T9 Intracranial Pressure and Brain Tumors

• What is normal ICP?

  5 - 15 mmHg.
• What is the Monro-Kellie doctrine?

  The 3 components of the brain must stay at a relatively constant volume so changes in one part can displace volume at another to maintain ICP.
• What are the 3 essential components of the skull?

  1. Brain tissue
  2. Blood
  3. Cerebrospinal fluid
• How much does the CSF count for?

  10%.
• How much does intravascular blood count for in the brain?

  12%.
• How much does brain tissue count for?

  78%.
• What is a good MAP for cerebral blood flow?

  70 - 150 mmHg.
• What is cerebral perfusion pressure (CPP)?

  MAP - ICP.
• What is normal CPP?

  60 - 100 mmHg.
• What is considered too little CPP?

  Less than 50 mmHg.
• What is the CPP level that is incompatible with life?

  Less than 30 mmHg.
• What are the stages of increased ICP?

  • Stage 1: Total compensation
  • Stage 2: Decreased compensation with risk for increased ICP
  • Stage 3: Failing compensation; signs of increased ICP (Cushing's triad)
  • Stage 4: Herniation imminent leading to death
• What are the 3 types of cerebral edema?

  Vasogenic, cytotoxic, interstitial.
• What is vasogenic cerebral edema?

  Increased permeability of blood-brain barrier leading to leaking from intravascular to extravascular space.
• What is cytotoxic cerebral edema?

  Brain swelling due to cell death, fluid and protein shifts from extracellular to intracellular.
• Which type of cerebral edema results in cerebral hypoxia or anoxia and SIADH secretion?

  Cytotoxic.
• What is interstitial cerebral edema?

  Too much CSF due to usually hydrocephalus.
• What is the most common type of cerebral edema?

  Vasogenic.
• How is interstitial cerebral edema treated?

  Ventriculostomy or shunt.
• What are manifestations of increased ICP?

  Change in level of consciousness, Cushing's triad, change in body temperature.
• What is Cushing's triad?

  Hypertension with widened pulse pressure, bradycardia, irregular respirations.
• What are signs of cranial nerve III dysfunctioning?

  Fixed, unilateral dilated pupils which indicate brain herniation.
• What are dysfunctions to cranial nerves II, IV, VI?

  Diplopia, blurred vision, extraocular movement changes.
• What is shown with a central herniation?

  Sluggish but equal pupil response.
• What is shown with an uncal herniation?

  Dilated unilateral pupil.
• What shows with papilledema?

  Edematous optic disc on retinal exam.
• What are the kinds of posturing for motor dysfunction?

  Decorticate (flexor) and decerebrate (extensor).
• Which kind of posturing indicates more serious damage to motor dysfunction?

  Decerebrate posturing.
• What are other manifestations for ICP?

  Headache worse in the morning that is continuous, vomiting not preceded by nausea (unexpected) and projectile.
• What should not be done as a diagnostic if there is increased ICP?

  Lumbar puncture.
• What are indications of ICP?

  GCS less than or equal to 8 and abnormal CT or MRI.
• What is the gold standard for monitoring ICP?

  Ventriculostomy inserted into lateral ventricle connected to an external transducer.
• What PaO2 should be done to care for increased ICP?

  Greater than or equal to 100 mmHg.
• What should the PaCO2 be when caring for patients with increased ICP?

  35 - 45 mmHg.
• What nutrition goals are there for increased ICP?

  Early feeding and keep patient euvolemic.
• What drug is used for increased ICP?

  • Mannitol for vascular osmotic gradient
  • Hypertonic saline for moving water out of cells and into blood
  • Corticosteroids to treat vasogenic edema
  • Antiseizure medications
• What should be done for a patient with increased ICP when managing respiratory?

  • Elevate HOB 30 degrees
  • Prevent abdominal distention
  • Maintain patent airway
  • Suction as needed
• What drugs can be used to manage anxiety and pain for increased ICP?

  Propofol, Precedex.
• What interventions should be done to optimize ICP and CPP?

  • HOB is elevated and head is midline
  • Avoid extreme neck flexion
  • Turn slowly
  • Prevent pain or discomfort
  • Avoid hip flexion
• How often are males more likely to get a TBI compared to women?

  2 times.