Albuterol delivery in a neonatal ventilated lung model: Nebulization versus chlorofluorocarbon‐ and hydrofluoroalkane‐pressurized metered dose inhalers *

The aim of this study was to compare albuterol delivery in a neonatal ventilated lung model, using three delivery methods: 1) jet nebulizer; 2) chlorofluorocarbon‐pressurized metered dose inhaler (CFC‐MDI) actuated into an ACE® spacer; and 3) hydrofluoroalkane‐pressurized MDI (HFA‐MDI) actuated into an ACE® spacer. The bench model consisted of a mechanically ventilated infant test lung with ventilator settings to simulate a very low birth weight neonate with moderate lung disease. Albuterol solution (0.5%) was nebulized at the humidifier and temperature port, 125 cm and 30 cm from the Y‐piece, respectively. Albuterol metered dose inhalers (MDIs) were actuated into an ACE® spacer that was tested in two positions: 1) inline between the endotracheal (ET) tube and the Y‐piece; and 2) attached to the ET tube and administered by manual ventilation. Albuterol was collected on a filter at the distal end of the ET tube and was quantitatively analyzed by high performance liquid chromatography. Albuterol delivery by CFC‐MDI (position 1, 4.8 ± 1.0%, vs. position 2, 3.8 ± 1.6%, P  > 0.05) and HFA‐MDI (position 1, 5.7 ± 1.6%, vs. position 2, 5.5 ± 2.4%, P  > 0.05) were significantly greater than delivery by nebulization at 30 cm (0.16 ± 0.07%) and 125 cm (0.15 ± 0.03%) from the Y‐piece ( P  < 0.001). A single actuation of albuterol MDI delivered the equivalent of nebulizing 2.5–3.7 mg of albuterol solution. We conclude that albuterol administered by MDI and ACE® spacer resulted in more efficient delivery than by nebulization in this mechanically ventilated neonatal lung model. There was no significant difference in drug delivery between CFC‐MDI and HFA‐MDI; nor did the placement of the spacer significantly affect drug delivery. Pediatr Pulmonol. 2001; 31:247–254. © 2001 Wiley‐Liss, Inc.