Transcript Inhaler devices for respiratory disease

Managing
asthma &
Inhaler devices
for respiratory
disease
Managing asthma
Unfortunately…asthma is a major cause of
chronic morbidity and mortality throughout
the world (estimated 300million) and there is
evidence that its prevalence has increased
considerably over the past 20 years,
especially in children.
Fortunately…asthma can be effectively
treated and most patients can achieve good
control of their disease.
Global Initiative for Asthma (2012)
When asthma is under control
patients can;
 Avoid
troublesome symptoms night &
day.
 Use
little or no reliever medication.
 Have
productive, physically active lives.
 Have
(near) normal lung function.
 Avoid
serious attacks.
Global Initiative for Asthma (2012)
Four components of asthma
care;
Global Initiative for Asthma (2012)
1.
Develop patient/doctor partnerships
2.
Identify and reduce exposure to risk
factors
3.
Assess, treat and monitor symptoms
4.
Manage asthma exacerbations
1. Develop patient/doctor
partnerships;
 Effective
management requires
partnership between the person with
asthma and the health care team.
 Education
should be an integral part of all
interactions between patient & HCP.
 Together
prepare a written, personal
asthma action plan.
With your help, the help of others on
the health care tem, patients can learn
to;
 Avoid
risk factors
 Take medication correctly
 Understand the difference between ‘controller’
& ‘reliever’ medication.
 Monitor their status using symptoms and, if
relevant PEFR.
 Recognise signs that asthma is worsening and
take action.
 Seek medical advice as appropriate.
2. Identify and reduce
exposure to risk factors;
 Many
patients react to multiple risk factors
that are ubiquitous to the environment,
avoiding these can be impossible, therefore
medication to maintain control have an
important role.
 Physical activity is common cause of asthma
symptoms but patients should not avoid
exercise.
 Moderate/severe asthma should receive flu
vaccination every year
Avoidance of common
allergens/pollutants
 Tobacco
 Drugs,
smoke
food & additives
 Occupational
 House
dust mite
 Animal
fur
 Outdoor
 Indoor
sensitizers
pollen & mold
mold
3. Assess, treat and monitor
symptoms
a.
Assessing asthma control
b.
Treating to achieve control
c.
Monitoring to maintain control
a. Assessing asthma control
 Current
treatment regime
 Adherence to current regime
 Level of asthma control
 Daytime
symptoms
 Limitation of activity
 Nocturnal symptoms/waking
 Need for reliever/rescue inhaler
 Lung function – rapid decline
 Risk of exacerbation
 instability
b. Treating to achieve control prescribing devices
 Inhaled
medications are preferred because
they deliver drugs directly to the airways, this
results in potent therapeutic effects with fewer
systemic side effects.
 Only prescribe inhalers after patient has
received training in the use of the device and
have demonstrated satisfactory technique.
 The choice of device may be determined by
the choice of drug.
(GINA 2012)
b. Treating to achieve control prescribing devices
 Patients
should have an assessment of their
ability to use an inhaler device by a competent
health care professional.
 Reassess inhaler technique as part of structured
clinical review.
 Exacerbations of mild/moderate asthma should
be treated by pMDI + spacer with dose titrated
according to clinical response.
(BTS/SIGN Quick Reference Guide 2011)
b. Treating to achieve control
 Use
a step-wise approach.
 At each step, reliever medication should be
provided for quick relief, as needed.
 If asthma is not controlled on current
treatment regime then treatment should be
stepped up until control is achieved.
 Patients who do not reach acceptable level
of control at step 4 should be referred to an
asthma specialist (unless already known to
specialist as difficult to treat)
c. Monitoring to maintain
control (GINA 2012)
 Ongoing
monitoring is essential to maintain
control & establish the lowest step & dose to
minimize cost & maximize safety.
 Review;
 1-3
months after initial diagnosis
 3 monthly
 2-4 weeks after exacerbation
 Monitoring
is necessary after control is achieved
as asthma is variable
 Treated has to be adjusted periodically in
response to exacerbation
4. Managing exacerbations
 Exacerbation
= episodes of increase in SOB;
cough; wheeze or chest tightness, or
combination of these symptoms
 Do not underestimate the severity of an
exacerbation – severe asthma can be life
threatening.
 Patients should be taught to recognise the
symptoms of an acute exacerbation and when
to seek immediate medical attention. Can be
part of a written management plan.
4. Managing exacerbations


Mild exacerbation may be treated at home, if the
patient is prepared.
Community
increased rapid acting B2-agonist
 oral glucocorticosteroids – prednisolone
 Oxygen





