Ch 36 Aerosol Drug Therapy – Flashcards
Unlock all answers in this set
Unlock answersquestion
What is an aerosol?
answer
A suspension of solid or liquid particles in gas
question
In the clinical setting, how are medical aerosols produced?
answer
Using devices that physically disperse matter into small particles and suspend them in gas
question
Why is inhaled medication effective?
answer
It targets the problem directly.
question
Why does medical aerosol provide a higher therapeutic index?
answer
-Higher drug concentration in lung -Has lower systemic effects (not the whole body)
question
What is an aerosol output?
answer
Mass of fluid or drug in the aerosol
question
What is the output rate of aerosol?
answer
Mass of aerosol generated per unit of time
question
What is the emitted dose?
answer
the mass of drug leaving mouthpiece of the nebulizer as aerosol
question
How is emitted dose measured?
answer
by collecting aerosol that leaves nebulizer on filters
question
2 methods to measure emitted dose
answer
-Gravimetric analysis -Assay
question
How does a garvimeter measure the emitted dose?
answer
measures aerosol weight
question
How does an assay measure the emitted dose?
answer
measures the drug quantity (volume)
question
What 3 factors affect the particle size?
answer
-Substance being nebulized -Method used -Environmental conditions
question
What is the amount of drug inhaled called?
answer
Inhaled mass
question
What is the portion of inhaled mass that can reach lower airways?
answer
Respirable mass
question
What is the portion of the inhaled mass that deposits in the lungs?
answer
Respirable dose
question
What does deposition mean?
answer
The area that a medication produces therapeutic effect on
question
What is deposition influenced by?
answer
-inspiratory flow rate -flow pattern -respiratory rate -inhaled volume -I:E ratio -Breath holding
question
How are aerosols deposited?
answer
-Inertial impaction -Gravimetric sedimentation -Brownian diffusion
question
When does inertial impaction occur?
answer
when an aerosol in motion collides with and are deposited on surface
question
What is inertia?
answer
The force of an object in motion
question
How big are large particles?
answer
> 5 micrometers
question
When does sedimentation occur?
answer
when aerosol particles setle out of suspension and are deposited due to gravity
question
How big are small particles?
answer
1-5 micrometers
question
What does inertial impaction mainly deposit?
answer
large particles
question
What does sedimentation usually deposit?
answer
small particles
question
What increases sedimentation and distribution across the lungs?
answer
Holding your breath after inhaling
question
How is the particle mass and sedimentation related?
answer
Directly (The greater the particle mass, the faster it setlles)
question
What sized particles does Brownian diffusion mainly deposit?
answer
very small particles
question
How big are very small particles?
answer
< 3 micrometers
question
What size are particles that remain in suspension and are exhaled back into the environment?
answer
1 and 0.5 micrometers
question
What size are particles that are retained in the lungs more?
answer
< 0.5 micrometers
question
Where does Brownian diffusion occur?
answer
deep within lung
question
What is aging?
answer
process by which aerosol suspension changes over time. Individual aerosols are constantly shrinking, growing, combining, and going out of suspension.
question
What ages faster, small or big particles?
answer
small particles
question
Aerosol changes depends on what?
answer
-composition of aerosol -initial size of its particles -time in suspension -ambient condition
question
What is the primary hazard of drug therapy?
answer
adverse reaction to medication
question
Other possible hazards of aerosol therapy
answer
-Infection -Airway reactivity -Pulmonary and systemic effects of bland aerosols -drug concentration changes during nebulization -eye irritation
question
What does pMDI stand for?
answer
pressurized metered-dose inhaler
question
What is a pressurized metered-dose inhaler?
answer
A pressurized canister containing prescribed drug in volatile propellant combined with surfactant and a dispersing agent
question
What is a pMDI most commonly used for?
answer
used for aerosol therapy
question
What are the benefits of a pMDI?
answer
-portable, compact, and easy to use -provides multidose convenience
question
What is a serious limitation of a pMDI?
answer
lacks counter to indicate number of doses remaining in canister
question
What are some kinds of pMDI?
answer
-Breath actuated -Aerocount autoinhaler -Easihaler and Tempo
question
What mechanism do most pMDIs use?
answer
"Press and Breathe"
question
How do you activate a breath actuated pMDI activated?
answer
by inhaling
question
What's one benefit of a breath actuated pMDI?
answer
Reduces need for patient/caregiver to coordinate metered dose inhaler actuation with inhalation
question
What activates an aerocount autohaler pMDI?
answer
Flow-triggered
question
What's one benefit of an aerocount autohaler pMDI?
answer
Eliminates need for hand-breath coordination
question
What activates an Easihaler & Tempo pMDI?
answer
activated by breathing
question
What factors affect pMDI performance and drug delivery?
answer
-temperature -nozzle size and cleanliness -priming -timing of actuation intervals
question
How does temperature affect the output of a pMDI?
answer
low temperature decreases the output
question
How does nozzle size and cleanliness affect the emitted dose?
answer
dirty nozzles reduce the output
question
What is priming?
answer
shaking a device and releasing one or more sprays
question
When is priming done?
answer
when pMDI has not been used for a while
question
What does priming do?
answer
mixes drug and propellant
question
Why is priming important?
answer
it is required to provide and adequate dose
question
What happens to the pMDI when propellants are released?
answer
the device cools and changes aerosol output
question
When is the timing of actuation intervals important?
answer
important with multiple doses
question
What range can pMDI particles achieve?
answer
Respirable range (MMAD)
question
What does MMAD stand for?
