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Aerosol Delivery Devices and Peak Flowmeters. Fritz Merkel , BS, RCP Community Healthworker Training February 2008. Hang in there!. Getting near the end. Hopefully we’ll have a little fun, and Learn something. NAEPP says….blah, blah, blah
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Aerosol Delivery Devices and Peak Flowmeters • Fritz Merkel, BS, RCP • Community Healthworker Training • February 2008
Hang in there! • Getting near the end. • Hopefully we’ll have a little fun, and • Learn something. • NAEPP says….blah, blah, blah • But you HAVE TO KNOW HOW TO USE THESE AEROSOL DEVICES.
Delivery Devices- Choices- • Choice of aerosol delivery system depends on: - Effective dose - Drug deposition - Patient ability - Patient acceptance - Cost (immediate vs. cost effective) 1 • Incorrect use of aerosol devices is a major factor in sub-optimal therapy.
Poor Technique =Poor Medication Delivery • Majority of health professionals teaching MDI use do not perform procedure perfectly. 2-3 • Allow 10-30 minutes for instruction. (Few patients ever get this) • Explain > Demonstrate > Practice > Return demonstration. • Repeated demonstration improves performance.(Up to 3 sessions required).
Output range is 30-100 ml. 4 Velocity 15 m/s > falls rapidly (0.2 second) 4 80% deposition in oropharynx. 10-15% deposited in in lungs. Optimal deposition size is < 6 mm (1-5 mm) 5 Propellant chlorofluorocarbon – banned 1987 (exempted under “essential use” ruling) -lose permanent exemption end 2008. MDI
Distribution of Aerosol-MDI • Radiolabeled aerosol delivered with no add-on spacer device. 16
MDI Problems - Common • Hard to do right for anyone: esp. very young, very old, handicapped, mentally compromised. • Cough (medication lost ). • Rapid inhalation. Short breath hold. • Cold MDI (poor aerosolization). • Plugged orifice-Keep capped when not in use. • Multiple actuations/breath. • Poor timing - too soon, too late, blow out… • Oral deposition
Oral & Vocal Cord Deposition **Candida (thrush)/hoarseness, mouth sore** (for inhaled steroids only) • Use a VHC or Spacer • Tilt head back and “open” the throat shaping it as though making a deep “O”. • Inhale slowly…slower…..even slower. • Immediately rinse, gargle and spit. • Use mouthwash instead of water.
Lose Track of Doses • Check package insert for number of doses. • Mark off on calendar. • Put tape on MDI and checkoff doses. • Dose counter-(30 day calendar) • Water floatation not recommended (inaccurate + may plug nozzle)17
Spacers • Add-on tube; no valve. • Needs sufficient volume (100-700cc) for propellant to evaporate. • Reduces oral/vocal cord deposition but does NOT help with hand-breath coordination problems. • Reduces (bad) “taste”. (users may need to be re-educated that this is OK.)
Valved Holding Chamber • One-way inspiratory valve protecting the patient from poor hand-breath coordination • Traps large particles:> reduce pharyngeal deposition > 10-15x less than MDI alone. 4-5 • Slows down & “matures” droplets. • Better lung distribution.
VHC & Infants • Infants/children (0~5/6) – May use multiple breaths to empty the aerosol from the VHC. • Minimal mask dead space > Good mask fit.
VHC & Infants • No benefit to VHC volume > 150cc. Need to be able to evacuate chamber. • Do not give to crying babies! - Poor deposition (same with nebs) - - Crying is an exhalation maneuver.
Young/Elderly/Handicapped • Young > add mask+VHC (<5-6 years) - “Parent” must know how to use. • Elderly > VHC • Explain > Demonstrate > Practice > Return demonstration • Analyze failure > Nebulizer if appropriate. • Add Leukotreine Modifiers ? (~ 50% effective)
Hydrofluroalkane (HFA) • Replaces chlorofluorocarbon (CFC). • Lower Jet velocity (slower med plume) • Quieter, softer sound. • Less affected by ambient temperature. • Less cold freon effect. • As effective as CFC MDI >>possibly more effective<< • QVAR (ICS), Proventil & XopenexHFA
Gamma scan: Beclomethasone (BDP)-healthy subject Right: BDP with HFA propellant = greater lung deposition & less oropharygeal deposition than CFC propellant. 9 (no spacer)
Beclomethasone with HFA (¨ ) vs CFC (*).HFA dose (200 µg) vs. half CFC (400 µg)Single dose14 Days
Don’t Use with HFABuilt in canister actuator Medispacer E Z Spacer
Spacer/VHC Variations • One device can increase lung drug delivery and decrease delivery with another drug. • 2-6 fold variation in respirable dose emitted with various devices. • Due to variations it may be best to use same combinations that were studied. • But-no specific combinations have been specifically approved by FDA.14
Spacer/VHC Cleaning & Prep • Rinse plastic Spacer/VHC when new and once a month with dilute liquid household detergent. • 1-2 drops/cup of water. • Let drip dry, do not rinse. • Defeats static cling (so does normal use)
DPI-Requirements • Rapid, deep inhalation critical: 30-120 lpm required. 5 • Inadequate flow = inadequate delivery. • Unsuited to the very young, very ill, weak patients, elderly, or altered mental status. (But so are MDI’s) • Conflicts with breathing pattern for MDI. (Slow vs. Fast)
Fast vs. Slow Inhalation • Higher flow picks up more medication.
