Sickle cell disease and commercial aviation. A retrospective analysis of in-flight and pre-flight medical events.

The cabin of an aircraft while at cruising altitude is a hypobaric hypoxic environment. The hypoxic nature of this environment may predispose sickle cell disease (SCD) passengers to vaso-occlusive episodes (VOEs). Evidence on pre-flight and in-flight events related to SCD is limited. A retrospective analysis was undertaken of records from a ground-based medical support (GBMS) provider (1.1.22-1.10.24) for pre-flight and in-flight events relating to SCD. Passenger demographics, presenting features, oxygen/analgesia use and flight characteristics were extracted. 84 pre-flight and 76 in-flight SCD-related cases were identified and analysed. Pre-flight, 73% (n = 61) were cleared to fly. 33% (n = 28) reported current symptoms or recent symptoms (≤10 days) and 31% sought oxygen for the flight/portable oxygen concentrator clearance. In-flight, analgesia was provided in 49% (non-narcotic in 37% and narcotic in 12%) of all cases. One diversion occurred (due to suspected stroke). No events were seen relating to departures from airports of high elevation. SCD-related events before or during air travel were uncommon, and current measures appear to be appropriate in the prevention of diversion.