Intro to Nebs Delivery of Medication to the Airways(1).pptx

Delivery of Medication to the Airways Pharmacology & Aerosol Therapy Terminology aerosol: a suspension of liquid and solid particles produced by an aerosol generator such as the small- volume nebulizer (SVN), the pressurized metered-dose inhaler (pMDI), or the dry-powder inhaler (DP...

Delivery of Medication to the Airways Pharmacology & Aerosol Therapy Terminology aerosol: a suspension of liquid and solid particles produced by an aerosol generator such as the small- volume nebulizer (SVN), the pressurized metered-dose inhaler (pMDI), or the dry-powder inhaler (DPI) aerosol deposition: process of aerosol particles depositing on absorbing surfaces aerosol generator: a device used for producing aerosol particles aerosol output: mass of medication exiting an aerosol generator Terminology aerosol therapy: delivery of solid or liquid aerosol particles to the respiratory tract for therapeutic purposes dead volume (or residual volume): the amount of medication that remains in the nebulizer after a treatment is complete diffusion: the mechanism of aerosol deposition for small particles less than 3 μm (Diffusion is also called Brownian motion.) dry-powder inhaler: an aerosol device that delivers the drug in a powdered form, typically with a breath-actuated dosing system Terminology fine-particle fraction (FPF): percentage of the aerosol between 1–5 μm that deposits in the lung hydrofluoroalkane (HFA): a nontoxic liquefied gas propellant developed to be more environmentally friendly than CFCs and used to administer the drug from a pMDI inhaled dose: the proportion of nominal or emitted dose that is inhaled inhaler: device used to generate an aerosolized drug for a single inhalation inertial impaction: the mechanism of aerosol deposition for particles larger than 5 μm gravitational sedimentation (gravitational settling): the settling rate of an aerosol particle due to gravity, particle size, and time  Terminology mass median aerodynamic diameter (MMAD): average aerosol particle size as measured by a cascade impactor monodisperse: aerosol particles of same or similar sizes nebulizer: an aerosol generator producing aerosol particles from liquid- based formulations pressurized metered-dose inhaler (pMDI): a drug device combination that dispenses multiple doses by means of a metered value; used interchangeably with pMDI residual volume (or dead volume): the amount of medication that remains in the nebulizer at the end of a treatment spacer: a valveless extension device that adds distance between the pMDI outlet and the patient’s mouth valved holding chamber: a spacer with a one-way valve used to contain aerosol particles until inspiration occurs  Aerosol Deposition Inertial impaction occurs with larger (>3 μm), fast-moving particles. Gravitational settling is a function of particle mass and time, with the rate of settling proportional to particle size and mass. Diffusion occurs with particles smaller than 1 μm. These mechanisms come into play as aerosol particles are inhaled orally or through the nose. Larger particles (>10 μm) are filtered in the nose and/or the oropharynx, largely by inertial impaction; particles of 5–10 μm generally reach the proximal generations of the lower respiratory  Types of Nebulizers Large Volume for delivering Bland Aerosol Small Volume for delivering medication Vibrating Mesh Ultrasonic How to… Slow tidal breathing with occasional deep breaths Use a tightly fitting face mask for those unable to use a mouthpiece Avoid using the "blow by" technique (i.e., holding the mask or open tube near the infant's nose and mouth) 08/31/2024 8 Delivery Device Selection Hazards of Aerosol Therapy 1. Bronchospasm: administration of a bronchodilator may decrease the potential of this hazard. 2. Overhydration 3. Overheating of inspired gas 4. Tubing condensation draining into the airway 5. Delivery of contaminated aerosol to the patient A baffle is used In a nebulizer in order to break up aerosol particles into smaller ones that are uniform is size. If a nebulizer is delivering large water droplets through the large bore tubing instead of a fine mist, then the nebulizer should be replaced because the baffle is probably missing. The baffle is responsible for breaking up the water particles into a fine mist.  Small-volume nebulizer a. Used as a handheld nebulizer or as a nebulizer on a ventilator or intermittent positive pressure breathing (IPPB) circuit to deliver medications. b. Usually holds 3 to 6 mL of liquid medications. 3 Important Points Concerning Nebulizers 1. Of all respiratory equipment, heated nebulizers are the greatest source of delivery of contaminated moisture to the patient; Pseudomonas species are the most common contaminant. These nebulizers should be replaced every 12 to 24 h. 2. Make sure that jets and capillary tubes are clear of debris or buildup of minerals by cleaning after each use. If the nebulizer is not producing adequate mist, a clogged capillary tube or jet may be the cause. 3 Important Points Concerning Nebulizers 3. Keep water drained out of the aerosol tubing because this increases the percentage of oxygen delivered to the patient. Water in the tubing obstructs gas flow, resulting in back pressure into the nebulizer. As pressure increases in the nebulizer, less air is entrained in the entrainment port; therefore delivered FiO2 increases, total flow to the patient decreases, and less aerosol is delivered. 08/31/2024 14 Stop and Think Why is inhalation an attractive route for drug delivery for drugs targeting both the lungs and other organ systems? Medications for Respiratory Disease Corticosteroids Leukotriene β-agonists modifiers Anticholinergics Mast cell Methylxanthines stabilizers Magnesium Anti-IgA Antimicrobials Secretion modifiers Epinephrine Has activity at α-receptors and β-receptors of the adrenergic nervous system. Primary use in respiratory diseases is for anaphylaxis when administered via the intramuscular or subcutaneous route. Aerosolized epinephrine is used for stridor. β2-Agonists SABA Short-acting β2-agonists Long-acting β2-agonistsLABA ICS Anticholinergic Agents (2 of 2) Ipratropium (Atrovent) SAMA Revefenacin (Yupelri) is approved for use in COPD. LAMA In COPD, the combination of either long- acting β2-agonists or short-acting β2-agonists with ipratropium is commonly used. Stop and Think You are caring for a patient with a COPD exacerbation in the emergency department. He has a heart rate of 120 beats/min, but also needs an inhaled bronchodilator. What options are available?