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 the 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 as first-line osmotic therapy for ICP >20-25 mmHg. 1, 2

Immediate Assessment and Monitoring

Clinical Recognition

• Look for declining consciousness, focal neurological deficits, abnormal pupillary responses, and abnormal posturing—these constitute a medical emergency requiring immediate intervention 3
• Severe headache worsening with Valsalva maneuvers, projectile vomiting without preceding nausea, and visual disturbances (blurred vision, diplopia) are common presenting symptoms 3
• Cushing's reflex (hypertension, bradycardia, respiratory irregularity) indicates severe intracranial hypertension with ICP typically >40 mmHg and requires emergent neurosurgical evaluation 2
• ICP 20-40 mmHg increases mortality risk 3.95-fold, while ICP >40 mmHg increases mortality 6.9-fold and is almost universally associated with severe consciousness impairment or coma 2

Diagnostic Imaging

• Obtain emergent non-contrast CT head immediately to identify hemorrhage, mass lesions, hydrocephalus, midline shift >5mm, and signs of herniation 1
• Look specifically for ventricular effacement, loss of basal cisterns, cerebral edema, and compression of basal cisterns as indicators of elevated ICP 1, 3
• Follow with MRI with contrast and MR venography if CT is non-diagnostic to evaluate for venous thrombosis, posterior fossa lesions, or small masses 1

ICP Monitoring Indications

• Insert ICP monitoring device (ventricular catheter or intraparenchymal probe) for patients with Glasgow Coma Scale ≤8, clinical evidence of herniation, or significant hydrocephalus 1, 2
• Ventricular catheters (external ventricular drains) are preferred over parenchymal monitors when safe and practical, as they allow both ICP monitoring and therapeutic CSF drainage 2
• Before inserting monitoring devices, evaluate coagulation status and consider platelet transfusion for patients on antiplatelet therapy and reversal for those on warfarin 2

Tier 1: Basic Management Measures

Head Positioning and Venous Drainage

• 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 drop blood pressure and worsen CPP 1, 2

Cerebral Perfusion Pressure Management

• Maintain CPP between 60-70 mmHg; avoid CPP <60 mmHg which is associated with cerebral ischemia and poor outcomes 1, 2
• Target CPP ≥60 mmHg at all head positions by managing blood pressure appropriately 1
• Avoid CPP >90 mmHg which may worsen vasogenic edema and paradoxically increase ICP 2

General Neuroprotective Measures

• 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
• Provide adequate analgesia and sedation to prevent coughing, agitation, or Valsalva maneuvers that increase intrathoracic pressure and worsen ICP 2
• Drain CSF through ventricular catheter if hydrocephalus is present 2

Tier 2: Osmotic Therapy

Mannitol Administration

• Administer mannitol 0.5-1 g/kg IV rapidly over 5-10 minutes as first-line osmotic therapy 2, 4
• Maximum effect occurs within 10-15 minutes with duration of 2-4 hours 2, 4
• For adults with elevated ICP, use 0.25-2 g/kg body weight as a 15-25% solution administered over 30-60 minutes 4
• For pediatric patients, use 1-2 g/kg body weight or 30-60 g/m² body surface area over 30-60 minutes 4
• For small or debilitated patients, use 500 mg/kg 4

Mannitol Monitoring and Complications

• Monitor for intravascular volume depletion, renal failure, and rebound intracranial hypertension with repeated dosing 5, 2, 4
• Avoid concomitant administration of nephrotoxic drugs or other diuretics with mannitol 4
• Discontinue mannitol if renal, cardiac, or pulmonary status worsens 4

Hypertonic Saline Alternative

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

Tier 3: Controlled Hyperventilation

• Use moderate hyperventilation (PaCO₂ 26-30 mmHg) only as a temporizing measure 2
• Do not use prophylactic hyperventilation, as excessive hypocapnia causes cerebral vasoconstriction and may worsen ischemia 1, 2
• Hyperventilation should be limited to emergency management of life-threatening raised ICP 5

Surgical Interventions

Mandatory Neurosurgical Consultation

• Obtain immediate neurosurgical consultation for potentially operable lesions: hematoma evacuation, tumor resection, or abscess drainage 1, 2
• External ventricular drain placement for hydrocephalus provides both diagnostic and therapeutic benefit 1, 2
• Decompressive craniectomy may be life-saving for malignant cerebral edema refractory to medical management, though it may result in more patients with poor neurological outcomes 1, 2

Critical Pitfalls to Avoid

• 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 1, 2
• Do not add mannitol to whole blood for transfusion 4
• Avoid hypotonic fluids and excessive glucose administration, which can worsen cerebral edema 1
• Daily interruption of sedation may be deleterious to cerebral hemodynamics in patients with signs of high ICP 2

Monitoring Parameters and Treatment Targets

• ICP >20-25 mmHg is generally considered elevated and requires aggressive therapy 2
• Monitor transcranial Doppler for decreased diastolic velocity and increased pulsatility index, which indicate elevated ICP 5, 2
• Discontinue treatment if renal, cardiac, or pulmonary status worsens, or if CNS toxicity develops 4