Transcript Asthma for Ped Grand Rounds

Diagnosis and Treatment of
Asthma in Children
Loran Clement, M.D.
Some Basic Facts About Asthma
• Asthma is very common
– Approximately 6-8% of children in the U.S. has asthma
– Prevalence ~10-15% reported in some inner city populations
• Asthma is very expensive
– Direct and indirect costs for asthma - > $15 billion a year
• Asthma significantly impairs quality of life
– Leading cause of missed school days
– Interrupted or impaired sleep for child and family
– Children don’t participate in physical activities
The prevalence of asthma is increasing
(1980 – 2000)
7
6
Under 18
5
4
3
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
Prevalence (%)
8
All Ages
In the United States, increases in the
prevalence, morbidity, and mortality of asthma
have been disproportionately great among:
•
•
•
•
Urban dwellers
Populations of low socioeconomic status
Ethnic minorities
Children
Although a variety of factors may play a role,
the cause of this epidemic remains unknown
Pathophysiology of Asthma
What causes asthma?
Susceptibility heavily influenced by
genetic factors that produce atopy (at
least 10-15 genes may be involved)
Allergic sensitization = a specific immune
response occurs when a susceptible
person is exposed to an antigen
Symptoms occurs when a person with
asthma is re-exposed to specific
allergen(s) or other triggers
Asthma Symptoms Result from
Inflammation and Bronchoconstriction
BRONCHIOLE
Reduced
airway opening
Tightened
muscle
Excess
Mucus
Thick
Muscle
Layer
Inflammation
Alveolus filled
with trapped
air
Bronchoconstriction
PATHOPHYSIOLOGY OF ASTHMA
Lung function during early and late
phases of allergic response
BEFORE STIMULUS
EARLY PHASE
LATE PHASE
BRONCHOSPASM
INFLAMMATION
Five Components of
Asthma Management
1. Diagnosis and Assessment of Activity
2. Pharmacologic Therapy
3. Control of Other Factors Contributing
to Asthma Severity
4. Establish an Educational Partnership
5. Re-assessment and Re-education
Diagnostic Criteria for Asthma
History of episodic symptoms of airflow obstruction
(especially at night, after exercise, or after
breathing cold air)
• coughing
• chest tightness or pain
• dyspnea
• wheezing
Airflow obstruction is at least partially reversible
• spirometry usually not very helpful in children
Alternative diagnoses are excluded
• differentiating asthma from recurrent respiratory
infections difficult during the first 3-6 years of life
CLASSIFYING ASTHMA SEVERITY AND INITIATING TREATMENT IN
YOUTHS > 12 YEARS AND ADULTS
EPR-3, p74, 344
Classification of Asthma Severity
Components of
Severity
Intermittent
Mild
Persistent
Moderate
Severe
Symptoms
<2 days/week
>2 days/week not daily
Daily
Nighttime
Awakenings
<2x/month
3-4x/month
>1x/week
Normal
FEV1/FVC
SABA use for sx
control
<2 days/week
>2 days/week not daily
Daily
Several times daily
8-19 yr 85%
Interference with
normal activity
none
Minor limitation
Some limitation
Extremely limited
Impairment
20-39 yr 80%
•Normal FEV1 between
exacerbations
40-59 yr 75%
60-80 yr 70%
not nightly
Lung Function
• FEV1 > 80%
• FEV1 >80%
•FEV1/FVC normal
•FEV1/FVC
reduced 5%
• FEV1/FVC normal
Exacerbations
Risk
(consider
frequency and
severity)
0-2/year
Often nightly
•FEV1 <60%
•FEV1/FVC
reduced> 5%
> 2 /year
Frequency and severity may vary over time for patients in any category
Relative annual risk of excaerbations may be related to FEV
Step 1
Recommended Step for
Initiating Treatment
• FEV1 >60%
but< 80%
Continuous
Step 2
Step 3
Step 4 or 5
Consider short course of oral steroids
In 2 -6 weeks, evaluate asthma control that is achieved and adjust therapy
accordingly
Classification of Asthma Severity & Activity:
Using Readily Identifiable Features
Days with
Symptoms
Nights with
Symptoms
PEF or FEV1
(% of normal)
PEF
Variability
Step 4
Severe
Persistent
Continuous
Frequent
 60%
>30%
Step 3
Moderate
Persistent
Daily
 5 per month
60 – 80%
>30%
Step 2
Mild
Persistent
3 - 6 per week
3 - 4 per month
 80%
20 - 30%
Step 1
Mild
Intermittent
 2 per week
 2 a month
 80%
 20%
Footnote: The patient’s step is determined by the most severe feature.
Spirometry
“A medical test that
measures the flow
and volume of air
entering and leaving
the lungs as a
function of time.”
(ATS, 1994)
Spirometry - Measurements Based on FVC maneuver

