The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Mitchell Goldstein, Michael Terry, Carter Tong, T. Allen Merritt, Elba Fayard, Ricardo Peverini; Neonatology, Loma Linda University ChildrenÂ’s Hospital, Loma Linda, CA

Background: The use of high frequency ventilation in neonates with significant lung disease has been difficult during transport. High gas requirements, bulky apparatus, and electrical power requirements have largely discouraged the use of the oscillator and jet ventilators more common in the NICU setting. The Bronchotron (Percussionaire Corporation, Sandy, Utah) requires no electricity for actuation and is much more amenable to transport because of its small size. However, its present lack of digital monitoring has largely made it more difficult to monitor or to understand the effects of various flow and pressure changes inherent in changes in the device usage. Purpose: We asked if there was a simple approach to analyzing the flow and pressure waveforems of the Bronchotron that could be used to more readily adapt to changes in the ventilatory dynamic in transport. Method: A Sinusoidal Bronchotron was attached in line to a Fleisch pneumotachograph. The pneumotachograph was attached to a pressure transducer (Validyne, Northridge, CA) imbedded in an IBM PC compatible computer running Easy Sense for Windows XP. The apparatus was then connected in line to a Copper Wire test lung of known compliance. Flow and pressure data were sampled at 1000 Hz with operational pressure fixed at 20 PSIG while varying pulse frequency and oscillatory CPAP across the full operational range. For the purposes of this study, I and E time were fixed. Results: As shown in the graphics and in the accompanying equations, changes in the flow- pressure dynamic can be describe mathematically by correlating pulse frequency and oscillatory CPAP using a higher order Polynomial fitting to peak maximal peak flow and pressure measurements. Conclusion: Fixed form equations can be used to describe the variability inherent in high frequency ventilation with the Sinusoidal Bronchotron in a more readily appreciable flow and pressure relationship. Understanding this relationship can give rise to a better sense of how to adjust the individual parameters without the luxury of a digital readout. Sponsored Research - None