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Figure 9.3: Diagram of the measurement of lung function and No in an infant
Syringe
Pneumotach
Pump
Resistancs
Blow-off at 20 crn H2O
chemiluminescence analyser
Taken from wildhaber JH, Hail GL, Stick sM. Measurements of exhaled nitric oxide with the single'
breath technique and positive expiratory ;;;il6 il infants..American Journal of Respiratory and
Criticat Care Medicine 'iggg; 159:74-78 (Wildhaber, Hallet al. 1999)'
using this technique there was successful measurement of FEVo.s in 27 of 30 sedated infants
aged 3-24 months and successful measurement of NO in all. The end tidal COz level at the
nose was not changed during expiration, indicating that the velum was closed during the
manoeuvre (wildhaber, Hall et al. 1999). Studies have now been carried out using variations
on this technique reporting 95To+ success in sedated or quiet infants (Buchvald and Bisgaard
Zxl:;Martinez, Weist et al. 2003; Franklin, Turner et al' 2004; Straub' Moeller et al' 2005)'
The other method is by using tidal breathing where NO can be measured online or by
reservoir collection. Again the infant is in a supine position asleep following sedation' with
direct online measurement recorded during 20 seconds of quiet breathing (Franklin, Turner et
a:.2004), or using a mean of five or ten consecutive breaths (Hall' Reinmann et al' 20/0.2;
colnaghi, condo et al. 2003; Iripala, williams et al.2004). For offline measurements' tidal
breathing can be collected into a gas sampling balloon which can then be attached to the
sampler inlet of the NO analyser -
collecting over a set time period such as 15-45 seconds
@inakar, Craff et al. 2006), or during a set number of breaths (most use three or five)
(Anlich, Busch et al. 1998; Baraldi, Dario et al. 1999: Ratjen, Kavuk et al' 2000; Artlich'
Jonsson et al. 2001; Franklin, Turner et al. 2o04; Franklin, Turner et al' 2004; Moeller'
Franklin er al. 2004; Gabriele, Nieuwhof et al. 2006). Results have been reported as peak,
average levels and the avengecalculated from the area under the curve during expiration'
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