ACUTE INTRACRANIAL PROBLEMS Flashcards
Three components of ICP
Brain tissue 78%
Blood 12%
CSF 10%
Primary injury
occurs at the initial time of an injury
Secondary injury
resulting in: -hypoxemia -ischemia -hypotension -edema -increased ICP follows the primary injury
Monroe-Kellie Hypothesis
If one of the three components goes up and the other two will try to compensate
Factors that influence ICP
Arterial pressure, venous pressure, intraabdominal and intrathoracic pressure, posture, temperature, blood gases
Normal ICP
5 to 15mmHg
Panic level for ICP
> 20mmHg for 5 minutes is considered abnormal and must be treated!!
Purpose of CBF
Purpose: (1) To ensure a consistent CBF to provide for the metabolic needs of brain tissue and (2) to maintain cerebral perfusion pressure within normal limits
Blood in milliliters passing through 100g of brain tissue in 1 minute
Cerebral blood flow (CBF)
<70 mmHg means that there is low brain perfusion due to?
diminished blood flow
> 150 mmHg low brain perfusion due to?
vasoconstriction
How to calculate CPP
MAP-ICP
MAP needs to be high!!
Normal range for CPP
60-100 mmHg
When CPP is <50 mmHg-
brain ischemia and neuronal death
When CPP is <30 mmHg-
incompatible with life
What happens when CPP decreases
autoregulation fails and CBF decreases
Cushing’s reflex body attempting to improve CBF by?
Increase BP
Wide pulse pressure
Bradycardia
CBF:
↑ CO2 in the blood and ↓ O2 indicates?
cerebral vasodilation, increases CBF
CBF:
↓ CO2 in the blood and ↑ O2
= cerebral vasoconstriction, decreases CBF
Risk factors for increase ICP with Increased brain volume are
Cerebral edema
Intracerebral mass
Risk factors for increase ICP with increased cerebral blood flow
Impaired autoregulation
Decreased cerebral oxygenation (hypoxemia, hypercapnia)
Increased O2 demand (seizures)
Impaired venous outflow (increased intrathoracic, intraabdominal pressure)
Risk factors for increase ICP with increased cerebrospinal fluid (CSF)
Hydrocephalus
Increased accumulation of fluid in the extravascular spaces of brain tissue; an increase in tissue volume that can also increase ICP
cerebral edema
3 types of cerebral edema
Vasogenic Cerebral Edema
Cytotoxic Cerebral Edema
Interstitial Cerebral Edema
Vasogenic Cerebral Edema
Most common type of edema
Leakage of large molecules from the capillaries into the surrounding extracellular space
Cytotoxic Cerebral Edema
Results from disruption of the integrity of the cell membranes; fluid goes from ECF to inside the cell resulting to cellular swelling
Interstitial Cerebral Edema
Build-up of fluid within the ventricles and interstitium of brain
Causes of cerebral edema
Mass Lesions: Brain Abscess Brain Tumor (Primary or Metastatic) Hematoma (Subdural, Epidural Hemorrhage (Intracerebral, Cerebellar, Brainstem)
Head Injuries & Brain Surgery:
Contusion
Hemorrhage
Posttraumatic Brain Swelling
Cerebral Infections:
Encephalitis
Meningitis
Vascular Insult:
Anoxic and Ischemic episodes
CVA (thrombotic, embolic)
Venous Sinus Thrombosis
Toxic or Metabolic Encephalopathic Conditions:
Hepatic Encephalopathy
Lead or arsenic intoxication
Uremia
What are the clinical manifestations of stroke
- change in LOC
- change in vital signs
- ocular signs
- motor function
- headaches
- vomiting
“Waxing and Waning
when they wake up, you ask how are you? And then they go back to sleep, come back to wake them up again and they’re restless
Cushing’s triad
increase BP, wide pulse pressure, bradycardia
What are some tests to check for
- NUMBER 1 CT scan!
- MRI is 2nd!
