Presentation on theme: "Scintigraphic Assessment of Radio-Aerosol Pulmonary Deposition With the Acapella Positive Expiratory Pressure Device and Various Nebulizer Configurations."— Presentation transcript:
1Scintigraphic Assessment of Radio-Aerosol Pulmonary Deposition With the Acapella Positive Expiratory Pressure Device and Various Nebulizer ConfigurationsBrian K. Walsh, RRT-NPS, RRT-ACCS, RPFT, FAARCBoston Children’s Hospital andHarvard Medical School
2BackgroundThere are several components to optimal delivery of medications to the pulmonary systemBreathing patterns – including muscle weaknessDiameter of the airway – mucus, inflammation, bronchospasm or maybe a combinationInhaled medications can promote hydration, reduce viscosity, bronchodilate and aide in mucociliary clearanceHas become an acceptable adjunct
3BackgroundBronchial hygiene therapy involves noninvasive and invasive techniques to assist with mobilization and clearance.Two modalities are:Positive expiratory pressure (PEP)High frequency oscillatory PEPPEP – to stabilize the airways, preventing collapse and possibly improving collateral ventilation
4Moving Stenosis and Collateral Ventilation Walsh, Resp Care, 2011; 56;9McCool, Chest 2006;129;250
5Oscillatory PEPMay have the added benefit of dislodging thick secretions and decrease mucus viscoelasticityAcapella high-frequency oscillatory PEP produces oscillations during EXHALATION by the use of a magnetic valve that creates intermittently occlusions.5 pressure settings at approximately 13 HzNot position dependent / two flow range devices
6Research QuestionProximal placement of nebulizer would be superior to manufacture recommended (distal) and equal to nebulizer aloneRecommendedHypothesisControlConflicts of interest are properly disclosed on page 329.
7Methods Randomized crossover clinical trial Approved by research committeeSubjectsNon-smoking, healthy males, no lung disease, years with normal spirometryProcedureSVN run at 7 L/min with 3.6um +/- 2.2um MMAD with 4 mL of saline and technetium-99m-labeled diethylene triamine penta-acetic acid (25mCi) and nebulized over 9 minsRandomized to 3 different configurations
8Procedure Continued Via mouth piece with subjects seated upright Breathing patterns were standardized with deep breaths and inspiratory pausesImmediately after administration scintigraphy was performedLung images were divided into regions of interest
10ScintigraphyMost commonly used for the diagnosis of pulmonary embolism via ventilation/perfusion scan. Less commonly used to evaluation lung transplants and right to left shunts.
11Results Enrolled 14 males, but only 10 completed Mean age was 24.4 (2.2)BMI 22.6 (2.6)Spirometry normalDeposition was similar in the right and left lungsThere was less total deposition in configuration A than B or C
12Lung Deposition Total Lung RecommendedExperimentControl
13Lung Deposition Upper, Middle and Lower RecommendedExperimentControl
14Lung Deposition Central, Intermediate and Peripheral
15DiscussionDespite the Acapella appearing to be a nice reservoir the distal placement likely creates impaction of larger particlesInternal mechanisms within the Acapella create turbulent or transitional flow that increase the deposition of larger particles in the deviceSome evidence that MMAD is reduced due to a filtering effect
16DiscussionRecommended – Demonstrating a large amount of aerosol depositing within the AcapellaProximal placement (Experiment) – Demonstrating a large amount of aerosol within the mouth piece and valve
17Discussion PEP in general may play a role in aerosol delivery Some findings supportiveSome findings within SDSome findings consistent with prolonged expiratory phases that may allow lower inspired drug delivery compared to normal breathing with periodic inspiratory holdsMaybe they should have used a breath actuated nebulizer??
18DiscussionLung deposition was not statically different however trends were noticedNormal distribution of ventilation were consistent with results.LimitationThese were normal subjects who do not exhibit the same breathing or flow patternThey didn’t describe or measure minute ventilation during the administration
19Editorial by Dr. Berlinski The Order of the Factors Affects a Product Combining therapies is attractiveIs marketed to reduces timeYet, can increase cost or reduce effectiveness by reducing aerosol delivery by 70%Limitations discussed regarding normal subjects, however concluded that it would likely be the same in lung diseased patientsOrder of therapies may matterSome have recommended a certain order of therapies in the past
20ConclusionsPlacing the nebulizer distal to the oscillatory PEP device decreased intrapulmonary deposition, compared to proximal placement, and compared to nebulizer alone.Three possible take home messages:You could say more data is needed to go against manufacturers recommendationsYou could apply the SVN at the proximal (mouth piece) of the oscillatory PEP device when therapy time is considered a factorYou could # 2 to all patients who require the combination of therapies
21What you cannot conclude… The experimental placement and combined therapy is superior to SVN aloneBAN would be better