Albuterol delivery with conventional and synchronous ventilation in a neonatal lung model.
OBJECTIVE
To compare the percentage of nebulized albuterol delivered with conventional (intermittent mandatory ventilation) vs. synchronous (assist-control and assist-control with flow synchronization) ventilation in a neonatal lung model.


METHODS
Prospective in vitro laboratory study.


METHODS
Research laboratory.


METHODS
Neonatal lung model.


METHODS
The model simulated an intubated neonate with a spontaneous respiratory rate of 40, 60, or 80 breaths per minute and compliance and resistance values of bronchopulmonary dysplasia. A VIP Bird ventilator was used for all ventilator modes. Albuterol 2.5 mg was administered with a T Up-Draft II Neb-U-Mist nebulizer attached to a 12.75-cm (10-mL) reservoir of circuit tubing. Albuterol was collected onto a filter (particle retention <or=0.3 microm) placed proximal to the test lung. After nebulization, the filter was rinsed with water, and albuterol concentrations were determined by high-performance liquid chromatography. Ten random trials for each mode were completed.


RESULTS
No significant differences in percentage albuterol delivered were found among the three modes or the three spontaneous respiratory rates (mean +/- sd): intermittent mandatory ventilation, 0.11 +/- 0.04%; assist-control, 0.12 +/- 0.03%; assist-control with flow synchronization, 0.10 +/- 0.04%; 40 breaths per minute, 0.11 +/- 0.03%; 60 breaths per minute, 0.11 +/- 0.04%; and 80 breaths per minute, 0.11 +/- 0.05% (p >.05, two-factor analysis of variance).


CONCLUSIONS
The percentage of nebulized albuterol delivered to the end of the endotracheal tube in a mechanically ventilated neonatal model was not affected by mode of ventilation under the conditions studied. Further clinical studies are needed to determine whether lung deposition and distribution or clinical efficacy of albuterol is influenced by synchronous ventilation in this patient population.
Garner
Sandra S
SS
Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC, USA.
Southgate
W Michael
WM
Wiest
Donald B
DB
Brandeburg
Scott
S
Annibale
David J
DJ