In-vitro/in-vivo comparison of inhaled salbutamol dose delivered by jet nebulizer, vibrating mesh nebulizer and metered dose inhaler with spacer during non-invasive ventilation

Abstract

ABSTRACTBackground: Patients receiving noninvasive ventilation (NIV) may benefit from medical aerosol, but most guidance on dosing with different aerosol devices is limited to in-vitro studies. The study was designed to in-vitro, ex-vivo, and in-vivo compare aerosol delivery during bilevel NIV with three types of aerosol generators: metered dose inhaler with AeroChamber-MV spacer (AC), Aerogen Pro vibrating mesh nebulizer (PRO), and Sidestream jet nebulizer (SIDE). Materials and Method: A bilevel ventilator with dry single limb circuit and fixed expiratory port was set in spontaneous mode with initial inspiratory and expiratory pressures of 20 and 5 cmH20, 1:3 inspiratory-expiratory ratio, and 15 breaths.min−1. Aerosol generators were placed proximal to facial mask of NIV chronic obstructive pulmonary disease (COPD) patients. 1 mL salbutamol nebulizer solution (5 mg/mL) was nebulized using PRO and SIDE. 12MDI doses, containing 100μg salbutamol each, were delivered using AC. In-vitro aerosol fate and aerodynamic droplet characteristics, in-vivo amount of salbutamol excreted 30 mins and pooled up to 24 h post inhalation in urine from 12 COPD patients (as indices of pulmonary deposition and systemic absorption, respectively) and amount of salbutamol deposited on ex-vivo filters (expected inhalable amount) was determined. Results: The in-vitro, in-vivo and ex-vivo testing showed that PRO had better aerosol delivery compared to SIDE (p < 0.01). However, with smaller nominal dose MDI with AC resulted in similar aerosol delivery to PRO suggesting better aerosol delivery stress on careful attention and proper delivery by health care provider. Conclusions: These similarities and differences between the three aerosol generators tested suggest that aerosol delivery methods should be carefully chosen or substituted in non-invasive ventilated patients.