PHTLS - Prehospital Trauma Life Support Traumatic Brain Injury 2 — Questions and Answers
Question 1: What is the most important prehospital intervention to prevent secondary brain injury according to PHTLS?
- Administering mannitol in the field
- Preventing hypoxia and hypotension (Correct answer)
- Applying ice packs to the head
- Elevating the head of the stretcher to 90 degrees
Correct answer: Preventing hypoxia and hypotension
PHTLS identifies hypoxia and hypotension as the two most devastating secondary insults to the injured brain.
Even a single episode of hypoxia (SpO2 <90%) or hypotension (SBP <90 mmHg) doubles mortality in TBI patients. Combined hypoxia and hypotension increase mortality by 75%. Prehospital goals include maintaining SpO2 >94% and SBP >110 mmHg.
Question 2: How does the Glasgow Coma Scale classify traumatic brain injury severity?
- Mild 3-8, Moderate 9-12, Severe 13-15
- Mild 13-15, Moderate 9-12, Severe 3-8 (Correct answer)
- All GCS scores below 15 are severe
- GCS is not used for TBI classification
Correct answer: Mild 13-15, Moderate 9-12, Severe 3-8
PHTLS classifies TBI as Mild (GCS 13-15), Moderate (GCS 9-12), and Severe (GCS 3-8).
GCS 8 or below generally indicates the need for definitive airway management. PHTLS emphasizes serial GCS assessment, with a drop of 2 or more points suggesting clinical deterioration. The motor component is the most prognostically valuable.
Question 3: What pupil findings suggest uncal herniation in a TBI patient?
- Bilateral pinpoint pupils
- Unilateral fixed and dilated pupil (blown pupil) on the side of the lesion (Correct answer)
- Bilateral equal and reactive pupils
- Alternating pupil size with each assessment
Correct answer: Unilateral fixed and dilated pupil (blown pupil) on the side of the lesion
A unilateral fixed and dilated pupil indicates compression of the third cranial nerve from uncal herniation.
Uncal herniation occurs when the medial temporal lobe pushes through the tentorial notch. This produces ipsilateral pupil dilation, contralateral hemiparesis, and progressive deterioration. Controlled hyperventilation is ONLY indicated when herniation signs are present.
Question 4: According to PHTLS, what blood pressure target should be maintained in a patient with severe TBI?
- Any blood pressure that produces a palpable pulse
- Systolic blood pressure greater than 110 mmHg (Correct answer)
- Permissive hypotension with SBP 80-90 mmHg
- Blood pressure is not important in TBI management
Correct answer: Systolic blood pressure greater than 110 mmHg
PHTLS recommends maintaining SBP >110 mmHg in severe TBI patients to ensure adequate cerebral perfusion pressure.
This creates a management conflict when TBI coexists with hemorrhagic shock. In combined TBI and hemorrhage, brain perfusion takes priority with a higher SBP goal. This exception to permissive hypotension is one of the most important clinical decision points in multisystem trauma.
Question 5: What is the role of hyperventilation in TBI management according to current PHTLS guidelines?
- Routine hyperventilation is recommended for all TBI patients
- Hyperventilation is ONLY indicated as a temporizing measure when signs of cerebral herniation are present (Correct answer)
- Hyperventilation should never be used under any circumstances
- Hyperventilation is the primary treatment for all levels of TBI
Correct answer: Hyperventilation is ONLY indicated as a temporizing measure when signs of cerebral herniation are present
PHTLS restricts hyperventilation to cases showing signs of active herniation as a temporizing measure, targeting ETCO2 of 30-35 mmHg.
Routine hyperventilation is harmful because cerebral vasoconstriction reduces blood flow to an already injured brain. The effect is temporary and bridges the patient to definitive neurosurgical intervention. Capnography monitoring is essential.
Question 6: How should a scalp laceration with active hemorrhage be managed in a TBI patient?
- Ignore the scalp wound and focus only on the brain injury
- Control hemorrhage aggressively with direct pressure and wound closure, as scalp bleeding can cause significant blood loss (Correct answer)
- Apply a loose bandage only
- Do not touch head wounds in TBI patients
Correct answer: Control hemorrhage aggressively with direct pressure and wound closure, as scalp bleeding can cause significant blood loss
Scalp lacerations can bleed profusely and may contribute to hemorrhagic shock, particularly in children.
Hypotension from scalp blood loss worsens secondary brain injury because each hypotensive episode doubles mortality. A pressure dressing wrapped around the head is often the most practical approach.
PHTLS - Prehospital Trauma Life Support Traumatic Brain Injury 2
What is the most important prehospital intervention to prevent secondary brain injury according to PHTLS?