Table 5 Emergency management in patients with elevated intracranial pressure and signs of impending or de facto cerebral herniation

1) Positioning:

• Elevate head of bed to 30^o, adjust or remove jugular obstruction, and maintain head in neutral position

• Facilitates venous blood drainage

2) Securing airway and hyperventilation:

• Intubate for airway protection and hyperventilation

• Establish a secure airway to allow the physician to identify and treat apnea quickly

• Hyperventilation reduces pCO₂, a potent cerebral vasodilator, and decreases cerebral blood volume. Over-aggressive hyperventilation should be avoided as it may critically decrease CBF and lead to ischemia/stroke

• Hyperventilation has a fast onset and is effective for lowering high ICP, but its effect only lasts for a short duration and may be harmful if applied aggressively

3) Neuromuscular paralysis:

• Facilitates intubation and prevents shivering

4) Fluid management:

• Monitor fluid balance, body weight, serum electrolytes, and serum osmolality

• Correct electrolyte disturbances and maintain euvolemia by giving isotonic (0.9%) saline

• Avoid free water including D5W, half normal (0.45%) saline, and enteral free water

• Serum osmolality should be kept > 280 mOsm/L (it is often kept in the 295 to 305 mOsm/L range)

5) BP control:

• Maintain BP, minimize large shifts in BP, and avoid hypotension (may lead to ischemia)

• BP should be sufficient to maintain CPP > 60 mmHg

• Vasopressors and inotropes (e.g., dopamine or norepinephrine) can be used to increase MAP and achieve optimal CPP

6) Sedation:

• Titrate propofol to a Ramsay score of 4. Do not exceed 5 mg/kg/h for more than 24 h. If maximum dose of propofol is reached while ICP > 20 mmHg, fentanyl drip can be started

• Reduces metabolic demand, ventilator asynchrony, venous congestion, and the sympathetic responses of hypertension and tachycardia

7) Maintain normothermia and treat temperature > 37.5 ^oC by giving antipyretic agents (e.g., acetaminophen)

8) Hyperosmolar therapy (mannitol or hypertonic saline):

• Give mannitol at dose of 1 g/kg IV for rapid reduction of ICP. Monitor fluids and electrolytes every 4 h (twice after each bolus)

• Hypertonic saline can be alternatively used to maintain hyperosmolarity and rapidly reduce ICP. It may be effective when mannitol is not. It needs central line placement for administration. Adverse effects: congestive heart failure, hyperchloremic acidemia, hypernatremia, and seizures

9) Glucocorticoids:

• Give dexamethasone (10–20 mg IV) followed by maintenance dose of 4–6 mg every 4–6 h

• Reduces cerebral vasogenic edema

• Adverse effects: hyperglycemia, insomnia, immunosuppression, mood fluctuations, myopathy, Cushing syndrome

10) Head CT as soon as possible. Moderate hyperventilation is advisable during transport and initial evaluation

11) Barbiturate coma therapy for refractory intracranial hypertension:

• Pentobarbital is generally used with a loading dose of 5 to 20 mg/kg as bolus, followed by 1–4 mg/kg/h

• Continuous EEG monitoring with EEG burst suppression as a guide to optimal dosage

• Additional boluses can be given during infusion for acute spikes in ICP

• Moderate doses cause sluggish pupils; large doses cause 3–5 mm nonreactive pupils

• Watch for hypotension

• Treatment should be assessed based on ICP and CPP response and development of unacceptable side effects

12) ICP monitoring:

• Performed when GCS < 8 with signs of elevated ICP on CT scan

• Ventriculostomy performed to drain CSF in case of hydrocephalus, and to monitor ICP

13) Surgical management:

• Resection of space-occupying lesion

• Decompressive craniectomy

• Trephination