Key points in Critical Care Medicine
“Adapted from Oxford Textbook of Critical Care”
Epidemiology and pathophysiology of Traumatic Brain Injury
- Traumatic brain injury (TBI) is a devastating injury that causes a huge burden of disease around the world; approximately 1.6 million people suffer a TBI in the USA each year.
- TBI is a bimodal disease that affects young adults (15-34), the elderly (>75), and males more than females.
- Mechanism of injury, age, gender, and initial severity of injury are the most significant predictors of mortality.
- Harm from TBI arises from direct damage to the brain at the time of the initial injury (primary injury), which places the brain at risk of further harm secondary injury.
- Secondary injury may occur due to intracranial hypertension, hypotension, hypoxia, reduced cerebral perfusion, and inflammation.
Assessment of Traumatic Brain Injury
- Early assessment is based on a careful history, clinical assessment, and neurological imaging-usually a CT scan of the brain.
- An immediate CT scan of brain should be obtained in any adult patient at risk of harbouring intracranial pathology.
- In adult patients who have a Glasgow Coma Scale score below 15 and indications for a brain CT scan, the scan should include the cervical spine by scanning from the base of skull to T4.
- Establishing a reliable prognosis early after injury is notoriously difficult, but recent predictive models are readily accessible to clinicians via a web-based calculator to aid early clinical decision making and to allow better informed discussions with patient’s families.
Management of Traumatic Brain Injury
- Admission to a centre offering specialist neurological critical care and management of extracranial injuries improves outcome.
- Initial management priorities address the ‘ABCs’-airway with cervical spine control, breathing, and circulation. Neurological assessment using the Glasgow Coma Score and pupillary reaction should be repeated regularly to detect deterioration.
- Intracranial haematomas causing mass effect should be surgically evacuated without delay.
- Specific TBI management focuses on avoiding secondary cerebral insults by avoiding hypotension and hypoxia, controlling ICP, and maintaining cerebral perfusion pressure.
