Pressure Support Ventilation - A New Triggered Venilation Mode for Neonates

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5.3.4 LIMITATIONS AND CONTRA-INDICATIONS
Each individual patient requires his/her own optimal ventilation mode and
parameters. Also Pressure Support Ventilation has its limitations and contraindications.
Bronchospasm and lack of spontaneous respiratory drive are two
contra-indications for PSV.
In patients with low respiratory drive, Pressure Support Ventilation only has
the advantage of automatic TI compared with Controlled Mandatory
Ventilation (CMV) (see also 5.3.3 Backup Ventilation).
In case of bronchospasm, peak flow is decreased and inspiratory flow comes
back to baseline very fast. Thus, spontaneous inspiration time is very short
and the pressure support very brief while the newborn needs a higher level
of support. This is a limitation for all ventilatory modes, that use the flow
signal to adapt the ventilatory support (i.e. Proportional Assist Ventilation).
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Volume Guarantee is a useful option for such cases. In case of brochospasm
Volume Guarantee will automatically increase the pressure support level in
order to deliver the set target tidal volume. Thus peak flow is not decreased,
and pressure support level is maintained during the whole spontaneous
inspiration (for more information a separate booklet about Volume
Guarantee is available).