ASTHMAGINA 2014

Asthma •Is a heterogeneous disease, usually characterized by chronic airway inflammation

•It is defined by the history of respiratory symptoms• Wheeze • Shortness of breath• Chest tightness• Cough

•Symptoms vary over time and in intensity, together with variable expiratory airflow limitation

•Variations are triggered by factors such as exercise, allergen or irritant exposure, change in weather, or viral respiratory infections

Asthma phenotypeASTHMA PHENOTYPE DESCRIPTION

Allergic asthma Starts in childhood, with hx of allergic diseases (eczema, rhinitis); responds well to ICS

Non-allergic asthma May be eosinophilic/neutrophilic or few inflammatory cells (paucigranulocytic); responds less well to ICS

Late-onset asthma Adults (women), non-allergic; requires higher doses of ICS (relatively refractory)

Asthma with fixed airflow limitation Thought to be due to airway wall remodeling

Asthma with obesity Prominent respiratory symptoms and little eosinophilic airway inflammation

DIAGNOSING ASTHMA

Increases risk of px having asthma•>1 symptom (wheeze, shortness of breath, cough, chest tightness), especially in adults•Symptoms often worse at night or early in the morning•Symptoms vary over time and in intensity•Symptoms are triggered by viral infections (common colds), exercise, allergen exposure, changes in weather, laughter or irritants (car exhaust fumes, smoke or strong smells)

Decreases risk of px having asthma•Isolated cough with no other respiratory symptoms •Chronic production of sputum•Shortness of breath associated with dizziness, light-headedness or peripheral tingling (paresthesia)•Chest pain•Exercise-induced dyspnea with noisy inspiration

Diagnosing Asthma•Respiratory symptoms such as wheezing, dyspnea, chest tightness, cough•Variable expiratory airflow limitation

DIAGNOSTIC FEATURE CRITERIA1. History of variable respiratory symptoms Wheezes, shortness of breath, chest tightness and cough

• Generally more than one type of respiratory symptom• Sx occur variably over time and vary in

intensity• Sx are often worse at night or on waking• Sx are often triggered by exercise,

laughter, allergens, cold air• Sx often appear or worsen with viral

infections

DIAGNOSTIC FEATURE CRITERIA2. Confirmed variable expiratory airflow limitation

Documented excessive variability in lung function

AND documented airflow limitation

The greater the variations, or the more occasions excess variation is seen, the more confident the diagnosis

At least once during diagnostic process when FEV1 is low, confirm that FEV1/FVC is reduced (normally >0.75-0.80 in adults, >0.90 in children)

Positive bronchodilator (BD) reversibility test (more likely positive if BD medication is withheld before test: SABA ≥ 4h, LABA ≥ 15h

Adults: increase in FEV1 of >12% and >200 ml from baseline, 10-15 minutes after 200-400 mcg albuterol or equivalent (greater confidence if increase is >15% and >400 ml)Children: increase in FEV1 of >12% predicted

Excessive variability in 2x-daily PEF over two weeks

Adults: average daily diurnal PEF variability >10%Children: average daily diurnal PEF variability >13%

DIAGNOSTIC FEATURE CRITERIA2. Confirmed variable expiratory airflow limitation

Significant increase in lung function after 4 weeks of anti-inflammatory treatment

Adults: Increase in FEV1 >12% or >200 ml from baseline after 4 weeks of treatment, outside of respiratory infections

Positive exercise challenge test Adults: fall in FEV1 of >10% and >200 ml from baselineChildren: fall in FEV1 of >12% predicted, or PEF >15%

Positive bronchial challenge test (usually only performed in adults)

Fall in FEV1 from baseline of ≥20% with standard doses of methacholine or histamine, or ≥15% with standardized hyperventilation , hypertonic saline or mannitol challenge

Excessive variation in lung function between visits (less reliable)

Adults: variation in FEV1 of >12% and >200 ml between visits, outside of respiratory infectionsChildren: variation in FEV1 of >12% in FEV1 or >15% in PEF between visits

History and PE•There is an increased risk that respiratory problems are due to asthma if :•Respiratory symptoms start in childhood•History of allergic rhinitis or eczema•Family history of asthma or allergy

•Nonspecific

PE•Often normal•Most frequent abnormality is expiratory wheezing (rhonchi) on auscultation (this may be absent or heard only on forced expiration) •Wheezing may also be absent in severe asthma exacerbations due to severely reduced flow (“silent chest”)•Wheezing may also be heard in upper airway obstruction, COPD, tracheomalacia, respiratory infection, and foreign body

PE•Crackles (crepitations) and inspiratory wheezing are not features of asthma•Examination of nose may reveal rhinitis or nasal polyposis•FEV1 (Forced Expiratory Volume) • Lung disease or poor spirometric technique• Reduced ratio of FEV1 to FVC - indicates airflow limitation• Normal: FEV1/FVC >0.75-0.80; >0.90 in children

Once an obstructive defect has been confirmed, variation in airflow limitation is generally assessed from variation in FEV1

or PEF

•VARIABILITY – refers to improvement and/or deterioration of symptoms and lung function•REVERSIBILITY•refers to rapid improvements in FEV1 or PEF measured within minutes after inhalation of a rapid-acting bronchodilator •or more sustained improvement over days or weeks after the introduction of effective controller treatment

How much variation in expiratory airflow is consistent with asthma?•The greater the variations in their lung function, or the more times excess variation is seen, the more likely the diagnosis is asthma•In adults with typical respiratory systems of asthma, an increase or decrease in FEV1 of >12% and >200 ml of baseline •(if spirometry is not available) a change of PEF of at least 20%

OTHER TESTS1. Bronchial provocation test –this test helps assess airway

hyperresponsiveness

2. Allergy tests – allergen test or sIgE o sIgE is preferred for uncooperative patients, those with widespread

skin disease, or hx suggests anaphylaxis)

3. Exhaled NO – FENO is increased in eosinophilic asthma but also in non-asthma conditions (e.g. eosinophilic bronchitis, atopy and allergic rhinitis).

