Long-term facilitation of ventilation following acute continuous hypoxia in awake humans during sustained hypercapnia

Key points • In awake humans, when CO(2) is maintained above normal levels, exposure to acute intermittent hypoxia causes a sustained elevation in ventilation that persists when normoxic breathing is resumed. • In this study we have demonstrated that when CO(2) is maintained above normal levels, exposure to acute continuous hypoxia also causes a sustained elevation in ventilation when normoxic breathing is resumed. • This sustained elevation in ventilation following both acute intermittent hypoxia and acute continuous hypoxia is maintained by mechanisms other than increased activity of the carotid body. • These results help develop our understanding of respiratory control in humans and may aid future development of treatments for respiratory control disorders, such as obstructive sleep apnoea.