Transcript asthma - Medicine is an art

ASTHMA
Asthma definition:
“Asthma is a chronic inflammatory disorder associated with variable airflow
obstruction and bronchial hyper responsiveness. It presents with recurrent
episodes of wheeze, cough, shortness of breath, and chest tightness.”
Clinical features that increase the probability of asthma
More than one of the following symptoms:
• Wheeze, cough, Difficulty in Breathing , chest tightness, particularly if
symptoms:
– are frequent and recurrent
– are worse at night and in the early morning
– occur in response to, or are worse after, exercise or other triggers,
such as exposure to pets, cold, damp air, or with emotions/laughter
• Personal history of atopic disorder
• Family history of atopic disorder and/or asthma
• Widespread wheeze heard on auscultation
• History of improvement in symptoms or lung function in response to
adequate therapy
Clinical features that lower the probability of asthma
• Symptoms with colds only, with no interval symptoms
• Isolated cough in the absence of wheeze or difficulty breathing
• History of moist cough
• Prominent dizziness, light-headedness, peripheral tingling
• Repeatedly normal physical examination of chest when symptomatic
• Normal peak expiratory flow (PEF) or spirometry when symptomatic
• No response to a trial of asthma therapy
• Clinical features pointing to alternative diagnosis
Causes of Asthma
•
The development of asthma appears to involve the interplay between host factors
(particularly genetics) and environmental exposures that occur at a crucial time in
the development of the immune system.
•
Innate immunity: Imbalance between Th1-type and Th2- type cytokine responses in
early life. The immune response will down regulate the Th1 immune response that
fights infection and instead will be dominated by Th2 cells, leading to the expression
of allergic diseases and asthma. This is known as the “hygiene hypothesis,”
•
which postulates that certain infections early in life, exposure to other children ,
less frequent use of antibiotics, and “country living” is associated with a Th1
response and lower incidence of asthma, whereas the absence of these factors is
associated with a persistent Th2 response and higher rates of asthma.
•
Genetics: Asthma has an inheritable component, but the genetics involved remain
complex.
•
Environmental factors: Two major factors are the most important in the
development, persistence, and possibly the severity of asthma:
 airborne allergens (particularly sensitization and exposure to house-dust mite and
Alternaria)
 viral respiratory infections (including respiratory syncytial virus [RSV] and
rhinovirus).
•
Other environmental factors are under study:
 tobacco smoke (exposure in utero is associated with an increased risk of wheezing,
but it is not certain this is linked to subsequent development of asthma),
 air pollution (ozone and particular matter) and
 diet (obesity or low intake of antioxidants and omega-3 fatty acids).
Mechanisms: Asthma Inflammation
Asthma Inflammation: Cells and Mediators
Early Childhood Risk Factors
Parental Asthma
Allergy
– Atopic dermatitis
– Allergic rhinitis
– Food allergy
– Inhalant allergen sensitization
– Food allergen sensitization
Precipitating and/or aggravating factors
• Viral respiratory infections
•
Environmental allergens, indoor (e.g., mold, house-dust mite, cockroach,
animal dander or secretory products) and outdoor (e.g., pollen)
• Characteristics of home including age, location, cooling and heating
system, wood-burning stove, humidifier, carpeting over concrete,
presence of molds or mildew, presense of pets with fur or hair,
characteristics of rooms where patient spends time (e.g., bedroom and
living room with attention to bedding, floor covering, stuffed furniture)
•
Smoking (patient and others in home or daycare)
• Exercise
• Occupational chemicals or allergens
• Environmental change (e.g., moving to new home; going on vacation;
and/or alterations in workplace, work processes, or materials used)
• Irritants (e.g., tobacco smoke, strong odors, air pollutants, occupational
chemicals, dusts and particulates, vapors, gases, and aerosols)
• Emotions (e.g., fear, anger, frustration, hard crying or laughing)
• Stress (e.g., fear, anger, frustration)
• Drugs (e.g., aspirin; and other nonsteroidal anti-inflammatory drugs, betablockers including eye drops, others)
•
Food, food additives, and preservatives (e.g., sulfites)
• Changes in weather, exposure to cold air Endocrine factors (e.g., menses,
pregnancy, thyroid disease)
• Comorbid conditions (e.g. sinusitis, rhinitis,GERD )
Classifying Severity and Initiating Treatment
CLINICAL FEATURES
Symptoms:
Intermittent dry cough
Expiratory wheezing
Shortness of breath
Chest tightness
Chest pain
Fatigue
Difficulty keeping up with peers in physical activities
Signs:
Expiratory wheezing
Prolonged expiratory phase
Decreased breath sounds
Crackles/ rales
Accessory muscle use
Nasal flaring
Absence of wheezing in severe cases
Pulses paradoxus
Spirometry:
Feasible in children >6 years of age
Monitoring Asthma and efficacy of treatment
Measures FVC, FEV 1 and FEV1/FVC Ratio
Normal values for children available on the basis of height, gender and ethnicity.