Age Condition Symptoms

6-11 years Chronic upper airway cough syndrome Inhaled foreign bodyBronchiectasisPrimary ciliary dyskinesia

12-39 years

40+ years

ASSESSMENT OF ASTHMA

Assessment of asthma should include the assessment of asthma

control (both symptom control and future risk of adverse outcomes)

Ms X has good asthma symptom control, but she is at risk of increased of future exacerbations because she

has had a severe exacerbation within the last year

Asthma sx control tools in 6-11 y/o•Based on symptoms, limitation of activities and use of rescue medication

Assessing Risk of adverse outcomes•Assess whether the patient is at risk of adverse asthma outcome •Exacerbations•Fixed airflow limitation •Side effects of medication

Assessing Asthma Severity•MILD – well controlled in Step 1or 2 treatment with as-needed reliever medication alone or with low intensity controller treatment•MODERATE – well controlled in Step 3 treatment •SEVERE – requires Step 4 or Step 5 treatment

TREATMENT

Long-term goals•To achieve good control of symptoms and maintain normal activity levels•To minimize future risk of exacerbations, fixed airflow limitation and side effects

ASTHMA MEDICATIONS•Controller medications: used for regular maintenance treatment. They reduce airway inflammation, control sx, and reduce future risks such as exacerbations and decrease in lung function

•Reliever (rescue) medications: as-needed relief for breakthrough symptoms, also recommended for short-term prevention of exercise-induced bronchoconstriction. REDUCING AND IDEALLY ELIMINATING RELIEVER TX IS BOTH AN IMPT GOAL IN ASTHMA MGT AND A MEASURE OF SUCCESS OF ASTHMA TX

•Add-on therapies for px with severe asthma: for px with persistent sx and severe exacerbations, despite optimized tx of high-dose controlled medications

Initial Controller Treatment •Regular daily controller should be started as soon as asthma is diagnosed, because:• Early initiation of low dose ICS in px with asthma leads to greater

improvement in lung function than if sx have been present for >2-4 years• Patients not taking ICS who experience a severe exacerbation have

a greater long-term decline in lung function than those who have already started ICS• For px with occupational asthma, early removal from exposure to

the sensitizing agent and early tx increase the probability of recovery

1`

Stepwise approach•Once tx has started: assessment adjustment review of response •Controller medication is adjusted up or down in a stepwise approach•Once asthma has been controlled in 2-3months, tx may be stepped down in order to find patient’s minimum effective tx

•If px has persisting sx despite 2-3 months of controller tx, assess• Incorrect inhaler technique• Poor adherence• Persistent exposure at home/work such as allergens, tobacco

smoke, indoor or outdoor air pollution, or medications such as beta-blockers, or NSAIDS• Comorbidities that may contribute to respiratory sx and poor

quality of life• Incorrect diagnosis

STEP 1AS NEEDED-RELIEVER INHALER

Preferred option As-needed inhaled SABA – insufficient evidence in safety of using alone, thus preferred in px with occasional daytime sx of short duration, with no night waking and with normal lung fxn. If not, regular controller tx is needed

Other option Regular low dose ICS in addition to SABA

Other options not recommended for routine use

Inhaled anticholinergic (ipratropium)Oral SABAOral acting theophylline

But with slower set of action and higher side effectsThe rapid onset LABA, formeterol, is as effective as SABA in reliever medication, but use of frequent SABA without ICS is discouraged because of risk of exacerbations

STEP 2LOW DOSE CONTROLLER MEDICATION PLUS AS-NEEDED RELIEVER MEDICATION

Preferred option Regular low dose ICS plus as-needed SABA – low doses ICS reduces asthma sx, inc lung fxn, reduces risk of exacerbation and asthma-related hospitalizations or deaths

Other option LTRA - alternative, or for px with allergic rhinitis

Other options not recommended for routine use

Sustained release in theophylline – weak efficacy in asthma, side effects are common, life-threatening at higher doses

Chromones (nedocromil sodium and sodium cromoglycate) – favourable safety profile but low efficacy, and their inhalers require burdensome daily washing to avoid blockage

Step 3ONE OR TWO CONTROLLERS PLUS AS-NEEDED RELIEVER MEDICATION

Preferred option Adults/adolescents: Combination low dose ICS/LABA as maintenance treatment plus as needed SABA OR (fluticasone furoate/vilanterol; fluticasone proprionate/formoterol; fluticasone proprionate/salmeterol, beclometasone/formeterol, budesonide/formeterol.; mometasone/formeterol)

combination low dose ICS/formoterol (budesonide or buclesonide) as both maintenance and reliever

Children (6-11 ) years old: moderate dose ICS plus as-needed SABA

Other option Increase ICS to medium dose – but less effective than adding a LABALow dose ICS plus either LTRA or low dose, sustained theophylline

Step 4TWO OR MORE CONTROLLERS MEDICATION PLUS AS-NEEDED RELIEVER MEDICATION

Preferred option Adults/adolescents: combination low dose ICS/formoterol as maintenance and reliever tx OR combination medium dose ICS/LABA plus as-needed SABA, in >1 exacerbations/yr, low dose ICS/formoterol as maintenance and reliever treatment is more effective than maintenance and high dose ICS/LABA

Children: refer to expert assessment and deviceOther option Combination high dose ICS/LABA – but increase in ICS dose has little benefi