Unit 1: Increased Intracranial Pressure Flashcards

1
Q

Monro-Kellie Doctrine

A
3 components (brain tissue, blood, and cerebrospinal fluid) occupy a rigid box, the skull
-When one of these 3 increases, the other components must decrease to maintain equilibrium, preventing further injury to the brain through compression of the tissue within the fixed box (skull)
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2
Q

What 3 components occupy the skull?

A
  • Brain tissue (80%)
  • Blood (10%)
  • Cerebrospinal fluid (CSF) (10%)
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3
Q

Intracranial Compliance

A

ability of the body to compensate by adjusting the levels of the components (brain tissue, blood, and CSF)

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4
Q

Brain Tissue

A

composed primarily of water

-makes up 80% of the intracranial components

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5
Q

Blood + Cerebrospinal fluid (CSF)

A

each make up 10% of the remaining contents within the cranium

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6
Q

Normal ICP

A

0-15

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7
Q

Herniation Syndromes

A

classified according to the region of tissue that is displaced

  • brain shifts
  • can occur with continued addition of volume
  • S/S: “Cushings Triad”: increased SBP w/ widening pulse pressure, bradycardia, and irregular respirations
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8
Q

Cushings Triad

A

-Increased Systolic BP w/ widening pulse pressure
-Decreased HR (bradycardia)
-Irregular Respirations
>late sign of Increased ICP
>occurs late in the herniation process as the brainstem is compressed

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9
Q

Increased ICP Assessment Findings

A
  • Increased confusion
  • Progressive lethargy
  • Sluggish pupils
  • Motor Weakness
  • Vomiting
  • No change in vital signs
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10
Q

Herniation Assessment Fidnings

A
  • Unresponsive (GCS <8); coma
  • Unilateral or Bilateral pupillary dilation
  • Contralateral (opposite side) Hemiparesis
  • Flexor or Extensor posturing
  • Positive Babinski reflex (toes flare out)
  • Cushings Triad
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11
Q

Glasgow Coma Scale

A

-Best Eye Opening (1-4)
-Best Motor Response (1-6)
-Best Verbal Response (1-5)
>15 highest score
>3-8= coma

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12
Q

What is the most sensitive indicator of increased ICP?

A

decreased LOC

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13
Q

How to detect Increased ICP?

A

-neurological assessments
-elements of wakefulness
-arousal
-cranial nerves
-motor function
>establish an accurate baseline of functioning from which to judge deterioration

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14
Q

Management of Increased ICP

A
  • Decreasing the volume of brain water, blood, or CSF in the intracranial space
  • Emergency management: airway management and therapies to decrease intracranial contents (osmotic diuretics, hyperventilation)
  • Vigilant monitoring (neurological status)
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15
Q

Management of Increased ICP: Vigilant monitoring

A
  • To identify neurological deterioration that places a patient at risk for increased ICP and cerebral herniation syndrome
  • Assess oxygenation, ventilation, and hemodynamic parameters to optimize therapy and prevent or mitigate brain injury
  • Full systems assessment to identify signs of complications/ conditions that may negatively impact the patient w/ increased ICP, such as respiratory compromise
  • Assess laboratory values (serum electrolytes, serum osmolality) to detect electrolyte imbalance and dehydration, which can lead to renal insufficiency or failure
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16
Q

Diagnosis of Increased ICP

A
  • CT Scan to determine the cause of increased ICP (e.g. collection of blood, cerebral edema)
  • Laboratory testing (serum osmolality, ABGs) to guide medical treatments
17
Q

CT Scan

A

uses x-rays to obtain many cross-section/ slices of the head and brain

  • allows detailed views of the skull, brain structures and tissue, facial bones, or sinuses
  • performed quickly
  • w/ or w/o contrast
  • first performed w/o contrast to visualize brain structures and detect bleeding (contrast and blood appear the same color (white) in the brain tissue)
  • images obtained after contrast if a mass (brain tumor, abscess) is suspected b/c IV contrast travels into brain tissue where the blood brain barrier has been disturbed; a mass “lights up” on a contrast CT scan b/c the BBB has been disrupted and the contrast has infiltrated the interstitial space in and around the mass
18
Q

Nursing Considerations for CT scan

A
  • Transport of the pt w/ increased ICP performed with the right team depending on stability of the pt (providers, nurse practitioners, or respiratory therapists; to ensure continuity of care from ICU to procedure area
  • Assess for contrast-induced nephropathy; hypotension, diabetes, and chronic kidney disease
  • Serum creatinine (within 24 hours of test) b/c contrast can damage the kidney
  • Serum Creatinine monitored at least once after the contrast administration and more often if acute kidney injury is suspected; an increase of at least 0.5 mg/dL is expected, will decrease over 24-48 hours
  • Pregnancy test performed prior
  • Assess ability to remain still
  • Patients with increased ICP may be confused, restless, or agitated, requiring sedation or anxiolysis
  • Assess ability to lie flat during the scan
  • Assess allergy to iodine or shellfish
  • Assess IV access
19
Q

Medications used to decrease cerebral edema

A

-Osmotic Diuretics (Mannitol)
-High concentration sodium chloride
>these medications are used to increase the osmolality of the blood (increase solute in the blood) in order to pull water from the interstitial space of the brain and other tissues into the vascular space; area from low concentration (brain tissue) to high concentration (blood)

20
Q

Osmotic Diuretic: Mannitol (Osmitrol)

A

pulls water from the interstitial spaces into the vascular space, and then diuresis occurs at the level of the kidney

  • IV fluid should be administered to replace fluid losses
  • Side Effects: hyponatremia, hyperkalemia, acute kidney injury
  • Assess BUN and Creatinine
  • Monitor Electrolytes
21
Q

