The effect of hypoxia on cognitive performance in patients with chronic obstructive pulmonary disease

Air travel may cause significant hypoxia in passengers with chronic obstructive pulmonary disease (COPD). It is not known whether this level of hypoxia will cause impairment in cognitive function. The aim of this study was to determine the effect of hypoxia on cognitive performance in patients with COPD when PaO2PaO2 was decreased <6.6 kPa. In ten patients with moderate to severe COPD trail making tasks and complex figure tasks were used to assess cognitive performance when the patients breathed 21% O2, and when PaO2PaO2 was decreased to <6.6 kPa. During administration of 21% O2, PaO2PaO2 was 9.5 (8.9–10.2) kPa. When SpO2SpO2 was decreased to 85% via manipulation of the FIO2FIO2 (inspired fraction of oxygen) PaO2PaO2, decreased to 6.1 (5.9–6.2) kPa. No short term deterioration in visual search, mental flexibility or visuospatial constructional ability was detected when PaO2PaO2 was decreased to <6.6 kPa. The results show that short term exposure to hypoxia had no adverse effect on cognitive function.