1. Tadalafil in patients with chronic obstructive pulmonary disease: a randomised, double- blind, parallel-group, placebo-controlled trial 
Dr Andrew R Goudie, MD, Prof Brian J Lipworth, MD, Pippa J Hopkinson, Li Wei, PhD, Prof Allan D Struthers, MD 
The Lancet Respiratory Medicine 
Volume 2, Issue 4, Pages (April 2014)
DOI: /S (14)70013-X
Copyright © 2014 Elsevier Ltd Terms and Conditions

2. Figure 1
Trial profile
*Ruptured abdominal aortic aneurysm; ventilator-associated pneumonia after exacerbation of chronic obstructive pulmonary disease. †Admitted to hospital.
The Lancet Respiratory Medicine 2014 2, DOI: ( /S (14)70013-X)
Copyright © 2014 Elsevier Ltd Terms and Conditions

3. Figure 2 Mean change in 6MWD between groups over time
Error bars 95% CIs. 6MWD=6 min walking distance.
The Lancet Respiratory Medicine 2014 2, DOI: ( /S (14)70013-X)
Copyright © 2014 Elsevier Ltd Terms and Conditions

4. Figure 3 Effects of one 50 mg dose of sildenafil on SpO2 over time
n=120. SpO2=peripheral oxygen saturations.
The Lancet Respiratory Medicine 2014 2, DOI: ( /S (14)70013-X)
Copyright © 2014 Elsevier Ltd Terms and Conditions