KEY VOCABULARY

The following terms will be used during this lesson:

· Ataxic Respirations: irregular breathing pattern

· Cheyne Stokes Respirations: breathing characterized by increasing rate and depth followed by a period of apnea

· Hyperextension of the neck: the cervical spine is extended as the head is bent back sharply

· Hyperflexion of the neck: extreme flexion of the cervical spine as the head is bent forward

· Paresthesia: feeling or "pins and needles"

· Paraplegia: paralysis of lower extremities

· Quadriplegia: paralysis of all extremities

KEY CONCEPTS

The following section provides information and space for taking notes on the key concepts discussed by the instructor.

ANATOMY AND PHYSIOLOGY

Central Nervous System (Brain and Spinal Cord)

BRAIN:

Cerebrum

¾ of the brain volume (gray matter). Divided into four lobes.

Main function of each lobe:

· frontal: personality and motor activity

· parietal: sensation

· temporal: hearing and speech

· occipital: sight

Cerebellum

"Little brain" Controls equilibrium and coordinates muscle

activity.

Signs of dysfunction can include:

· ataxia: incoordination of voluntary muscular movement such as walking or reaching for objects

· dysarthria: difficulty speaking

· nystagmus: involuntary rapid eye movements

Brainstem

Controls most automatic functions of the body:

· reticular activating system (RAS): controls level of consciousness

· vasomotor center: controls tone of blood vessel in smooth muscle (constricts/dilates) in response to the baroreceptors which sense changes in blood pressure

· cardiac center: controls heart rate and contractility

· respiratory center: controls rate and depth of respirations in response to levels of CO₂ which are sensed by the chemoreceptors

Spinal Cord

Carries messages between the brain and the body

Central Nervous System Protection

Bone:

· skull (cranium): surrounds and protects the brain

· vertebral column: protects the spinal cord

cervical (neck) 7 vertebrae

thoracic (upper back) 12 vertebrae

lumbar (lower back) 5 vertebrae

sacral (part of pelvis) 5 vertebrae

coccygeal (tailbone) 4 vertebrae

Meninges:

Group of three tissues between skull and brain which act as a protective covering

· dura mater: tough, thick, fibrous tissue (outermost layer-furthest from the brain)

· arachnoid: spider-like interlacing fibers (middle layer)

· pia mater: the innermost layer (next to the brain)

Cerebrospinal Fluid:

(flows throughout the brain & spinal cord)

Protects and cushions the brain & spinal cord

HEAD TRAUMA

Classifications of Head Trauma

Blunt: External force impacts the head

Penetrating: Object penetrates the head

Open:

Signs/symptoms of head injury with fracture to the skull

· linear fracture: small cracks in the skull

· depressed fracture: inward displacement of the skull's surface

· comminuted fracture: fragments of the skull may penetrate the meninges and cause physical harm to the cerebrum or cerebellum underneath

· basilar skull fracture: fracture in the floor of the skull

Closed:

· Signs/symptoms of head injury, skull remains intact

Coup:

Injury on original site of impact

Contrecoup:

Injury on opposite side of impact due to brain rebounding

Major Types of Head Trauma

Concussion:

Brain is "jarred" resulting in an altered level of consciousness with no residual neurologic deficit. Disability is brief, and recovery is usually within 3 - 5 minutes

Contusion:

Bruising to the brain, with altered level of consciousness for approximately 24 hours or more. Cerebral edema often occurs leading to increased intracranial pressure

Intracranial Hemorrhage:

· Epidural bleed:

Bleeding between the dura and the skull. Usually involves arterial vessels (most common: middle meningeal artery). Bleeding progresses rapidly and accumulation of blood causes increased intracranial pressure

Classic sign: initial loss of consciousness, followed by a lucid

period an last up to 2 hours) then a quick deterioration

· Subdural bleed:

Bleeding below the dura. Bleeding is venous and therefore slower than an epidural bleed. Condition may not be diagnosed for several hours to days after initial injury

· Intracerebral bleed:

Bleeding within the brain tissue. Signs and symptoms are often similar to a stroke

Brain Responses to Acute Injury

Edema:

Brain cells swell due to direct compression of the cells or hypoxia causing additional injury and decreased perfusion

Vasodilation:

Due to increased CO₂ levels. Reduced cerebral blood flow causes brain cells to become hypoxic and carbon dioxide concentrations to rise

Increased intracranial pressure:

Swelling or bleeding causes increased pressure within the skull

Herniation syndrome:

As swelling and bleeding continue, increased pressure pushes the brain out of the cranium through an opening at the base of the skull (foramen magnum)

Signs/Symptoms of Increased Intracranial Pressure

Altered Level of Consciousness: first sign of increasing pressure

· decreasing level of consciousness: significant sign of brain injury

· personality changes ranging from irritable to irrational behavior

Pupillary changes:

· unequal pupils

· compression of the 3rd cranial nerve causes pupillary dilation

Nausea/vomiting

Brainstem posturing (late sign):

· decorticate: arms flexed

· decerebrate: arms and legs extended

Cushing Triad (late sign):

· systolic hypertension

· bradycardia

· ·respiratory pattern changes

(i.e.: cheyne stokes, ataxic respirations, or apnea)

SPINAL TRAUMA

· Whiplash:

Soft tissue injury caused by hyperextension of the neck, usually with sudden deceleration

· Fracture:

Break in one or more of the vertebrae caused by penetrating trauma, hyperflexion, hyperextension, diving accidents or falls

· Transection:

Partial or complete severing of the spinal cord

· Dislocation:

Separation of the spinal column which may result in cord transection (seen in hangings)

Signs/Symptoms of Spinal Cord Trauma

· Pain:

With or without movement

· Deformity:

Gap between the spinous process of vertebrae or a broken spinous process

· Impaired breathing:

Injury above C5 can cause paralysis of the muscles of respiration

· Involuntary loss of bowel and bladder control

· Priapism:

Painful penile erection

· Neurogenic Shock:

Caused by massive vasodilation and manifested by hypotension and bradycardia

· Paresthesia

Weakness, numbness or tingling in extremities

· Paralysis

Loss of feeling in upper and/or lower extremities

· paraplegia: paralysis of lower extremities

· quadriplegia: paralysis of all extremities

INITIAL ASSESSMENT AND FOCUSED HISTORY AND DETAILED PHYSICAL EXAMINATION OF HEAD AND SPINAL TRAUMA

1) Assess Environment: (may need to manipulate the environment)

Safety of rescuers and environment

Environmental Factors

Patient Location (home, street, convalescent, etc.)

Weapons (may indicate trauma mechanism)

Medications (may offer clues to past medical history)

Witnesses (may help to explain circumstances)

Mechanism of Injury

Number of Patients

GOLDEN RULE:

Manual spinal immobilization should be maintained throughout initial assessment.

2) Airway: (determine responsiveness and patency of airway)

·        Initiate spinal precautions if indicated

·        Introduce self to patient

·        Obtain patient’s name and age

·        Determine LOC: day/time/place

·        Patient may be unconscious and unable to protect or maintain their airway

3) Breathing: assess for rate, rhythm, and tidal volume

Is the breathing labored or unlabored

If labored, place the patient on oxygen

Abnormal breathing patterns occur when brainstem involvement and spinal cord injury may cause impaired breathing

4) Circulation:

a) Palpate for pulse noting: rate/rhythm/quality