Traumatic brain injury is a major public health problem both in the developed and developing world. Its effects can be measured both in its costs to society and its effects on individual survivors and their families. Sustained effort on the part of researchers as well as clinicians, and major technological advances over the last 5 decades have improved survival from major head trauma and allowed more patients to achieve meaningful neurologic recovery, primarily through improvements in recognition, medical imaging, post-trauma monitoring, and surgical therapeutics.1 Nevertheless, especially in the acute phase, the care of these patients is extremely resource intensive, highly complex, and is best served by a team of specialized clinicians in a dedicated neurocritical care unit. Management of traumatic brain injury (TBI) in a crisis situation—be it a mass casualty incident caused by a natural disaster, a terrorist attack, or any event which overwhelms a healthcare delivery system—adds an entirely different set of challenges to an already formidable problem.
DEFINITIONS AND CLASSIFICATION BY SEVERITY
TBI is a heterogeneous entity with a variety of different potential manifestations depending on the mechanism of injury, as well as the magnitude, directionality, and type of extrinsic forces applied to the brain. The severity can be described as mild, moderate or severe. Criteria will depend on which of the numerous classification systems is being employed, and whether the determination is based on clinical or pathologic findings.
The CDC defines TBI as “disruption of normal function of the brain caused by a bump, blow, jolt, blast, or penetrating injury.”2 From a clinical standpoint, severity is based on the presence or absence of loss of consciousness; loss of memory, including both retrograde or post-traumatic amnesia; the presence or absence of accompanying neurologic deficits; and alteration of mental state following the injury, such as confusion, disorientation, slowed thinking, or difficulty concentrating. Mild TBI is characterized by preserved consciousness or loss of consciousness lasting less than 30 minutes, and normal CT or MR imaging of the brain. Loss of consciousness lasting 30 minutes to 24 hours comprises a moderate TBI, while loss of consciousness lasting more than 24 hours constitutes a severe TBI.3
In the prehospital or austere setting, severity of TBI has been based on injury severity scores, the most common of which worldwide is the Glasgow Coma Scale (GCS), which is a standardized and quickly and easily reproducible score based on the clinical exam. The GCS assigns a total number of points from 3 to 15 depending on the presence of spontaneous eye opening or the type of stimulation required to induce eye opening, with 1–4 possible points assigned; the degree of verbal responsiveness, with 1–5 possible points; and the type of spontaneous or evoked motor responses observed in the injured person, with 1–6 possible points. Minor TBI is described as GCS 13–15; a GCS of 9–12 is moderate, while ...