Airflow Limitation:
 Low FEV1
 FEV1/ FVC ratio < 0.80
Bronchodilator response to β-agonist:
 Improvement in FEV1 ≥ 12%
Exercise challenge:
 Worsening of FEV1 ≥ 15%
Peak expiratory flow rate: It is highly suggestive of asthma when:
>15% increase in PEFR after inhaled short acting β2 agonist
>15% decrease in PEFR after exercise
Diurnal variation > 10% in children not on bronchodilator
X-ray : Often normal, sometimes Hyperinflation
DIFFERENTIAL DIAGNOSTIC POSSIBILITIES FOR ASTHMA
Age
Common
Uncommon
Rare
Less than
6 months
Bronchiolitis
Gastro-esophageal
reflux
Aspiration pneumonia
Bronchopulmonary dysplasia
Congestive heart failure
Cystic fibrosis
Asthma
Foreign body aspiration
6 months 2 years
Bronchiolitis
Foreign body
aspiration
Aspiration pneumonia
Asthma
Bronchopulmonary dysplasia
Cystic fibrosis
Gastro-esophageal reflux
Congestive heart failure
2 - 5 years
Asthma
Foreign body
aspiration
Cystic fibrosis
Gastro-esophageal reflux
Viral pneumonia
Aspiration pneumonia
Bronchiolitis
Congestive heart failure
Gastro-esophageal reflux
APPROACH
Detailed history
Symptoms
Cough, Wheezing, Shortness of breath, Chest tightness, Sputum production
Pattern of symptoms
Perennial, seasonal, or both
Continual, episodic, or both
Onset, duration, frequency (number of days or nights, per week or month)
Diurnal variations, especially nocturnal and on awakening in early morning
Family history
History of asthma, allergy, sinusitis, rhinitis, eczema, or nasal polyps in close
relatives
Social history
Daycare, workplace, and school characteristics that may interfere with
adherence
Social factors that interfere with adherence, such as substance abuse
Social support/social networks
Level of education completed
Employment
History of exacerbations
Usual prodromal signs and symptoms
Rapidity of onset
Duration
Frequency
Severity (need for urgent care, hospitalization, intensive care unit (ICU)
admission.)
Life-threatening exacerbations (e.g., intubation, intensive care unit admission)
Number and severity of exacerbations in the past year.
Usual patterns and management (what works?)
