altered cerebral function & increased intracranial pressure

RNSG 2432 Enhanced Concepts of Adult Health

Fall 2011Lisa Randall, RN, MSN, ACNS-BC

Define and discuss altered cerebral function and increased ICP

Analyze etiology and pathophysiology of altered cerebral function

Discuss/illustrate signs and symptoms, diagnostics, and treatment

Formulate nursing diagnoses that address physical, psychosocial, and learning needs

Prioritize and evaluate nursing interventions

Cerebral function◦ Mental status◦ Speech◦ Eyes◦ Cranial nerves◦ Motor◦ Sensory◦ Reflexes

Consciousness◦ Arousal◦ Awareness

Lethargy◦ < alertness◦ < awareness◦ < thought process

Obtundation◦ << A/A◦ Clouding

Stupor◦ Deep sleeplike state◦ Vigorous stimulation

Coma◦ Unresponsiveness

PVS MCS

Unarousability Absence of sleep/wake cycles Inability to interact with the environment GCS =/< 8

Intermittent wakefulness Sleep-wake cycles No awareness of self or environment

http://youtu.be/Pl1IPTpHUHs

Altered consciousness Evidence of self or environmental

awareness is demonstrated

http://www.youtube.com/watch?feature=player_detailpage&v=HVGlfcP3ATI

Reticular Activating System (RAS) ◦ Reticular Formation ◦ Gray cells within brainstem extends into

thalamus Wakefulness Arousal Alertness

Lesion/injury to the RAS or cerebral cortex Metabolic disorders Anoxic injury Drugs Seizures

LOC Health history

◦ drugs/head injury/metabolic Physical exam Vital signs

◦ Temperature◦ Cushing’s reflex/triad

Neuro Vital Signs ◦ LOC, Pupils, Strength/Movement, Sensation

Glasgow coma scale NIH Stroke Scale

Edema Increased intracranial pressure

◦ Increased systolic BP ◦ Widening pulse pressure

Normal = 40 mmHg ◦ Decreased pulse rate ◦ Irregular respirations

Eyes

Spontaneous opening 4

Open to speech 3

Open to pain 2

Do not open 1

Verbal Response

Oriented 5

Confused 4

Inappropriate 3

Incomprehensible 2

None 1

Motor Response

Obeys commands 6

Localizes to pain Pushes your hand away

5

Withdraws from pain 4

Decorticate/flexion 3

Decerebrate/extension 2

None 1

Range of possible scores = 3-15 A score of 13 to 14 indicates mild deficit. A score between 9 and 12 points to moderate deficit, and a score of 8 or less indicates severe coma.

Mental status General appearance/behavior State of conciousness Mood and affect Thought content Intellectual capacity

Sensory: CN II - Optic ◦ Visual acuity

Motor: CN III - Oculomotor◦ PERRL◦ Direct/consensual ◦ EOMs (CN IV/VI)

http://www.youtube.com/watch?v=cuZXz92hd8g&feature=relate

Eye movement CN III,IV,VI Oculocephalic reflex

◦ Doll’s eyes◦ Sensory CN VIII ◦ Motor CN III,IV,VI

Dolls eyes ◦ (+) opposite direction◦ intact brain stem ◦ (-) no movement

Trigeminal (V)◦ Corneal reflex◦ Sensory◦ mastication

Facial (VII)◦ Expression◦ Taste

Acoustic (VIII)

Glossopharyngeal (IX)◦ Gag/swallow

Vagus (X)◦ Gag/Swallow

Spinal Accessory (XI)◦ Shoulder shrug

Hypoglossal (XII)◦ TML

Ability to move, strength, and symmetry◦ Grips, arm strength, & drift◦ Planter flexion, dorsiflexion, & leg strength

Coordination ◦ Finger to nose, heel up and down shin

Planter Reflex- Babinski testing Meningeal signs- Brudzinski & Kernig’s sign

Babinski's reflex◦ (+) great toe flexes

and the other toes fan out

Abnormal after the age of 2.

Hips and knees flex when the neck is flexed

Stiffness of the hamstrings causes an inability to straighten the leg when the hip is flexed to 90 degrees.

