PHTLS Traumatic Brain Injury 4 — Questions and Answers
Question 1: A pediatric TBI patient, age 4, has a GCS of 8 and blood pressure of 70/40 mmHg. What is the minimum acceptable systolic BP target in PHTLS for this child?
- 70 mmHg
- 80 mmHg (Correct answer)
- 90 mmHg
- 100 mmHg
Correct answer: 80 mmHg
PHTLS targets a minimum SBP of 80 mmHg for pediatric TBI patients, compared to 90 mmHg for adults, reflecting age-related physiologic norms.
Question 2: Which prehospital intervention has been shown to MOST reliably reduce secondary brain injury from TBI?
- Administration of hypertonic saline
- Prevention and correction of hypoxia and hypotension (Correct answer)
- Early mannitol administration
- Prophylactic anticonvulsants
Correct answer: Prevention and correction of hypoxia and hypotension
Preventing and correcting hypoxia and hypotension are the most impactful prehospital interventions to reduce secondary injury in TBI patients.
Question 3: A patient with known TBI begins having a generalized tonic-clonic seizure en route to the hospital. After ensuring airway safety, what is the next PHTLS priority?
- Initiate hyperventilation immediately
- Protect the patient from injury and monitor for airway compromise (Correct answer)
- Administer mannitol IV push
- Apply spinal immobilization board during seizure
Correct answer: Protect the patient from injury and monitor for airway compromise
Seizure management focuses on patient safety (preventing fall injury) and airway protection; definitive anticonvulsant treatment is typically a hospital intervention.
Question 4: Why is hyperthermia particularly harmful in TBI patients?
- It causes peripheral vasoconstriction reducing cardiac output
- It increases cerebral metabolic demand, worsening ischemia in injured tissue (Correct answer)
- It directly causes cerebral vasospasm
- It reduces cerebral blood flow by increasing blood viscosity
Correct answer: It increases cerebral metabolic demand, worsening ischemia in injured tissue
Hyperthermia raises cerebral metabolic rate, increasing oxygen demand in already-vulnerable injured brain tissue and exacerbating ischemic damage.
Question 5: A TBI patient who was initially alert (GCS 15) deteriorates to GCS 9 over 20 minutes. This pattern is MOST consistent with:
- Diffuse axonal injury
- Epidural hematoma with an expanding hematoma (lucid interval) (Correct answer)
- Concussion with post-traumatic amnesia
- Cervical spinal cord injury
Correct answer: Epidural hematoma with an expanding hematoma (lucid interval)
A lucid interval followed by rapid neurologic deterioration is the classic presentation of an expanding epidural hematoma compressing the brain.
Question 6: When managing a TBI patient's airway with BVM ventilation, what EtCO2 target should be maintained to avoid secondary injury?
- 20–25 mmHg
- 25–30 mmHg
- 35–40 mmHg (Correct answer)
- 45–50 mmHg
Correct answer: 35–40 mmHg
A target EtCO2 of 35–40 mmHg maintains normocapnia, preventing both vasodilatory hypercarbia and vasoconstrictive hypocapnia.
Question 7: Which mechanism BEST explains why hypocapnia worsens outcomes in most TBI patients?
- It causes systemic vasodilation and drops MAP
- It causes cerebral vasoconstriction, reducing cerebral blood flow and worsening ischemia (Correct answer)
- It increases intracranial pressure by raising CSF production
- It directly depresses brainstem respiratory centers
Correct answer: It causes cerebral vasoconstriction, reducing cerebral blood flow and worsening ischemia
Hypocapnia causes cerebral vasoconstriction, which reduces blood flow to already-injured tissue, converting ischemic penumbra to infarction.
PHTLS Traumatic Brain Injury 4
A pediatric TBI patient, age 4, has a GCS of 8 and blood pressure of 70/40 mmHg.
What is the minimum acceptable systolic BP target in PHTLS for this child?