Severe traumatic brain injury

Abstract

Traumatic brain injury (TBI) is a nondegenerative, noncongenital insult to the brain from an external mechanical force, possibly leading to permanent or temporary impairment of cognitive, physical and psychosocial factors with an associated diminished or altered state of consciousness.1 TBI is a heterogeneous disease. There are many different ways to categorise patients in terms of clinical severity, mechanism of injury, and pathophysiology, each of which may impact prognosis and treatment.2 TBI has traditionally been classified using injury severity scores. The Glasgow Coma Scale (GCS) is the most commonly used.3 The GCS is universally accepted because it is simple, reproducible and has predictive value for overall prognosis. A GCS score of 13–15 is considered mild TBI, 9–12 is considered moderate TBI, and 8 or less is considered severe TBI. It is, however, limited by confounding factors such as medical sedation and paralysis, endotracheal intubation, and intoxication. All these factors are often prominent in patients with a low GCS score.4,5