PMC3590513_01
PMC3590513_02
PMC3590513_03
Capnogram showing elevated baseline and higher end-tidal carbon dioxide
JOACP-29-108-g001.jpg
PMC3590513_03_JOACP-29-108-g001.jpg
F1
After a few breaths, FiCO2 increased to 9 mmHg [Figure 1].
Deformed 'flexible leaflet' of expiratory unidirectional valve (shown after removing the covering dome)
JOACP-29-108-g002.jpg
PMC3590513_03_JOACP-29-108-g002.jpg
F2
We noted that the leaflet of the expiratory UDV was deformed and part of it remained open during inspiration [Figure 2].
Ventilator display showing the abnormal reverse flow through expiratory unidirectional valve during inspiratory phase (I) and the normal flow during expiration (E)
JOACP-29-108-g003.jpg
PMC3590513_03_JOACP-29-108-g003.jpg
F3
The flow waveform on the ventilator showed minimal flow during inspiration [Figure 3].