1. HEAD INJURY

• Scalp: The skin (bleeds easily because of many blood vessels).

• Skull: The bone (can fracture).

• Brain: The soft tissue (the most serious area of injury).

Three Layers of a head injury

Rhinorrhea

Fluid leaking from the Nose

Otorrhea

Fluid leaking from the Ear.

How to check: Dab the clear/yellowish fluid onto a white gauze. If a yellowish concentric circle (a ring) forms around the blood, it is CSF (Cerebrospinal Fluid). This means the skull is fractured and the fluid protecting the brain is leaking out.

way to check nasal or ear discharge

Concussion

Think of this as the "Temporary" injury. It usually involves a brief loss of consciousness or feeling "dazed."

TBI (Traumatic Brain Injury):

This is the "Big Umbrella" term. While often used interchangeably with "head injury," TBI specifically focuses on the damage to the brain tissue itself.

Coup

The injury happens on the same side as the impact (where the object hit).

Contrecoup

The injury happens on the opposite side of the impact.

• Why? The brain is like jelly in a jar. If you hit the front of the jar, the jelly slams into the back.

Diffuse Axonal Injury

In the third panel of your image, you see the brain twisting/sliding. This "shears" or tears the brain's long-distance wiring (axons).

Primary Injury

• What it is: The direct physical damage at the second of impact.

• Types: * Acceleration: You hit a wall.

  • Penetration: An object goes through the skull.

  • Physical damage: Contusions (bruises) or lacerations (cuts).

• Key phrase: "The Damage is Done."

Secondary Injury

• What it is: Damage that evolves hours or days later.

• The Cause: The brain isn't getting enough Oxygen or Nutrients.

• The Deadly Trio:

  1. Anoxia/Hypoxia: No oxygen to the brain.

  2. Ischemia: No blood flow.

  3. Result: Irreversible Brain Death.

Closed (Blunt) Injury

The skull is INTACT.

• Think of a "brain in a shaken jar." The jar (skull) doesn't break, but the jelly (brain) gets damaged by hitting the walls.

• Causes: Acceleration/Deceleration (car dashboard, hitting a wall).

Open Brain Injury

The skull is FRACTURED or pierced.

• The brain is exposed to the outside world.

• Causes: Bullets, knives, or a blunt hit so hard it cracks the skull wide open.

TRAUMATIC BRAIN INJURY

External physical force
Falls, Crashes, Assaults, Surgery.

NON-TRAUMATIC BRAIN INJURY

Internal or biological force

Strokes, Tumors, Infections (Meningitis), Anoxia.

Closed

• This is the "invisible" killer.

• Shearing happens when the brain twists inside the skull, tearing the microscopic fibers (axons).

• Pressure builds up because there is no "vent" (the skull is closed).

Open

• The damage follows the path of the object.

• If a nail goes into the frontal lobe, the damage is primarily in that "path."

• Risk: Extremely high risk of infection because the "protective box" is open.

Concussion

is a temporary loss of neurologic function with no apparent structural damage. (also

referred to as a mild TBI) may or may not produce a brief loss of consciousness.

• The mechanism of injury is usually blunt trauma from an acceleration deceleration force, a direct blow, or a blast injury

Type	Signs	Loss of Consciousness?
Mild	Confusion, "seeing stars," or disorientation.	No (or very brief).
Classic	Memory lapse, significant disorientation.	Yes (but less than 30 mins).

The Two Types of Concussion

Petit Mal Seizure

• The Physical: Headache, dizziness, fatigue.

• The Mental: Irritability, poor concentration.

• The "Blank" Moment (Seizure): Your notes mention that "spacing out" or blank thinking can actually be a _______ (also called an Absence Seizure). This is a tiny electrical "glitch" in the brain.

Feature	Concussion	Contusion
Simple Term	A Shake	A Bruise
Damage	Functional (The "Software" glitches)	Structural (The "Hardware" is bleeding)
Physical Sign	No visible damage on scans	Hematoma (bleeding) and bruising visible
Severity	Usually Mild TBI	Moderate to Severe TBI

Concussion vs. Contusion

contusion

is more serious because it involves actual tissue damage and bleeding beneath the surface.

• The "Bruise" Mechanism: Just like hitting your arm causes blood vessels to leak under the skin (a bruise), hitting the head causes blood to leak into the brain tissue.

• Most Common Locations:

  • Anterior Frontal & Temporal Lobes: These are the "high-traffic" areas for hits.

  • Orbital Areas: Around the eyes.

  • Sylvian Fissure: A deep fold in the brain often affected by the force.