- Transcranial doppler studies
- EEG for brain wave and SEIZURES
- skull xray
- spinal xray
- lumbar puncture contraindicated for increased ICP
Ventriculostomy
Gold standard on monitoring ICP
Catheter inserted into lateral ventricle connected to a transducer projected into monitor
Facilitates removal and/or sampling of CSF, and allows for intraventricular drug administration
A reference point ventriculostomy is the tragus
Inaccurate ICP readings can be caused by:
- CSF leaks around the monitoring device
- Obstruction of the intraventricular catheter
- Difference between the height of the catheter and the transducer
- Kinks in the tubing
- Incorrect height of the drainage system
- Bubbles or air in the tubing
Examples of mass lesions include
Brain Abscess
Brain Tumor (Primary or Metastatic)
Hematoma (Subdural, Epidural
Hemorrhage (Intracerebral, Cerebellar, Brainstem)
What’s the difference between hemorrhagic stroke vs ischemic stroke?
Hemorrhagic- bleeding occurs inside or around the brain tissue
Ischemic-clot blocks the blood flow to an area of the brain
Causes of Ischemic stroke are
Large Artery Thrombosis (20%)
Small Penetrating Art.Thrombosis (25%)
Cardiogenic emboli (20%) Cryptogenic (no known cause) (30%)
Other (5%)
Causes of Hemorrhagic stroke are:
Intracerebral
Subarachnoid
Cerebral aneurysm
AV Malformation
Clinical manifestations for ICP :
Changes in LOC Changes in VS Ocular signs (CN || and |||) Decrease in motor function Headache Vomiting Seizures
Decorticate posturing
BUE: Adduction, flexion of
arms, wrists, fingers
• BLE: extension, internal rotation, plantar flexion
Decerebrate posturing
• BUE, BLE rigid extension, with hyperpronation of forearms and plantar flexion of feet
Herniation syndrome that Shift of brain tissue from one cerebral hemisphere under the falx cerebri to the other
Cingulate
Downward shift cerebral hemisphere, basal ganglia, through tentorial notch compressing brainstem
Central
Unilateral lesion forces uncus to displace through tentorial notch
Uncal
Displacement of cerebella tonsil through foramen magnum, compressing pons and medulla; Changes on breathing and cardiac functions
Cerebellar tonsil
Management for ICP
Elevation of head of bed to 30 degrees with head in a neutral position
Infection is a serious complication with ICP monitoring.
- Routinely assess the insertion site
- Use aseptic technique
- Monitor CSF for a change in drainage color or clarity
Possible association with air in forehead tissue, CSF rhinorrhea, or pneumocranium (air between cranium and dura mater)
Frontal skull facture
Periorbital ecchymosis (raccoon eyes), optic nerve injury
Orbital skull fracture
Oval-shaped bruise behind ear in mastoid region (Battle’s sign), CSF otorrhea, middle meningeal artery disruption, epidural hematoma
Temporal skull fracture
Deafness, CSF or brain otorrhea, bulging of tympanic membrane caused by blood or CSF, facial paralysis, loss of taste, Battle’s sign
Parietal skull fracture
Occipital bruising resulting in cortical blindness, visual field defects, rare appearance of ataxia or other cerebellar signs
Posterior fossa
CSF or brain otorrhea, bulging of tympanic membrane caused by blood or CSF, Battle’s sign, tinnitus or hearing difficulty, rhinorrhea, facial paralysis, conjugate deviation of gaze, vertigo
Basilar skull fracture
P1 percussion wave
Arterial pulsation
P2 rebound/tidal wave
Intracranial compliance or brain volume; If P2 higher that P1, intracranial compliance compromised
P3 dicrotic wave
Follows dicrotic notch , AV valve closure
Two testing to determine whether fluid leaking from the nose or ear is CSF
➢ Dextrostix
➢ Tes-Tape strip
Risk for meningitis is?
