What are the recommended steps to reduce elevated intracranial pressure?

How to Lower Elevated Intracranial Pressure

Elevate the head of the bed to 30 degrees with the neck in neutral midline position, ensure adequate sedation and analgesia, administer mannitol 0.25–0.5 g/kg IV over 20 minutes (or hypertonic saline as an alternative), maintain cerebral perfusion pressure between 60–70 mmHg, and consider external ventricular drainage or decompressive craniectomy for refractory cases. 1, 2

Initial Positioning and Basic Measures

• Elevate the head of the bed to 30 degrees with the neck in a neutral midline position to improve jugular venous outflow and reduce ICP; this is a simple, first-line intervention that should be implemented before escalating to more aggressive therapies. 1, 2

• Confirm the patient is not hypovolemic before head elevation, as this maneuver can drop mean arterial pressure and worsen cerebral perfusion pressure (CPP). 2, 3

• Avoid lateral head turning, which obstructs venous drainage and increases ICP. 3

• Never place the patient flat (0 degrees head elevation), as this impairs jugular venous outflow and worsens intracranial hypertension. 3

Sedation and Analgesia

• Administer intravenous propofol as the preferred sedative because its short duration permits rapid neurological assessment when needed. 1

• Use continuous intravenous infusion of morphine or fentanyl for analgesia and antitussive effect, avoiding intermittent boluses that cause unpredictable ICP spikes. 1

• Titrate sedation to prevent agitation, coughing, or straining (which raise ICP) while maintaining a level shallow enough to allow regular neurological examinations. 1

• Do not perform routine daily sedation interruption in patients with radiographic signs of elevated ICP, as interruption may worsen cerebral hemodynamics. 1

Osmotic Therapy

• Administer mannitol 0.25–0.5 g/kg IV over 20 minutes as the primary osmotic agent; this can be repeated every 6 hours with a usual maximum dose of 2 g/kg. 4, 2, 5

• Expect maximal effect within 10–15 minutes and duration of 2–4 hours; monitor for complications including intravascular volume depletion, renal failure, and rebound intracranial hypertension with repeated dosing. 3, 5

• Hypertonic saline (3% or 23.4%) at equiosmotic doses (~250 mOsm) is equally effective to mannitol and is preferred when hypovolemia, hypotension, or hypernatremia are concerns. 2, 3

• In patients with established anuria or severe renal disease, avoid mannitol and switch to hypertonic saline as the primary osmotic agent. 2

Cerebral Perfusion Pressure Management

• Maintain CPP between 60–70 mmHg (CPP = Mean Arterial Pressure − ICP) to ensure adequate cerebral blood flow; CPP below 60 mmHg is associated with cerebral ischemia and worse outcomes. 1, 2, 3

• Use norepinephrine infusion to sustain mean arterial pressure and maintain CPP within the target range. 3

• Avoid antihypertensive agents that cause cerebral vasodilation (e.g., nitroprusside, nitroglycerin), as they can exacerbate intracranial hypertension. 4, 1

• Never lower systemic blood pressure in an attempt to reduce ICP, as this compromises CPP and worsens cerebral ischemia. 3

Ventilation Strategy

• Maintain PaCO₂ between 35–40 mmHg; avoid prophylactic hyperventilation except as an emergency measure for life-threatening ICP spikes or imminent herniation. 1, 3

• Prolonged hyperventilation (PaCO₂ < 25 mmHg) causes cerebral vasoconstriction and ischemia, worsening neurological outcomes. 3, 6

• Correct hypoxemia and hypercarbia through proper airway management, as both exacerbate cerebral edema. 4, 2

Temperature and Metabolic Control

• Maintain normothermia and treat fever aggressively, as hyperthermia worsens cerebral edema. 2

• Minimize emotional stimulation (e.g., family visits) that can increase ICP through sympathetic activation and heightened cerebral metabolic demand; manage with appropriate sedation if necessary. 3

Surgical and Advanced Interventions

• External ventricular drainage (EVD) is the most effective intervention for persistent intracranial hypertension when hydrocephalus is present; drainage of small volumes of CSF can markedly reduce ICP. 4, 2

• Consider decompressive craniectomy for refractory ICP despite maximal medical therapy; this should be discussed in a multidisciplinary setting and performed without undue delay once indicated. 4, 2

• For cerebellar swelling, perform decompressive suboccipital craniectomy to remove necrotic tissue. 4

• Removal of symptomatic extradural hematoma, significant acute subdural hematoma (thickness >5 mm with midline shift >5 mm), or brain contusions with mass effect are additional surgical options. 4

Agents and Interventions to Avoid

• Do not use corticosteroids for ICP management in traumatic brain injury, intracerebral hemorrhage, or ischemic stroke, as they are ineffective and potentially harmful. 4, 3

• Avoid prophylactic neuromuscular blockade; it does not improve outcomes, increases risk of pneumonia and sepsis, and masks seizure activity. Reserve neuromuscular blockade only for patients who remain agitated or have uncontrolled ICP despite optimal analgesia and sedation. 1

• Do not use barbiturates as first-line sedatives; high-dose barbiturate therapy (e.g., pentobarbital) should be reserved only for refractory intracranial hypertension after failure of all other measures, recognizing substantial risks of cardiovascular depression, prolonged coma, and hypotension. 1, 7

ICP Monitoring

• Place an intraparenchymal fiberoptic monitor or ventricular catheter in patients at risk of elevated ICP based on clinical and imaging features; these are the most accurate and reliable instruments. 2, 6

• ICP >20–25 mmHg is generally considered elevated and warrants treatment. 4, 2

• Use transcranial Doppler to assess mass effect and track ICP changes noninvasively. 3

Critical Pitfalls

• Over-sedation can obscure neurological assessment and mask clinical deterioration or seizure activity; balance sedation depth with the ability to perform serial examinations. 1

• Failure to maintain CPP >60 mmHg while attempting to lower ICP can lead to cerebral ischemia even when ICP values appear controlled; the therapeutic goal is adequate perfusion, not merely an ICP <20 mmHg. 1, 3

• Restrict free water to avoid hypo-osmolar fluid that may worsen edema. 4