Increased intracranial pressure (ICP) occurs when the volume of brain tissue, blood, or cerebrospinal fluid within the rigid skull increases, according to the Monro-Kellie hypothesis. Common causes of elevated ICP include head injuries, brain tumors, and hemorrhages. Increased ICP decreases cerebral perfusion and can lead to brain herniation if left untreated. Management focuses on reducing cerebral edema, CSF volume, and intracranial blood flow through osmotic diuretics, corticosteroids, CSF drainage, hyperventilation, and maintaining cerebral perfusion pressure above 70 mmHg. ICP is monitored to identify pressure elevations and guide treatment effectiveness.

1. Increased ICP
• The rigid cranial vault contains:
- Brain tissue (1,400 g)
- Blood (75 ml), and
- CSF (75 ml).

2. Continued…..
• ICP is usually measured in the lateral
ventricles;
• normal ICP is 10 to 20 mm Hg
• Monro-Kellie hypothesis : states that because
of the limited space for expansion within the
skull, an increase in any one of the
components causes a change in the volume of
the others.

3. Patophysiology
• Increased ICP is a syndrome that affects many
patients with acute neurologic conditions.
• This is because pathologic conditions alter the
relationship between intracranial volume and
pressure.

4. Continued……
• Elevated ICP is most commonly associated
with:
- head injury
- secondary to brain tumors, subarachnoid
hemorrhage, and toxic and viral
encephalopathies

5. Continued…..
 Increased ICP from any cause leads to:
- decreases cerebral perfusion
- swelling (edema), and
- shifts brain tissue through openings in the
rigid dura, resulting in herniation,

6. Continued…..
*A rise in carbon dioxide partial pressure (PaCO2)
causes
- cerebral vasodilatation, leading to increased cerebral
blood flow and increased ICP
* Fall in PaCO2 has a vasoconstrictive effect
- Decreased venous outflow may also increase cerebral
blood volume, thus raising ICP.

8. Compensatory Mechanisms
• As brain tissue swells within the rigid skull,
- autoregulation →change the size of blood
vessels
- decreasing the production and flow of CSF.

9. Continued…..
• Cerebral response to increase ICP
**. At a certain volume or pressure, the brain’s
ability to autoregulate becomes ineffective and
decompensation (ischemia and infarction) begins.
- patient exhibits significant changes in mental status
and vital signs.
→ Cushing’s triad: occurs due to the above
deterioration
- Bradycardia
- hypertension, and
- bradypnea

10. Clinical Manifestations
* Change in LOC
- Restlessness (without apparent cause)
- confusion, or increasing drowsiness
- stuporous, reacting only to loud auditory or painful
stimuli.
* abnormal motor responses in the form of
decortication, decerebration, or flaccidity.

12. Assessment and Diagnostic Findings
• Hx
• P/E
• CT scan
• MRI
• Transcranial Doppler studies provide information about
cerebral blood flow.
• electrophysiologic monitoring to monitor cerebral blood
flow indirectly.
NB:Lumbar puncture is avoided in patients with increased
ICP because the sudden release of pressure can cause the
brain to herniate.

13. Complications
• Brain stem herniation,
• Diabetes insipidus, and
• Syndrome of inappropriate antidiuretic
hormone (SIADH)

14. Management
• Immediate Management To Relieve Increased
ICP Involves
- Decreasing Cerebral Edema
- Lowering The Volume of CSF
- Decreasing Cerebral Blood Volume While
Maintaining Cerebral Perfusion

15. These goals are accomplished By:
1. Administering osmotic diuretics and corticosteroids,
2. Restricting fluids,
3. Draining CSF, controlling fever,
4. Maintaining systemic blood pressure and
oxygenation, and
5. Reducing cellular metabolic demands

16. I. Monitoring ICP
The purposes of ICP monitoring are:
• to identify increased pressure early in its course
(before cerebral damage occurs),
• to quantify the degree of elevation, to initiate
appropriate treatment,
• to provide access to CSF for sampling and
drainage
• to evaluate the effectiveness of treatment.

17. II. Decreasing cerebral edema
• Osmotic diuretics (Mannitol) : They act by
drawing water across intact membranes
• Corticosteroids (eg, Dexamethasone): Help
reduce the edema surrounding brain tumors
when a brain tumor is the cause of increased
ICP.
* Fluid restriction

18. III. Maintaining Cerebral Perfusion
• Improvements in cardiac output
- Inotropic agents such as dobutamine hydrochloride
• The effectiveness of the cardiac output is reflected in
the cerebral perfusion pressure, which is maintained
at greater than 70 mm Hg.

19. IV. Reducing CSF and intracranial blood flow
• CSF drainage : ventriculostomy
• Hyperventilation: results in vasoconstriction,
- Maintaining the PaCO2 at 30 to 35 mm Hg
NB: Hyperventilation is indicated in patients whose
ICP is unresponsive to conventional therapies.

20. V. Reducing metabolic demands
• High doses of barbiturates
• Pharmacologic paralyzing agents : decreasing
the metabolic demands