INTRACRANIAL PRESSURE Flashcards
What’s the normal ICP?
5-15 mmHg
Hydrostatic force measured in the intracranial CSF compartment
Intracranial Pressure (ICP)
Factors Influencing ICP
-Pressure in the body cavities
- Carbon dioxide levels in the blood
- Posture
- Body Temperature
- Blood Pressure
ICP greater than 20 mmHg for longer than 5 minutes
Intracranial Hypertension
“If the volume of any one of three components increases within the cranial vault and the volume from another is displaced, the total intracranial pressure will not change”
Monroe-Kellie Hypothesis
Causes of Intracranial Hypertension
-Head Injury (most common)
- Brain Tumor
- Encephalopathies
- Subarachnoid hemorrhage
- Hydrocephalus
-Infection
Pressure needed to ensure blood flow to the brain
Cerebral Perfusion Pressure
Formula for CPP
CPP= MAP-ICP
Normal CPP
70-100 mmHg
if CPP is <50mmHG
CPP <50mmHg produces irreversible neurologic damage
What happens if ICP is increased?
Decreased cerebral blood flow
Decreased cerebral blood flow is resulting to CUSHING’s RESPONSE
CUSHING’s RESPONSE- Systolic Hypertension, Widened Pulse Pressure, Bradycardia
Decreased cerebral blood flow results to Hypoxia, Death of Brain Cells, Edema around necrotic tissue, Compression of brainstem and respiratory center and Cushing’s Triad
CUSHING’S TRIAD- Hypertension, Bradypnea, Bradycardia
BRADYPNEA- Accumulation of CO2, Vasodilation, Further increase in ICP and leads to DEATH
What’s the early manifestations of ICP?
-Changes in LOC (restlessness, confusion
- Anisocoria (Ipsilateral)
- Vision is blurred and doubled
- Extremity is weak
- Headache
Worsened by movement or straining
Headache
What’s the Late Manifestations of ICP?
-Progressively declining LOC
- Cushing’s Triad
- Projectile Vomiting
- Abnormal Posturing (Decorticate/Decerebrate)
- Flaccidity
-Loss of Reflexes
- Death
What’s the complication of ICP?
Brain herniation
Ipsilateral Dilatation of Pupils
Anisocoria
A catheter is placed through a burr hole into the lateral ventricle of the brain
Intraventricular Catheter Monitoring (Ventriculostomy)
This device can only measure ICP and drain CSF
Intraventricular Catheter Monitoring (Ventriculostomy)
The main concern of Intraventricular Catheter Monitoring (Ventriculostomy)
High Risk For Infection
Essential Concept of Intraventricular Catheter Monitoring (Ventriculostomy)
Right Hemisphere is the NON- DOMINANT hemisphere for language, so insertion into the right lateral ventricle reduces risk of language dysfunction.
> 40 mmHg is considered as
Considered as widened pulse pressure
Landmarks of the Foramen of Monroe (FOM)
- Supine
- Lateral
If supine position, the landmarks of the foramen must be
Tragus
If lateral or side-lying position, the landmarks of the foramen must be
Between the eyebrows
Errors in Positioning of Transducer
The outcome if ZERO is far above FOM
- False low reading
- Insufficient drainage
Errors in Positioning of Transducer
The outcome if ZERO is far below FOM
-False high reading
-Excessive drainage
Important nursing actions for ventriculostomy
-Check levelling of ventriculostomy everytime a patient is repositioned
-Routinely assess insertion site using aseptic (sterile) technique
-Monitor the CSF for a change in drainage color or clarity
Normal Appearance: clear and colorless
Turbidity means presence of bacterial infection
Medical Management of ICP (Airway Support)
Priority: Airway Support
-Oxygen Supplementation if Sp02 <94%
-Intubation, if severely hypoxemic
- Suction secretions, as ordered and as necessary
Medical Management of Increased ICP (DRUG)
Mannitol IV
Mechanism of action of Mannitol IV
-Osmotic diuretic that can cross the BBB
-Used to reduce ICP to normal level
Side Effects of Mannitol
-Polyuria
- Crystallization of IV ports
Position for the Management of Increased ICP
Low-fowler’s
Rationale of Low-Fowler’s Position
Promotes drainage of venous blood from brain
What’s the diet for the management of Increased ICP?
Blenderized, if with dysphagia
-Feed via NGT during acute period
-Check placement of tip
- Flush NGT with water (b4 and after)
-Position: Fowler’s
-Trial feeding prior to diet progression
Supportive Care for the Management of Increased ICP
-Oral care every shift
- Laxatives, as ordered
- Reposition every 2 hours and provide necessary skin care
- Monitor diaper for soiling and change ASAP
Rationale of Laxatives
To prevent straining at stool
Surgical Management of ICP
Craniotomy and Decompressive Hemicraniectomy
Used to evacuate hematoma for patients showing signs of worsening neurologic exam, increased ICP, or signs of brainstem compression
Craniotomy
Considered as a surgical strategy to assist in management of refractory intracranial HTN
Decompressive Hemicraniectomy
Decrease cerebral edema by reducing the oxygen and metabolic requirements of the brain, thus protecting the brain from continued ischemia
Decompressive Hemicraniectomy
