PHTLS Traumatic Brain Injury 2 — Questions and Answers
Question 1: A patient with a severe TBI has a GCS of 6 and a systolic BP of 80 mmHg. What is the PHTLS priority for this patient?
- Administer mannitol immediately
- Restore systolic BP to ≥90 mmHg as quickly as possible (Correct answer)
- Hyperventilate to reduce ICP
- Perform rapid sequence intubation before fluid resuscitation
Correct answer: Restore systolic BP to ≥90 mmHg as quickly as possible
Hypotension (SBP <90 mmHg) doubles mortality in severe TBI, so restoring perfusion pressure is the immediate priority.
Question 2: Which herniation pattern is characterized by unilateral fixed and dilated pupil combined with contralateral motor weakness?
- Central herniation
- Uncal (transtentorial) herniation (Correct answer)
- Tonsillar herniation
- Upward cerebellar herniation
Correct answer: Uncal (transtentorial) herniation
Uncal herniation compresses CN III on the ipsilateral side, causing a blown pupil, and compresses the cerebral peduncle, causing contralateral weakness.
Question 3: In the context of TBI, what does the Monroe-Kellie doctrine state?
- Cerebral perfusion pressure equals MAP minus ICP
- The skull is a rigid compartment so any volume increase must displace another component (Correct answer)
- Autoregulation is lost at a CPP below 50 mmHg
- Cerebral blood flow is directly proportional to PaCO2
Correct answer: The skull is a rigid compartment so any volume increase must displace another component
The Monroe-Kellie doctrine holds that brain, blood, and CSF occupy a fixed skull volume, so expansion of one component compresses the others.
Question 4: A TBI patient is breathing at a rate of 6 breaths per minute. What is the PHTLS-recommended bag-valve-mask intervention?
- Assist ventilations to achieve 20 breaths/min
- Assist ventilations to achieve 10 breaths/min for adults (Correct answer)
- Allow the patient to self-regulate and provide supplemental O2 only
- Immediately hyperventilate at 20 breaths/min to decrease ICP
Correct answer: Assist ventilations to achieve 10 breaths/min for adults
PHTLS recommends assisting ventilation to approximately 10 breaths/min in adults to correct hypoventilation without causing harmful hypocapnia.
Question 5: Which of the following BEST describes cerebral perfusion pressure (CPP)?
- Systolic BP minus diastolic BP
- Mean arterial pressure minus intracranial pressure (Correct answer)
- Diastolic BP minus intracranial pressure
- Systolic BP minus intracranial pressure
Correct answer: Mean arterial pressure minus intracranial pressure
CPP = MAP − ICP; maintaining adequate CPP is the primary goal in managing severe TBI.
Question 6: During transport of a severe TBI patient, SpO2 drops to 88%. What is the correct action?
- Continue transport without adjustment as this is acceptable in trauma
- Increase supplemental oxygen and reassess airway positioning immediately (Correct answer)
- Hyperventilate the patient to compensate
- Administer furosemide to reduce cerebral edema
Correct answer: Increase supplemental oxygen and reassess airway positioning immediately
Hypoxia (SpO2 <90%) causes secondary brain injury; correcting it immediately with supplemental oxygen and airway optimization is the priority.
Question 7: A helmeted motorcyclist is unresponsive after a crash. When should the helmet be removed in the prehospital setting?
- Never; always leave the helmet in place until arrival at the ED
- Only if it prevents airway assessment or management (Correct answer)
- Immediately and always, to assess for skull fractures
- Only if the patient is conscious and requests removal
Correct answer: Only if it prevents airway assessment or management
PHTLS recommends helmet removal when it prevents adequate airway management or assessment, requiring a two-rescuer technique to maintain spinal alignment.
PHTLS Traumatic Brain Injury 2
A patient with a severe TBI has a GCS of 6 and a systolic BP of 80 mmHg.
What is the PHTLS priority for this patient?