Clinical priorities
At the moment of injury, the energy transmitted to the brain causes destruction of brain tissue including axonal death; this is known as the primary brain injury and cannot be modified by medical treatment.
Medical treatment is targeted at preventing secondary brain injury, which relates to failure to deliver oxygenated and glucose-rich blood to the brain and to remove waste products (e.g. CO2).
The initial management of the head injured patient is targeted at ensuring the patient has a patent airway, is adequately oxygenated and maintains a sufficient blood pressure to perfuse the brain.
It is also recognised that in patients who develop a mass lesion (collection of blood somewhere within or around the brain), surgical removal of this mass is time-critical. Studies suggest that those patients who develop a mass lesion and who undergo neurosurgery within 4 hours of the injury, have improved outcomes compared to those whose surgery takes place beyond 4 hours.
Head injury is a medical emergency, with efforts being focused on rapid extrication, scrupulous cervical spine immobilisation (unless contraindicated), oxygen provision, and maintenance of an adequate blood pressure.