The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Michael O’Connor, Stephen Boak, Jason Semple, Heather Conner, Aaron E. Light; Respiratory Therapy, Ozarks Technical Community College, Springfield, MO

Introduction: The Hamilton G5 ventilator flow sensor is placed between the patient and the ventilator wye. We set out to determine if the flow sensor blocks aerosol particles during treatments in-line with the ventilator. We hypothesized that the flow sensor reduces the amount of aerosol delivery to patients. Methodology: A Servoi ventilator was connected to a Michigan 5601i test lung with a Hamilton flowsensor placed at the ventilator wye. The ventilator was setup in VC mode with VT of 500 ml, RR 12, and PEEP of 5. Two Guardian disposable filters were placed between the Wye and the test lung. Prior to insertion, the filter closest to the wye was weighed to determine pretreatment weight. An Aerolife small volume nebulizer (SVN) was then placed in-line, 6 inches from the ventilator wye and filled with 5 ml of 10% hypertonic saline. The SVN was run for 5 min at 8 L/min. After the treatment, the filter was weighed to determine post treatment weight. The flow sensor was then removed and new filters were weighed and placed inline. This methodology was then repeated two times with new filters and SVNs. The weights of the filters were then compared to determine which set-up delivered the most aerosol to the filter. Results: The mean filter weight gain was 0.04g (StDev 0.00817 g) when the flow sensor was in-line and 0.097g (StDev 0.1247 g) when there was no flowsensor. The difference between mean filter gains were statistically different with a pvalue of 0.026 Conclusion: This bench study demonstrates that the flow sensor stops medication from reaching the patient. Further studies need to be performed to investigate this further and determine the clinical significance. Sponsored Research - None