high with a CSF leak
GCS Scale includes
- Minor (GCS 13 to 15)
- Moderate (GCS 9 to 12)
- Severe (GCS 3 to 8)
Classic signs of epidural hematoma:
• Initial period of unconsciousness at the scene • Brief lucid interval followed by a decrease in LOC • Headache • Nausea and vomiting
Subdural hematoma
Occurs from bleeding between the dura mater and arachnoid layer of the meninges
Results from injury to the brain tissue and its blood vessels
May be caused by arterial hemorrhage May be acute, subacute, or chronic
Acute subdural hematoma
manifests within 24 to 48 hours of injury
Subacute subdural hematoma
usually occurs within 2 to 14 days of the injury
Chronic subdural hematoma
develops over weeks or months after a seemingly minor head injury
Drug therapy for Ischemic/Hemorrhagic stroke
Alteplase (clot buster) will not decrease ICP
Osmotic diuretic (mannitol) big molecule of sugar
Hypertonic saline (use this instead)
NaCl 3%
Antiseizure drugs (e.g., phenytoin [Dilantin])
Corticosteroids (dexamethasone)
Histamine (H2)-receptor antagonist (e.g., cimetidine) or proton pump inhibitor (e.g., pantoprazole [Protonix]) to prevent GI ulcers and bleeding
Management for ICP
Elevation of head of bed to 30 degrees with head in a neutral position
Intubation and mechanical ventilation
Most common cause of ischemic/hemorrhagic stroke
uncontrolled hypertension
Ventriculostomy includes
Gold standard on monitoring ICP
Catheter inserted into lateral ventricle connected to a transducer projected into monitor
Facilitates removal and/or sampling of CSF, and allows for intraventricular drug administration
A reference point ventriculostomy is the tragus
ICP >20 mmHg for 5 minutes should be reported to physician
How often should you do neuro assessment for a patient with ICP
Q15 mins x 2 hours, Q30 mins x 2, Q1 hr until discontinued
Two testing to determine whether fluid leaking from the nose or ear is CSF:
when its bleeding??
Dextrostix
Test-Tape strip
If there’s bleeding from the CSF, test for halo sign
GCS measures …
eye opening
motor response
verbal response
Minor (GCS 13 to 15)
Moderate (GCS 9 to 12)
Severe (GCS 3 to 8)
GCS less than 8= intubate!!
Typical signs of concussion:
Brief disruption in LOC (woke up for a little bit and goes back to sleep)
Amnesia regarding the event (retrograde amnesia)
Headache
Classic signs of epidural hematoma:
Initial period of unconsciousness at the scene
Brief lucid interval followed by a decrease in LOC
Headache
Nausea and vomiting
Focal findings
Occurs from bleeding between the dura mater and arachnoid layer of the meninges
subdural hematoma
the most common primary tumor from the CNS
Meningiomas
Brain tumor management includes
- Surgical therapy
- Ventricular Shunts
- Radiation Therapy and Stereotactic Radiosurgery
- Chemotherapy and Targeted Therapy
Opening into the cranium with a drill. Used to remove localized fluid and blood beneath the dura.
craniotomy
Excision into the cranium to cut away bone flap
craniectomy
Repair of cranial defect Artificial material used to replace damaged or lost bone
cranioplasty
the leading cause of bacterial meningitis
Streptococcus pneumoniae and Neisseria meningitidis
test used to rapidly diagnose viral meningitis
Xpert EV test
Ticks and mosquitoes transmit ..
encephalitis
Kernig’s sign
pain at the back of the neck (meningitis)
Brudzinski’s sign
pain in the back of the lower back in the lumbar area; stretching the meninges
(meningitis)
Most common causes of viral meningitis:
Enteroviruses
Arboviruses
HIV
Herpes simplex virus
Accumulation of pus within the brain tissue that can result from a local or systematic infection
brain abscess
Shift of brain tissue from one cerebral hemisphere under the falx cerebri to the other; no specific symptoms
cingulate
Downward shift cerebral hemisphere, basal ganglia, through tentorial notch compressing brainstem; Decrease LOC, Motor weakness, Cheyne-Stoke respiration, small reactive pupils (late: dilated) posturing
central/tentorial herniation
Unilateral lesion forces uncus to displace through tentorial notch; Increase muscle tone, Babinski, ipsilateral dilated pupil
Uncal
Displacement of cerebella tonsil through foramen magnum, compressing pons and medulla; Changes on breathing and cardiac functions
cerebellar tonsil
