Aerosolised Drug Administration in the Ventilated Patient: In-Vitro and In-Vivo Correlates

Abstract

ABSTRACT The use of drugs administered via the airways for the treatment of ventilated patients in an intensive care setting is common. The spectrum of drugs administered this way include bronchodilators, steroids and antimicrobial agents. Despite the administration of these agents directly into a ventilator circuit which communicates directly with the patients lungs, the evidence available suggests that the lung deposition from aqueous aerosols is poor with only 1.2-2.8% of the nebuliser dose reaching the lungs. A variety of factors affect the delivery of drug to the lung: the type of nebuliser used, the nebuliser efficiency, the particle size of the aerosol, the ventilator settings (respiratory rate, tidal volume and inspiratory time) and the position of the nebuliser in the ventilator circuit. A number of these have been explored in-vitro with the results showing that depending on the ventilator settings, the addition of a spacer, the type of nebuliser (e.g. jet or ultrasonic) and the humidification of...