Definition
Intracranial pressure (ICP) is the pressure within the cranial vault, determined by the combined volumes of brain tissue, cerebrospinal fluid (CSF), and cerebral blood (Monro–Kellie doctrine). Normal regulation of ICP is critical to maintaining cerebral perfusion and preventing secondary brain injury. Normal Values
- Adults: 5–15 mmHg
- Sustained ICP ≥20–22 mmHg is considered pathologic and requires intervention
Pathophysiology Any increase in one intracranial component must be compensated by a decrease in another. Failure of compensation leads to:
- Reduced cerebral perfusion pressure (CPP)
- Cerebral ischemia
- Brain herniation (life-threatening)
CPP = MAP − ICP Common Causes of Elevated ICP
- Traumatic brain injury
- Intracranial hemorrhage
- Ischemic or hemorrhagic stroke
- Brain tumors or abscesses
- Hydrocephalus
- Cerebral edema (e.g., hyponatremia, hepatic failure)
- CNS infections (meningitis, encephalitis)
Clinical Manifestations
- Headache (worse in morning)
- Nausea and vomiting (often projectile)
- Altered level of consciousness
- Papilledema
- Cushing triad (late sign):
- Hypertension
- Bradycardia
- Irregular respirations
Pharmacist’s Role & Clinical Pearls Pharmacologic Management of Elevated ICP Osmotherapy
- Mannitol
- Rapid onset
- Monitor serum osmolality, renal function
- Hypertonic saline (3%–23.4%)
- Increases intravascular volume
- Monitor sodium, osmolality
Adjunctive Therapies
- Sedation and analgesia (e.g., propofol, opioids)
- Antipyretics (fever increases cerebral metabolism)
- Antiseizure prophylaxis (post-TBI or hemorrhage)
Corticosteroids
- Indicated only for vasogenic edema from brain tumors
- Contraindicated in traumatic brain injury and stroke
Monitoring & Safety Considerations
- Avoid hypotonic IV fluids
- Maintain adequate MAP to preserve CPP
- Monitor electrolytes closely (Na⁺, serum osmolality)
- Watch for rebound ICP elevation after osmotic therapy
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