Table 1—

Effect of discarded dead space volume on off-line fractional exhaled nitric oxide concentration (FEno) and correlation with on-line values

Discarded volume mLFEno# ppbPearson rMean±sd difference on-/off-line ppb
On-line21.9
Off-line
 3 s15020.00.951.1±1.3
 4 s20020.90.961.0±1.3
 6 s30021.90.971.0±1.2
 8 s40021.90.981.0±1.2
 10 s50021.70.981.0±1.2
  • #: Geometric mean FEno

  • : Pearson correlation coefficient for on-line and off-line values. n=19