Pulmonary Artery Pressure Response to Simulated Air Travel in a Hypobaric Chamber.

BACKGROUND: Hypoxia-induced elevation in pulmonary artery pressure during air travel may contribute to the worldwide burden of in-flight medical emergencies. The pulmonary artery pressure response may be greater in older passengers, who are more likely to require flight diversion due to a medical event. Understanding these effects may ultimately improve the safety of air travel. METHODS: We studied 16 healthy volunteers, consisting of a younger group (aged <25 yr) and an older group (aged >60 yr). Using a hypobaric chamber, subjects undertook a 2-h simulated flight at the maximum cabin pressure altitude for commercial airline flights (8000 ft; 2438 m). Higher and lower altitudes within the aeromedical range were also explored. Systolic pulmonary artery pressure (sPAP) was assessed by Doppler echocardiography. RESULTS: There was a progressive increase in sPAP which appeared to be biphasic, with a small initial increase and a larger subsequent rise. Overall, sPAP increased by 5±1 mmHg from baseline to 35±1 mmHg at 8000 ft, an increase of 18%. The sPAP response to 8000 ft was greater in the older group than the younger group. CONCLUSIONS: This study confirms that pulmonary artery pressure increases during simulated air travel, and provides preliminary evidence that this response is greater in older people. Advancing age may increase in-flight susceptibility to adverse pulmonary vascular responses in passengers, aircrew, and aeromedical patients.

A 5-year review of atrial fibrillation in military aircrew.

INTRODUCTION: Atrial fibrillation (AF) is a common cause of disqualification from flying in both civilian and military aircrew. We reviewed 5 yr of atrial fibrillation management in the Royal Air Force (RAF) from both a clinical and occupational perspective. METHODS: Patients were identified from the RAF Medical Boards (RAFMB) electronic database using search terms "atrial," "fibrillation," and "arrhythmia." Management was compared to current RAF and national clinical guidelines and current civilian and military aviation medicine policy. RESULTS: Over the 5-yr period assessed, 23 aircrew were identified with AF. Paroxysmal AF (PAF) was the most common diagnosis. Five aircrew remained fit to fly with no limitations, 12 fit to fly with restrictions, and 6 were graded permanently unfit for flying, with one of these being medically discharged. DISCUSSION: The incidence and demographics of aircrew identified with AF in this paper is comparable to previous studies. All aircrew in our study were treated in accordance with current RAF/national guidelines. Emerging treatments such as radiofrequency ablation and the new anticoagulants remain to be assessed for suitability in a military context. CONCLUSION: Management of AF in RAF aircrew requires a holistic approach, with an awareness of the arrhythmogenic aviation environment in which RAF aircrew operate. Most RAF aircrew with AF will retain a restricted flying status, but this should be considered on a case-by-case basis.