2004 OPEN FORUM Abstracts
A Comparison of Oxygen concentration delivery by small volume nebulizers
Donna D. Gardner, MSHP, RRT; Richard B. Wettstein,
BS, RRT; Jana Wallace, BSRT, CRT; Anna Hernandez-Sanchez, BSRT, CRT;
David C. Shelledy, PhD, RRT; Jay I. Peters, MD. The University of
Texas Health Science Center at San Antonio, San Antonio, Texas.
INTRODUCTION: Small volume nebulizers
(SVN) are commonly powered by oxygen or medical air. A review of the
literature did not find any expected oxygen concentration (OC)
associated with SVN's. We determined the oxygen concentrations (OC)
delivered by three different small volume nebulizers (Salter Labs,
Hudson and Airlife) by measuring pharyngeal OC in 10 normal subjects
at flows of 6, 8, and 10 L/min.
METHOD: A nasal
catheter was positioned with the tip in the pharynx immediately
behind the uvula. Oxygen flow of 6 L/min was administered via mouth
piece on the Salter Labs SVN. Three samples were taken while the
subject breathed at their resting level. The subject was then asked
to double their respiratory rate for one minute at which time a
fourth sample was taken. The procedure was then repeated with the
subject breathing through an aerosol mask. This whole process was
replicated at each L flow and on each device.
RESULTS: The
mean (SD) for OC on all brands using the mouthpiece and mask during
normal and rapid breathing at prescribed flow rates were:
| All Nebulizers with mouthpiece | All Nebulizers with a Mask | |||
| Normal breathing | Rapid breathing | Normal breathing | Rapid breathing | |
| Flow L/Min | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) |
| 6 | 42 (11) | 40 (11) | 44 (11) | 41 (12) |
| 8 | 49 (14) | 47 (15) | 51 ( 14) | 48 (15) |
| 10 | 55 (14) | 51 (15) | 57 (15) | 54 (14) |
The
mean OC delivered increased with each increase in liter
flow (6, 8 and 10 L/min) for all brands using mouthpiece or mask
during normal and rapid breathing.
CONCLUSION: Our data found
a mean pharyngeal OC delivered via SVN was 40% or greater
on flows of 6, 8, or 10 L/min. This has clinical implications when
delivering medication via small volume nebulizer powered by oxygen.
Departmental
Funding