Visual fields Dull vs. sharp

◦ Sensation same or different with eyes closed Face Hands Arms Abdomen Feet Legs

Brainstem compression◦ Yawning & sighing ◦ Cheyne-Stokes◦ Central neurogenic hyperventilation◦ Apneustic breathing◦ Cluster breathing ◦ Ataxic respirations

http://www.youtube.com/embed/CUaEwgfKOEc

A patient with an intracranial problem does not open his eyes to any stimulus, has no verbal response except muttering when stimulated, and flexes his arm in response to painful stimuli. The nurse records the patient’s GCS score as◦ A. 6◦ B. 8◦ C. 9◦ D. 11

The nurse recognizes the presence of Cushing’s triad in the patient with ◦ A. increased pulse, irregular respiration, increased

BP◦ B. decreased pulse, irregular respiration,

increased pulse pressure◦ C. Increased pulse, decreased respiration,

increased pulse pressure◦ D. decreased pulse, increased respiration,

decreased systolic BP

CN III originating in the midbrain is assessed by the nurse for an early indication of pressure on the brainstem by◦ A. assessing for nystagmus◦ B. testing the corneal reflex◦ C. testing pupillary reaction to light◦ D. testing for oculocephalic (doll’s eyes) reflex

An unconscious patient with increased ICP is on ventilatory support. The nurse notifies the healthcare provider when arterial blood gas (ABG) measurement results reveal a ◦ A. pH of 7.43◦ B. SaO2 of 94%◦ C. PaO2 of 50mm Hg◦ D. PaCO2 of 30mm Hg

◦ BG◦ Electrolytes/

Osmolality◦ ABGs◦ CBC◦ Liver function◦ Kidney function◦ Toxicology

◦ CT◦ MRI◦ EEG◦ Cerebral angiogram◦ TCD◦ LP

Monro-Kellie hypothesis◦ 80/10/10 rule

Autoregulation◦ Cerebral arterioles ◦ MAP (Mean arterial pressure)

Perfusion depends on B/P and chemical (CO2) Normal MAP is 70 to 100 < 60 - peripheral organs not perfused < 50 – brain not perfused Critical to maintain normal MAP with Increased

ICP

Vasoconstriction Decreased CSF CSF shunting Increased CSF reabsorption

Brain’s ability to tolerate an increase in volume without an increase in pressure

Indications of decreased compliance:◦ Sustained increase in ICP in response to stimuli◦ Greater increases to non-noxious stimuli

NP Compensated Uncompensated

10mmHg 15mmHg 30mmHg

Blood 10%, CSF 10% Blood 5%, CSF 5% Blood 4%, CSF 4%

Stable Stiff ICP increases

A slowly expanding mass is tolerated better that a rapidly expanding mass

Brain tissue is compressible, but functional impairment, possibly irreversible does occur

Location matters

Pressure needed for adequate blood flow to brain◦ CPP = MAP – ICP

Need higher MAP if ICP increased◦ 70-100 mmHg◦ <50 mmHg = ischemia◦ <30 mmHg = death

MAP

50 to 150 mmHg

Normal ICP

0 to 15 mmHg

CPP

70 to 100 mmHg

Increased ICP

> 20 mmHg

Increased MAP needed to perfuse brain

Danger of CPP < 50 mmHg

Au

tore

gula

tion

Arterial Blood Pressure - Brain & CS Fluid Compression = Actual Cerebral Blood Flow

Ed

ema,

CS

Flu

id, T

um

or

Changes in contents of cranial vault

Mass effect◦ Tumor◦ Blood clot◦ Edema

Increased CBF◦ Increased blood flow◦ Increased PaCO2◦ Decreased PaO2◦ Vasodilators

Increased intrathoracic pressure◦ Coughing◦ Straining◦ Suctioning◦ Peep

Impairment of cerebral venous drainage◦ Positioning

Changes in LOC Worsening headache Cognitive deficits Pupillary changes Increasing B/P with widening pulse pressure Irregular respiratory patterns Bradycardia Seizures Aphasia Dysconjugate gaze Hemiparesis or hemiplegia

Health history- assess brain involvement PE

◦ Altered cerebral function assessment Frequency depends on potential IICP Early sign- change in LOC 3rd Cranial nerve compression Papilledema Projectile vomiting Vision changes Seizures

◦ Late sign- Cushing VS changes

Ineffective tissue perfusion: cerebral◦ Assess/report sign IICP◦ Adequate airway◦ Promote venous drainage◦ Control environment stimuli◦ Plan nursing care – avoid clustering care◦ Avoid Valsalva’s maneuver◦ If bone flap out post op- assess & position◦ Assess external shunts/drains

Maintenance of airway and ventilation Endotracheal intubation Oxygenation Mechanical ventilation Fluid balance/Euvolemia Medications

Sedation, analgesia, neuromuscular blockade

Barbiturate coma Prophylactic anticonvulsant Mannitol/3% NaCl Lasix Atracrium Vasopressors Tylenol

Temperature control Electrolyte balance Proper positioning Adequate nutrition Ventriculostomy Paralytics Hypothermia Pentobarbital coma Craniectomy

