Med Administration Flashcards
Off Label Use
- Off the label is when drugs have FDA approval but are being used for a specific age, group, or purpose in which they do not have FDA approval for
- Ex. Aspirin for prophylaxis of heart attack
- This practice is legal as the FDA cannot by law regulate how is drug is medically used
- Virtually all inhaled beta agonists and corticosteroid formulations have FDA approval for 12 year and older.
- These will be prescribed when a suitable alternative does not exist
Why do we use off label uses for Pediatric populations so much
Pediatric patient are the most common group for which off label use medications are prescribed
Due to the fact that it is so hard to get studies approved for pediatric patients
What factors will affect depoistion in in children
Smaller tracheal diameter
Shorter trachea
Higher RR
Lower MV
Lower deadspace
Lower inspiratory flow rate
DEPOSITION OF MEDICATION IN CHILDREN
A smaller fraction of the dose of aerosol medication will reach the lower airways
Decreased aerosol drug deposition to lungs due to smaller diameter of NN and pediatric lower airways.
Lower deposition may provide a comparable safety and efficacy profile to adults.
What is the acutal dose that is though to be given to neonates, ped, and adulst
~1% in Neonates and Infants
2.5% in young children
10-15% in adults
Even though smaller %, small patients may receive a higher drug/kg than adults
Aerolsolized Therapy
When less than 6 months old
The child will have a small Vt which will affect TCT and inspiratory flow
Decreased time in the airways= decreased aerosol deposition
This means they will inhale a lower % of emitted aerosol dose
What is an anatomical saftey feature in children airway
Age and size have a self limiting effect on lung dose
Produces a natural titration of dose
Aerosol doses to neonates and children and thought to be self limiting
This is due to differences between pediatric and adult airways
Dosing for Infants and NN
Generally dosing with inhaled aerosols for neonatal and pediatric patients is not based on body size and blood level
Rather it will be based on a target effect strategy with avoidance of toxicity
We give the same dose (5 puff) of Ventolin to kids that are one as we do for kids that are 3
The 3 year old will still get more medication as their airway is bigger, they have a smaller RR, etc.
DEPOSITION FACTORS
Patient
Breathing Pattern
Inspiratory Flow Rate
Tidal Volume
Cry and distress-This will seriously effect efficiency of aerosol administration
DEPOSITION FACTORS
Device
Chamber Volume
Design of inspiratory and expiratory valves if present
Amount of deadspace in mouthpiece
Electrostatic charge on plastic devices
Higher RR
Higher RR will affect sedimentation
Faster Inspiratory Flow Rate
The faster they breath in the more intertia of impactation
Breathing Pattern in Young Children
Slow, fast, holding their breath (use a spacer), crying
Look at the value on the spacer as it will open as they breath or you can look at their chest and count 5 breaths
Spacers
- The more expensive spacers will be antistatic, but when people take it home they tend to scrub it clean which can scrub off the antistatic coating
- Kid spacer is smaller than adult spacers
- What makes spacers effective
- Slow down breathing
- Children that are 2-3 is when you can start using a mouthpiece instead of a mask
Aerosol vs. MDI, MDI with Spacer vs. DPI
All are equally effective when used properly for delivering short acting B agonists
Nebs and MDI + Spacer
Nebs and MDI + Spacer are most useful in young children because they only require tidal breathing
Holds true even in acute asthma attacks
When the Child is 4 Years or Less
SVN with mask or mouthpiece if able
MDI plus Valved holding device (VHD)
For 3 years or older: mouthpiece preferable to mask if tolerated
For smaller children a smaller volume VHD is preferable, less time to empty chamber=higher delivery
When the Child is more than 4 Years
- MDI with VHD
- MDI should not be used without a VHD
- VHD also reduces oral-pharyngeal deposition
- We can recommend a DPI when the child is four
SLEEPING KIDS
~70% of children will wake up when aerosol is given during sleep
When they wake up they will become distressed and cry
Try to distract and comfort them
Age and Dose Regulating Effects
Age will have a dose regulating effect on the amount of aerosol drug reaching the lungs
Less drug will reach the lung in younger subjects, but more studies are needed
It is important to monitor the patient for adverse systemic effects
Choose appropriate device for the patient based on ability
DPI vs. MDI
DPI is more effective than MDI without a spacer. If their MDI does have a spacer then it is about equivilantto the effectiveness of DPI
Humidity
Water that exists in the form of individual molecules in the vaporous or gaseous state.