answer
Mass Median Aerodynamic Diameter
question
How far is the respirable range?
answer
2-6 micrometers
question
What percent of aerosols deposit in the oropharynx?
answer
about 80%
question
What's the percent range of pulmonary deposition in adults and larger children?
answer
10% and 20%
question
With the open mouth technique, where do you have the most deposition?
answer
in the lungs
question
With the closed mouth technique, where do you get the most deposition?
answer
In your tongue
question
When is a breath actuated pMDI useful?
answer
when pt cannot coordinate inhalation with actuation
question
What is a spacer?
answer
simple valveless extension device that adds distance between pMDI outlet and pt's mouth
question
What do spacers do?
answer
reduce oropharyngeal deposition and need for hand-breath coordination
question
What does a chamber do?
answer
incorporates one or more valves that prevent aerosol in chamber from being cleared on exhalation
question
What are the advantages of chambers over spacers?
answer
-less oropharyngeal deposition -higher respirable drug doses -better protection from poor hand-breath coordination
question
What dosing system do dry powder inhalers use?
answer
breath actuated system
question
How do pts create aerosol woth a DPI?
answer
inhaling air through dose of finely milled drug powder
question
With DPIs, what does the dispersion of powder depend on?
answer
creation of turbulent flow in the inhaler
question
What created flow in a DPI?
answer
patient inhalation with sufficiently high inspiratory flow rate
question
What factors affec DPI performance and drug delivery?
answer
-intrinsic resistance and inspiratory flow rate -exposure to humidity and moisture -pt's inspiratory flow rate
question
When using a DPI, how much inspiratory flow rate must a pt produce?
answer
40-60 L/min
question
Who shouldn't use DPIs?
answer
-infants -small children -those who cannot follow instructions (e.g. small children) -Pts with airway obstruction
question
What powers most nebulizers?
answer
high pressure oxygen or air
question
What factors affect nebulizer performance?
answer
-Nebulizer design -gas pressure -gas density -medication characteristics
question
What kind of inspiratory flow optimizes SVN aerosol deposition?
answer
slow inspiratory flow
question
How do you know when your patient is breathing through they nose while on a nebulizer?
answer
You can see a constant flow of aerosol. They are not receiving the medication.
question
What factors affects selection of delivery method for SVNs?
answer
-patient ability (mask or mouthpiece) -preference -comfort
question
What should be used to rinse off nebulizers?
answer
Sterile water then air dried
question
When are large volume jet nebulizers particularly useful?
answer
when traditional dosing strategies for pts with bronchospasm are not effective
question
How long does a large volume jet nebulizer aerosol therapy last?
answer
1-2 hours
question
How ling does a small volume nebulizer therapy last?
answer
10-15 minutes
question
What special large volume nebulizers provide?
answer
Continuous Bronchodilator Therapy (CBT)
question
What does HEART mean?
answer
High output Extended Aerosol Respiratory Therapy
question
What does SPAG stand for?
answer
Small particle aerosol generator
question
What is SPAG specifically used for?
answer
administration of ribavirin
question
Why does a SPAG incorporate a drying chamber with its own flow?
answer
to produce a stable aerosol
question
What are some concerns with a SPAG?
answer
-caregiver exposure to drug -precipitate can jam breathing valves in mechanical ventilator circuit
question
What's one problem with ribavirin?
answer
it can make you sterile
question
What does ribavirin kill?
answer
respiratory syncytial virus
question
What output can a USN produce?
answer
0.2-1.0 ml/min with higher aerosol densities and higher outputs than conventional jet nebulizers
question
What are some special medication delivery issues for infants and children?
answer
-Smaller airway diameter -faster breathing rate -nose breathing filters out large particles -lower minute volumes -may have poor cooperation
question
Why shouldn't u administer aerosol to crying kids?
answer
because crying reduces lower airway deposition of aerosol medication
question
When do u use a blow by technique?
answer
when pt cannot tolerate a mask treatment
question
How do u perform a blow by technique?
answer
direct aerosol from nebulizer toward pt nose and mouth several inches away from the pt's face
question
What is the key to effective bronchodilator therapy protocol?
answer
Ongoing pt assessment
question
What measurement can provide trends if same device is used from one treatment to next?
answer
peak flow measurement
question
What's the gold standard for determining the effectiveness of a breathing treatment?
answer
Spirometry
question
What does PEFR stand for?
answer
Peak Expiratory Flow Rate
question
What are the components of pt assessment?
answer
-pt nterview -observation -VS -ausculatation -ABG -oximetry
question
What should you do to determine the best dosage for pts with moderate obstruction?
answer
conduct dose-response titration
question
What is the goal of pt education?
answer
To have pts independently self administer their own medications
question
What dose of CBT with nebulized albuterol is proven to be effective for adults and children with severe asthma?
answer
5-20 mg/hr
question
For the first 2 hours after CBT therapy, how often should a pt be assessed?
answer
every 30 minutes, then hourly after
question
What kind of ventilators is non invasive ventilation administered with?
answer
bi-level ventilators
question
What drugs were associated with health risks to caregivers?
answer
-Pentamidine -Ribavirin
question
How can nebulized drugs enter the room?
answer
directly from the nebulizer or during pt exhalation
question
What nebulizers produce the greatest amount of second-hand aerosol?
answer
Continuos pneumatic nebulizers
question
How do u control environmental contamination?
answer
-use of one way valves and filters -negative pressure rooms and treatment booths -PPE for pts with airborne disease