LICOX ◦ PbtO2◦ Normal 37-47 mmHg

Jugular venous bulb cath ◦ SjvO2◦ Normal SjvO2 is 60% to 80%◦ <50 to 55% of O2 in venous blood indicates

impairment of flow and brain taking out more O2 than normal

ICP Waveforms (P1, P2, & P3) ◦ P1 arterial pulse wave should be highest◦ P2 is intracranial compliance – if higher than P1

compliance is compromised ◦ P3 is the venous pulsation and should be the lowest

P1 P2 P3

Standing OrdersPer hospital policy

Neurological◦ Meningitis◦ Seizures◦ Cerebral salt wasting (CSW)◦ Syndrome of inappropriate antidiuretic hormone

(SIADH)◦ Hydrocephalus◦ Cerebral edema/Increased ICP

Increased secretion of ADH from abnormal stimuli

Results in water retention Hyponatremia

◦ Na+ excreted in urine

Decreased UOP Increased urine specific gravity Low serum osmo Hyponatremia Hypervolemia

Fluid restrictiion Replace sodium

◦ Democlocycline◦ Fludrocortisone◦ Hypertonic saline◦ Oral salt

Diuretics

Controversial Hyponatremia Failure of CNS to regulate Na+ reabsorption Increase in circulating atrial natriuretic

peptide (ANP)

Increased UOP Hyponatremia Normal to increased osmo Hypovolemia Increased urine specific gravity

Volume replacement Sodium replacement Reducing renal Na+ excretion

◦ Fludrocortisone◦ Urea

Parameter SIADH CSW

Serum Na+ Decreased Decreased

Serum osmolarity Decreased Decreased

Urine Na+ Increased Normal-increased

Urine OP Decreased Increased

Volume Normo/hypervolemic Hypovolemic

Body weight Increased Decreased

Cerebral edema◦ Vasogenic◦ Cytotoxic◦ interstitial

Hydrocephalus◦ Noncommunicating◦ Communicating◦ ICP

Production – choroid plexus;

Absorption – arachniod villi

Normal MRI Brain MRI Hydrocephalus

Irreversible coma◦ Persistent vegetative state

Locked-in Syndrome (not true coma)◦ Functioning RAS & cortex; pons level

interference◦ Aware, communicate with eyes◦ http://youtu.be/xWHnkFaxMxM

Brain death◦ Loss of all brain function- flat EEG, no blood

flow

A. Cingulate B. Uncal C. Central D. Extracranial E. Tonsillar

Cingulated Herniation (a)

Cingulate gyrus slips under falx cerebri

Usually caused tumor or bleed

Non life threatening

Uncal or Lateral Herniation (b)

Uncus of temporal lobe slips through notch of tentorium and compresses the ipsilateral CN 3, brainstem, & vital centers

Life threatening

Central or Transtentorial Herniation (c)

Downward pressure

General cerebral edema

Brainstem compression

Compresses RAS & vital centers

Abnormal heart rhythms, disturbances or cessation of breathing, cardiac arrest, and death

Life threatening

Infratentorial (subtentorial or Tonsillar) Herniation (e)

Downward displacement of infratentorial structures through the foramen magnum

Life threatening

Extracranial Herniation (d)

Occurs with displacement of brain through a cranial defect.

Usually Non-life threatening

http://youtu.be/dLMCwGmWvrw

A patient has ICP monitoring with an intraventricular catheter. A priority nursing intervention for the patient is ◦ A. aseptic technique to prevent infection◦ B. constant monitoring of ICP waveforms◦ C. removal of CSF to maintain normal ICP◦ D. sampling CSF to determine abnormalities

A patient has a nursing diagnosis of altered cerebral tissue perfusion related to cerebral edema. An appropriate nursing intervention for the patient is◦ A. avoiding positioning the patient with neck and

hip flexion◦ B. maintaning hyperventilation to a PaCO2 of 15-

20mm Hg◦ C. clustering nursing activities to provide periods

of uniterrupted rest◦ D. routine suctioning to prevent accumulation of

respiratory secretions

The earliest signs of increased ICP the nurse should assess for include◦ A. Cushing’s triad◦ B. unexpected vomiting◦ C. decreasing level of consciousness (LOC)◦ D. dilated pupil with sluggish response to light

VS/NVS ICP CPP MAP PbtO2 PaCO2 CVP Labs Imaging

Category status Advanced directives Prognosis Withdraw of care Palliative care End of life specialists SW/Chaplain

Varies according to underlying cause and pathologic process

GCS GOS Physical/mental disability

22 yo female Harvard law

student Horseback riding GCS 7

◦ Localized

Day 2◦ ICP◦ Hypothermia◦ Tracrium

Day 3◦ Flexion

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