Effects of high-dose supplemental oxygen therapy on pulmonary haemodynamics at 3250 m in high-altitude residents at risk for pulmonary hypertension

Hypoxic pulmonary vasoconstriction increases systolic pulmonary artery pressure (sPAP) and may contribute to high-altitude pulmonary hypertension (HAPH). While supplemental oxygen therapy (SOT) lowers sPAP during acute hypoxic exposure, its haemodynamic effects in permanent high-altitude residents remain unclear. In particular, the relative contribution of fixed vascular remodelling to chronically elevated sPAP is uncertain.

In this open-label, non-randomised, sequential interventional trial, Kyrgyz highlanders living >2500 m with tricuspid regurgitation velocity >2.8 m/s underwent echocardiography under ambient air and after >15 min of high-dose SOT (FiO₂≈0.95, 10 L/min) at 3250 m.