A Comparison of Inline MDI Actuators for Delivery of a Beta Agonist and a Corticosteroid with a Mechanically Ventilated Lung Model

Abstract

INTRODUCTION

The type of metered dose inhaler(MDI)actuator/adaptor as well as the type of drug used may influence the dose of drug delivered to intubated, ventilated subjects.

PURPOSE

The purpose of this study was to evaluate MDI aerosol drug delivery of albuterol (Proventil®) and flunisolide (Aero Bid®) through an endotracheal tube (ETT) using a novel bidirectional nonreservoir actuator, the Allegiance Healthcare Corp Airlife MiniSpacer (MiniSpacer) in comparison with four other MDI actuator/reservoir devices.

METHODS

The Mini Spacer was compared to the DHD Healthcare Aerosol Cloud Enhancer (ACE), the Allegiance Healthcare Corp Airlife MediSpacer (MediSpacer), the Mon aghan Medical Corp AeroVent (AeroVent), and the Hudson RCI® Inline MDI Adaptor (Hudson Inline) for MDI administration of albuterol and flunisolide, using a mechanically ventilated lungmodel. Drug dose was collected at the end of the ETT on a filter and was analyzed by spectrophotometer. Drug deliveryat the end of the ETT is expressed as a percent ofthe dose measuredfrom the MDI.

RESULTS:

Mean (standard deviation) doses of albuterol were: Hudson Inline-12.0% (0.9), MiniSpacer-17.2% (1.2), AeroVent-17.7% (2.5), ACE-30.0% (2.0), and MediSpacer-31.8% (1.6). Mean (standard de viation) doses of flunisolide were: Hudson Inline-5.0% (0.9), AeroVent-11.4% (1.8), ACE-12.4% (2.8),MiniSpacer-13.1% (2.2)and MediSpacer-21.0% (1.8). There were significant differences across device types (p < 0.005), for both albuterol and flunisolide delivery by one-way analysis of variance (ANOVA).

CONCLUSION:

The new nonreservoir bidirectional MDI adaptor (MiniSpacer) was supe rior to the unidirectional Hudson nonreservoir adaptor in dose delivery through an ETT for both albuterol and flunisolide. For delivery of albuterol, the bidirectional adaptor was equivalent to the AeroVent reservoir but notas efficient as the MediSpaceror ACE reservoirs. Fordelivery offlunisolide, the bidirectional adaptor was equivalent to both the ACE and the AeroVent, but lower than the MediSpacer. Delivery of the corticosteroid flunisolide was lower for all devices compared to albuterol.