In volume guarantee (VG) mode, the Dräger Babylog 8000plus ventilator targets a set expired tidal volume (VT) by adjusting the PIP between the positive end expiratory pressure (PEEP) and the maximum PIP limit (Pmax). If Pmax is too low, VT may not be delivered and the ventilator alarms. If too high, infants may be at risk of unnecessarily high inflation pressures and VT. Three strategies for selecting Pmax were compared.
Infants were eligible if stable on assist control (AC) VG for the previous 24 hours. Three strategies for setting Pmax were compared during 20 minute epochs in random order: F=Fixed unit setting (30 cm H2O); C=Pmax set 5 cm H2O above the typical peak pressure reported by the clinical staff; T=Pmax set 5 cm H2O above the average PIP during triggered ventilation. Ventilator data and measures of cardiorespiratory stability were recorded. Analysis was repeated excluding spontaneous large breaths.
15 infants were studied. Median (IQR) corrected gestation, weight and FiO2 were 27 (25, 30) weeks, 0.78 (0.73,1.5) kg and 0.23 (0.21,0.31) respectively. Mean (SD) results shown below:
Cardiorespiratory parameters were stable at all settings.
Strategies which set Pmax 5cm H2O above the triggered PIP reduced the proportion of inflations with VT>200% target.
About this article
Cite this article
Wheeler, K., Wong, C., Morley, C. et al. Strategies for Setting the Pip Limit during Volume Guarantee Ventilation. Pediatr Res 70, 750 (2011). https://doi.org/10.1038/pr.2011.975