Aerosol
a suspension of particles (solid or liquid) present in gas (air):
Clinical Use of Aerosols
Humidify dry inspired gas, using water aerosol
Sputum induction & to improve mobilization and clearance of respiratory secretions using bland aerosols
Deliver aerosolized drugs (bronchodilators, anti-inflammatories and antibiotics) to respiratory tract
Medication delivery with Croup
With croup we will give something that settles in the upper airway as opposed to something that is avaliabelin the lower airway
Ultrasonic Nebulizer vs Small Volume Nebulizer
- SVN do not have a high quality control where as USN will have a higher quality control
- To get rid of residual volume in a SVN you need to top it up
- Deadvolume= residual volume
- There will be no residual volume with a USN
- USN is fading away and we are using a ultrasonic mesh instead
Hand Bulb Atomizers
Do not use baffle
Aerosol suspension designed for upper airway deposition.
nasal spray pumps (steroids) rhinitis,
high MMAD and GSD
Will give us big particles and the high the particle the high it will settle
Hand Bulb Atomizer Used for
Upper airway inflammation
Rhinitis
Local anesthesia
Particle Size and Predicted Lung Deposition
Upper Airway
Particle 5-10 micron range tend to deposit in UA and early airway generations
Ex. Medicine for Croup
Particle Size and Predicted Lung Deposition
Nose
100% deposition of particle sizes >10 microns
Particle Size and Predicted Lung Deposition
Mouth
100% deposition of particle sizes >15 microns
Particle Size and Predicted Lung Deposition
Lower Airway
Particles 1-5 micron range able to reach LRT and lung periphery
This range also called ‘respirable fraction’
Measures of Central Tendency
lMedical aerosols contain particles of many different sizes.
2 Common Ways of Measuring Central Tendency
- The average particle size is expressed in terms of a measure of central tendency.
- Mass Median Aerodynamic Diameter (MMAD)*
- Variability of particle sizes in an aerosol.
- Geometric Standard Deviation (GSD)
Mass Median Aerodynamic Diameter (MMAD)
Describes average particle diameter (µm).
50% of the particles are smaller & have less mass.
50% of the particles are larger & have greater mass.
Geometric Standard Deviation (GSD) “The Spread”
- The greater the GSD, the wider the range of particle sizes produced by a device.
- GSD < 1.22, aerosol considered monodispersed = single particle size
- GSD > 1.22, aerosol considered heterodispersed= range of particle sizes
- Most aerosols used in respiratory care
Aerosol output
Weight or mass of aerosol particles produced by nebulizer (usually per minute)
Does not indicate amount of drug reaching lungs as majority of particles leaving neb never reach lungs
Only 10-50% of administered dose actually reaches LRT, depending on device used & technique
Deposition
Particles depositing out of suspension to remain in lung
Particle Size And Lung Distribution
- Particle size is one of major factors affecting aerosol deposition in lung
- Despite knowing its size, not possible to specify exactly where particle will deposit in lung
- Particle deposition is function of several mechanisms:
- Breathing pattern
- Inspiratory flow rate
- Thus site of penetration can be predicted but not confirmed
Particles > 10 microns
Tx nasopharyngeal or oropharyngeal regions
e.g. nasal spray for rhinitis
Particles 5- 10 microns
Deposition to more central airways with significant deposition in oropharyngeal region
Particles 2- 5 microns
Deposition in LRT
More adrenergic receptors in bronchioles (compared to rest of airway) thus response with bronchodilators
Particles 0.8- 3 microns
Delivery of aerosol to lung parenchyma
Used for anti-infective drugs such as pentamidine where intra-alveolar deposition needed with minimum deposition in airways due to irritation
Mass Median Aerodynamic Diameter (MMAD)
Describes average particle diameter (µm).
50% of the particles are smaller & have less mass.
50% of the particles are larger & have greater mass.
Aerosol Output:
Aerosol output: Weight or mass of aerosol particles produced by nebulizer (usually per minute)
Does not indicate amount of drug reaching lungs as majority of particles leaving neb never reach lungs
Only 10-50% of administered dose actually reaches LRT, depending on device used & technique
Fast the flow the smaller the particales
Mechanisms of Deposition
Inertial impaction
Gravitational settling (sedimentation)
Diffusion
Recommended MMAD for Mouth
> 15 um
Recommended MMAD for Nose
10-15 um
May just say > 10 um
Recommended MMAD for Lower Airways
2-5 um
Medicated Aerosol Therapy
Delivery of aerosol particles to respiratory tract for therapeutic purposes
Desposition
Particles depositing out of supsension to remain in the lung
Particle Size And Lung Distribution
- Particle size is one of major factors affecting aerosol deposition in lung
- Despite knowing its size, not possible to specify exactly where particle will deposit in lung
- Particle deposition is function of several mechanisms:
- Breathing pattern
- Inspiratory flow rate
- Thus site of penetration can be predicted but not confirmed