In-vitro characterisation of the nebulised dose during non-invasive ventilation.
OBJECTIVE
Non-invasive ventilation (NIV) with nebulised bronchodilators helps some patients to maintain effective ventilation. However, the position of the nebuliser in the ventilation circuit may affect lung delivery.


METHODS
We placed the nebuliser proximal (A) and distal (B) to a breathing simulator in a standard NIV circuit with inspiratory (I) and expiratory (E) pressures of 20 and 5 cm H(2)O, 1 : 3 I : E ratio, 15 breaths/min and a tidal volume of 500 ml. Five milligrams of terbutaline solution was nebulised using an Aeroneb Pro (AERO) and a Sidestream (SIDE) nebuliser. The fate of the nebulised dose was determined and the aerodynamic droplet characteristics were measured using a cooled Next Generation Impactor.


RESULTS
More terbutaline was entrained on the inhalation filter in position A than in position B (P < 0.001) for both nebulisers. These amounts were greater (P < 0.001) for AERO than SIDE due to a smaller (P < 0.001) residual volume. The mean (SD) fine particle doses for AEROA, AEROB, SIDEA and SIDEB were 1.31 (0.2), 1.13 (0.14), 0.56 (0.03) and 0.39 (0.13) mg. These amounts from AEROA were significantly greater (P < 0.001) than those of the other three methods.


CONCLUSIONS
The results highlight the differences between nebulisers and the influence on the placement of the nebuliser in the NIV circuit.
Abdelrahim
Mohamed E
ME
Institute of Pharmaceutical Innovation, University of Bradford, UK and Faculty of Pharmacy, University of Bani Suef, Egypt.
Plant
Paul
P
Chrystyn
Henry
H
D000280:Administration, Inhalation; D000336:Aerosols; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000737:chemistry; D004867:Equipment Design; D045853:Exhalation; D006801:Humans; D001239:Inhalation; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D011312:Pressure; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial / Q000295:instrumentation*; D013726:Terbutaline / Q000008:administration & dosage* / Q000737:chemistry; D014732:Vibration
D000336:Aerosols; D001993:Bronchodilator Agents; D013726:Terbutaline