Lecture on Increased Intracranial Pressure (ICP)

Introduction

• Presenter: Cereth, Registered Nurse
• Topic: Increased Intracranial Pressure
• Series: Part of NCLEX Review Series on the Neuro System

Key Definitions

• Increased Intracranial Pressure: A dramatic increase in pressure within the skull, a medical emergency that can lead to brain death.

Intracranial Pressure Details

• Creation: By cerebrospinal fluid (CSF), brain tissue, and blood.
• Normal ICP: 5 to 15 mmHg.
• Critical ICP: Greater than 20 mmHg requires immediate treatment.

Anatomy Impact

• Human Skull: Limited in expansion; pressure changes affect ICP.
• Three Structures: Brain tissue, CSF, and blood within the brain.

Factors Influencing ICP

• Body Temperature: Hyperthermia increases ICP.
• Oxygenation: Hypoxia and high CO2 levels increase ICP via vasodilation.
• Body Position: Proper alignment (head midline, certain angle) prevents increased ICP.
• Other Factors: Arterial/venous pressure, intra-abdominal/thoracic pressure.

Monroe-Kellie Hypothesis

• Concept: Balancing volumes of CSF, brain tissue, and blood to maintain cerebral perfusion pressure (CPP).
• Body Compensation: Shifts CSF, alters cerebral artery constriction.

Cerebral Perfusion Pressure (CPP)

• Definition: Pressure pushing blood to the brain, affecting cerebral blood flow (CBF).
• Normal Range: 60 to 100 mmHg.
• Calculation: CPP = MAP - ICP.

Clinical Conditions Causing Increased ICP

• Examples: Head trauma, hydrocephalus, hemorrhage, tumors, infections like meningitis.

Pathophysiology

• Sequence: Increased pressure reduces blood supply -> ischemia -> decreased CPP -> brain damage.
• Signs: Cushing’s triad, irregular breathing, deterioration in motor function.

Signs and Symptoms

• Mnemonic: MIND CRUSH
  • M: Mental status changes (earliest sign).
  • I: Irregular breathing (Cheyne-Stokes).
  • N: Nerve changes (optic, oculomotor).
  • D: Decerebrate/decorticate posturing.
  • C: Cushing's triad (late sign).
  • R: Reflex positive (Babinski).
  • U: Unconsciousness (late stage).
  • S: Seizures.
  • H: Headache, emesis, hemiplegia.

Nursing Interventions

• Goals: Preventing further increases, monitoring ICP, and providing patient care.
• Mnemonic: PRESSURE
  • P: Positioning (30-35 degrees, midline head, no flexion).
  • R: Respiratory management (prevent hypoxia/hypercapnia).
  • E: Elevated temperature management.
  • S: Systems monitoring (neuro checks, Glasgow Coma Scale).
  • S: Straining activities avoidance.
  • U: Unconscious patient care.
  • R: Prescriptions (medications for ICP management).
  • E: Edema management (use of hyperosmotic drugs like Mannitol).

Medications and Treatments

• Barbiturates: Decrease brain metabolism and ICP.
• Vasopressors & IV Fluids: Manage blood pressure.
• Anticonvulsants & Hyperosmotic Drugs: Prevent seizures and manage edema.
• Mannitol: Dehydrates brain to reduce ICP.
• Other Drugs: Loop diuretics, corticosteroids to manage protein leakage and swelling.

Conclusion

• This lecture reviewed increased intracranial pressure and its management essential for NCLEX preparation.
• Additional Resources: Free quiz available to test knowledge on this condition.