Fig. 3

Partial pressure of oxygen (PaO2) in KPa from arterial blood gases taken at baseline and after 30 min with mask. error bars = 95% confidence interval of the mean. *** = p value < .001 from paired t-test
Partial pressure of oxygen (PaO2) in KPa from arterial blood gases taken at baseline and after 30 min with mask. error bars = 95% confidence interval of the mean. *** = p value < .001 from paired t-test