Delivery of Nebulizers and Inhalers to Patient

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Delivery of Inhaled Medication in Adults

• SHAMS ALI SHAH RT
• PRINCE SULTAN CARDIAC CENTER QASSIM
• KINGDOM OF SAUDI ARABIA

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INTRODUCTION

• The inhalation of therapeutic aerosols is an
  effective method of drug delivery frequently
  applied to the management of respiratory disease.
  
• Inhalation (or aerosol) therapy can be employed
  with a range of medications using a number of
  different techniques.

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OVERVIEW

• Three principal types of devices are used to
  generate therapeutic aerosols nebulizers,
  metered dose inhalers, and dry powder inhalers.
• All three generate aerosols using different
  mechanisms. In many cases, clinicians must choose
  the most appropriate device for drug delivery as
  well as the appropriate therapeutic agent .

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NEBULIZERS

• The basic design and performance of pneumatic (or
  jet) nebulizers have changed little over the past
  25 years.
• Mechanism The operation of a pneumatic
  nebulizer requires a pressurized gas supply,
  which acts as the driving force for liquid
  atomization. Compressed gas is delivered as a jet
  through a small orifice, generating a region of
  negative pressure above the medication reservoir.

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Pneumatic nebulizer
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Factors Determine the Efficiency of a Nebulizer
system

• The respirable dose,
• Nebulization time,
• Dead volume of the device,
• The gas used to drive the nebulizer.

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Respirable dose

• The most important characteristic of nebulizer
  performance is the respirable dose delivered to
  the patient.
• The respirable dose is a function of the mass
  output of the nebulizer and the size of the
  particles produced.
• Droplet size should be 2 to 5 µm for airway
  deposition and 1 to 2 µm or smaller for
  parenchymal deposition.

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Nebulization time

• In addition, a reduction in nebulization time may
  decrease the need for clinical supervision.
• In general, the greater the volume of drug to be
  delivered and the lower the flow rate of the
  driving gas, the longer the nebulization time.
• Treatment is complete when the nebulizer begins
  sputtering.

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Dead volume

• The volume of medication trapped inside the
  nebulizer, and therefore not available for
  inhalation, is referred to as the dead volume of
  the device.
• The dead volume is typically in the range of 1 to
  3 mL. Increasing the amount of solution within
  the nebulizer (the fill volume) reduces the
  proportion of the dose lost as dead volume.
• Although nebulizer output increases with a
  greater fill volume, this also results in an
  increase in nebulization time. Considering both
  factors, a nebulizer fill volume of 4 to 6 mL is
  recommended

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Driving gas

• Increasing the flow rate of the driving gas
  results in an increase in nebulized output and a
  reduction in particle size.
• A flow of 8 L/min is recommended to optimize drug
  delivery. T
• his may be problematic when a compressor is used
  to power the nebulizer, as the flow from these is
  often lt8 L/min, resulting in sub-optimal drug
  aerosolization and delivery.

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Gas density

• The density of the gas powering the nebulizer
  affects nebulizer performance.
• For example, the inhaled mass of albuterol is
  significantly reduced when a nebulizer is powered
  with a mixture of helium and oxygen (heliox).
• Accordingly, the flow to the nebulizer should be
  increased by 50 percent if it is powered with
  heliox.

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Mouthpieces and facemasks

• Inhaled aerosols can be administered using a
  mouthpiece or a facemask.
• Significant facial and eye deposition of aerosol
  can occur when a face mask is used, especially in
  young children .
• Eye deposition is of particular concern when
  aerosolized anticholinergic agents are
  administered, as this can result in blurring of
  vision, pupil dilation, and worsening of narrow
  angle glaucoma.

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Breathing pattern

• The breathing pattern of the patient affects the
  amount of aerosol deposited in the lower
  respiratory tract.
• To improve aerosol penetration and deposition in
  the lungs, the patient should be encouraged to
  use a slow breathing pattern with an occasional
  deep breath.

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Drug formulation

• Drug formulation can affect nebulizer performance
  .
• Metered dose inhalers and dry powder inhalers
  have always been tested and approved as a
  drug-delivery system combination.

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Nebulizers for specific medications

• Specially constructed small-volume nebulizers,
  such as the Respirgard II for aerosolized
  pentamidine, should be used when contamination of
  the ambient environment with the aerosolized drug
  needs to be avoided

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New nebulizer designs

• Breath-enhanced nebulizers, such as the Pari LC,
  are designed to allow release of more aerosol
  during inhalation.
• The Circulaire nebulizer reduces waste from a
  constant-output nebulizer by attachment of a
  storage bag with a one-way valve in the
  mouthpiece connector.
• The AeroEclipse nebulizer has a breath-actuated
  valve that triggers aerosol generation only
  during inhalation, eliminating the need for a
  storage bag or reservoir

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Ultrasonic nebulizers

• Ultrasonic nebulizers consist of a power unit and
  transducer, with or without an electric fan.
• The power unit converts electrical energy to
  high-frequency ultrasonic waves with a frequency
  of 1.63 megahertz

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DRY POWDER INHALERS

• Dry powder inhalers (DPIs) create aerosols by
  drawing air through a dose of powdered medication
  .
• Because DPIs are breath-actuated, they reduce the
  problem of coordinating inspiration with
  actuation. Breath coordination is still important
  because exhalation into a DPI blows the powder
  from the device.

