2007 OPEN FORUM Abstracts
EVALUATION OF POSITION OF AEROSOL DEVICE IN TWO DIFFERENT VENTILATOR CIRCUITS DURING MECHANICAL VENTILATION
A. Ari1, H. Aerabi1, J. Sampson1
Background: The position of nebulizers in the ventilator circuit affects drug delivery during mechanical ventilation. These effects have not been evaluated with all types of nebulizers.
Methods: Representative jet (Misty-neb; Cardinal Health), vibrating mesh (AeronebPro; Aerogen Inc), and ultrasonic (Easyneb; PB) nebulizers were compared in both heated and unheated ventilator circuit during mechanical ventilation. Nebulizers were operated continuously with albuterol (2.5 mg / 3 mL) in 3 positions: 1) between the endotracheal tube (ETT) and “Y”; 2) 6 in from “Y” on the inspiratory limb ; 3) 6 inches from the ventilator (n=3). A ventilator (Vt 500 mL, ramp flow pattern, 15 breaths/min) with circuit (heated or unheated) was attached to an intubated lung model. Drug deposited on an absolute filter distal to an 8.0 mmID ETT (n=3) was eluted and analyzed by spectrophotometry (276 nm). A 2 x 3 x 3 repeated measures ANOVA test was used for the statistical analysis of the study. Multiple follow-up comparisons were performed using the Bonferronni method (p<0.05).
Results: Table 1 shows mean (standard deviation) percent of dose delivered in a heated (wet) and unheated (dry) circuit, respectively. There were significant differences between nebulizers and for each nebulizer across the positions tested.
Conclusion: During CMV, the optimal aerosol efficiency is nebulizer and position dependent.
| Position 1 | Position 2 | Position 3 | ||||
| Wet | Dry | Wet | Dry | Wet | Dry | |
| Jet Neb | 7.62 (0.9) | 4.66 (0.5) | 3.61 (0.2) | 9.66 (1.5) | 5.98 (0.1) | 14.66 (1.5) |
| Vibrating Mesh | 12.82 (0.5) | 14.54 (1.0) | 16.79 (2.6) | 30.24 (1.0) | 8.39 (2.1) | 24.20 (1.2) |
| Ultrasonic | 10.07 (3.9) | 10.70 (1.5) | 16.53 (4.3) | 24.68 (4.4) | 4.59 (2.0) | 10.51 (0.3) |