What are the effects of Traumatic Brain Injury (TBI)?

From the Guidelines

Traumatic Brain Injury (TBI) management should prioritize targeted temperature control (TTC) to prevent further brain injury and improve neurological outcome, as recommended by the latest consensus guidelines 1.

Introduction to TBI Management

TBI is a complex and heterogeneous disease, and a major cause of death and disability globally, with an estimated 60 million people affected annually 1. The injury processes that follow from a TBI are divided into two stages: primary and secondary, where primary injury refers to the damage caused by the original physical impact, and secondary injury refers to the subsequent pathophysiological cascade resulting in deleterious effects on neurological outcome and survival 1.

Current Recommendations

The latest guidelines recommend the use of TTC in severe TBI with ICP guided treatments, as it can modulate important physiological parameters such as cerebral metabolism and ICP 1. The term TTC may refer to different degrees of temperature control, from fever prevention, maintenance of normothermia to the induction of hypothermia, at different levels 1.

Treatment Approach

Initial management of TBI focuses on stabilizing vital signs, preventing secondary injury, and may include medications like anti-seizure drugs (levetiracetam 500-1000mg twice daily), analgesics for pain (acetaminophen 650mg every 6 hours), and in severe cases, osmotic diuretics like mannitol (0.25-1g/kg IV) to reduce intracranial pressure. Recovery involves a multidisciplinary approach including physical, occupational, and speech therapy, with gradual return to activities. Long-term complications may include cognitive deficits, mood disorders, and seizures, requiring ongoing management.

Prevention and Public Health

Prevention is crucial through measures like wearing helmets during high-risk activities, using seatbelts, and avoiding alcohol before driving or operating machinery. The economic and societal burden of TBI is significant, with an estimated lifetime economic cost of $76.5 billion in the United States in 2010 1.

Key Considerations

• TBI can result from various mechanisms, including falls, motor vehicle crashes, and sports injuries 1.
• Approximately 70% to 90% of patients with a head injury and TBI presenting to the ED will be diagnosed with mild traumatic brain injury (mTBI) 1.
• The Glasgow Coma Scale (GCS) score is used to assess the severity of TBI, with scores ranging from 3 to 15 1.
• The use of TTC in TBI management is supported by the latest consensus guidelines, which recommend its use in severe TBI with ICP guided treatments 1.

From the Research

Definition and Classification of TBI

• Traumatic brain injury (TBI) is a leading cause of mortality and morbidity in children and young adults worldwide 2.
• TBI can be classified into mild, moderate, and severe by the Glasgow coma scale (GCS) 3.

Management of TBI

• The management of severe TBI is ideally based on protocol-based guidelines provided by the Brain Trauma Foundation 2.
• The aims and objectives of TBI management are prophylaxis and prompt management of intracranial hypertension and secondary brain injury, maintenance of cerebral perfusion pressure, and ensuring adequate oxygen delivery to injured brain tissue 2.
• Prehospital, initial emergency department, and subsequent intensive care unit (ICU) management of severe TBI should focus on avoiding secondary brain injury from hypotension and hypoxia, with appropriate reversal of anticoagulation and surgical evacuation of mass lesions as indicated 3.

Treatment Strategies

• Utilizing principles based on the Monro-Kellie doctrine and cerebral perfusion pressure (CPP), a surrogate for cerebral blood flow (CBF) should be maintained by optimizing mean arterial pressure (MAP), through fluids and vasopressors, and/or decreasing intracranial pressure (ICP), through bedside maneuvers, sedation, hyperosmolar therapy, cerebrospinal fluid (CSF) drainage, and, in refractory cases, barbiturate coma or decompressive craniectomy (DC) 3.
• Direct ICP monitoring, in conjunction with clinical examination and imaging as indicated, should help guide severe TBI therapy, although new modalities, such as brain tissue oxygen (PbtO2) monitoring, show great promise in providing strategies to optimize CBF 3.
• Optimization of the acute care of severe TBI should include recognition and treatment of paroxysmal sympathetic hyperactivity (PSH), early seizure prophylaxis, venous thromboembolism (VTE) prophylaxis, and nutrition optimization 3.

Seizure Prophylaxis

• Levetiracetam does not reach levels needed for seizure prophylaxis in human CSF when loaded at standard dosing regimens in the acute setting 4.
• Phenytoin does reach levels needed for seizure prophylaxis in human CSF with standardized regimen dosing when dosages approximate weight-based dosing 4.
• If needed, in the acute setting phenytoin should have additional doses given prior to six hours after the loading dose to achieve therapeutic CSF levels 4.

Medical Management

• Medical management of the severe TBI patient, beginning with prehospital triage, is aimed at preventing secondary brain injury 5.
• Areas of emphasis include intracranial pressure management, neuromonitoring, management of paroxysmal sympathetic hyperactivity, neuroprotective strategies, prognostication, and communication with families about goals of care 5.