Forced Vital Capacity (FVC): Volume expired by a forced
maximal expiration after maximal inhalation

Forced Expiratory Volume in 1 second (FEV1): Volume of air
forcefully expired in the first 1 second

Forced Expiratory Flow from 25-75% of Exhalation (FEF25-75):
Average air flow rate during the middle half of the FVC
maneuver; reflects flow through the small airways

FEV1/FVC ratio - the ratio of FEV1 to FVC (expressed as a
percent)

Peak expiratory flow rate (PEFR)
Spirometry Interpretation: FVC and FEV1

Interpretation of % predicted FVC:





80-120%
70-79%
50%-69%
<50%
Normal
Mild reduction
Moderate reduction
Severe reduction
Interpretation of % predicted FEV1 :




>75%
60%-75%
50-59%
<50%
Normal
Mild obstruction
Moderate obstruction
Severe obstruction
Spirometry Pre- and Post-bronchodilator






Obtain a flow-volume loop
Administer a bronchodilator
Obtain a second flow-volume loop 15-20 minutes after
bronchodilator administration
Calculate percent change in FEV1 (or FEF 25-75)
Obstruction is considered to be reversible if the
change is 12% or greater
Failure to demonstrate a change after bronchodilator
does not exclude a reversible component of
obstruction because airway inflammation that does
not responsive to B2 agonist may be present
Pre-Post Bronchodilator
ATS recommends a positive response is > 12% improvement
in FEV1
Special Considerations in Pediatric Patients

Ability to perform spirometry dependent on
developmental age of child, personality,
cooperation, and interest of the child

Best results in children >6 years old

Patients need a calm, relaxed environment and
good coaching. Patience and experience is key.

Younger children may require more than 3 tests
Special Considerations in Pediatric Patients

Must perform a maximal forced exhalation for at
least 3 seconds

Incentive screens on monitor often very helpful
“Blow out all your birthday candles….”

