PHTLS Shock and Hemorrhage Control 3 — Questions and Answers
Question 1: Tranexamic acid (TXA) is most effective when administered within what time frame after traumatic injury?
- Within 30 minutes
- Within 1 hour
- Within 3 hours (Correct answer)
- Within 6 hours
Correct answer: Within 3 hours
The CRASH-2 trial demonstrated TXA is most effective when given within 3 hours of injury; after this window it may increase mortality.
Question 2: A patient has an arterial bleed from the axilla that cannot be controlled with a standard tourniquet. What is the BEST hemorrhage control option?
- Pack the wound with hemostatic gauze and apply direct pressure (Correct answer)
- Apply a second tourniquet distally
- Elevate the extremity above the level of the heart
- Wrap the entire torso with an abdominal binder
Correct answer: Pack the wound with hemostatic gauze and apply direct pressure
Junctional wounds like the axilla cannot be controlled with a standard tourniquet, so wound packing with hemostatic gauze and sustained direct pressure is the appropriate technique.
Question 3: What is the primary mechanism by which hypothermia worsens hemorrhagic shock?
- It increases cardiac output
- It impairs coagulation enzyme function (Correct answer)
- It causes vasodilation
- It increases red blood cell production
Correct answer: It impairs coagulation enzyme function
Clotting enzymes are temperature-dependent; hypothermia slows their activity, impairing coagulation and worsening the lethal triad.
Question 4: Which component of Damage Control Resuscitation (DCR) directly addresses dilutional coagulopathy?
- Early surgical hemorrhage control
- High-ratio packed red blood cells to FFP (Correct answer)
- Large-volume crystalloid infusion
- Permissive normotension
Correct answer: High-ratio packed red blood cells to FFP
DCR uses a balanced 1:1:1 ratio of PRBCs to FFP to platelets to replace all lost blood components and prevent dilutional coagulopathy.
Question 5: A motorcyclist ejected at high speed has distended neck veins, absent breath sounds on the left, and hypotension. After needle decompression fails to improve vitals, what condition should you consider?
- Hemorrhagic shock from splenic laceration
- Cardiac tamponade (Correct answer)
- Massive hemothorax
- Neurogenic shock
Correct answer: Cardiac tamponade
Persistent hypotension with distended neck veins after ruling out tension pneumothorax suggests cardiac tamponade (Beck's triad), which requires pericardiocentesis or thoracotomy.
Question 6: In the context of PHTLS, the term 'lethal triad' refers to which combination of conditions?
- Hypotension, tachycardia, and altered mental status
- Hypothermia, acidosis, and coagulopathy (Correct answer)
- Hemorrhage, hypoxia, and hypovolemia
- Pain, hypoxia, and hyperthermia
Correct answer: Hypothermia, acidosis, and coagulopathy
The lethal triad of hypothermia, acidosis, and coagulopathy creates a vicious cycle that dramatically increases mortality in trauma patients.
Question 7: When packing a wound for junctional hemorrhage control, approximately how long should direct pressure be maintained after packing?
- 30 seconds
- 1 minute
- 3 minutes (Correct answer)
- 5 minutes
Correct answer: 3 minutes
PHTLS and TCCC guidelines recommend at least 3 minutes of direct pressure after wound packing to allow clot formation with hemostatic agents.
PHTLS Shock and Hemorrhage Control 3
Tranexamic acid (TXA) is most effective when administered within what time frame after traumatic injury?