• Manifestation: Because there is physical bleeding (hematoma), the symptoms are often more severe and longer-lasting than a concussion.

Diffuse Axonal Injury (DAI)

• The Mechanism: Widespread shearing (tearing) and rotational (twisting) forces.

• What happens: Imagine the brain is made of millions of tiny electrical wires (axons). When the head accelerates or rotates violently, these wires get overstretched and snap.

• The Result: Because the damage is "diffuse" (all over), it affects the cerebral hemispheres, the corpus callosum, and the brain stem.

• Key Phrase: If you see "Shearing" or "Twisting," the answer is _____.

Epidural Hematoma

• Location: Above the Dura (between the skull and the dura).

• Source: Usually Arterial blood (High pressure).

• Key Sign: Often caused by a Skull Fracture.

• Patient Pattern: They might get knocked out, wake up and act fine for a "lucid interval," and then suddenly collapse and die as the arterial pressure builds up.

Subdural Hematoma

• Location: Below the Dura (between the dura and the brain).

• Source: Usually Venous blood (Low pressure).

• Key Sign: The dura is still attached to the skull. Because it's venous, it bleeds much slower—sometimes symptoms don't show up for days or weeks.

Intracerebral Hematoma

• Location: Within the brain tissue itself.

• Note: This is the deepest and hardest to treat.

Feature	Diffuse Axonal Injury (DAI)	Epidural Hematoma	Subdural Hematoma
Main Issue	Torn Neurons (Wiring)	Arterial Bleed (Above Dura)	Venous Bleed (Below Dura)
Cause	Twisting/Shearing	Skull Fracture/Impact	Blunt Trauma/Slow Leak
Visual	Overstretched Axons	"Lemon" shape on scan	"Banana" shape on scan
Urgency	Severe/Long-term	Immediate Surgical Emergency	Can be Acute or Chronic

Comparison

Diffuse Axonal Injury (DAI)

Epidural Hematoma

Subdural Hematoma

EPIDURAL HEMATOMA

Blood collects in the epidural space between the skull and the dura mater.

SUBdural

Collection of blood between the dura and the brain, a space normally occupied by a thin cushion of fluid

• The Rupture: Usually, an Epidural Hematoma is caused by a skull fracture that tears an artery (specifically the Middle Meningeal Artery).
  

• The Pressure: Because arteries are high-pressure, the blood collects very quickly. It "peels" the dura away from the skull, creating that lemon-shaped pocket of blood The
  
  Warning Sign: Look for the "Lucid Interval." The patient gets knocked out, wakes up feeling 100% fine for a few minutes/hours, then suddenly collapses as the brain starts to herniate.

Why Epidural Hematoma is an Emergency

Stiff Neck

This suggests the pressure from the hematoma is pushing the brain down toward the spinal cord.

• The Hit: Brief loss of consciousness.

• The Lucid Interval: The "Trick" phase. The patient wakes up, talks, and seems fine. Inside, blood is collecting, but the brain hasn't been squished yet.

• The Compensation: ICP rises. The patient becomes restless, agitated, and confused.

• The Herniation: The brain is pushed downward. The patient loses consciousness again.

• The Focal Deficits: One pupil becomes fixed and dilated (the "blown pupil") or an arm/leg becomes paralyzed.

  • Warning: Once these signs appear, the patient's condition deteriorates rapidly.

Epidural Hematoma signs and symptoms

Burr Holes (Trephination)

Epidural Hematoma treatment

Small holes drilled into the skull.

• Purpose: To quickly drain the blood and lower ICP.

• Trivia: This is one of the oldest surgical practices in history!

Mannitol (Osmotic Diuretic)

Epidural Hematoma treatment

This is the gold-standard drug for high ICP.

• How it works: It pulls fluid out of the swollen brain tissue and back into the blood vessels. The kidneys then filter it out as urine.

Procedure	Action	Complexity
Burr Holes	Tiny holes drilled.	Fast, for quick drainage.
Craniotomy	Bone flap removed & replaced.	Major surgery to fix the source.
Craniectomy	Bone flap removed & not replaced.	Emergency; gives brain room to swell.

Comparison
Hematoma treatment

Subdural Hematoma

• Location: Between the Dura and the Brain.

• The Source: Usually Venous (blood vessels that "bridge" the space).

• The Vibe: Slower than an Epidural because venous pressure is lower.

• Non-Trauma Causes: * Coagulopathies: Blood-thinning issues (blood can't clot).

  • Aneurysm: A weakened blood vessel that finally pops.

