Management of Suspected Intracranial Hypertension with Impending Herniation in Children
The most appropriate initial step is to immediately elevate the head of the bed to 30 degrees, ensure the neck is in neutral position, and administer hyperosmolar therapy (mannitol 0.25-1 g/kg IV over 20-30 minutes or hypertonic saline 250 mOsm over 15-20 minutes) while simultaneously performing brief hyperventilation (target PaCO₂ approximately 30 mmHg) only as a temporizing rescue measure for signs of impending herniation. 1, 2, 3
Immediate Airway and Breathing Management
Secure the airway immediately if the child shows signs of impending herniation (dilated pupils, bradycardia, hypertension, or rapidly deteriorating neurological status), as airway compromise can lead to hypoxia which dramatically worsens outcomes. 1, 2
Maintain oxygen saturation ≥94% (target PaO₂ ≥98 mmHg) to prevent hypoxic secondary injury, as even brief periods of hypoxia can exacerbate brain damage. 1, 2
Institute brief hyperventilation (target PaCO₂ approximately 30 mmHg) using bag-valve-mask ventilation only as a short-term rescue measure for signs of impending herniation, as prolonged hyperventilation can worsen cerebral ischemia through excessive vasoconstriction. 1, 2, 3
Critical Positioning Maneuvers
Elevate the head of the bed to 30 degrees immediately to optimize cerebral perfusion while minimizing intracranial pressure and facilitating venous drainage. 1, 2, 4
Ensure neutral head and neck position to prevent obstruction of venous drainage, which can exacerbate intracranial hypertension. 1, 2
Hyperosmolar Therapy (First-Line Medical Intervention)
Administer mannitol 20% at 0.25-1 g/kg IV over 20-30 minutes OR hypertonic saline at 250 mOsm over 15-20 minutes to treat threatened intracranial hypertension or signs of brain herniation. 1, 5, 3
Osmotherapy produces maximum ICP reduction after 10-15 minutes with effects lasting 2-4 hours, making it the cornerstone of acute medical management. 1
At equiosmotic doses, mannitol and hypertonic saline have comparable efficacy; mannitol induces osmotic diuresis requiring volume compensation, while hypertonic saline causes hypernatremia and hyperchloremia. 1
Include a filter in the administration set when infusing 25% mannitol and do not infuse if crystals are present. 5
Hemodynamic Support
Maintain systolic blood pressure >110 mmHg (or mean arterial pressure >80 mmHg) to ensure adequate cerebral perfusion pressure, as hypotension combined with hypoxemia carries approximately 75% mortality. 1
Target cerebral perfusion pressure (CPP) between 60-70 mmHg when multimodal monitoring is unavailable, as CPP below 60 mmHg is associated with poor neurological outcomes. 1, 6
Administer vasopressors if needed to maintain blood pressure targets and adequate cerebral perfusion. 1
Surgical Considerations
Obtain urgent neurosurgical consultation for decompressive craniectomy, which is suggested to treat neurologic deterioration, herniation, or intracranial hypertension refractory to medical management. 7
The Brain Trauma Foundation guidelines (2019) specifically recommend decompressive craniectomy for these indications in pediatric patients with severe traumatic brain injury. 7
Critical Pitfalls to Avoid
Never delay treatment while waiting for neuroimaging in a child with clear signs of impending herniation—begin medical management immediately. 1, 2
Do not use prolonged hyperventilation as routine ICP management; it should only be used briefly for impending herniation as it may worsen cerebral ischemia. 1, 3
Avoid corticosteroids for ICP control, as they are not suggested to improve outcome or reduce ICP in pediatric severe traumatic brain injury. 7
Do not allow even brief periods of hypoxia or hypotension, as these dramatically worsen outcomes, particularly when combined. 1
Monitoring Requirements
Monitor serum sodium and potassium carefully during mannitol administration, as electrolyte imbalances can occur. 5
Assess for signs of increased ICP including pupillary changes, Cushing's triad (bradycardia, hypertension, irregular respirations), and deteriorating level of consciousness. 2, 8
When high-dose barbiturate therapy is used for refractory intracranial hypertension (after maximal medical and surgical management), continuous arterial blood pressure monitoring and cardiovascular support are required because cardiorespiratory instability is common. 7