The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

A COMPARISON OF THE CONSISTENCY OF OUTPUT OF A LOW FLOW NEBULIZER POWERED WITH ALTERNATIVE GAS SOURCES

Emily L. Zyla1, Doug A. Campbell1, Michael I. Stembol2



Background: The Cardinal Health Misty Finity™ low flow nebulizer is rated to deliver 8 mL (+/- 20%) of solution per hour when run on 2.5 Lpm. This nebulizer is used in our PICU for continuous treatment delivery and frequently powered by alternative gas sources. This study was designed to verify consistency in delivered medication volume with the Misty Finity™ nebulizer regardless of the driving gas used.

Methods: Five representative gas combinations were chosen: room air, 50% oxygen, 100% oxygen, 80/20 heliox and 50/50 heliox. A pre-mixed 240 mL bag of 10 mg Albuterol in 8 mL of 0.9% NaCl solution was obtained from the pharmacy. 8 mL of the solution was dispensed into each of 8 Misty Finity™ nebulizers via a Graseby 3100 modular micro infusion pump. Each nebulizer was weighed on an OHaus ProSeries scale (accurate to 0.01 g) and the pre-treatment weight recorded. The nebulizer was powered by a flow of 2.5 L/m (flowmeter calibrated with a PB PTS2000 Calibration Analyzer) on each of 5 different gas sources while medication was delivered into the nebulizer via the same infusion pump at a rate of 8 mL per hour. After one hour the process was halted and a post treatment weight was obtained using the same scale. The results were placed into the SPSS 13.0 Statistics program and analyzed using a comparative means of One-Way ANOVA.

Results: Only one nebulizer trial run had a weight loss. The mean gain for the room air, 50% oxygen and 100% oxygen are 2.70, 2.43 and 2.23 grams respectively. The 80/20 and 50/50 heliox mean gain was 1.06 and 1.52 grams. While not statistically significant, both heliox trials had less residual volume but a wider range of standard deviation than the other trials.

Conclusion: The results of the nebulizer trials were consistently inconsistent in medication amounts delivered. With this type nebulizer, we can not insure the ordered amount of medication is being delivered regardless of the driving gas.