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1 CARE AND MANAGEMENT OF CLIENTS WITH INCREASED INTRACRANIAL PRESSURE
2 Elements of Performance
Topic 11.1 - Explain the mechanisms that affect cerebral blood flow
Topic 11.2 – Describe the common etiologies, clinical manifestations, and the collaborative care of
the client with increased intracranial pressure.
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3 Cerebral Blood Flow(CBF) (Topic 11.1)
◦ Amount of blood (mL’s) that passes through 100 g of brain tissue per minute
◦ Adults – 750 mL/min (50 mL of blood per minute/100 g)
◦ Brain is unable to store oxygen or glucose – essential to have adequate blood flow to perform
neuronal functioning (**and to survive)
◦ Brain accounts for only 2% of body weight, but uses 20% of body’s oxygen and 25% of glucose
◦ Autoregulation – alteration of cerebral blood vessels to maintain constant blood flow during
changes of BP, Purpose: to keep up with metabolic demands and maintain cerebral perfusion
◦ Autoregulation fails with extreme hypotension or hypertension
◦ If MAP is less than 50 mmHg = cerebral ischemia
◦ If MAP is greater than 150 mmHg = intracranial hypertension
4 Cerebral Blood Flow
◦ Other factors:
◦ PaCO2
◦ Increase = relax smooth muscle, dilate cerebral vessels, increases CBF
◦ Decrease = opposite effect (constriction and decrease CBF)
◦ PaO2
◦ Falls below 50 mmHg = cerebral vascular dilation
◦ If not raised, then anaerobic metabolism leads to lactic acid accumulation
**As lactic acid builds….Hydrogen ions accumulate
◦ hydrogen ions accumulate = acidic cerebral environment
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↓PaO2 + ↑H+(acidosis) = failure to meet tissue metabolic demands
5 Alterations to CBF
1 ◦ Cardiac arrest
◦ Respiratory arrest
◦ Diabetic coma
◦ Encephalopathies
◦ Systemic infections
2 ◦ Toxicities
◦ Trauma
◦ Tumours
◦ Cerebral Hemorrhage
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◦ Cerebral Hemorrhage
◦ Stroke
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6 Intracranial Pressure (Topic 11.2)
◦ ICP is the result of the pressure exerted from the total amount of brain tissue, intracranial blood
volume, and CSF within the skull at any time.
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◦ Normal ICP is 5-15 mmHg
◦ Increased ICP is anything over
20mmHg
7 Intracranial Pressure (ICP)
◦ The brain requires a certain level of cerebral pressure for adequate function
◦ balance is obtained by varying the amounts of CSF, intracranial blood (CBF) and brain tissue
◦ The volume and pressure of these three components maintain a state of equilibrium and produce
the intracranial pressure ICP of 0 to 15 mmHg
◦ compensatory mechanisms allow for a 5% sudden shift in volume before ICP rises
◦ a rise in volume of 8-10% may lead to death, particularly if rapid
8 Pathophysiology
◦ Because of the limited space for expansion in the skull, a change in any one of the components
causes a change in the volume of the others.
◦ Compensation usually occurs by shifting the CSF or decreasing cerebral blood flow by
vasoconstriction.
◦ Without such changes, ICP will rise.
◦ Increased ICP causes decreased cerebral perfusion, which causes further swelling or edema of the
brain. Leads to ischemia and cell death.
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9 Cerebral Edema
◦ Table 59.2
“Causes of Cerebral Edema”
10 Concussion
◦ Associated with mild brain injury
◦ Sudden transient mechanical head injury with disruption of neural activity and a change in LOC
◦ Brief disruption in LOC, amnesia, and headache – short duration
◦ May or may not lose total consciousness
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12 Contusion
◦ Much more severe head injury
◦ Frequently occurs near the site of a skull fracture, involves bruising of the brain tissue within a
focal area
◦ Often develops areas of hemorrhage, infarction, necrosis and edema
◦ Coup-contrecoup
◦ As hematoma expands, there is an increase in ICP
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◦ As hematoma expands, there is an increase in ICP
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14 Clinical Manifestation of Increased ICP
◦ Changes to LOC (See next slide)
◦ Changes to vital signs (Cushing's Triad)
◦ Hypertension (with wide pulse pressure)
◦ Bradycardia
◦ Irregular respiratory pattern
◦ Hyperthermia (pressure on hypothalamus)
◦ Ocular signs
◦ Decrease in motor function
◦ Headache
◦ Vomiting
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15 Figure 59.5. Clinical manifestations of increased intracranial pressure. LOC, level of
consciousness.
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17 Collaborative Care for Increased ICP
◦ Drug therapy
◦ Anticonvulsants
◦ Antipyretics
◦ Corticosteroids
◦ Histamine H2- receptor antagonist
◦ Hypertonic saline solution
◦ Nutritional support osmotic diuretics (**mannitol)
◦ Stool softeners
18 Interprofessional Care:
◦ HOB 30° - head in neutral position
◦ Avoid positions and activities that increase ICP
◦ i.e. bending hips (Even relatively minor position changes can increase ICP)
◦ Neuro checks: Glasgow coma scale (standard scoring)
◦ Watch for changes in LOC
◦ Decrease cerebral edema
◦ Intubation and mechanical ventilation
◦ Maintain patent airway – if ventilated then oxygenate pre + post suctioning (no longer than 15
secs)
◦ Monitor ICP
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19 Figure 59-07. Coronal section of the brain shows potential sites for placement of
intracranial pressure monitoring devices.
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20 Collaborative Care:
◦ Intubation and mechanical ventilation
◦ Maintain patent airway – if ventilated then oxygenate pre + post suctioning (no longer than 15
secs)
◦ Reduce CSF and intravascular volume
◦ Maintain cerebral perfusion
◦ Control fever
◦ Reduce metabolic demands
◦ 24 hour fluid balance
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21 Refer to Moodle
◦ Case study – Head Injury
◦ Answer key in Moodle
◦ NCP – Increased Intracranial Pressure
