The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts

COMPARISON OF TWO HIGH FREQUENCY DEVICES FOR AIRWAY CLEARANCE IN A SIMULATED PEDIATRIC LUNG MODEL.

Cynthia C. White, James Johnson; Respiratory Care Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH

Background: Two devices are available that enable clinicians to utilize an intrapulmonary Continuous High Frequency Oscillatory (CHFO) modality for airway clearance and lung recruitment. The IPV® (Percussionaire) uses a sliding phasitron to create the percussive flow waveform. The Metaneb® (Hillrom) functions with a fixed orifice adjustable venturi. No published data is currently available that compares the two devices. We tested the hypothesis that there is no difference in mean pressure or flow delivery comparing similar frequencies with the Metaneb to the IPV in a simulated pediatric lung model. Methods: A dual chamber TTL Lung model 5601i (Michigan Instruments, Grand Rapids, MI) was used with a lift bar to simulate a pediatric spontaneously breathing lung model. A pneumotachometer (AD instruments) was calibrated and was placed at the proximal airway. Two minutes of continuous data was recorded to a laptop computer for each testing variable. The IPV was tested at 4 frequencies ranging from 150 to 300 Hz. The Metaneb was tested with both the black and green rings at two positions, (high and low) ranging from 180-220 Hz. Statistical Analysis was performed in SigmaPlot version 11.0. One way ANOVA was used to compare mean outcome variables with Holm Sidak for post hoc analysis. Significance was set at p = < .05. Results: There was no difference in mean pressure with the IPV, Hz 250 compared to high Hz with Metaneb, green ring, or compared to the low Hz, black ring. With the Metaneb, black ring at the high Hz, MAP was higher in all testing conditions. (p= < .001). There was also no difference between IPV, Hz 150 and Metaneb, green ring, low Hz. There was a significant difference in mean flow at most frequencies with both devices.( p= < .01). There was no difference in mean flow between IPV, 250 Hz and low Hz Metaneb black ring, or the Metaneb green and black ring at low Hz. Max flow ranged from 1.5LPS -2.2LPS with IPV and 1.71-2.35LPS with Metaneb. Conclusion: Mean pressure and flow varied at each testing frequency, but were acceptable at comparable frequencies with both the IPV and Metaneb. Max pressure was slightly higher with IPV than Metaneb using the green ring. Using the black ring appears to achieve a higher MAP. Further testing needs to be conducted to compare pressure with additional flow to set a CPEP with the metaneb compared to an external PEEP valve with IPV. The Metaneb should also be tested with mechanical ventilation. Sponsored Research - None