate and the clot to form. Releasing pressure too early disrupts clot formation and restarts bleeding.

Question 4

The 'lethal triad' in trauma, which PHTLS providers are taught to recognize and prevent, consists of:

Accepted Answer

Hypothermia, acidosis, and coagulopathy

Answer

The lethal triad — hypothermia, acidosis, and coagulopathy — is a self-reinforcing cycle in trauma patients. Hypothermia impairs clotting enzyme function, acidosis worsens coagulopathy, and ongoing bleeding deepens acidosis; PHTLS providers focus on prevention through rapid hemorrhage control and warming.

Question 5

PHTLS supports a strategy of 'permissive hypotension' in penetrating trauma patients with uncontrolled internal hemorrhage. What is the PRIMARY goal of this approach?

Accepted Answer

To avoid diluting clotting factors and dislodging early clots while maintaining minimal perfusion

Answer

Aggressive IV fluid resuscitation raises blood pressure, which can mechanically dislodge early clots and dilute remaining clotting factors, worsening coagulopathy. Permissive hypotension targets a mean arterial pressure sufficient for minimal brain and organ perfusion while limiting this harm until surgical hemorrhage control.

PHTLS - Prehospital Trauma Life Support Practice Test

PHTLS - Prehospital Trauma Life Support Practice Test

PHTLS - Prehospital Trauma Life Support Prehospital Trauma Life Support Shock and Hemorrhage Control 1