This study will screen all consecutive intubated patients transported by pressurized fixed wing aircraft and unpressurized rotor wing aircraft. Patients will be screened beginning July 1, 2011 and ending when the requisite number of patients have been receuited on each aircraft type. Patients will be eligible if they are adult (actual or estimated age >18 years), undergoing interfacility patient transfer, intubated with a cuffed tracheal tube and mechanically ventilated prior to transport, transported by an Ornge's dedicated aircraft and flight paramedic crew, with a planned flight of >20 minutes (rotor wing) or >30 minutes (fixed wing). Patients are excluded if they do not meet all inclusion criteria or have any condition that requires a cabin altitude of <1000 feet to prevent barotrauma. For ineligible patients, paramedics will submit the completed screening tool and copy of the patient care report to the research coordinator. Investigators will retrospectively review dispatch records to identify intubated patients who were transported to determine the total patient population eligible for this study. Planned flight times of >20 minutes (rotor wing) and >30 minutes (fixed wing) were selected because review of records for flights of lesser duration would not typically have enough time at cruising altitude to stabilize cabin pressure, equilibrate tracheal tube cuff pressure, and complete the in-flight portion of this protocol.