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Flashcards in ICP Module Deck (18):
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How to calculate cerebral perfusion pressure

Cerebral perfusion pressure (CPP)
CPP is the pressure needed to ensure blood flow to the brain
CPP = MAP – ICP

MAP-mean Arterial Pressure (roughly 2 times your diastolic +your systolic divided by three)
50 mm Hg is the low range below this CBF decreases and you get blurred vision and syncope
150 mm Hg is high range above this the vessels can not constrict anymore
ICP-intracranial pressure (normal is 0-15)

1

Increased Cerebral Pressure: Manifestations

Earliest signs may be
Blurred vision/decreased visual acuity
Followed by headache and vomiting (projectile) not preceded by nausea
Change in level of consciousness (most significant sign)
Change in vital signs
Cushing’s triad
Hypertension (high systolic with widening pulse pressure)
Bradycardia
Irregular respirations
Ocular signs
Pupil dilation and changes in reactivity
unilateral at first depending on what side of brain affected
Bilateral when swelling becomes systemic
SUSPECT ↑ ICP of any patient who becomes acutely unconscious!!!!!!!!!!

2

ICP: Complications

Two major complications of uncontrolled increased ICP
Inadequate cerebral perfusion
Cerebral herniation
Tentorial herniation
Uncal herniation
Cingulate herniation

3

ICP: Nursing Care

Monitor
Neurological status every 1-2 hours
Fluid and electrolyte balance
Intracranial pressure
Monitor Adequate oxygenation/respiratory function
PaO2 maintenance at 100 mm Hg or greater
ABG analysis guides the oxygen therapy
May require mechanical ventilator
MAINTAIN AIRWAY

4

ICP:Nursing care continued

Body position maintained in head-up position (30 degrees if not contraindicated)
Make sure high enough to lower ICP
Protection from injury (i.e. turning to prevent pressure ulcers)
Monitor for constipation and bladder distension and prevent patient from coughing (why?)
Place in quiet environment to limit stimuli spread out nursing activities since increase activity may increase ICP.

5

ICP: Nursing care continued again

Measuring intercranial pressure
ICP Can be measured in
Ventricles (gold standard)
Subarachnoid space
Epidural space
Brain parenchymal tissue
ICP monitoring used to guide clinical care when patient at risk for increased ICP
Those admitted with a Glasgow Coma Scale of 8 or less
Those with abnormal CT scans or MRI

6

ICP: Nursing care continued again again

Infection is always a serious consideration with ICP monitoring
ICP should be measured as a mean pressure at the end of expiration
Waveform should be recorded
Shaped similar to arterial pressure trace
Inaccurate readings can be caused by
CSF leaks
Obstruction in catheter
Differences in height of bolt/transducer
Kinks in tubing
Incorrect height of drainage system relative to patient’s reference point

7

what is involved in measuring ICP

Measuring intercranial pressure
ICP Can be measured in
Ventricles (gold standard)
Subarachnoid space
Epidural space
Brain parenchymal tissue
Infection is always a serious consideration with ICP monitoring
ICP should be measured as a mean pressure at the end of expiration
Waveform should be recorded
Shaped similar to arterial pressure trace
Inaccurate readings can be caused by
CSF leaks
Obstruction in catheter
Differences in height of bolt/transducer
Kinks in tubing
Incorrect height of drainage system relative to patient’s reference point

8

Cushings Triad

Cushing’s triad
Hypertension (high systolic with widening pulse pressure)
Bradycardia
Irregular respirations

9

Decerebrate posturing

Decerebrate posturing in comatose patient
Upper and lower limbs extend following stimulus (pain, startle, auditory).
Normal inhibition by cortex on the extensor facilitation par of the reticular formation is missing, so extensors are hyperactive
Lat vest nuclei involved, ablate and extensor posturing reduced.

10

Decorticate posturing

Decorticate posturing in comatose patient
Lesion above the red nucleus
lower limbs extend, upper limbs flex following stimulus
activity in the brainstem flexor center, the red nucleus.

11

Basilar fracture

Fracture of bones at the base of the skull
Requires more force to cause than other skull fractures
Least common
Have hallmark signs due to force necessary to cause them (see next slide)
Treatment involves regular neurological assessment and observations for meningitis

12

Basilar fracture: Signs and symptoms

Raccoon eyes (periorbital edema and ecchymosis)
Battle's sign (postauricular ecchymosis and otorrhea [CSF leaking out of the ear])
Rhinorrhea (CSF leaking out of the nose)
Leaking fluid should be tested at the lab
Halo sign (blood in the middle surrounded by CSF

13

Minor head injuries

Scalp lacerations
The most minor type of head trauma
Scalp is highly vascular → profuse bleeding
Major complication is infection
Concussion
A sudden transient mechanical head injury with disruption of neural activity and a change in LOC
Brief disruption in LOC
Amnesia
Headache
Postconcussion syndrome
2 weeks to 2 months
Persistent headache
Lethargy
Personality and behavior changes
Shortened attention span, decreased short-term memory
Changes in intellectual ability

14

Major head trauma
Contusions

Includes cerebral contusions and lacerations
Both injuries represent severe trauma to the brain
Contusion
Bruising of brain tissue within a focal area that maintains the integrity of the pia mater and arachnoid layers
Usually associated with closed head injury
Coup-countrecoup injury
Prognosis is dependent on amount of bleeding around the contusion site

15

Major head trauma
Lacerations

Involve actual tearing of the brain tissue
Often occur in association with depressed and open fractures and penetrating injuries
Intracerebral hemorrhage is generally associated with cerebral laceration
Surgical repair of laceration is impossible
Prognosis is poor with large intracerebral lacerations
Any trauma with acceleration/deceleration

16

Head injury nursing care

Maintain cerebral perfusion
Prevent secondary cerebral ischemia
Monitor for changes in neurologic status
Glasgow Coma Scale
CSF leaks (Raise the head of patients leaking CSF)
Treatment of life-threatening conditions will initially take priority in nursing care
Prevention of infection
Major focus of nursing care relates to increased ICP
Eye problems
Hyperthermia

17

Linear skull fracture

Occurs when a widely distributed force makes the skull bend inward forcing areas around it to buckle outward
Most common type of skull fracture
Dura remains intact therefore infection and CSF leakage minimal
Hematoma formation is possible
Treatment
Bed rest
Observation for brain injury
No specific treatment necessary