Monitor response to treatment
Follow up
Severity of Asthma Exacerbation – GINA 2012 p.22
Special Consideration in Managing Asthma – GINA
2012 p.23
Special considerations in
managing asthma
 Pregnancy
 Obesity
 Rhinitis,
sinusitis & nasal polyps
 Occupational asthma
 Gastroesophageal reflux
 Aspirin & asthma
 anaphylaxis
http://www.asthma.org.uk/about
Inhaler medication
RELIEVERS
Short acting bronchodilators
PREVENTERS
Corticosteroids
CONTROLLERS
Long acting bronchodilators
COMBINATION
Inhaler
technique
What is an aerosol?
An aerosol is a microscopic
substance of fine solid
particles or liquid droplets
dispersed in air or another
gas
Therefore;
all
inhaler devices generate an
aerosol
Some are PASSIVE the device
creates the aerosol
Some are ACTIVE the person
has to create the aerosol
Sort the
devices into
passive and
active devices
Where does the medication need to
go?
What are the
barriers to good
deposition?
Fate of inhaled drugs – Good Technique
20%
Mouth
pharynx
Metabolism or absorption
from the lung
Deposited in lung
Lungs
mucociliary
clearance
80%
Systemic
Circulation
Swallowed
Oral
bioavailability
Absorption
from gut
Liver
GI tract
First-pass
metabolism
Adapted from Barnes et al. AJRCCM 1998;157:S1-S53
Schematic representation of potential dose distribution
A Guide to Aerosol Delivery Devices for Respiratory Therapists. American Association for
Respiratory Care. 1st Edition. Page 1.
Webpage: http://www.aarc.org/education/aerosol_devices/
Fate of inhaled drugs – Poor Technique
5%
Mouth
pharynx
Metabolism or absorption
from the lung
Deposited in lung
Lungs
mucociliary
clearance
95%
Systemic
Circulation
Swallowed
Oral
bioavailability
Absorption
from gut
Liver
GI tract
First-pass
metabolism
Adapted from Barnes et al. AJRCCM 1998;157:S1-S53
Schematic representation of potential dose distribution
A Guide to Aerosol Delivery Devices for Respiratory Therapists. American Association for
Respiratory Care. 1st Edition. Page 1.
Webpage: http://www.aarc.org/education/aerosol_devices/
Aerosol Deposition at varying Particle Size
Micron size
10
Deposition
Aerosol
Deposition at varying Particle Size
Micron size
Deposition
10
Pharynx, larynx &
Upper respiratory
tract
5
5
Optimal
tracheobronchial
Optimal
tracheobronchial
deposition
deposition
2
0.5
0
2
0.5
0
Optimal
alveolar
Optimal
alveolar
deposition
deposition
Particles
exhaled
<0.5 micron
micron
Particles
exhaled
if if<0.5
Deposition in the lungs –
consider what is happening to
the aerosol
Particles of drug are moving,
when something that possesses
weight is travelling at speed it
has momentum,
(mass x velocity = momentum)
an energy that travels in a
straight line
Mechanical activation
 Passive


MDI – the device creates
the aerosol
GENTLE inspiration
 Active


DPI – person dependent –
relies on personal effort, the
energy of inspiration
FORCEFUL inspiration
Lung deposition from HFA-Beclometasone provides
equivalent lung deposition with or without add-on spacers
Press and
Breathe MDI
Deposition
75
Spacer
29%
Spacer
33%
5% Mouth
(% of inhaled
dose)
50
25
Mouth
29%
2% Mouth
Lungs
53%
Lungs
45%
Lungs
51%
0
P&B +
Aerochamber
P&B +
Volumatic
P&B Alone
Deposition from T99-labelled HFA-Beclometasone measured by gamma scintigraphy.
Leach, C. L., P. J. Davidson and R. Boudreau: HFA-Beclomethasone Provides
Equivalent Lung Deposition with or without Add-on Spacers. Eur. Res. J. 10(25):
P1522, p. 236S, 1997.
Lung deposi on from pMDIs is influenced
by inspiratory flow
10
80%VC
20%VC
20%VC
(% of inhaled
dose)
5
50%VC
50%VC
Total lung
deposition
80%VC
15
0
30L/min
Metered Dose
Inhaler (MDI)
90L/min
10 second breath hold
Newman S et al, Eur J Respir Dis 1982;63: Suppl 119 57-65
Mean resistance of various DPIs
Resistance in (cmH2O)½Lmin-1
Aeroliser Accuhaler Turbohaler Clickhaler Twisthaler Easyhaler
MDI /
Spacer
Assi KH, Chrystyn H. The different resistance of dry powder inhalers (DPIs).
Am. J Respir. Crit. Care Med. 2001;163(5): A443
(Adapted from)
 Inhaled
medications is a waste of money
if not used properly
 Poor technique is a barrier to good
control
 Check at each visit
 Don’t rely on patient’s knowledge – ask
them to demonstrate
 Use aids such as the in-check dial, AIMS