2012 OPEN FORUM Abstracts
DEVELOPMENT OF RELIABLE VENTILATOR METHODOLOGY TO DISPLAY NEONATAL PRESSURE VOLUME LOOPS USING A SIMULATED LUNG MODEL.
Allan Prost; 1Health & Public Safety, SAIT, Calgary, AB, Canada; 2Neonatal Intensive Care, Foothills Medical Center, Calgary, AB, Canada A
Background: There is limited data describing the reliability or methodology of how to obtaining accurate pressure-volume loops (PVL) on neonatal patients and ventilators. Objective: To describe and test a methodology to obtain accurate neonatal PVL. Methods: Neonatal lung models with different lower and upper inflection points were developed on the ASL 5000 lung simulator and verified by using external syringe volume measurements. The Servo-i neonatal mechanical ventilator was used to ventilate the ASL lung simulator and adjusted to find a reliable method to display the lung characteristics of the model using the PVL graphics. We compared the modes of PC-CMV, PC-CMV adaptive, and VC-CMV using a variety of volume, flow, and pressure strategies. Results: There are observable differences when comparing the modes of VC and PC on the generated PVL and in the reliability of determining the LIP. VC modes using flow rates of less than 1.0 Lpm with inspiratory times (Ti) of more than 1 second were required to accurately displayed the LIP. The UIP could be seen in both VC and PC modes if the delivered tidal volume (Vt) was large enough for the simulated models. There were no observable differences in the expiratory limbs of the PVL regardless of the modes or settings. Conclusion: Only a low-flow volume controlled method should be used to display PVL and to determine LIP and UIP on neonatal mechanical ventilators. The PVL may inaccurately display lung mechanics on the expiratory curve due to the effects of resistance and flow regardless of the technique used. Sponsored Research - None