Effect of wash-in methodology on wash-in time and other parameters

 OpenRebreathep-value for open versus rebreathe
Healthy volunteers
 Total wash-in time s202 (142–229)101 (89–142)0.0005
 Cumulative inspired volume L19.8±4.317.9±5.40.2
 Wash-in incompleteness %1.25±0.360.53±0.600.003
 Median end wash-in CO2 %1.4 (1.0–3.5)
Cystic fibrosis
 Total wash-in time s230 (204–280)*156 (132–173)*<0.0001
 Cumulative inspired volume L38.4±8.4#32.2±6.2#0.01
 Wash-in incompleteness %1.76 (0.74)1.18 (0.82)*0.0007
 Median end wash-in CO2 %1.3 (1.1–1.7)
  • Data are presented as median (interquartile range) or mean±sd, unless otherwise stated. *: p<0.05 for healthy volunteers versus CF; #: p<0.0001 for healthy volunteers versus CF.