Traumatic Brain Injury

Why this matters

The injured brain does poorly with low oxygen and with low blood pressure. Secondary injury is the harm that follows the first hit. That is where field care can help or harm.

First, treat oxygen saturation under 90% and support blood pressure. Check the airway and the end-tidal carbon dioxide when you have a waveform. End-tidal carbon dioxide, written EtCO2, is the carbon dioxide measured at the end of a breath. Do not delay oxygen or blood pressure for a board. Do not hyperventilate every head injury. Herniation means the brain is being forced downward. Hyperventilate only for herniation, and only as your protocol writes it.

Clinical sequence

1. Protect the airway. Vomiting and a falling level of consciousness are common.
2. Give oxygen. Treat a saturation under 90% now. Continuous oxygen is for suspected severe traumatic brain injury. Examples are a Glasgow Coma Scale score of 8 or less, or a patient who cannot protect the airway. It is not an automatic non-rebreather mask for every concussion. Do not wait for the saturation to fall further in the severe group.
3. Support blood pressure per protocol. Avoid low blood pressure. If the patient is bleeding, hemorrhage control still comes first. Adult systolic teaching is about 110 mm Hg, not the old cutoff of 90. Follow your protocol's number. Each episode of low oxygen or low blood pressure is tied to a worse outcome. Both together are worse.
4. Do not delay oxygen and blood pressure for a longboard. Use spinal motion restriction per protocol. The board is for the move, then take the patient off it. Use a collar only if your protocol says so. See spinal motion restriction.
5. Move to a trauma or neurosurgical destination per your system plan.
6. Check glucose if mental status is altered and your protocol supports it.
7. Treat seizures per protocol if they occur. This site does not list a milligram dose.
8. Do not let the patient get cold. Aim for a normal temperature when you can.

Herniation Red Flags

• Watch for a falling level of consciousness, one pupil that dilates, posturing, or a Cushing pattern. That pattern is a slow heart rate, high blood pressure, and irregular breathing. These signs are late and serious.
• For most traumatic brain injury, ventilate toward an EtCO2 of about 35 to 45 mm Hg when a waveform is available. Routine hyperventilation, with an EtCO2 under 35, is not indicated. Brief hyperventilation is reserved for signs of active herniation, and only as your protocol writes it. Do not invent a field target in the low 30s.

Key points

• Prevent the secondary injury you can control. That means the airway, oxygen, blood pressure, and ventilation quality.
• EtCO2 can guide ventilation when you have a waveform. Routine hyperventilation is outdated.
• A history of a medicine that slows clotting is critical for the trauma team.
• Do not stay on scene for a long packaging routine.

Common errors

• Hyperventilating every head injury as a routine.
• Missing bleeding outside the skull while you focus on the Glasgow Coma Scale score.
• Having no suction ready.
• Delaying oxygen or blood pressure to chase a board and a collar.

Practice

Related: Massive hemorrhage, Capnography, Spinal motion restriction.

Sources & Further Study

Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.

• NASEMSO National Model EMS Clinical Guidelines (2022) — U.S. EMS model language; your protocol decides
• BTF Prehospital Guidelines for the Management of Traumatic Brain Injury, 3rd Edition (2023)
• ATLS / ACS trauma education
• BTF 2023: correct SpO₂ under 90% immediately; continuous supplemental oxygen for suspected severe TBI; adult SBP teaching target about 110 mm Hg or greater (weak); EtCO₂ about 35 to 45 mm Hg; routine hyperventilation is not indicated. Brief hyperventilation is reserved for signs of herniation in many protocols. Follow your trauma protocol.
• Your trauma and destination protocols.