Study Notes on Head Injuries

Head Injury Overview

  • Presented by Jennifer Merrick DNP, APRN FNP-C, CCRN in NSC 484

Learning Objectives

  • Define head injuries.

  • Differentiate between concussion and diffuse axonal injury (DAI).

  • Understand cerebrospinal fluid (CSF) leaks.

  • Identify the different types of hematomas and their impact on the skull, brain, and scalp.

Definition of Head Injury

  • Head injury encompasses any injury or trauma to the scalp, skull, or brain.

  • Statistics (2019):

    • Annual ER Visits: 2.9 million

    • Deaths: 56,800

    • Hospitalizations: 288,000

    • Long-term Disabilities: 80,000 - 90,000

  • Demographics:

    • Higher incidence in men compared to women.

  • Causes of Head Injury:

    • Falls: 48%

    • Motor Vehicle Accidents (MVA): 14%

    • Assaults: 10%

  • Trajectory of the Problem:

    • High poor outcomes associated with head injuries.

    • Potential for death immediately post-injury, 2 hours later, or 3 weeks after.

    • Significant brain injury, especially in adults, whereas outcomes may be better in children.

    • Significant injury often causes complications like brain swelling leading to infections.

Types of Head Injuries

Scalp Lacerations

  • Caused by external head trauma

  • Characteristics include profuse bleeding.

  • Possible complications:

    • Blood loss

    • Internal bleeding

    • Infection (e.g., from hair bugs).

Skull Fractures

  • Types of Skull Fractures (as per Table 61.6, pg. 1496):

    • Comminuted

    • Compound

    • Depressed

    • Linear

    • Simple

  • Localization Indicators:

    • "Raccoon eyes": bruising around the eyes.

    • "Battle’s sign": Bruising behind the ear.

  • Severity:

    • There are no minor head injuries; all can result in significant brain damage.

    • Inward fractures risk damaging brain tissue.

    • Hairline fractures may appear as fine lines in the skull but may lead to delayed symptoms like bruising (1-2 days post injury).

Basilar Skull Fractures

  • Located at the base of the skull; require significant force.

  • Associated with cervical spine injuries until proven otherwise.

  • Considerations:

    • Avoid inserting NG tubes without imaging due to risk of intracranial injury.

CSF Leak

  • Common complication associated with skull fractures.

  • Leads to high risk for meningitis; requires immediate antibiotic treatment.

  • Testing for CSF Leak:

    • Rhinorrhea (nasal): Clear discharge from the nose.

    • Otorrhea (ear): Clear discharge from the ear.

    • HALO Test: Apply 4x4 gauze around fluid; a yellow ring indicates CSF if blood is present.

    • Risk of profound infection; always notify the provider.

Traumatic Brain Injury (TBI)

  • Closed (Blunt) TBI: Damage without skull opening.

  • Open (Penetrating) TBI: Damage with an object (bullet, knife) leading to CSF leaks.

Primary vs. Secondary Brain Injury

  • Primary Injury: Occurs at the moment of trauma, leading to cranial displacement and bruising.

  • Secondary Injury: Develops hours to days after the initial impact, characterized by hypotension, edema, hypoxia, and ischemia.

  • Example: Gunshot wounds leading to brain swelling.

Diffuse Injuries

Concussion

  • Characterized by sudden disruption of neural function and potential loss of consciousness (LOC).

  • Symptoms may include:

    • LOC

    • Behavioral changes; frontal lobe due to bizarre behavior; temporal lobe disorientation.

    • Symptoms can last up to two weeks.

  • Management includes acetaminophen for headaches; allowable sleep with periodic checks.

Diffuse Axonal Injury (DAI)

  • Involves widespread axonal damage occurring 12-24 hours post-injury.

  • Associated with poorer prognosis, presenting with:

    • Change in LOC

    • Increased intracranial pressure (ICP)

    • Decorticate or decerebrate posturing.

  • Requires close monitoring of ICP and supportive care.

Specific Types of Brain Injuries

Focal Injuries

  • Types include:

    • Lacerations: Severe tearing of brain tissue, medically challenging to repair.

    • Contusions: Coup injury (directly at impact site) and contrecoup injury (opposite side bruising).

Impact on Different Brain Lobes

  • Frontal Lobe: Impulsivity, aphasia, behavioral changes, decision-making problems.

  • Parietal Lobe: Numbness; difficulties with coordination and sensory discrimination.

  • Occipital Lobe: Visual disturbances including partial blindness and hallucinations.

  • Temporal Lobe: Hearing loss, memory issues, and emotional behavior changes.

Hematomas

Epidural Hematoma

  • Located between the dura and skull; considered a neurological emergency.

  • Symptoms may include brief LOC followed by a lucid interval, then rapid deterioration.

  • Management involves CT scans, evacuation, and monitoring for increased ICP.

Subdural Hematomas

  • Acute: Develops 24-48 hours post-injury; requires immediate medical management.

  • Chronic: Can develop weeks or months post-injury; may present with nonspecific mental changes. Managing risks includes recognizing susceptible populations (like the elderly).

Intracerebral Hematoma

  • Formed within brain tissue; generally associated with hypertension, arteriovenous malformations (AVM), or aneurysms.

  • Management may require surgery; focuses on monitoring blood pressure and ICP.

Nursing Considerations

  • Focused Neurological Exams: Critical for patient assessment.

  • Maintenance of Cerebral Perfusion Pressure (CPP): Manage ICP to ensure adequate cerebral blood flow.

  • Management of Symptoms: Recognizing symptoms of complications like CSF leaks and its respective care protocols.