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Increased Intracranial Pressure

4 min read

References:

  1. Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th Edition, ISBN 978-197-51-6103-3, by Janice L. Hinkle, Kerry H. Cheever, and Kristen J. Overbaugh** (pp. 2000 - 2004)
  2. Lecturer (VJVS)

ICP is normally 0 to 10 mmHg, and 15 mmHg at most for normal cases. An increased ICP is most commonly elevated due to head injury.

Clinical Manifestations

  • Impaired neural function, initially manifested as altered LOC, later on by abnormal respiratory and vasomotor responses. Pupillary dysfunction is noted. Restlessness, confusion, and drowsiness are neurologically significant. This progresses to stupor then to a coma. Brain death may be evaluated if no confounding factors are known and the coma is profound and irreversible.
  • Decortication, decerebration or flaccidity may occur in late ICP elevation.
  • Changes in VS: Cushing’s triad (1) hypertension, widening pulse pressure as systolic BP increases, (2) bradycardia, (3) irregular breathing, and elevated temperature.
  • Complications:
    • Brain Stem Herniation: brain tissue presses down on the brain stem, restricting blood flow, leading to irreversible brain anoxia and brain death.
    • DI: neurologic DI results from decreased ADH secretion.
      • SIADH: neurologic SIADH results from increased ADH secretion.

Diagnostic Examination

  • Imaging (CT, MRI, Angiography, PET, SPECT)
  • Transcranial Doppler

Lumbar Puncture

A lumbar puncture is never done for a patient with an increased ICP. The creation of an “exit point” increases the possibility of a brain herniation.

Medical Management

  • Monitor ICP and Cerebral Oxygenation: Invasive monitoring is necessary (ventriculostomy [golden standard], intraventricular catheter, subarachnoid bolt, epidural or subdural catheter, fiberoptic transducer-tipped catheter).
  • Decrease ICP: decrease cerebral edema (osmotic diuretics), CSF volume (draining CSF), or cerebral blood volume.
    • Cerebral edema can be reduced with Mannitol, an osmotic diuretic, or hypotonic saline (3%) that draws out fluids from the cerebral tissue into the serum. Fluid restriction also aids in reducing edema. Fevers affect cerebral edema, and therefore should be controlled. Antipyretics, a hypothermia blanket, etc. may be used.
    • CSF volume reduction is done through continuous drainage. A ventriculoperitoneal shunt (VP Shunt) connects the ventricles into the peritoneum to facilitate drainage. Monitor effectiveness and infection after insertion of shunt.
    • Decompressive hemicraniectomy (craniotomy; “burr holes”): removal of bone to allow for expansion of the brain. It may be replaced once problems are resolved.
  • Maintain cerebral perfusion: cardiac output may be manipulated for brain perfusion. Fluid volume changes and inotropic agents (dobutamine, norepinephrine) improve cardiac output.

Pharmacologic Management

  • Anticonvulsants: Phenytoin (Dilantin); prevent seizures
  • Antipyretics, Muscle Relaxants: Acetaminophen (Tylenol) and Diazepam (Valium) to reduce temperature.
  • Blood Pressure Medications: Beta-Blockers (Propanolol) to maintain cerebral perfusion.
  • Corticosteroids: Dexamethasone (Decadron) reduces cerebral edema.
  • Hyperosmotic Agents: Mannitol (Osmitrol) induces diuresis, drawing fluids out from the brain. IVF given is hypertonic to avoid promoting cerebral edema and draw fluids from body tissues. Other types of diuretics are unable to cross the blood-brain barrier.
  • Laxatives and stool softeners reduce constipation, preventing ICP elevation
  • Mild analgesia is used, and not strong analgesics as it may mask the client’s signs and symptoms.
  • An antitussive is used to prevent coughing, which prevents ICP elevation. Ideally, this can be achieved with codeine, which fulfills the analgesic needs.
  • Antiemetics (Metoclopramide) are given to prevent ICP elevation during emesis.

Nursing Management

  • Maintain breathing: ensuring patency, removing secretions, and auscultation is done. Coughing can lead to increased ICP, and hypoxia results in cerebral edema.
  • Breathing can be impaired due to increased ICP: Cheyne-Stokes respirations manifest from pressure on the frontal lobe or deep midline structures.
  • Positioning and Avoiding activities that increase ICP:
    • Elevate the head of the bed to 30-45 degrees.
    • Keep the head midline and in neutral alignment.
    • Avoid neck, or hip flexion
    • Avoid exertion and straining. Objects that are carried should be limited to 5 lbs.
    • Increase dietary fiber and administer laxatives when indicated.
    • Give an antitussive, preferable codeine as it also provides analgesia.
  • Mechanical Ventilation may be required.
  • Optimizing cerebral tissue perfusion: reduce factors contributing to ICP. Maintain elevation of the head to reduce ICP. Extreme hip flexion and neck flexion and extreme rotation of the head increase ICP.
  • Maintain body temperature: shivering increases ICP. Fever increases cerebral edema.
  • Monitor electrolytes, acid-base, and I&O.
  • Maintain Negative Fluid Balance: limit intake to 1200 mL/day. Monitor fluid balance; catheterization is used to assess fluid balance. A urine output of 200 mL or more for two hours may indicate onset of neurologic DI.

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