The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts

AN IN-VITRO EVALUATION OF AEROSOL DELIVERY THROUGH TRACHEOSTOMY AND ENDOTRACHEAL TUBES USING DIFFERENT INTERFACES.

Arzu Ari, Robert Harwood, Meryl Sheard, James Fink; Georgia State University, Atlanta, GA

BACKGROUND: There is little data on effects of artificial airways and their interfaces on aerosol delivery. The purpose of this study was to compare aerosol delivery between tracheostomy and endotracheal (ETT) tube using different interfaces such as tracheostomy mask, t-piece and ambu bag. METHOD: A teaching manikin was intubated with ETT (Mallinckrodt) and tracheostomy tube (Portex) with 8 mm IDs. A filter (Respirgard II) was placed between the trachea and sinusoidal pump simulating a spontaneously breathing adult (Vt 450 mL, RR 20 bpm, I:E ratio 1:2) for testing with tracheostomy mask (Airlife, Cardinal Health), t-piece (Airlife, Cardinal Health) and a passive test lung for testing with ambu bag without PEEP. Albuterol sulfate (2.5 mg/3mL) was nebulized with a jet nebulizer (eValueMed, Trianim) and administered via appropriate appliance to the tracheostomy tube and ETT (n=3). Drug was eluted from the filter and analyzed with spectrophotometry (276 nm). Descriptive statistics, student t-tests and one-way ANOVA were used for data analysis at the significant level of 0.05 (p< 0.05). RESULTS: The table shows percentage of nominal dose delivered distal to the trachea (mean ± SD). Deposition was lower with tracheostomy collar than other appliances (p< 0.05). Aerosol delivery was greater with the tracheostomy tube than ETT with both t-piece and ambu bag (p=0.038 and p=0.025, respectively). Use of ambu bag during aerosol therapy increased lung dose more than 3 fold with both tracheostomy tube and ETT. It is unclear how the shift from active lung simulator to passive test lung impacted deposition. CONCLUSION: Efficiency of aerosol deposition is impacted by type of artificial airway and interface used. Aerosol therapy through ETT was less efficient than tracheostomy, across interface devices. Aerosol delivery from a jet nebulizer via ambu bag was most efficient using this bench model. Further studies with other types of aerosol generators, interfaces and valve bag designs are warranted to find the best method for aerosol therapy in patients with artificial airways. Sponsored Research - None