Increased Intracranial Pressure (ICP)

Overview

• Definition: An increase in pressure inside the skull and around the brain.
• Normal ICP: 5 to 15 mmHg.
• Abnormal ICP: Above 20 mmHg, which should be reported.

Causes

• Tumors
• Trauma (e.g. head injury or stroke)
• Infection (e.g. meningitis or encephalitis)

Signs and Symptoms

Main Sign

• Decrease in Level of Consciousness (LOC)
  • Symptoms: Lethargy, confusion, restlessness, agitation
  • Measured with the Glasgow Coma Scale (GCS)

Glasgow Coma Scale (GCS)

1. Eye Opening
   • Spontaneously: Score 4
   • To speech: Score 3
   • To pain: Score 2 (methods: sternal rub, trapezius squeeze, supraorbital/mendibular pressure)
   • No response: Score 1
2. Best Verbal Response
   • Correctly answers orientation (3 questions): Score 5
   • Confused: Score 4
   • Inappropriate words: Score 3
   • Incomprehensible sounds: Score 2
   • No response: Score 1
3. Best Motor Response
   • Obeys commands: Score 6
   • Localizes pain: Score 5
   • Withdraws from pain: Score 4
   • Decorticate (flexes inward): Score 3
   • Decerebrate (extends outward): Score 2
   • No response: Score 1

Important: GCS < 8: Intubate (Pt. in coma)

Additional Symptoms

• Headache
• Vomiting
• Seizures
• Eye Issues
  • Ipsilateral dilation: Early sign (compression of cranial nerve III)
  • Fixed dilated pupils: Late sign
  • Sluggish pupils
  • Ptosis (droopy eyelids)
  • Blurred vision
  • Diplopia (double vision)
  • Papilledema (swelling of optic nerve)
• Motor and Reflex Issues
  • Hemiplegia (weakness on the opposite side of the injury)
  • Positive Babinski's sign: abnormal response (toes fan out)
  • Decorticate and Decerebrate posturing
• Vital Sign Changes (Cushing's Triad)
  • Increased temperature (possibly due to hypothalamus injury)
  • Low, bounding pulse (<60 bpm)
  • High blood pressure
  • Respiratory changes (Cheyne-Stokes respirations)
  • Increased or widening pulse pressure (Systolic minus Diastolic)

Remember: Cushing's Triad is the opposite of hypovolemic shock.

Complications

• Herniation
  • Brain moves towards brainstem opening
  • Main sign: Fixed dilated pupils
  • High risk of brain death or severe disability

Diagnostics

• CT Scan: Main diagnostic tool, quick results
• MRI: More specific but slower than CT
• Important: No lumbar puncture as it can lead to brain herniation
• Monitoring: Indicated when GCS < 8 and abnormal CT/MRI
  • Technique: Ventriculostomy (External Ventricular Drain or EBD)
  • Risk: Infection (monitor temperature)

Nursing Interventions

• Positioning: Elevate head of bed to 30 degrees, midline neutral position
  • Avoid flexing neck or hips
• Avoiding Triggers
  • Fever, high CO2 levels, intra-abdominal pressure (straining, coughing, etc.)
  • Suctioning (PRN only, pre-oxygenate)
  • Seizures, pain, environmental stimuli (dim lights, cool room, reduce noise)

Medical Interventions

• Medications
  • Mannitol: Osmotic diuretic, reduces ICP
    • Monitor for pulmonary edema
  • Hypertonic Saline: Similar action to Mannitol
  • Steroids (e.g., Dexamethasone): Reduce inflammation
    • Not for head injury patients
    • Combine with antacids to prevent ulcers and GI bleed
  • Anti-seizure drugs (e.g., Phenytoin, Phenobarbital)
    • Monitor respirations (CNS depressant)
  • Acetaminophen: Reduce fever
    • Monitor liver
  • Sedatives: Propofol, Fentanyl, Midazolam
  • Neuromuscular Blocking Agents: Example: Cisatracurium

Overall Goal: Maintain ICP within normal limits and improve level of consciousness.