gas volume–related issues during air transport For the reasons noted above, hypoxia can also be a major issue This can usually be overcome with addition of 100% FiO2 —unless the patient’s baseline is hypoxia at lower altitudes while on 100% oxygen Positive end-expiratory pressure is usually not effective in reversing the hypoxemia that occurs secondary to an increase in altitude Most air transports, however, not reach an altitude or experience barometric pressure changes that will greatly influence the patient’s care Helicopter transport routinely occurs at 1,000 ft or less above ground level, although this may not be the case in mountainous regions where traversing high-altitude peaks may be necessary or when operating under Instrument Flight Rules (IFR) FW transport aircraft are usually pressurized, meaning that they can simulate the atmospheric pressure of a lower environment Air pressure in these aircraft is often set at a level of 5,000 to 8,000 ft, which can, however, still lead to a significant increase in gas volume Opportunities for achieving higher ambient pressure (lower altitude pressure) may be available, depending on the limitations of the particular aircraft If an aircraft cannot be pressurized to a higher pressure, one can consider flying at a lower altitude Trade-offs include increased turbulence, speed restrictions, and increased fuel consumption