Impact of asthma on patient and family
Episodes of unscheduled care (emergency department (ED), urgent care,
hospitalization)
Number of days missed from school/work
Limitation of activity, especially sports and strenuous work
History of nocturnal awakening
Effect on growth, development, behavior, school or work performance, and
lifestyle
Impact on family routines, activities, or dynamics Economic impact
Assessment of patient’s and family’s perceptions of disease
• Patient’s, parent’s, and spouse’s or partner’s knowledge of asthma and
belief in the chronicity of asthma and in the efficacy of treatment
• Patient’s perception and beliefs regarding use and longterm effects of
medications
• Ability of patient and parents, spouse, or partner to cope with disease
• Level of family support and patient’s and parents’, spouse’s, or partner’s
capacity to recognize severity of an exacerbation
• Economic resources
• Sociocultural beliefs
Asthma Management and Prevention
Program: Five Components
1. Develop Patient/Doctor Partnership
2. Identify and Reduce Exposure to Risk Factors
3. Assess, Treat and Monitor Asthma
4. Manage Asthma Exacerbations
5. Special Considerations
1. Develop Patient/Doctor Partnership
Guidelines on asthma management should be available for local use by
local asthma planning teams
Clear communication between health care professionals and asthma
patients is key
Educate continually
Include the family
Provide information about asthma
Provide training on self-management skills
Emphasize a partnership among health care providers, the patient, and the
patient’s family
2. Identify and Reduce Exposure to Risk Factors
Asthma exacerbations may be caused by a variety of risk factors – allergens,
viral infections, pollutants and drugs.
Reducing exposure to some categories of risk factors improves the control
of asthma and reduces medications needs.
Reduce exposure to indoor allergens
Avoid tobacco smoke
Avoid vehicle emission
Identify irritants in the workplace
Explore role of infections on asthma development, especially in children
and young infants
Influenza vaccination should be provided to patients with asthma when
vaccination of the general population is advised
3. Assess, Treat and Monitor Asthma
The goal of asthma treatment, to achieve and maintain clinical control, can be
achieved in a majority of patients with a pharmacologic intervention strategy
developed in partnership between the patient/family and the health care
professional.
The focus on asthma control is important because:
Attainment of control correlates with a better quality of life, and
reduction in health care use
Determine the initial level of control to implement treatment (assess
patient impairment)
Maintain control once treatment has been implemented (assess
patient risk)
Levels of Asthma Control (Assess patient impairment)
Characteristic
Controlled
Partly controlled
(All of the following)
(Any present in any week)
Daytime symptoms
Twice or less
per week
More than
twice per week
Limitations of activities
None
Any
Nocturnal symptoms /
awakening
None
Any
Need for rescue /
“reliever” treatment
Twice or less
per week
More than
twice per week
Normal
< 80% predicted or
personal best (if known)
on any day
Lung function
(PEF or FEV1)
Uncontrolled
3 or more
features of
partly
controlled
asthma present
in any week
Assess Patient Risk
Features that are associated with increased risk of adverse events in the
future include:
Poor clinical control
Frequent exacerbations in past year
Ever admission to critical care for asthma
Low FEV1, exposure to cigarette smoke, high dose medications
Depending on level of asthma control, the patient is assigned to one of five
treatment steps
Treatment is adjusted in a continuous cycle driven by changes in asthma control
status. The cycle involves:
- Assessing Asthma Control
- Treating to Achieve Control
- Monitoring to Maintain Control
A stepwise approach to pharmacological therapy is recommended
The aim is to accomplish the goals of therapy with the least possible medication
Although in many countries traditional methods of healing are used, their
efficacy has not yet been established and their use can therefore not be
recommended
The choice of treatment should be guided by:
Level of asthma control
Current treatment
Pharmacological properties and availability of the various forms of
asthma treatment
Economic considerations
Cultural preferences and differing health care systems
Medications in Asthma
Controller Medications
•
Inhaled glucocorticosteroids
•
Leukotriene modifiers
•
Long-acting inhaled β2-agonists in
combination with inhaled
glucocorticosteroids
•