High Concentration Sodium Chloride

A

pull water from the interstitial spaces into the vascular space w/o the dramatic fluid shifts caused when osmotic diuretics are utilized

22
Q

Physical Interventions for Increased ICP

A
  • Raise HOB to 30-45 degrees
  • neck in neutral position
  • hip flexion minimized
  • hyperventilation
  • external drainage of CSF
23
Q

Surgical Management: Hemicraniectomy w/ a durotomy

A

removal of a section of the cranium and dura in order to create space for the swelling brain

  • removal of a section of the skull and opening of the dura
  • the skull is removed and stored in a tissue bank or tissue pocket within the patients abdomen
  • dura is replaced w/ synthetic material that allows for brain tissue expansion and watertight closure of the meningeal layer
24
Q

Intracranial Pressure Monitoring

A

ICP can be monitored using a catheter or sensor placed in one of the lateral ventricles of the brain, in the brain tissue/ parenchyma, or in the subarachnoid space

  • used for pt’s w/ a traumatic brain injury (TBI) or GCS of <8
  • can increase risk of infection; risk of bleeding along catheter tract
  • an accurate ICP can be monitored only when the drainage system is closed to CSF drainage
  • drainage system must be correctly leveled after the HOB is repositioned to safely drain CSF
  • maintain system as a closed system to prevent infection
25
Q

Complications of CSF Drainage

A
  • infection
  • over-drainage of CSF
  • blockage
  • introduction of air into the ventricular system if proper leveling is not maintained
  • if excessive amount of CSF is drained rapidly through an IVC, a subdural hematoma (collection of blood in the subdural space) can result b/c of contraction of brain tissue that stretches small bridging blood vessels traversing the space between the dura and brain tissue
26
Q

Preventing Overdrainage of CSF through an IVC

A
  • maintaining proper level

- proper adjustment of the drainage burette at the ordered level above the external auditory meatus

27
Q

Nursing Management: Assessment + Analysis

A
  • Vigilant serial assessments of neurological status
  • Assessments of oxygenation, ventilation, and hemodynamic parameters
  • Full system assessment
  • Assessment of Lab Values (Serum electrolytes, Serum osmolality
  • manifestations of increased ICP
28
Q

Nursing Assessments

A
  • Serial neurological assessments q 1 to 2 hours in the critical phase, decreasing in frequency as the risk of cerebral edema and secondary brain injury decreases
  • Vital Signs and oxygen saturation q 1-2 hours
  • Temperature q 1-2 hours
  • Intracranial pressure and CPP q 1 to 2 hours or more frequently if the patient is experiencing an increase in ICP and/or deterioration of neurological assessment
  • Cardiac Rhythm: serum markers of myocardial injury (creatinine kinase, creatinine kinase specific to cardiac muscle, and troponin)
  • Intake and Output q 1-2 hours
  • Serum Sodium and/or Serum Osmolality
  • Serum Electrolytes
  • BUN and Creatinine
  • ABGs
  • End-Tidal carbon dioxide (E+CO2) continually to guide hyperventilation therapy during increased ICP (keep in range of 30-35 mmHg)
29
Q

Why would you monitor Urine amount and Specific Gravity?

A

d/t increased ICP and resultant cerebral edema, pt’s can develop Diabetes Insipidus or SIADH

30
Q

Nursing Actions/Interventions

A
  • Maintain HOB >30 degrees
  • Patients head midline
  • Avoid sharp hip flexion
  • Avoid position that allows pressure directly on the operative site/side after craniectomy
  • Endotracheal suctioning only as needed; preoxygenate with 100% oxygen for 1-2 minutes prior suctioning
  • Administer sedative medications as prescribed
  • Administer osmotic agents (Mannitol, Hypertonic saline)
  • Ensure continuous drainage of CSF through the external ventricular drainage system
  • Administer antipyretics/ cooling measures
31
Q

Perform Endotracheal suctioning only as needed

A
  • preoxygenate with 100% oxygen for 1 to 2 minutes prior to suctioning
  • suctioning a pt with increased ICP can further increase the risk of elevating ICP b/c the act induces coughing, which raises pressure inside the chest may reduce drainage of blood from veins in the neck
  • should be performed when demonstrates mucus in the endotracheal tube or q 4 to 6 hours to maintain patency of tube
32
Q

Administer Sedatives as prescribed

A

-sedation used in pts w/ acutely increased ICP to treat pain, anxiety, and restlessness b/c it decreases ICP when titrated to appropriate levels

33
Q

Administer antipyretics and/or implement cooling measures

A
  • prevent an increase in cerebral metabolism that accompanies elevated body temperature
  • water cooled blankets or pads
  • ice packs in axilla and groin
34
Q

Nursing Teachings

A
  • Devices used during the course of treating ICP (central lines, ICP monitoring devices, endotracheal tubes, and gastric tubes)
  • Medications used to treat ICP
  • Complications of Increased ICP
  • Rationale for helmet after craniectomy
  • Importance of Rest
35
Q

Why Assess Cardiac Rhythm and biomarkers in a pt with increased ICP?

A

-myocardial ischemia, injury, or dysrhythmias may occur as a result of neurological injuries such as TBI or aneurysmal subarachnoid hemorrhage (SAH)

36
Q

Why Monitor Arterial Blood Gases? (ABGs)

A
  • allows precise measurement of gases dissolved in the plasma
  • allows evaluations of PaCO2 which causes vasoconstriction (decreased PaCO2) or vasodilation (increased PaCO2) of cerebral blood vessels
  • Cerebral vasoconstriction reduces ICP
  • Cerebral vasodilation of blood vessels can increase ICP and brain injury