Figure 1From: Long-term gas exchange characteristics as markers of deterioration in patients with cystic fibrosis Annual changes of gas exchange characteristics (PaO 2 , PaCO 2 ) shown as mean ± SEM of repeated annual measurements over the age range 5 to 18 years (halftone symbols), stratified into measurements concomitantly obtained under normal FEV 1 > -2 SDS (open symbols) and abnormal, FEV 1 < -2 SDS solid symbols. Measurement numbers (n) are given along the x-axis.Back to article page