How should aerosols be delivered during invasive mechanical ventilation?

Abstract

The delivery of aerosols to mechanically ventilated patients presents unique challenges and differs from inhaled drug delivery in spontaneously breathing patients in several respects. Successful aerosol delivery during invasive mechanical ventilation requires careful consideration of a host of factors that influence the amount of drug inhaled by the patient. Pressurized metered-dose inhalers and nebulizers (jet, ultrasonic, and vibrating mesh) are the most commonly used aerosol delivery devices in these patients, although other delivery devices, such as dry powder inhalers, soft mist inhalers, and intratracheal nebulizing catheters, could also be adapted for in-line use. Bronchodilators, inhaled corticosteroids, antibiotics, pulmonary surfactant, mucolytics, biologicals, genes, prostanoids, and other agents are administered by inhalation during mechanical ventilation for a variety of indications. The goals of inhalation therapy during mechanical ventilation could be best achieved by (1) assuring drug delivery; (2) optimizing drug deposition in the lung; (3) providing consistent dosing; (4) avoiding inappropriate therapies; (5) achieving reproducible dosing; (6) employing clinically feasible methods; (7) enhancing the safety of inhaled drugs; and (8) controlling costs of aerosol therapy. The techniques of administration of aerosols with various delivery devices during mechanical ventilation are well known, but there continues to be significant variation in clinical practice and guidelines are needed to provide best practices for a wide range of clinical settings encountered in mechanically ventilated patients.