MS W11 PART 1 ICP

• CNS


  Central nervous system, a vast network of neurons that control the body's vital function
• CNS


  • Vulnerable, structure and function may be disrupted by injuries
  • Head injury, brain tumor, intracranial hemorrhage, infection and stroke or CVA can disrupt it
• Increased intracranial pressure (ICP)

  1. Brain tissues expand in the inflexible cranium

  2. Volume increases in the brain

  3. ICP rises

  4. Cerebral perfusion will be impaired

  5. Can cause permanent neurologic dysfunction or brain death
• Cranial vault


  Skull vault, skullcap, calvaria
• Components within the brain

  • Brain tissue (1400g)
  • Blood (75mL)
  • CSF (75mL)
• Normal ICP


  0-10 mmHg
• Normal upper limit of ICP

  15 mmHg
• Monro-Kellie hypothesis (Monro-Kellie doctrine)


  • Explains the dynamic equilibrium of cranial contents
  • Because of limited space for expansion within the skull, an increase of any one of the components causes change in the volume of others
• Compensation for increased ICP

  1. Displacing/ shifting the CSF

  2. Increasing absorption or diminishing production of CSF

  3. Decreasing cerebral blood volume
• Increased ICP


  Can decrease cerebral perfusion, stimulate cerebral edema which may result in shifting of brain tissues which may result in brain herniation, which usually occurs in fatal events
• Cerebral ischemia


  Stimulates vasomotor centers, found in the medulla which is responsible for regulation of cardiac activity and myocardial performance
• Stimulation of vasomotor centers


  Required to maintain cerebral blood flow by increasing systemic pressure (compensation)
• Compensation for increased ICP

  • Slow bounding pulse (change in BP, HR, RR- sign of ⬆ ICP)
  • Respiratory irregularities (can result in changes in the concentration of O2 and CO2 in the blood which plays a role in CBF)
• Increased PaCO2


  Can lead to cerebral vasodilation which can lead to ⬆ CBF therefore increase ICP
• Decreased venous outflow


  Can result in increased cerebral blood volume thus increasing ICP
• Autoregulation


  The brain's ability to change the diameter of the blood vessel to maintain constant CBF
• Cushing's reflex


  • Occurs when there is a significant decrease of CBF
  • The sympathetic NS increases systolic BP which may result in to widening of PP, slowing HR
• Cushing's reflex is a late sign that requires intervention
• If cushing's reflex is not treated rapidly, autoregulation fails and decompensation occurs
• Cushing's triad


  A grave sign which is worrying
• Brain herniation


  • The shifting of brain tissue from an area of high pressure to lower pressure
  • Herniated tissue will exert pressure on the area where it has shifted, interfering with blood supply leading to cessation of blood flow= cerebral ischemia, infarction and brain death
• Clinical manifestations of increased ICP

  • Changes in LOC
  • Restlessness w/o apparent cause
  • Confusion
  • Increasing drowsiness
  • Pupillary changes, impaired extraocular movements
  • Unilateral / bilateral body weakness
  • Headache and projectile vomiting
  • Stuporous
  • Cushing's triad
  • Comatose as neurologic function deteriorates further
  • Decortication
  • Decerebration
  • Flaccidity
  • Brain death
• Diagnostic tests


  • CT SCAN & MRI
  • CEREBRAL ANGIOGRAPHY
  • PET
  • TRANSCRANIAL DOPPLER STUDIES
  • LUMBAR PUNCTURE
• Lumbar puncture is contraindicated in pts with increased ICP as the sudden release of pressure in the lumbar area can cause brain herniation
• Neurogenic diabetes insipidus


  • Result of decreased secretion of ADH
  • Pt has excessive UO, decreased urine osmolality, and serum hyperosmolarity
• SIADH


  • Result of increased secretion of ADH
  • Manifestations of volume overload, diminished UO, diluted serum concentration
• Goals of medical management for increased ICP

  • Decrease cerebral edema
  • Decrease CSF volume
  • Decrease blood volume
  • Maintain cerebral perfusion
• Ventriculostomy (intraventricular catheter)


  • A fine-bore catheter is inserted into a lateral ventricle, preferably in the nondominant hemisphere of the brain
  • Records pressure in the form of electrical impulse by a transducer
  • Continuous ICP recording, CSF drainage especially during acute increases in pressure, drain blood from the ventricle
• Subarachnoid screw or bolt


  • Hollow device that is inserted through the skull and dura mater into the cranial subarachnoid space
  • Record ICP, prevent brain shifting
• Epidural monitoring


  • Detects ICP
  • Has a low incidence of infection and complication
  • Disadvantage is that it cannot withdraw CSF for analysis
• Fiberoptic monitoring (transducer-tipped catheter)

  • Alternative to intraventricular, subarachnoid, and subdural systems
  • Catheter can be inserted into the ventricle, subarachnoid space, subdural space, or brain parenchyma or under a bone flap
  • Reflects pressure changes, which are converted to electrical signals
  • Drains CSF (when used in conjunction with drainage device)
• Medical management interventions for increased ICP

  • Mannitol
  • Fluid restriction
  • CSF drainage
  • Corticosteroids
  • Fever control
  • Maintain systemic BP
  • Oxygenation
• Nursing management for increased ICP

  • Monitor for respiratory irregularities- maintain patent airway
  • Discourage coughing
  • Promote cerebral tissue perfusion
  • HOB elevated at 30-45o
  • Head in neutral position (midline)
  • Avoid increase in abdominal or intra abdominal thoracic pressure
  • Avoid emotional stress
  • Avoid frequent arousal from sleep
• Types of craniotomy


  • Supratentorial craniotomy
  • Infratentorial craniotomy
  • Transsphenoidal
• Supratentorial craniotomy


  Above the tentorium and into the supratentorial compartment
• Infratentorial craniotomy


  Below the tentorium into the infratentorial (posterior fossa)
• Transsphenoidal


  Through the mouth and nasal sinuses, often to gain access to the pituitary gland
• Nursing interventions for craniotomy

  • Maintain HOB elevated at 30o-b 45o with neck in neutral alignment
  • Avoid positioning on operative side of large tumor was removed to prevent pressure on operative site
  • Maintain neck in straight alignment, avoid flexion of neck
  • Maintain nasal packing in place and reinforce as needed, instruct pt to avoid blowing the nose, provide oral care
• HOB elevated at 30o-45o


  • With neck in neutral alignment
• Position patient


  • On either side or back
  • Avoid positioning on operative side of large tumor was removed to prevent pressure on operative site