The “best” test is the one with the greatest sum of
FEV1 and FVC

Even with the best of environments and coaching, a
child may not be able to perform spirometry (or may
have normal spirometry despite having asthma)
Spirometry Quality
Five Components of
Asthma Management
1. Diagnosis and Assessment of Activity
2. Pharmacologic Therapy
3. Control of Other Factors Contributing
to Asthma Severity
4. Establish an Educational Partnership
5. Re-assessment and Re-education
Overview of Asthma Medications
Quick Relievers
Long-Term Controllers
Bronchodilators
• Short-acting inhaled
beta2-agonists
Anti-inflammatory drugs
• Inhaled corticosteroids
• Leukotriene modifiers
• (Anticholinergics)
Systemic Corticosteroids
Long-acting b2-agonists
Acute Asthma
Treatment of acute asthma attack
•
•
•
When asthma symptoms occur, inspire
2 puffs of a beta2-agonist from a MDI or
give an albuterol treatment with a nebulizer
This can be repeated 20 minutes later if
symptoms continue
If symptoms persist, child should be seen
by a health care provider and/or commence
oral steroid therapy
ED Care
•
•
•
•
•
•
•
Begin beta2-agonist treatment immediately
Get short history (prior intubations or respiratory
failure?), recent medication use, triggers
Oxygen to maintain SaO2 >90%
ABG in patients with suspected hypo-ventilation
or with severe distress
Ancillary studies (CBC, CXR) when indicated
Corticosteroids (unless albuterol rapidly clears)
Hospitalization if not clear after three treatments
Danger Signs
• History of rapid or severe deterioration
• Severe symptoms at rest (accessory
muscle use, chest retraction, difficulty
speaking, cyanosis, agitation)
• FEV1 or PEF <50% of personal best
• pCO2 >42 mm Hg
Hospital Management
•
•
•
•
•
Inhaled beta2-agonist (and an anti-cholinergic?) by
MDI or via nebulization. Albuterol can be given
continuously, at regular intervals, or as needed
Intravenous or oral corticosteroids
Oxygen to achieve O2 saturation >90%
Repeat assessment (symptom assessment, physical
exam, PEF, O2 saturation, other tests as needed)
For impending or actual respiratory failure, admit
to ICU for intubation and mechanical ventilation
Quick Reliever Therapy
MDI + spacer or Nebulizer?
The MDI + spacer combination has been evaluated in
acute asthma attacks in all age groups and all asthma
severity ranges. When properly used, this combination
has been shown to be at least as effective or better
than use of a nebulizer in outpatient, inpatient, ED, and
intensive care unit settings
•
•
•
•
•
Therapeutic benefits commence sooner
Medications given by MDI + spacer are cheaper
Administration of medication is easier
Medications given by MDI and chamber have
fewer side effects
Administration of medications by MDI and
chamber can be done anywhere
Asthma Controller Therapy
Where do we stand in our efforts to control
the current asthma epidemic?
Multiple studies have shown that asthma is
• under-diagnosed
• under-treated
Multiple other studies have shown that
• disease activity can be controlled in the
vast majority of asthmatic children if the
disease is recognized and treated with
anti-inflammatory medications
CLASSIFYING ASTHMA SEVERITY AND INITIATING TREATMENT IN
YOUTHS > 12 YEARS AND ADULTS
EPR-3, p74, 344
Classification of Asthma Severity
Components of
Severity
Intermittent
Mild
