Table 2

Effects of pre-breathing oxygen and air on 6 minute walk distance, oxygen saturation, breathlessness, and recovery time in 34 patients with COPD

OxygenAirMean differencep value95% CI
Values are mean (SE) with 95% confidence limits for differences.
Distance walked (m)288 (20.8)283 (20.3)5NS−1.2 to +9.7
Fall in Sao2 (%)11.0 (1.1)9.4 (1.1)1.6<0.01+0.4 to +2.8
Change in VAS between baseline and end of walk (mm)58 (4.3)54 (3.8)4NS−1.2 to +9.7
Subjective recovery time (s)111 (19.6)142 (16.5)13NS−12 to +37
Objective recovery time (s)177 (20.6)184 (31.7)7NS−59 to +73