DPI-Problems • Particulate irritation may cause cough (rare). • High humidity may cause clumping of powder, esp. when leaving the cap off or moving from very cold to warm environment (non-blister pack). • Blowing into DPI may blow drug out and will introduce internal humidity. • Different inhalation pattern from MDI.
DPI – Internal Resistance • Turbuhaler greater resistance than Discus (easier for kids). Aerosolizer = low
Lung deposition; % of the emitted dose, Different DPIs 2 different inspiratory flow rates.Dolovich.9
DPI-Instruction • Health care provider MUST know technique appropriate to the device to teach effectively. • New devices and techniques being developed requiring providers to stay abreast of developments. • Different devices = different techniques.
DPI - Models and Instruction • DISKUS - 60 doses (blister pack tape) • Pulmicort Turbuhaler – 200 dose (single container) • Floradil Aerosolizer – single doses (blister pack - pill) • Asmanex Twisthaler - 30, 60, 120 dose (single cont.)
Nebulizer • Newer designs provide enhanced performance. • Breath Actuated Nebs > BAN - one-way valves; Pari AeroEclipse. • Various reservoir types. • Thumb valves.
Nebulizer Cups • Many different kinds. Little attention often paid to matching compressor to cups. • Some models are proprietary and MUST be matched. • Inexpensive models are usually disposable but may be used (regularly) for > 1 month if cleaned regularly. • Non-disposable (Pari) may have superior output and may be used for 6-12 months.
Neb - Medication Problem • Unit-dose bronchodilator usual Rx. • Mixing medication problems > Children:Unit-dose bronchodilator + Unit-dose Intal = excessive dilution > (longer treatment). • Get “concentrate” bronchodilator solution. • Less of a problem than it used to be. • “Blow by” has not been found to be effective in children-use a mask. 14
Neb Cleaning • After each treatment, rinse the nebulizer cup with warm water, shake off excess water and let it air dry. • At the end of each day, the nebulizer cup, mask or mouthpiece should be washed in warm, soapy water using a mild detergent, rinsed thoroughly and allowed to air dry. The Pari reusable nebulizer is dishwasher safe, run through cycle on top rack only in a small parts basket.
Neb Disinfecting • Every third day, after washing your equipment, disinfect using a vinegar/water solution or the disinfectant solution your supplier suggests. • Vinegar solution-mix 1/2 cup white vinegar with 1-1/2 cups of water. Soak for 30 minutes and rinse well under a steady stream of water. Shake off the excess water and allow to air dry on a paper towel. Always allow the equipment to completely dry before storing in a plastic, zipper storage bag.
Nebulizer vs. MDI+VHC • Several studies done with acutely ill infants and children in the ER. • With PROPER instruction and administration of MDI+VHC: > No difference shown in rate of improvement or clinical score over conventional nebulizer treatment. 6-7
Drug Deposition • Deposition from major types of early (pre-1990) aerosol delivery devices: MDI, MDI-spacer, SVN, DPI 15
Approx.% ofdrug dose depositedDPI’s vs. pMDI Dolovich.11 (Turbuhaler, Diskus, Spiros, and Clickhaler)
Traditional vs. Newer Devices Lung Deposition (various studies) between traditional and newer devices. hydrofluroalkane-beclomethasone, small volume neb, dry powder inhaler. 40-50% possible now vs. 10-15% 16
Dosage Differencesfor Various Devices • Deposition of devices to the lungs (**has been**) similar. • Starting (nominal) dose is not the same. • Nebulizer starting dose is 11-12x larger than the MDI dose. • MDI’s can have similar clinical effect but may need increased # of puffs. 14
Ultrasonic Nebulizer • More Expensive • Special batteries • Fragile • No insurance coverage • Silent • Fast > Dense output • Possibly less waste
Respimat Soft Mist Inhaler (propellant free, spring driven “MDI” - Boehringer Ingelheim) Mouthpiece Uniblock Dosing Chamber Dose-release button Upper housing Capillary tube Transparent base Spring Cartridge
Spiros DPI Breath-actuated, multi-dose cassette, battery-powered inhalation assist12
AERx Pulmonary Device Aradigm Corporation • Pre-packaged, single-use disposable blister packet and disposable nozzle. • Utilize a piston mechanism to expel formulation from the AERx Strip
Mystic Inhaler Ventaira Pharmaceuticals Pharmaceuticals Pharmaceuticals • Electronic nebulization process. Electrical field is applied to a conductive liquid leading to the formation of a soft mist droplet aerosol. • Soft mist, breath-activated, robust, easy to use, programmable hand-held device.
Aria Chrysalis Technologies >Altria >Phillip Morris (that’s right!) • Looking for a cigarette that would appeal to health-conscious smokers ( speaker’s note - ????) • Device that allowed smokers to inhale a mist laced with nicotine rather than inhale smoke – Didn’t take off. • Aerosol device could be used to deliver drugs to the lungs.
Peak Flow Meters • Most useful for moderate-to severe persistent asthma. • Designed for monitoring. • Not a diagnostic tool. • Dependent on effort and technique. • Good instruction and frequent review is needed.
PFM-Reliability • Most units provide highly repeatable est. of PF. • Recommended > + 10% over full range: 100-400 L/min-children; 100-700 L/min-adults. • Reproducibility of + 10% or 5% of reading. • Different PFM’s will give different readings. • Astech met all criteria. 13
PFM - Real World Use • Most useful with an ACTION PLAN. • The patient must know WHAT to do with the PFM information. • Instruction is often inadequate due to time constraints. (So-what’s new?) • Action plans may take multiple visits and considerable time to set up. • Follow-ups necessary for maintenance.