Intracerebral Hemorrhage

This is bleeding directly into the "meat" (substance) of the brain.

• The Cause: Usually high-force trauma to a small, specific area.

• The Examples: Missiles (shrapnel), bullet wounds, or stab injuries.

• The Memory Hook: Intracerebral = Inside the tissue.

The "Big Three" Physical Checks

LOC (Level of Consciousness): Are they confused? This is always your first sign.

The Eyes (The Windows to the Brain): * Check for shape, size, and if they react to light.

Absent Corneal Reflex: If you touch the eye (don't actually do this, use a puff of air!) and they don't blink, that's a bad sign.

Reflexes: * Absent Gag Reflex: This means the brainstem (which controls basic survival) might be under pressure.

The Vital Sign "Triangle" (Cushing's Triad Recap)

Watch for the Upward/Widening movement:

Pulse Pressure: Widening (Top number goes up).

Heart Rate: Bradycardia (Slows down).

Breathing: Altered patterns (Bradypnea).

Temperature: Can go high (Hyperthermia) or low (Hypothermia) if the brain's "thermostat" is squished.

Sudden "Neurologic Deficits"

Sensory/Motor: Can't feel their arm or can't move their leg.

Senses: Vision or hearing impairment.

Pain/Electrical: Severe headache or sudden seizures

ASSESSMENT OF BRAIN INJURY

Injury Type	Source	Location	Severity Hook
Epidural	Arterial	Above Dura	Lucid Interval (Sudden Death)
Subdural	Venous	Below Dura	Slower leak (Bridge vessels)
Intracerebral	Varies	Inside Brain	Deep trauma (Bullets/Stabs)

Summary Epidural Subdural Intracerebral

Physical/Neuro Exam

Assessment of brain injury

Checking reflexes, pupils, and LOC (your first line of defense).

CT & MRI

These show the Structure. They look for "hardware" issues like fractures, swelling, or bleeding.

Positron emission tomography (PET)

This shows the Function. It looks at how the brain is "breathing" and using energy.

A Cervical Collar (C-Collar)

stays on the patient until an X-ray clears the spine. In any head injury, you must assume the neck is broken until proven otherwise!

ICP (Intracranial Pressure)

The "Bad" pressure inside the skull.

CPP (Cerebral Perfusion Pressure)

The "Good" pressure that pushes blood into the brain.

1. Elevate Head of Bed (HOB): Usually 30-45 degrees. This uses gravity to help blood and CSF drain out of the head, lowering ICP.

2. Maintain Oxygenation: The brain needs constant O_2. If the patient can’t breathe well, we intubate and use a ventilator.

3. Aseptic Technique: If the doctor inserts an ICP monitor or a CSF drain, you must keep it sterile. An infection in the brain (Meningitis) is often fatal.

Nursing Interventions for ICP

Monitoring

Surgical & Technical Management ICP

Using devices (like an Extraventricular Drain or bolt) to measure the exact pressure inside the "rigid box."

Elevation

Surgical & Technical Management ICP

Lifting "depressed" (pushed in) skull fractures so they don't poke the brain.

Debridement

Surgical & Technical Management ICP

Cleaning out "junk" (dirt or bone fragments) from the wound.

Evacuation

Surgical & Technical Management ICP

Removing blood clots to create space

Measure	Why we do it
Seizure Prevention	Seizures use up massive amounts of O_2, causing Hypoxia (secondary damage). Use anti-seizure meds.
Benzodiazepines	Used for agitation. Tip: We want them calm, but we try not to mask their LOC, so we use specific doses.
NG Tube	Head injuries often cause vomiting/nausea. A tube prevents aspiration (choking on vomit).
Fluids/Nutrition	The brain needs "fuel" (glucose) and electrolytes to repair itself.

Supportive Measures ICP

• Coma: The patient is completely unresponsive to all stimuli.

• Absence of Brain Stem Reflexes: Essential survival reflexes (like pupil reaction, gag reflex, and corneal reflex) are gone.

• Apnea: The patient cannot breathe independently without a ventilator.

Three Cardinal Signs of Brain Death

• EEG (Electroencephalogram): Checks for electrical "silence".

• Cerebral Blood Flow Studies: Proves blood has stopped flowing to the brain.

• Transcranial Doppler & Brain Stem Auditory Evoked Potential: Additional specialized tests to verify the loss of brainstem function.

how to confirm brain death

1. Maintain Adequate Airway? (PRIORITY)

The Golden Rule: You cannot assess a patient who isn't breathing. Establish and maintain the airway first.

when asked for the Priority Intervention for a head injury