Persistent
Moderate
Severe
Symptoms
<2 days/week
>2 days/week not daily
Daily
Nighttime
Awakenings
<2x/month
3-4x/month
>1x/week
Normal
FEV1/FVC
SABA use for sx
control
<2 days/week
>2 days/week not daily
Daily
Several times daily
8-19 yr 85%
Interference with
normal activity
none
Minor limitation
Some limitation
Extremely limited
Impairment
20-39 yr 80%
•Normal FEV1 between
exacerbations
40-59 yr 75%
60-80 yr 70%
not nightly
Lung Function
• FEV1 > 80%
• FEV1 >80%
•FEV1/FVC normal
•FEV1/FVC
reduced 5%
• FEV1/FVC normal
Exacerbations
Risk
(consider
frequency and
severity)
0-2/year
Often nightly
•FEV1 <60%
•FEV1/FVC
reduced> 5%
> 2 /year
Frequency and severity may vary over time for patients in any category
Relative annual risk of excaerbations may be related to FEV
Step 1
Recommended Step for
Initiating Treatment
• FEV1 >60%
but< 80%
Continuous
Step 2
Step 3
Step 4 or 5
Consider short course of oral steroids
In 2 -6 weeks, evaluate asthma control that is achieved and adjust therapy
accordingly
STEPWISE APPROACH FOR MANAGING ASTHMA IN
EPR-3, p333-343
YOUTHS > 12 YEARS AND ADULTS
Intermittent
Asthma
Persistent Asthma: Daily Medication
Consult with asthma specialist if step 4 or higher care is required
Consider consultation at step 3
Step 6
Step 5
Step 4
Step 3
Step 2
Step 1
Preferred:
SABA prn
Preferred:
Medium-dose
ICS
Preferred:
OR
Low-dose ICS
Low-dose
ICS+
Alternative:
either LABA,
LTRA
LTRA,
Cromolyn
Theophylline
Theophylline
Or Zileutin
Preferred:
Medium-dose
ICS+LABA
Alternative:
Medium-dose
ICS+either
LTRA,
Theophlline
Or Zileutin
Preferred:
High dose ICS
+ LABA
Preferred:
High-dose ICS
+ LABA + oral
Corticosteroid
AND
AND
Consider
Olamizumab
for
Consider
patients with
Olamizumab for
allergies
patients with
allergies
Patient Education and Environmental Control at Each Step
Step up if
needed (check
adherence,
environmental
control and
comorbidities)
Assess
Control
Step down
if possible
(asthma well
controlled
for 3
months)
ASSESSING ASTHMA CONTROL AND ADJUSTING THERAPY IN
YOUTHS > 12 YEARS OF AGE AND ADULTS
EPR-3, p77, 345
Classification of Asthma Control
Components of Control
Well Controlled
Symptoms
Nighttime awakenings
IMPAIRMENT
Interference with
normal activity
SABA use
FEV1or peak flow
Validated questionnaires
RISK
ATAQ/ACT
Exacerbations
Progressive loss of lung
function
Rx-related adverse effects
Recommended Action
For Treatment
< 2 days/week
< 2/month
none
Not Well
Controlled
> 2 days/week
1-3/week
Some limitation
< 2 days/week
> 80% predicted/
personal best
0/> 20
0- 1 per year
Very Poorly
Controlled
Throughout the day
> 4/week
Extremely limited
> 2 days/week
Several times/day
60-80% predicted/
personal best
<60% predicted/
personal best
1-2/16-19
3-4/< 15
2 - 3 per year
> 3 per year
Evaluation requires long-term follow up care
Consider in overall assessment of risk
•Maintain current step
•Step up 1 step
•Consider step down
if well controlled at
least 3 months
•Reevaluate in 2 - 6
weeks
•Consider oral
steroids
•Step up 1-2 weeks
and reevaluate in 2
weeks
Five Components of
Asthma Management
1. Diagnosis and Assessment of Activity
2. Pharmacologic Therapy
3. Control of Other Factors Contributing
to Asthma Severity
4. Establish an Educational Partnership
5. Re-assessment and Re-education
Control Other Factors That
Can Influence Asthma Severity

