The Science Journal of the American Association for Respiratory Care

1998 OPEN FORUM Abstracts

PLACEMENT OF AN ULTRASONIC NEBULIZER AT THE VENTILATOR CIRCUIT WYE DOES NOT REDUCE AEROSOL DELIVERY During CMV

James B. Fink, MS, RRT, Martin J. Tobin, MD and Rajiv Dhand, MD. Hines VA Hospital, Division of Pulmonary and Critical Care Medicine, Loyola Stritch School of Medicine, Hines, IL

Background: During controlled mechanical ventilation (CMV), placement of pneumatic small volume nebulizers (SVNs) in the inspiratory limb of a ventilator circuit 18 inches from the wye provided more aerosol to the lower respiratory tract than placement at the ventilator circuit wye. Our goal was to determine the most efficient site for operation of an ultrasonic nebulizer (USN) during CMV.

Method: To determine the effect of the placement of a protoype USN (Nellcor Puritan Bennet) (n=3) in each of 5 sites in a ventilator circuit, we nebulized albuterol sulfate during CMV (V_{T} 680 ml, PIF 40 L/min, rate 12). Drug was collected on a filter in a tracheal model, distal to a 9.0 mm ET tube. Humidity was provided with an active humidifier (MR 730 Fisher-Paykel) and a heated wire circuit (Isothermal, Baxter Health Care). Albuterol was collected on the filter and assayed (276 NM). ANOVA was performed with p < 0.05 considered significant.

Results: Placement of the USN at sites C, D, and E delivered more drug to the trachea than site A and B (*p < 0.0001).

Site of USN in Circuit Deposition

µg (Mean±SD)

A - proximal to vent, before heater 51.6±21.0

B - immediately distal to heater 49.8±11.1

C - 18 inch from wye 200.3± 6.1*

D - between inspiratory limb and wye 223.6±31.5*

E - between wye and ET tube 210.6±46.0*

Conclusion: In contrast to previous reports with SVNs, the placement of the USN at or before the wye provided similar or greater aerosol delivery than placement at other sites in the ventilator circuit during CMV.

Funded by a grant from Nellcor Puritan Bennet

The 44th International Respiratory Congress Abstracts-On-Disk®, November 7 - 10, 1998, Atlanta, Georgia.

You are here: RCJournal.com » Past OPEN FORUM Abstracts » 1998 Abstracts » PLACEMENT OF AN ULTRASONIC NEBULIZER AT THE VENTILATOR CIRCUIT WYE DOES NOT REDUCE AEROSOL DELIVERY During CMV