In the prehospital environment, paramedics can encounter three different types of head injuries: scalp injuries, cranial fractures, and traumatic brain injuries.  These can occur in isolation, but are commonly associated with each other, and are the result of blunt or penetrating trauma to the head.  Head injuries are the most common cause of death and severe disability in trauma.  Immediate post-injury management can have a profound effect on the patient’s long-term prospects for both survival and recovery. 

• Hypoxia and hypotension, in conjunction with traumatic brain injury, are universally lethal conditions.  It is imperative that paramedics work to maintain a normal blood pressure and oxygen saturation. 
• Use intravenous fluids to target a mean arterial pressure of at least 80 mmHg (or a systolic blood pressure of at least 110 mmHg).
• Patients must not be hypo- or hyperventilated; paramedics must take all appropriate measures to protect the airway and ensure adequate oxygenation and ventilation at all times, up to and including supraglottic airway devices and endotracheal intubation.
• Seizures and vomiting are common complications of head injuries.  Prepare to intervene as necessary. 
• Except in the case of isolated penetrating trauma, head injuries are seldom isolated.  Identify and manage other injuries concurrently.  

• Select transport destinations in accordance with provincial and local trauma triage guidelines.  In general, transport patients to facilities that have neurosurgical capabilities.  Consider the use of Autolaunch or Early Fixed-Wing Activation where appropriate. 
• Endotracheal intubation in head injuries remains fraught.  The risk of hypotension and hypoxia in the peri-intubation period is significant, and adversely affects mortality.  Paramedics electing to intubate patients with traumatic brain injuries must choose an induction strategy with those goals in mind.
• Moderate to severe traumatic brain injuries are often accompanied by injuries to other parts of the body.  In these cases, paramedics must not neglect these injuries.
• Temperature control of patients with traumatic brain injuries can be challenging.  Although the hazards of hypothermia in the context of trauma are relatively well understood, the injured brain is at equal risk from hyperthermia.  Paramedics should strive to keep patients normothermic.  If the patient is, or becomes hyperthermic, paramedics should promote passive heat loss.  Do not begin active cooling.

• Traumatic brain injuries can be further classified based upon the degree of disability, as measured by the Glasgow Coma Scale.
  • A GCS greater than 13 is indicative of mild injury
  • A GCS that falls between 9 and 12 is suggestive of a moderate injury
  • A GCS below 9 is defined as a severe traumatic brain injury
• “Concussion” is a term that has been used synonymously with “mild traumatic brain injury” but more accurately describes the signs and symptoms experienced by an individual who has suffered a mild traumatic brain injury.
  • Signs and symptoms of a concussion include, but are not limited to: grossly observable loss of coordination, vacant stare, disorientation, delayed or difficult responses to questions, slurred speech, inappropriate emotional responses, and memory deficits. Headache, dizziness, nausea, and vomiting are common.  These symptoms may immediately follow the traumatic injury, or may take hours to fully evolve. 
  • Differentiating between mild traumatic brain injuries that require imaging and hospital evaluation and those that do not is extremely difficult in the prehospital environment, and carries significant risk for paramedics.  Therefore, as a general rule, patients who are “concussed” – who have experienced an alteration in mental status that may not necessarily be associated with a loss of consciousness – should be transported for further evaluation.
• Scalp lacerations are associated with extensive bleeding because the blood vessels of the scalp lack the ability to vasoconstrict as effectively as elsewhere in the body.  Direct pressure is usually sufficient to control these types of wounds, but paramedics should be aware that open scalp wounds are occasionally the only indication of deeper, more serious injuries. 
• Caution should be exercised in elderly patients, or individuals taking anticoagulant medications: relatively minor mechanisms of injury can cause significant (and catastrophic) hemorrhage that may be undetected during the initial assessment.
• The skull is a relatively strong body part and so cranial injuries, including basilar skull fractures, require a significant amount of force.  Battle’s sign (raccoon eyes) is a late finding in these patients; its absence does not exclude the possibility of a basilar fracture. 
• Cerebral herniation is a complication of traumatic brain injury where the rising intracranial pressure begins to push the cerebrum caudally, obstructing the flow of cerebrospinal fluid and compressing the brainstem.  Signs include a falling level of consciousness, dilation of the pupil and an outward-downward deviation of the eye on the affected side, paralysis of the arm and leg on the opposite side, and decerebrate posturing.  Patients may yawn, sigh, take intermittent deep breaths, or progress to Cheyne-Stokes respirations. 
• Trismus is commonly seen following severe traumatic brain injuries. In the majority of cases, these patients can be effectively ventilated using good bag-valve mask techniques, though suctioning can be difficult and adjunct placement may be impossible. 
• Mean arterial pressure can be calculated by the formula ((DBP x 2) + SBP) / 3, and is in general a more meaningful measure of cerebral perfusion than systolic blood pressure alone.

Traumatic Brain Injury 

Head Injury

1. Alberta Health Services. AHS Medical Control Protocols: Adult Head Injury. 2020. [Link]
2. Carney N, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. 2017. [Link]