View - ResearchSpace@Auckland - The University of Auckland

concenrration of exhaled NO was 84.8ppb (SEM 14.0, range 25.I - 189.0). There was greater
variation shown in the female subjects with a mean of 92.4ppb (SEM 36.9,26.2 - 189.0) than
the male subjecrs with a mean of 71.7ppb (SEM 28.7, range 25.1 - 141.0). The peak exhaled
NO levels measured through the t-piece system were lower in all the subjects with a total
subject mean of 41.2ppb (SEM 10.8, range 10.00 - 101.6). The mean in males was 33.2ppb
(SEM 8.4) versus females of 50.7ppb (SEM 12.3) (see Figure 6.6). The data for one
individual as the change occurred from t-piece to direct measurement is shown in Figure 6.7.
Note again that the chart recording is read from right to left so the exhalation commences at
the right hand side of each set of tracings. The scales were added for convenience of viewing
this single tracing as the scales were worked out on each graph depending on the checks with
the calibration gases. The main point depicted is the change with higher NO levels being
measured in the direct rather than the t-piece system.
Figure 6.5: Example of recording on one subject - direct and t-piece measurements
Note the chart is read from right to left, NO is recorded in green, COz is recorded in red, mouth
pressure is recorded in blue and flow (seen only in the t-piece measurements) is recorded in brown'
The exhaled NO levels increase when the tiace moves from t-piece to direct recordings. The
calculations made for each exhalation can also be seen on the chart.
t4l