From the Guidelines
To manage changes in intracranial pressure (ICP) and cerebral perfusion during high elevation travel and flight, a balanced approach is recommended, focusing on gradual acclimatization, prophylactic medications, and careful monitoring. When traveling to high elevations, gradual acclimatization is crucial, allowing 1-2 days at intermediate altitudes before ascending further 1. For individuals with known intracranial pathology or recent neurosurgery, consider prophylactic medications like acetazolamide (Diamox) at 125-250mg twice daily, starting 24 hours before ascent and continuing for 48 hours after reaching high altitude. Dexamethasone 4mg every 6 hours can be used for those at high risk of cerebral edema.
During air travel, patients with increased ICP should ensure adequate hydration, avoid alcohol and sedatives, and consider supplemental oxygen if necessary. Those with recent neurosurgical interventions should typically wait 2-4 weeks before flying, depending on the procedure. The medications work by improving ventilation, reducing cerebrospinal fluid production, and decreasing inflammation and vascular permeability, thereby helping maintain appropriate cerebral perfusion pressure despite environmental challenges. It's essential to note that the exact frequency of increased ICP in patients with intracranial hemorrhage is not known, and a balanced approach to ICP management should be tailored to each patient's specific needs, with appropriate monitoring safeguards in a critical care unit 1.
Some key considerations for managing ICP and cerebral perfusion during high elevation travel and flight include:
- Gradual acclimatization to high elevations
- Prophylactic medications for those with known intracranial pathology or recent neurosurgery
- Careful monitoring of ICP and cerebral perfusion pressure
- Avoidance of alcohol and sedatives during air travel
- Consideration of supplemental oxygen if necessary
- Delayed air travel for those with recent neurosurgical interventions.
The goal of these recommendations is to minimize the risk of increased ICP and cerebral hypoxia during high elevation travel and flight, thereby reducing the risk of morbidity and mortality. By taking a balanced and individualized approach to ICP management, patients with intracranial pathology or recent neurosurgery can safely travel to high elevations and participate in air travel.
From the Research
Changes in Intracranial Pressure and Cerebral Perfusion
- High-altitude travel can lead to changes in intracranial pressure (ICP) and cerebral perfusion due to hypoxia and hypoxemia 2, 3.
- Rapid ascent to high altitude can result in high altitude headache, acute mountain sickness, and less commonly, high altitude cerebral or pulmonary edema 2.
- Direct and indirect measures of ICP usually demonstrate a rise in pressure when human subjects and animals are exposed to acute hypoxia 2.
Managing Changes in ICP and Cerebral Perfusion
- Medical advice for travelers to high altitudes should be based on an assessment of the risk of illness in relation to the intended altitude profile of the trip, in consideration of the prospective traveler's suitability for high altitudes and individual susceptibility to high-altitude-related illnesses 4.
- The symptoms and treatment of high-altitude-related illnesses should be thoroughly explained to prospective travelers 4.
- Effective preparation options for air travel to high altitude include the use of modern pre-acclimatization strategies and pharmacological prophylaxis by acetazolamide or dexamethasone, or even considering alternate itineraries with more gradual ascent 5.
- Monitoring ICP and cerebral perfusion pressure can play a role in guiding therapy in select patients, particularly those with elevated ICP that fails to respond to treatment 6.
Recommendations for High Elevation Travel and Flight
- Prospective travelers should seek medical advice before traveling to high altitudes, especially if they have preexisting illnesses or are at risk for high-altitude-related illnesses 4, 5.
- Travelers should be aware of the risks of acute mountain sickness and take steps to prevent it, such as gradual ascent and pre-acclimatization strategies 5.
- In cases where ICP monitoring is necessary, the technique used should be similar to that used in traumatic brain injury, with indications for ICP monitoring often intertwined with the presence of obstructive hydrocephalus 6.