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DRY POWDER INHALERS
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Vibrating mesh nebulizers

• The iNeb nebulizer uses vibrating mesh technology
  with adaptive aerosol delivery .
• This nebulizer is used specifically for the
  administration of Ventavis (iloprost) Inhalation
  Solution (CoTherix, Inc) for the treatment of
  pulmonary arterial hypertension

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Nebulizers vibrating mesh
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Nebulizer iNeb
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METERED DOSE INHALERS

• A metered dose inhaler (MDI) consists of a
  pressurized canister, a metering valve and stem,
  and a mouthpiece actuator .

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Metered dose inhaler
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Spacers and holding chambers

• Spacers and valved holding chambers are accessory
  devices that reduce oropharyngeal deposition of
  drug, improve distal delivery, and minimize the
  importance of hand-breath coordination.

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MDI with counter
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MDI spacers
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The Things We should Care

• Patient teaching .
• Determining when an MDI is empty .
• Spacers and holding chambers .
• DRY POWDER INHALERS .

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Equipment for aerosol delivery to tracheostomy in
spontaneously breathing patients
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MECHANICALLY VENTILATED PATIENTS

• Nebulized medications can be delivered to
  patients receiving mechanical ventilation using
  either an MDI or a nebulizer.
• A DPI cannot be used to deliver dry powder
  during mechanical ventilation because ventilator
  circuit humidification impairs aerosol formation.

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MDI in-line spacer
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Neb or MDI use with NPPV
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REFERENCES

• Olschewski, H, Simonneau, G, Galie, N, et al.
  Inhaled iloprost for severe pulmonary
  hypertension. N Engl J Med 2002 347322.
• Henry, RR, Mudaliar, SR, Howland III, WC, et al.
  Inhaled insulin using the AERx insulin diabetes
  management system in healthy and asthmatic
  subjects. Diabetes Care 2003 26764.
• Dolovich, MB, Ahrens, RC, Hess, DR, et al. Device
  selection and outcomes of aerosol therapy
  evidence-based guidelines American College of
  Chest Physicians/American College of Asthma,
  Allergy, and Immunology. Chest 2005 127335.
• Hess, DR. Nebulizers principles and performance.
  Respir Care 2000 45609.
• Rau, JL. Design principles of liquid nebulization
  devices currently in use. Respir Care 2002
  471257.
• Leung, K, Louca, E, Coates, AL. Comparison of
  breath-enhanced to breath-actuated nebulizers for
  rate, consistency, and efficiency. Chest 2004
  1261619.
• Hess, D, Fisher, D, Williams, P, et al.
  Medication nebulizer performance. Effects of
  diluent volume, nebulizer flow, and nebulizer
  brand. Chest 1996 110498.
• Fink, JB. Aerosol device selection Evidence to
  practice. Respir Care 2000 45874.
• Kacmarek, RM, Hess, D. The interface between
  patient and aerosol generator. Respir Care 1991
  36952.
• Rodrigo, GJ, Rodrigo, C. Continuous vs
  intermittent beta-agonists in the treatment of
  acute adult asthma a systematic review with
  meta-analysis. Chest 2002 122160.
• Reisner, C, Katial, RK, Bartelson, BB, et al.
  Characterization of aerosol output from various
  nebulizer/compressor combinations. Ann Allergy
  Asthma Immunol 2001 86566.
• Standaert, TA, Bohn, SE, Aitken, ML, Ramsey, B.
  The equivalence of compressor pressure-flow
  relationships with respect to jet nebulizer
  aerosolization characteristics. J Aerosol Med
  2001 1431.
• Standaert, TA, Vandevanter, D, Ramsey, BW, et al.
  The choice of compressor effects the aerosol
  parameters and the delivery of tobramycin from a
  single model nebulizer. J Aerosol Med 2000
  13147.
• Hess, DR, Acosta, FL, Ritz, RH, et al. The effect
  of heliox on nebulizer function using a
  beta-agonist bronchodilator. Chest 1999 115184.
• Kress, JP, North, I, Gelbach, BK, et al. The
  utility of albuterol nebulized with heliox during
  acute asthma exacerbations. Am J Respir Crit Care
  Med 2002 1651317.
• Henderson, SO, Acharya, P, Kilaghbian, T, et al.
  Use of heliox-driven nebulizer therapy in the
  treatment of acute asthma. Ann Emerg Med 1999
  33141.
• Anderson, M, Svartengren, M, Philipson, K, et al.
  Deposition in man of particles suspended in air
  or in helium-oxygen mixture at different flow
  rates. J Aerosol Med 1990 3209.
• Anderson, M, Svartengren, M, Bylin, G, et al.
  Deposition in asthmatics of particles inahled in
  air or in helium-oxygen. Am Rev Respir Dis 1993
  147524.

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THANKS