PHTLS - Prehospital Trauma Life Support Shock and Hemorrhage Control 2 — Questions and Answers
Question 1: What is the definition of shock according to PHTLS?
- Low blood pressure only
- Inadequate tissue perfusion and oxygenation (Correct answer)
- Rapid heart rate with normal blood pressure
- Loss of consciousness after trauma
Correct answer: Inadequate tissue perfusion and oxygenation
PHTLS defines shock as inadequate tissue perfusion, when oxygen delivery fails to meet metabolic demands.
Patients can be in shock with normal blood pressure (compensated shock) and conversely may have low blood pressure without being in shock. Recognizing shock requires integrating mental status, skin signs, heart rate, blood pressure, respiratory rate, and urine output.
Question 2: Which class of hemorrhagic shock typically presents with the first measurable drop in systolic blood pressure?
- Class I
- Class II
- Class III (Correct answer)
- Class IV
Correct answer: Class III
Class III hemorrhage (30-40% blood volume loss) is typically when systolic blood pressure measurably drops, as compensatory mechanisms become overwhelmed.
By the time hypotension is detected, the patient has already lost approximately one-third of their blood volume. PHTLS emphasizes recognizing earlier signs: tachycardia, narrowing pulse pressure, anxiety, and delayed capillary refill.
Question 3: What is the PHTLS-recommended first-line treatment for life-threatening extremity hemorrhage?
- Elevation of the extremity
- Tourniquet application (Correct answer)
- Pressure point compression
- Wound packing with gauze
Correct answer: Tourniquet application
PHTLS now recommends early tourniquet application as the first-line treatment for life-threatening extremity hemorrhage.
Evidence from military conflicts demonstrated that tourniquet application significantly reduced preventable hemorrhagic deaths. The shift from 'tourniquet as last resort' to 'tourniquet as first line' represents one of the most significant changes in modern prehospital trauma care.
Question 4: How does PHTLS recommend managing junctional hemorrhage (neck, axilla, groin)?
- Tourniquet application at the wound site
- Wound packing with hemostatic gauze and sustained direct pressure (Correct answer)
- Immediate surgical clamping in the field
- No intervention is possible prehospitally
Correct answer: Wound packing with hemostatic gauze and sustained direct pressure
Junctional hemorrhage is managed with wound packing using hemostatic agents and sustained direct pressure.
Hemostatic gauze is packed firmly into the wound cavity, layer by layer, then sustained direct pressure is applied for at least 3 minutes. Junctional tourniquets are specialized devices designed for these areas.
Question 5: What is the concept of permissive hypotension in trauma resuscitation?
- Allowing blood pressure to drop to zero during transport
- Targeting a lower-than-normal blood pressure to prevent disruption of clots while maintaining organ perfusion (Correct answer)
- Using vasopressors to artificially lower blood pressure
- Withholding all fluids from trauma patients
Correct answer: Targeting a lower-than-normal blood pressure to prevent disruption of clots while maintaining organ perfusion
Permissive hypotension involves accepting a systolic blood pressure of 80-90 mmHg to maintain basic perfusion while avoiding elevated pressures that might dislodge clots.
Aggressive fluid administration causes hemodilution of clotting factors, hypothermia from room-temperature fluids, disruption of forming clots, and acidosis worsening. Important exception: traumatic brain injury requires MAP >80 mmHg to maintain cerebral perfusion.
Question 6: Which physical finding helps differentiate neurogenic shock from hemorrhagic shock?
- Both present identically
- Warm dry skin and bradycardia in neurogenic versus cool clammy skin and tachycardia in hemorrhagic (Correct answer)
- Neurogenic shock always causes unconsciousness
- Hemorrhagic shock never causes tachycardia
Correct answer: Warm dry skin and bradycardia in neurogenic versus cool clammy skin and tachycardia in hemorrhagic
Neurogenic shock causes vasodilation (warm dry skin) and loss of sympathetic cardiac stimulation (bradycardia), while hemorrhagic shock causes vasoconstriction (cool skin) and tachycardia.
PHTLS critically emphasizes that spinal cord injury patients may have CONCURRENT hemorrhagic shock. Hemorrhage must be ruled out before attributing hypotension solely to neurogenic causes. Neurogenic shock is treated with vasopressors after hemorrhage is excluded.
PHTLS - Prehospital Trauma Life Support Shock and Hemorrhage Control 2
What is the definition of shock according to PHTLS?