This article discusses the physiology of altitude exposure, the current state of knowledge in children and adults with PAH, and provides a balanced overview of the latest recommendations for safe travel in pediatric PAH.
Cardiopulmonary response to high altitudeWith increasing altitude, barometric pressure, air temperature and air humidity decrease. As a consequence, the inspired oxygen partial pressure and the alveolar oxygen pressure decline in an exponential fashion (1-3) (Figure 1). At sea level, oxygen constitutes 21% of inspired air, which