Notes on Head Injuries and Traumatic Brain Injury
Head Injuries and Traumatic Brain Injury (TBI)
Introduction to Head Trauma
Head trauma, also known as cranial cerebral trauma, involves an alteration in consciousness, regardless of how brief it may be.
Epidemiology:
Approximately million head injuries occur annually.
Head injuries account for more than of all injury-related deaths.
They are the second most common cause of neurologic injuries.
A major cause of death in ages through .
Firearm-related head injury death rates have been increasing.
Causes: Recreational activities, sports-related trauma, and assaults.
Demographics: Males in every age group have higher head injury rates than females.
Nature of Head Injuries
Cranial cerebral trauma is synonymous with head trauma and head injury.
Range of Injuries: Can range from minor scalp wounds to concussions to open fractures of the skull with severe brain damage.
Potential Consequences: Can cause cerebral edema, sensory and motor defects, and increased intracranial pressure.
Mechanism of Injury: Brain injuries can result from direct or indirect trauma.
Direct vs. Indirect Trauma
Direct Trauma: The head is directly injured.
Examples: Getting a blow to the head, hit with a board or bat, falling and hitting the head.
Indirect Trauma: Involves tension strains and shearing forces transmitted to the head by stretching the neck.
Examples: Whiplash, shaken baby syndrome.
Consequences: Can lead to bruising or contusion of the occipital and frontal lobes, brain stem, and cerebellum.
Whiplash (Acceleration-Deceleration Injury):
Occurs when a vehicle makes an impact, causing the head to suddenly move forward and then jerk backward.
The brain tissue inside the skull hits the front of the skull and then whips back to the back, causing internal bruising.
Classifications of Head Injuries
Head injuries are classified into mild, moderate, severe, and catastrophic.
Mild Head Injuries
Represent the majority of head injuries.
Loss of Consciousness: Brief or no loss of consciousness.
Post-Concussive Syndrome: May persist for months or longer.
Signs and Symptoms: Fatigue, headache, vertigo, personality changes, difficulties with memory, learning, and perception.
Moderate Head Injuries
Loss of Consciousness: Unconsciousness for minutes or more.
Cognitive Impairment: Usually impaired cognitive scales, such as planning, sequencing, and judgment.
Signs and Symptoms: Self-centeredness, mood swings, agitation, emotional lability, poor judgment.
Severe Head Injuries
Loss of Consciousness/Amnesia: Unconsciousness or amnesia for days or more.
Disabilities: Result in cognitive, psychosocial, and behavioral disabilities.
Catastrophic Head Injuries
Coma: Comatose state lasting months or longer.
Consciousness: Patients may appear awake but never fully regain communication.
Emotional Impact: As memory returns, patients may experience depression, requiring vigilance.
Types of Head Injuries by Manifestation
Head injuries can present as open or closed head injuries.
Open Head Injury
Involves fractures or penetrating wounds.
Severity Factors: The amount of injury is determined by velocity, mass, shape, and direction of impact.
Skull Fractures: Can be linear, comminuted, depressed, or compound.
Basilar Skull Fractures: Fractures at the base of the skull are more serious due to proximity to the medulla; referred to as basilar skull fractures.
Clinical Signs of Basilar Skull Fracture:
Battle Signs: Ecchymosis (bruising) behind the ear.
Raccoon Eyes: Bruising around both eyes.
Rhinorrhea: Nasal discharge.
Otorrhea: Discharge from the ear.
Halo/Ring Sign: Cerebral spinal fluid (CSF) mixes with blood on an absorbent surface (e.g., pillow); blood forms an inner ring, and CSF forms an outer ring/halo.
CSF Test: If unsure about CSF, a glucose test strip will show positive for glucose if it is CSF.
Closed Head Injury
Includes concussion, contusion, lacerations, epidural hematoma, or subdural hematoma.
Concussion: Violent jarring of the brain against the skull.
Contusions and Lacerations: Can also occur.
Scalp Lacerations: Bleed profusely due to extensive vascularity; many small arteries on the head and skull can cause spurting blood.
Hemorrhage and Hematomas
Hemorrhage can occur from the scalp or in epidural, subdural, intracerebral, and intraventricular areas.
Hematomas: Two primary types requiring careful, continuous observation:
Epidural Hematoma
Type of Bleed: Arterial bleed (blood collects rapidly).
Location: Between the dura mater and the skull.
Progression: Lethargy or unconsciousness developing after the patient regains consciousness necessitates immediate treatment.
Suture Line: Does not cross the suture line.
Subdural Hematoma
Type of Bleed: Venous bleed (blood collects relatively slowly).
Location: Below the dura.
Suture Line: Can cross the suture line.
Progression: Clot causes pressure on the brain surface and displaces brain tissue; patient loses consciousness or develops neurologic signs/symptoms several days after injury.
Classification: Acute, subacute, or chronic.
Assessment and Clinical Manifestations
History: How did the injury happen?
Symptoms: Headache, nausea, vomiting, loss of consciousness (duration), bleeding from orifices.
Respiratory Status: Assess respiration.
Alertness/Consciousness: Level of alertness and consciousness.
Cognitive Issues: Loss of memory, loss of initiative, poor judgment.
Behavioral Changes: Recklessness (investigate as it could indicate pain, need to change position, or use the restroom).
Pupils: Size and reactivity of pupils (check frequently); slow reaction or inequality are red flags.
Motor Status: Assess motor function.
Vital Signs: Monitor vital signs.
Speech Patterns: Note any abnormal speech patterns.
Diagnostic Testing
Initial Assessment: Primarily assess for soft tissue injuries.
Imaging: Computerized Tomography (CT) scan is primary; Magnetic Resonance Imaging (MRI) or Positron Emission Tomography (PET) scan may be used.
Treatment and Interventions
Airway Management: Maintain a patent airway and ensure adequate oxygenation.
ABGs: Check arterial blood gas levels.
Cervical Spine Stabilization: Always stabilize the cervical spine with a hard collar until X-rays, CT, or MRI rule out a neck injury.
Medications
To Decrease Cerebral Edema and ICP: Mannitol, Dexamethasone (most common problem in head injuries).
Analgesics: Codeine (does not depress the respiratory system, important due to medulla controlling respiratory center).
Anticonvulsants: To prevent seizures.
Antipyretics: To control hyperthermia (increased brain metabolism can cause damage).
Nursing Interventions
Orifice Assessment: Carefully check ears and nose for blood or serous drainage (indicates torn meninges and CSF escape).
CSF Testing: Bedside glucose test for drainage.
Orifice Care: Do not clean out orifices.
Patient Instructions: If drainage from nose, instruct patient not to cough, sneeze, or blow their nose.
Patient Interaction: Do not argue with the patient; redirect their attention.
Cognitive Aids: A logbook or written schedule can assist with memory loss.
Complications and Prognosis
Meningitis: Possible complication; watch for a stiff neck as a red flag.
Personality Changes: Can be short-term or permanent, dependent on injury level.
Examples: Depression, mood swings, anger.
Outcomes: Unpredictable, dependent on the extent of brain damage; changes can be short-term or permanent.
Warning Signs After a Head Injury (Especially in the First Hours)
Changes in level of consciousness.
Increased drowsiness or confusion.
Seizures.
Bleeding or watery drainage from the nose or ears.
Projectile vomiting.
Slurred speech.
Loss of sensation to any extremities.
Vision problems.
Pupils slow to react or unequal.
Patient Teaching
Educate patients and their families on these warning signs to look for and observe for complications.
Emphasize careful and vigilant monitoring for head injuries.