Introduction
Head injury is a common feature of major trauma and patients with a moderate or severe head injury have both increased morbidity and mortality as victims can often be left with significant permanent neurological disability. The proportion of major trauma patients who sustained a serious head injury was 37% in 2017-18, 37% in 2018-19, 37% in 2019-20, 36% in 2020-21 and 36% in 2021-22 (2). Over 1/3rd of major trauma patients are diagnosed with a serious head injury, and this has remained constant over almost a decade (2)
Severe head injury is defined as an Abbreviated Injury Scale (AIS) head region injury severity
score greater than two and a Glasgow Coma Scale (GCS) score of 3 to 8 on arrival at an
emergency department (ED) or at scene if not valid on arrival at the ED (2, 3). The proportion
of major trauma patients with a severe head injury was 6.3% in 2017–18, 5.1% in 2020–21 and
5.6% in 2021–22 (2).
The mechanism of injury for those with severe head injury due to transport-related incidents has decreased in recent years driven by a decline in the number of cases resulting from motor vehicle incidents; 30% in 2017–18, 23% in 2020–21 and 17% in 2021–22 (2). This is most likely attributed to improvements in injury prevention including reduced speed limits, speed reduction campaigns and improved car design and safety features. In contrast the percentage of major trauma patients with a severe head injury sustained by elderly patients in a low-fall mechanism has gradually increased over the last 5 years (2)
Many incidents of traumatic brain injury (TBI) occur in rural areas where access to medical services is limited and delay to definitive care may occur. It is important for health professionals working in these isolated areas to be aware of how to manage patients with an acute head injury in order 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 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 (4).
Primary injury
This 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 (4, 5). Common mechanisms include direct impact, rapid acceleration / deceleration, penetrating injury, and blast waves.
Secondary injury
This can occur minutes, hours, days or even weeks after the initial injury and the damage can be avoided or reduced by appropriate clinical management.
- Hypoxia (SpO2 <90%) and/or hypotension (SBP <90mmHg) in a moderate to severely injured brain, even briefly, can have a harmful impact on outcome and survival (6). 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.
Spinal Considerations
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.
- The aims of treatment are to prevent further brain injury, treat the underlying condition, minimise symptoms and optimise neurological and functional recovery.