Control exposure to asthma triggers
(tobacco smoke, air pollution, known allergens)

Control rhinitis
–

Intranasal corticosteroids are most effective
Recognize and treat chronic sinusitis
Five Components of
Asthma Management
1. Diagnosis and Assessment of Activity
2. Pharmacologic Therapy
3. Control of Other Factors Contributing
to Asthma Severity
4. Establish an Educational Partnership
5. Re-assessment and Re-education
Key Educational Tasks in the
Asthma Care Partnership
1. Patient & physician must agree on the treatment goals
•
•
Doctors must know what is important to patients, and visa versa
“Control of asthma” must be defined and explained
Key Educational Tasks in the
Asthma Care Partnership
1. Patient & physician must agree on the treatment goals
•
•
Doctors must know what is important to patients, and visa versa
“Control of asthma” must be defined and explained
2. Physician must teach the basic facts about asthma
•
•
Contrast normal and asthmatic (hyperreactive, inflamed) airways
Emphasize the importance of controlling inflammation
Key Educational Tasks in the
Asthma Care Partnership
1. Patient & physician must agree on the treatment goals
•
•
Doctors must know what is important to patients, and visa versa
“Control of asthma” must be defined and explained
2. Physician must teach the basic facts about asthma
•
•
Contrast normal and asthmatic (hyperreactive, inflamed) airways
Emphasize the importance of controlling inflammation
3. Teach the therapeutic roles of different medications
•
•
Patients must learn that different inhalers are NOT interchangeable
Long-term controllers have different effects than quick relievers
Key Educational Tasks in the
Asthma Care Partnership
4. Identify factors that make asthma worse and agree on
relevant environmental control measures
Two recent studies showed that children participating
in highly successful asthma management programs
experienced dramatic improvement in all measures of
disease activity UNLESS they were exposed to
tobacco smoke in their home environment (i.e., it isn’t
that dusty teddy bear’s fault)
Some potential triggers
Key Educational Tasks in the
Asthma Care Partnership
4. Identify factors that make asthma worse and agree on
relevant environmental control measures
5. Teach patients when they should take rescue actions
•
Develop and explain an appropriate Asthma Action Plan
ASTHMA ACTION/MEDICINE PLAN
Green means Go
Use preventative medicine
John Doe
Patient Name________________
123-456-789
PF#________________________
Doctor’s Tel._______________
323-226-5049 (Dr. Asthma)
Yellow means Caution
Start quick relief medicine and
increase the dose of preventative medicine
11/9/98
Date___________
300
Personal Best Peak Flow__________
Use symptoms or
peak flows
to determine zone
Red means Danger
Give oral steroids immediately
Seek medical attention immediately
Green - Go
(Use preventative medicine)
•Easy normal breathing
Medicine
Amount
How often
•No limitations on activity
ICS
2 puffs
Twice a day
__________________________________________
•No wheezing, coughing or
shortness of breath
Leukotriene
inhib 1 tab
Each evening
__________________________________________
240
•Peak flows are above_____________
Albuterol
2 puffs
Every 3-4 hrs as needed
__________________________________________
Yellow – Caution (Start quick relief medicine and increase the dose of preventative medicine)
•At first sign of a viral infection
•Wheezing, coughing or
shortness of breath
•Waking up at night with
asthma symptoms
Peak flows are______to_______
150 240
Medicine
Amount
How often
__________________________________________
ICS
4 puffs
Twice a day
__________________________________________
Leukotriene inhib 1 tab
Each evening
Albuterol
2 puffs
3-4 Times a day
__________________________________________
Red - Danger (Give oral steroids immediately Seek medical attention immediately)
•Medicine is not helping
Medicine
Amount
How often
•Hard and fast breathing
Prednisone
(20mg) 2 Tablets
Once a day
__________________________________________
•Ribs showing when breathing
•Cannot talk in complete sentences
__________________________________________
Albuterol
2 puffs
Every 1 to 3 hrs
•Cannot walk
__________________________________________
ICS
4 puffs
Twice a day
•Nose flares open when breathing
150
Leukotriene inhib 1 tab
Each evening
•Peak flows are Below________________
Call 911
or go to
the
Emergency
Room
Peak Expiratory Flow (PEF) Meters
Peak Flow Monitoring
 Simple, quantitative, reproducible measure of
the existence and severity of airflow obstruction
(correlates with FEV1)
 May be useful for monitoring pulmonary
function, managing therapy, and detecting
asthma exacerbations
 Suitable for patients > 5 years old
 Can use patient’s personal best as the
reference value over time
Shortcomings of Peak Flow Monitoring
 Results are heavily dependent on patient effort
and, thus, less reproducible than spirometry
 Appears to be inferior to symptom assessment
for detecting asthma exacerbations (this may
delay starting appropriate therapy by >1 day)
 Compliance with performing test and recording
results very poor (<10% of patients comply)
 May distract patients from regular use of
controller medications (“one more thing to do”)
Conclusions
 Daily
peak flow monitoring is rarely
effective for monitoring asthma
status in children and may delay
appropriate changes in therapy
Key Educational Tasks in the
Asthma Care Partnership
4. Identify factors that make asthma worse and agree on
relevant environmental control measures
5. Teach patients when they should take rescue actions
•
Develop and explain an appropriate Asthma Action Plan
6. Physician must teach the necessary skills
•
Patients must be shown how to properly use inhalers, spacers,
and, when applicable, peak flow monitors
Medical Staff’s Ability to Effectively
Demonstrate Proper Inhaler Techniques
100
98*
97*
82
80
78
69
Mean
Demonstration
60
Score
(%)
40
60*
RT
RN
MD
57
21
20
12
0
MDI
*P<0.0001 vs. RN and MD
Hanania et al. Chest. 1994;105:111-116.
Turbuhaler®
MDI + AeroChamber®
Five Components of
Asthma Management
1. Diagnosis and Assessment of Activity
2. Pharmacologic Therapy
3. Control of Other Factors Contributing
to Asthma Severity
4. Establish an Educational Partnership
5. Re-assessment and Re-education