2001 OPEN FORUM AbstractsTheEvaluation of Aerosolized Albuterol Deposition In-line via Conventional Ventilationversus High Frequency Oscillatory Ventilation (HFOV)
JasonHiggins, BS RRT, Adam Diebold, RRT, Sean Mellor, BS RRT, Anthony Dal Nogare, MD;Parkland Health & Hospital System,Dallas, Texas, Department ofRespiratory Care
Purpose: Toour knowledge, there have not been any studies evaluating aerosolized medicationdeposition with the High Frequency Oscillatory Ventilator (HFOV). We hypothesizethat aerosolized medications would be efficiently deposited when given in-linewith HFOV. We therefore compared the deposition of albuterol given with ConventionalVentilation versus HFOV in an in-vitro lung model.
Methods: An in-vitro lungmodel with specially designed filters was developed for this study. We comparedaerosolized albuterol deposition with Conventional Ventilation (Bear 1000, BearMedical Systems, Inc, Riverside, CA) and HFOV (3100A, Sensormedics, Yorba Linda,CA) at two separate sites in the lung model. The first set of data was collected2 cm distal to a #8 ETT that represented the carina. The second set of datawas collected 6 cm to the left and right of a bifurcation (90 angle) in themodel that represented right and left mainstem branches. Ten small volume nebulizers(Misty-Neb Nebulizer, Allegiance, McGaw Park, IL) were administered with 3 mlsof albuterol (Warrick Pharmaceuticals, Reno, NV) containing a total of 1.5 milligramsat 7 lpm for 7 minutes for each site and each type of ventilator. Bias flowon the HFOV was reduced when additional flow from the nebulizer was introducedso that mean airway pressure was unchanged. After each nebulizer was completed,the filters were removed from the circuit and dissolved with 6 mls of ethanolin a sterile container. Samples from each container were then analyzed witha spectrophotometer at 278 nm to calculate albuterol deposition amounts.
Results: Deposition amountsin milligrams:
|Filter location||Conventional Ventilator (Bear1000)||HFOV (Sensormedics 3100A)|
|Carina||Mean- .1249 SD-.01539||Mean- .2141 SD-.05866|
|Range- (.109-.147)||Range- (.053-.250)|
|% Deposited- 8.3%||% Deposited- 14.3%|
|Left Mainstem||Mean- .0807 SD-.00532||Mean- .0781 SD-.00647|
|Range- (.075-.089)||Range- (.068-.090)|
|% Deposited- 5.4%||% Deposited- 5.2%|
|Right Mainstem||Mean- .0844 SD-.00581||Mean- .0838 SD- .00469|
|Range- (.076-.093)||Range- (.075-.091)|
|% Deposited- 5.6%||% Deposited- 5.6%|
Conclusion: Studies haveshown that when nebulized aerosols are given in-line with conventional mechanicalventilation, approximately 1.5-15% of the medication is deposited in the airways.We found that aerosolized medication given in-line with HFOV using a speciallydesigned adapter will result in similar findings. We feel that patients whoare on HFOV and have been diagnosed with hyper-reactive airway disease wouldbenefit from this data.