Increased intracranial pressure (ICP) results from a buildup of cerebrospinal fluid in the brain. It can affect people of all ages, but is most common in people older than sixty.

Introduction to Increased Intracranial Pressure (ICP)

Increased intracranial pressure (ICP) is a condition that results when the volume of cerebrospinal fluid in the skull increases. ICP is most often caused by head trauma or bleeding in the brain, but sinus infections, tumors, or cancerous growths can also cause it. 

The increased pressure on the brain will cause symptoms similar to other conditions that cause headaches and irritability. The main symptom of increased ICP is a headache.

Pathophysiology of Increased Intracranial Pressure (ICP)

The volume of the brain is typically fixed, and the two most important components contributing to ICP are cerebral blood flow and the balance between the cerebral spinal fluid (CSF). If the volume of either of these two components increases, by intracranial hemorrhage or an inability to effectively absorb or drain CSF, then this will lead to increased ICP. 

Increased pressure within the head compresses blood vessels leading to cerebral hypoxia and pressure on the brain stem, which can lead to headaches, nausea/vomiting, loss of vision, seizures, and even death if left untreated.

Causes of Increased Intracranial Pressure (ICP)

The most common cause of increased ICP is brain swelling due to infection or inflammation. Brain swelling can result from bacterial meningitis or viral meningitis, as well as infections like tuberculosis or fungal infections such as cryptococcus (Cryptococcus neoformans) and histoplasmosis (Histoplasma capsulatum). Other causes include:

• Aneurysms
• Head trauma or meningitis
• Brain tumors
• Inflammation of brain tissue
• Increased cerebral spinal fluid (CSF)

Signs and Symptoms of ICP

Increased ICP is a common problem in clients with closed-head injuries. Other conditions, such as brain tumors or hydrocephalus can also increase the intracranial pressure. Signs and symptoms of increased ICP include:

• Headache
• Dizziness
• Confusion
• Blurred or double vision
• Nausea and vomiting

Early vs Late Signs of Increased ICP

The early signs of increased ICP are subtle, and they can be challenging to diagnose. However, knowing the early signs of increased ICP can help make a timely doctor referral and prevent complications from developing.

The late signs of increased ICP are much more obvious, including headache, nausea, vomiting, and difficulty breathing or speaking. These symptoms are indicative of a serious problem and should not be ignored.

Early Signs

• Altered level of consciousness (LoC)
• Irritability
• Restless
• Decreased Mental Status
• Drowsiness

Critical Late Signs 

• Cushing triad (wide pulse pressure) 
• High blood pressure (hypertension) 
• Low heart rate (bradycardia)
• Low respiratory rate 

Late Deadly Signs

Lungs:

• Irregular respirations (especially Cheyne Stokes)

 Neck & Brain:

• Nuchal rigidity (stiff neck)
• Unable to flex chin toward chest
• Seizures and coma

 Eyes:

• Pupils fixed and dilated
•  Doll’s eyes (this means the brainstem is intact)
  • The brainstem is affected if the eyes stay fixed and dilated when the head is turned.

 Foot:

• Babinski reflex (toes fan out when stimulated)
  • This indicates brain stem herniation! Normal in an infant, not normal in adults.

Arms:

• Decorticate (arms flex toward core)
• Decerebrate (arms flexed out to sides)

ICP Nursing Interventions

• Assess client’s level of consciousness, orientation to events surrounding them (Glasgow coma scale), peripheral circulation, and motor responses.
• Increase blood volume status (by initiating fluids or blood products if necessary).
• Decrease cerebral edema (to protect the client from trauma or infections, like meningitis).
• Position in Semi-Fowler’s (30-35 degrees or higher with no flexion or bending).
• Perform suctioning (ten seconds or less, administer O₂ at 100% before and after suction).
• Provide client education regarding the illness, treatment options, and expected outcomes.

• Monitor for signs of hydrocephalus and seizures (puffy face, widened sclera, bulging fontanelles, and irritability)
• Administer prescribed medications such as Mannitol or Dexamethasone to reduce cerebral edema and relieve cerebral vasospasm.

Medications Used to Treat Increased Intracranial Pressure

Phenytoin

Phenytoin prevents seizures, and works by reducing the amount of fluid within the spaces between the brain and its outer layer (the dura mater). This allows the client’s brain to expand without putting pressure on itself.

Dexamethasone

Dexamethasone is a steroid that decreases the swelling and inflammation that causes increased pressure inside the skull. This allows room for blood flow to the brain, which improves the delivery of oxygen and nutrients.

Phenobarbital 

Phenobarbital is a barbiturate used to decrease brain activity. It works by decreasing the amount of fluid in the brain, which helps relieve pressure on the brain.

Mannitol 

Mannitol is an osmotic diuretic that reduces this pressure by reducing the amount of fluid in the brain tissue. This lowers the overall volume of fluid pushing against the skull.

Increased Intracranial Pressure (ICP) Conclusion

Intracranial pressure (ICP) is a condition when the amount of cerebrospinal fluid in the skull elevates. ICP can result from sinus infections, tumors, or malignant growths, although head injuries or brain bleeding are some of the most frequent causes.

The increased pressure on the brain will cause symptoms similar to those of other conditions that cause headaches and irritability. The main symptom of early increased ICP is a headache.

Sources

https://www.hopkinsmedicine.org/health/conditions-and-diseases/headache/increased-intracranial-pressure-icp-headache 

https://medlineplus.gov/ency/article/000793.htm 

https://www.cedars-sinai.org/health-library/diseases-and-conditions/i/increased-intracranial-pressure-icp-headache.html