What is the management plan for a patient with intracranial hypertension (increased intracranial pressure, ICP)?

Management of Intracranial Hypertension

Elevate the head of bed to 20-30 degrees with neck in neutral midline position, maintain cerebral perfusion pressure (CPP) 60-70 mmHg, and administer mannitol 0.5-1 g/kg IV over 5-10 minutes for ICP >20-25 mmHg, while immediately consulting neurosurgery for potentially operable lesions. 1, 2

Immediate Assessment and Monitoring

Clinical Recognition

• Obtain emergent non-contrast CT head as first-line imaging to identify hemorrhage, mass lesions, hydrocephalus, midline shift >5mm, and signs of herniation 1
• Look specifically for ventricular effacement, loss of basal cisterns, and cerebral edema as indicators of elevated ICP 1
• Assess consciousness using Glasgow Coma Scale (GCS); ICP monitoring should be considered for patients with GCS ≤8 or clinical signs of herniation 1, 2

ICP Monitoring Indications

• Place ventricular catheter (external ventricular drain) as preferred monitoring device when safe and practical, as it allows both ICP measurement and therapeutic CSF drainage 2
• Intraparenchymal fiberoptic monitors are alternative when ventricular access is not feasible 3, 2
• Before inserting monitoring device, evaluate coagulation status and consider platelet transfusion for antiplatelet therapy history, plus reversal for warfarin patients 2
• ICP >20-25 mmHg is generally considered elevated and requires aggressive therapy 2, 4

Tier 1: Basic Management (First-Line Interventions)

Positioning and General Measures

• Elevate head of bed to 20-30 degrees with neck in neutral midline position to improve jugular venous outflow 1, 2
• Never allow neck rotation or flexion, as this directly obstructs internal jugular vein drainage and raises ICP 1
• Avoid tight cervical collars or neck dressings that may compress the internal jugular vein 1
• Ensure patient is not hypovolemic before head elevation, as this can decrease CPP 2

Physiological Targets

• Maintain CPP between 60-70 mmHg; avoid CPP <60 mmHg which is associated with cerebral ischemia and poor outcomes 1, 2, 4
• Ensure adequate oxygenation and avoid hypoxemia, hypercarbia, and hyperthermia, as these worsen ICP 1, 2
• Maintain controlled normothermia (36.0-37.5°C) as hyperthermia independently worsens intracranial hypertension 1

Sedation and Analgesia

• Provide adequate sedation to prevent coughing, agitation, or Valsalva maneuvers that increase intrathoracic pressure and worsen ICP 2
• Daily interruption of sedation may be deleterious to cerebral hemodynamics in patients with signs of high ICP 2

CSF Drainage

• Drain CSF through ventricular catheter for patients with hydrocephalus as an effective first-line intervention 2

Tier 2: Osmotic Therapy

Mannitol Administration

• Administer mannitol 0.5-1 g/kg IV infused rapidly over 5-10 minutes as first-line osmotic therapy 2, 5
• Maximum effect occurs within 10-15 minutes with duration of 2-4 hours 2
• Maximum dose is 2 g/kg 1
• Monitor for complications including intravascular volume depletion, renal failure, and rebound intracranial hypertension with repeated administration 3, 2, 5
• Avoid concomitant administration of nephrotoxic drugs (e.g., aminoglycosides) or other diuretics with mannitol 5
• When infusing 25% mannitol, the administration set should include a filter 5

Hypertonic Saline

• Hypertonic saline (3%) provides rapid ICP reduction and may be superior to mannitol in some cases 1, 2

Tier 3: Controlled Hyperventilation

Ventilation Strategy

• Moderate hyperventilation (PaCO₂ 26-30 mmHg) may be used for elevated ICP 2, 6
• Do not use prophylactic hyperventilation, as excessive hypocapnia (PaCO₂ <25 mmHg) causes cerebral vasoconstriction and may worsen ischemia 1, 2
• Hyperventilation should be limited to emergency management of life-threatening raised ICP 7

Surgical Interventions

Neurosurgical Consultation

• Neurosurgical consultation is mandatory for potentially operable lesions such as hematoma evacuation, tumor resection, or abscess drainage 1, 2
• External ventricular drain placement for hydrocephalus provides both diagnostic and therapeutic benefits 1, 2
• Decompressive craniectomy may be life-saving for malignant cerebral edema refractory to medical management 1, 2

Critical Pitfalls to Avoid

Contraindicated Interventions

• Do not perform lumbar puncture before neuroimaging in patients with suspected elevated ICP, as this can precipitate herniation 1
• Avoid corticosteroids for ICP management in intracerebral hemorrhage or ischemic stroke, as they are ineffective and potentially harmful 3, 1
• Avoid hypotonic fluids and excessive glucose administration, which can worsen cerebral edema 1

Monitoring for Complications

• Discontinue mannitol if renal, cardiac, or pulmonary status worsens, or CNS toxicity develops 1
• Monitor serum sodium and potassium carefully during mannitol administration 5
• Mannitol may increase cerebral blood flow and worsen intracranial hypertension in children who develop generalized cerebral hyperemia during the first 24-48 hours post-injury 5

Prognostic Considerations

ICP Thresholds and Outcomes

• ICP 20-40 mmHg is associated with 3.95-fold increased risk of mortality 2
• ICP >40 mmHg increases mortality risk 6.9-fold and is almost universally associated with severe consciousness impairment or coma 2
• Cushing's reflex (hypertension, bradycardia, respiratory irregularity) indicates severe intracranial hypertension with ICP typically >40 mmHg requiring emergent neurosurgical evaluation 2

Advanced Therapies for Refractory ICP

Second-Tier Options

• High-dose barbiturate therapy (pentobarbital) for ICP refractory to maximum standard medical treatment 2, 7, 8
• Therapeutic hypothermia (32-35°C) should be considered only for refractory intracranial hypertension that fails standard medical treatments 1, 7
• Systemic cooling to 34°C can be effective but is associated with pulmonary, infectious, coagulation, and electrolyte complications, plus significant rebound ICP when reversed 3