Head injury is a common feature of major trauma and patients with a moderate or severe head injury have a higher mortality as well as a higher morbidity, with victims often being left with a permanent neurological disability. The percentage of major trauma patients who have sustained a serious head injury has remained consistent since 2011-12, and accounted for 6.8% of hospitalised major trauma patients in 2015-16.
The mechanism of injury, however, has changed for this group of patients. Motor vehicle crashes accounted for 27.6% of severe head injuries in 2015−16 compared with 20.9% in 2011-12.The decrease in severe head injuries could be attributed to improvements in injury prevention including reduced speed limits, speed reduction campaigns and improved car design such as airbags and anti-lock braking systems. Pedestrians and pedal-cyclists comprised 17.6% % of severe head injury cases in 2015−16 compared with 19.1% % in 2011-12. In contrast the percentage of major trauma patients with a severe head injury sustained by elderly patients in a low-fall mechanism has increased from 17.3% in 2011−12 and to 15.8% in 2015−16.
In patients with multisystem injuries, the head is the most frequently injured part of the body.2 Many incidents of traumatic brain injury (TBI) occur in rural areas where access to medical services is limited and a delay in definitive care may occur. It is important for health professionals working in these isolated areas to be aware of how to manage acute patients to prevent any secondary injury.
Patients presenting with TBI can be a challenging group to deal with. They are often confused and combative, which can make assessments and even the most basic clinical tasks difficult and time consuming.
TBI is generally classified according to the Glasgow Coma Scale (GCS). A GCS score of 13–15 is considered a mild injury; 9–12 is considered a moderate injury, and 8 or less as a severe TBI. The GCS is universally accepted as a tool for TBI classification because of its simplicity, reproducibility and predictive value for overall prognosis. However, its use may be limited by confounding factors such as intoxication and ongoing medical treatment such as sedation and/or paralysis.
There are two types of brain injury: primary and secondary.
Primary injury occurs at the moment of the traumatic incident and reflects the mechanical events in the brain at that instant. There may be gross disruption of brain tissue that is not preventable.3 Common mechanisms include direct impact, rapid acceleration/deceleration, penetrating injury and blast waves.
Secondary injury can occur minutes, hours, days or even weeks after the initial injury and the damage can be averted or lessened by appropriate clinical management. Causes of secondary brain injury include haematoma, contusion, diffuse brain swelling, systemic shock and intracranial infection.
Hypoxia and/or hypotension in a moderate to severely injured brain, even briefly, can have a harmful impact on outcome and survival. A single systolic blood pressure (SBP) of under 90 mmHg is associated with a 150% increase in mortality.4 Action to prevent secondary brain injury must commence at the scene of the accident and continue through all stages of care. It is important to remember that this is not about complex, specialist care but about applying basic principles in support of the injured brain.
A patient who has suffered a severe head injury should be assessed and managed as a major trauma patient. Patients with TBI should be assumed to have a spinal fracture until proven otherwise and appropriate precautions taken to immobilise the spine until injury can be excluded.5 The aims of treatment are to prevent further brain injury, treat the underlying condition, minimise symptoms and optimise neurological and functional recovery.