Transcript Chapter 3
Chapter 3 Administration of Aerosolized Agents Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Three Main Uses of Aerosol Therapy Humidification of dry inspired gases Improved mobilization and clearance of respiratory secretions Delivery of aerosolized drugs to the respiratory tract Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Physical Principles of Inhaled Aerosol Drugs Aerosol particle size distributions Count mode Count median diameter (CMD) Mass median diameter (MMD or MMAD) Geometric standard deviation (GSD) Measurement of particle size distributions Aerodynamic diameter Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Physical Principles of Inhaled Aerosol Drugs Particle size and lung deposition Fine particle fraction Particle size and therapeutic effect • Particles >10 microns • Particles 5 to 10 microns • Particles 2 to 5 microns • Particles 0.8 to 3 microns Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Physical Principles of Inhaled Aerosol Drugs Mechanisms of deposition Inertial impaction Gravitational settling Diffusion (Brownian motion) Effect of temperature and humidity Hygroscopic increase in MMAD Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Ultrasonic nebulizers Small particle aerosol generator (SPAG) Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Small volume nebulizers (SVNs) Dead volume Filling volume and treatment time Effect of flow rate Type of power gas Type of solution Development of various nebulizer designs Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Metered dose inhalers (MDIs) Technical description Correct use Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Metered dose inhalers Factors affecting MDI performance • Loss of dose • Shaking the canister • Timing of actuation intervals • Open-mouth versus closed-mouth use • Loss of prime • Storage temperature Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Metered dose inhalers Breath-actuated inhalers • The Autohaler • Other devices Hydrofluoroalkane (Nonchlorofluorocarbon) propellants • Equivalence and safety • Improved drug delivery with HFA formulation Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery MDI reservoir devices Reservoir devices Design variables Electrostatic charge Size Other MDI auxiliary devices Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Aerosol Devices for Drug Delivery Dry powder inhalers (DPIs) Inspiratory flow rate Humidity Clinical efficacy Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Recommendations based on clinical evidence Aerosol delivery of short-acting β2 agonists in the ER Aerosol delivery of short-acting β2 agonists in the hospital Intermittent versus continuous nebulizer delivery of β2 agonists Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Recommendations based on clinical evidence (continued) Aerosol delivery of β2 agonists to patients receiving mechanical ventilation Aerosol delivery of short-acting β2 agonists for asthma in the outpatient setting Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Recommendations based on clinical evidence (continued) Inhaled corticosteroids for asthma β2 Agonists and anticholinergic agents for COPD Device selection Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Lung deposition and loss patterns with traditional aerosol devices MDI (CFC) = 8.8% deposition MDI (HFA) = 53% deposition MDI (CFC) with spacer = 14.8% deposition SVN = 12.4% deposition DPI = 14.8 to 27.7% deposition Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Equivalent doses among device types Lung deposition with newer aerosol devices Clinical equivalence of MDIs and SVNs Age guidelines for the use of aerosol devices Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Clinical Application of Aerosol Delivery Devices Patient-device interface Administration by intermittent positive-pressure breathing Face mask administration Endotracheal tube administration Mosby items and derived items © 2008, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.