Introduction Flight has become an integral part of modern life: 65.9 million passengers used Heathrow airport in 2009.1 Flight, however, exposes us to a unique environment with a reduced FiO2−, increased humidity and relative immobility. Although guidelines have been published,2 there are relatively limited published data regarding flight safety. Patients with particular conditions may provide high risk models for the general population regarding the safety of the flight environment. Here we report the results of a questionnaire-based study in individuals with hereditary haemorrhagic telangiectasia (HHT), a condition that leads to recurrent nosebleeds, but more importantly for respiratory physicians, frequent pulmonary arteriovenous malformations (PAVMs) that result in a right to left shunt, hypoxaemia, and risk of paradoxical embolic stroke.3
Methods PubMed searches identified no studies into the effect of flight in HHT or PAVM patients. With ethical approval (NRES 10/H0806/8), patients with definite HHT who had attended our hospital's HHT clinic, were sent a questionnaire. Participants were asked to document flights they had taken, and to list any symptoms they experienced during or shortly afterwards. Responses were correlated with physiological variables in their hospital records.
Results 156 replies were received from 308 questionnaires (response rate 50.6%). 145 individuals (95 [65%] with pulmonary AVMs), had flown, reporting 18 943 flight hours in 3950 flights. The median number of flights per patient was 17 short haul, and 8 long haul. There was no difference in erect SaO2 between those who reported breathlessness and those who did not (median 93 (range 85–96)% vs median 94 (84–99)% respectively. Individuals who reported breathlessness stated that in-flight oxygen was of benefit (Abstract P37 Table 1).
Conclusion These data suggest that even in a population group expected to be more susceptible to complications, flying appeared safe for the vast majority of individuals. A minority of HHT patients did experience adverse symptoms. These were difficult to predict based on clinic measurements.