ICP Module Flashcards
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!!!!!!!!!!
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)
ICP: Complications
Two major complications of uncontrolled increased ICP Inadequate cerebral perfusion Cerebral herniation Tentorial herniation Uncal herniation Cingulate herniation
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
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.
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
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
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
Cushings Triad
Cushing’s triad
Hypertension (high systolic with widening pulse pressure)
Bradycardia
Irregular respirations
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.
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.
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
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
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
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