Systemic glucocorticosteroids
•
Theophylline
•
Cromones
•
Anti-IgE
Reliever Medications
• Rapid-acting inhaled β2-agonists
• Systemic glucocorticosteroids
• Anticholinergics
• Theophylline
• Short-acting oral β2-agonists
Estimate Comparative Daily Dosages for Inhaled
Glucocorticosteroids by Age
Drug
Low Daily Dose(g)
>5y
Age < 5 y
Medium Daily Dose (g)
> 5 y Age
<5y
Beclomethasone
200-500
100-200
>500-1000
>200-400
Budesonide
200-600
100-200
600-1000
>200-400
Budesonide-Neb Inhalation
Suspension
Ciclesonide
250-500
80 – 160
High Daily Dose (g)
> 5 y Age < 5 y
>1000
>1000
500-1000
>400
>400
>1000
80-160
>160-320
>160-320
>320-1280
>750-1250
>2000
>1250
>200-500
>500
>500
Flunisolide
500-1000
500-750
>1000-2000
Fluticasone
100-250
100-200
>250-500
Mometasone furoate
200-400
100-200
> 400-800
>200-400
>800-1200
Triamcinolone acetonide
400-1000
400-800
>1000-2000
>800-1200
>2000
>320
>400
>1200
Allergen-specific Immunotherapy
Greatest benefit of specific immunotherapy using allergen extracts has been
obtained in the treatment of allergic rhinitis
The role of specific immunotherapy in asthma is limited
Specific immunotherapy should be considered only after strict
environmental avoidance and pharmacologic intervention, including
inhaled glucocorticosteroids, have failed to control asthma
Perform only by trained physician
REDUCE
LEVEL OF CONTROL
TREATMENT OF ACTION
maintain and find lowest
controlling step
partly controlled
consider stepping up to
gain control
INCREASE
controlled
uncontrolled
exacerbation
REDUCE
step up until controlled
treat as exacerbation
TREATMENT STEPS
INCREASE
STEP
STEP
STEP
STEP
STEP
1
2
3
4
5
Treating to Maintain Asthma Control
When control as been achieved, ongoing monitoring is essential to:
- maintain control
- establish lowest step/dose treatment
Asthma control should be monitored by the health care professional and by
the patient
Stepping down treatment when asthma is controlled
When controlled on medium- to high-dose inhaled glucocorticosteroids:
50% dose reduction at 3 month intervals.
When controlled on low-dose inhaled glucocorticosteroids: switch to oncedaily dosing
When controlled on combination inhaled glucocorticosteroids and longacting inhaled β2-agonist: reduce dose of inhaled glucocorticosteroid by 50%
while continuing the long-acting β2-agonist
If control is maintained: reduce to low-dose inhaled glucocorticosteroids
and stop long-acting β2-agonist
Stepping up treatment in response to loss of control
Rapid-onset, short-acting or long-acting inhaled β2-agonist bronchodilators
provide temporary relief.
Need for repeated dosing over more than one/two days signals need for possible
increase in controller therapy
Use of a combination rapid and long-acting inhaled β2-agonist (e.g., formoterol)
and an inhaled glucocorticosteroid (e.g., budesonide) in a single inhaler both as
a controller and reliever is effecting in maintaining a high level of asthma control
and reduces exacerbations
Doubling the dose of inhaled glucocortico-steroids is not effective, and is not
recommended
Component 4: Manage Asthma Exacerbations
Exacerbations of asthma are episodes of progressive increase in shortness of
breath, cough, wheezing, or chest tightness
Exacerbations are characterized by decreases in expiratory airflow that can
be quantified and monitored by measurement of lung function (FEV1 or PEF)
Severe exacerbations are potentially life-threatening and treatment requires
close supervision
Treatment of exacerbations depends on:
The patient
Experience of the health care professional
Therapies that are the most effective for the particular patient
Availability of medications
Emergency facilities
Primary therapies for exacerbations:
Repetitive administration of rapid-acting inhaled β2-agonist
Early introduction of systemic glucocorticosteroids
Oxygen supplementation
Closely monitor response to treatment with serial measures of lung function
5.Special considerations
Special considerations are required to manage asthma in relation to:
Pregnancy
Surgery
Rhinitis, sinusitis, and nasal polyps
Occupational asthma
Respiratory infections
Gastroesophageal reflux
Aspirin-induced asthma
Anaphylaxis and Asthma
STATUS ASTHAMATICUS
• Status asthmaticus is the condition of a patient in progressive
respiratory failure due to asthma, in whom conventional
forms of therapy have failed
Status Asthamaticus Assessment
Findings consistent with impending respiratory failure:
Altered level of consciousness
Inability to speak
Absent breath sounds
Central cyanosis
Diaphoresis
Inability to lie down
Marked pulsus paradoxus
Clinical Asthma Score
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