Bronchial Asthma
Risk factors of bronchial Asthma
Atopy
Pathophysiology of bronchial Asthma
Diagnosis of bronchial Asthma
DDx of bronchial Asthma
Classification of bronchial Asthma
Aims of asthma management
Medications
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Language: en
Added: Jul 04, 2024
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Dr P Mayurathan
Bronchial Asthma
•The chronic reversible inflammation is associated with
airway hyper responsiveness that lead to recurrent
episodes of wheezing, breathlessness, coughing and
chest tightness
•Symptoms occur mainly at night or in the early morning
•Episodes are associated with widespread and variable
airway obstruction within the lungs which is often
reversible either spontaneously or with treatment
What is atopy?
•Atopy is defined as thetendency to be allergic and/or intolerant
to many substances
•It is the medical term used to describe a particular group of
patients with a genetic predisposition to allergies
•It is the tendency to produce an exaggeratedIgEimmune
response to otherwise harmless environmental substances
•Atopy may have ahereditarycomponent, although contact with
theallergenor irritant must occur before the hypersensitivity
reaction can develop
Pathophysiology of Asthma
Allergens and Triggers
Inflammation
Airway hyper-responsiveness
Symptoms
Cough
SOB
Wheeze
Chest tightness
Pathophysiology of Asthma
Pathophysiology of Asthma
Triggers
Pathophysiology of Asthma
•Limitation of airflow
–is due mainly to bronchoconstriction
–but airway edema, vascular congestion, and luminal
occlusion with exudate may also contribute
•This results in a reduction in
–Forced expiratory volume in 1 s (FEV1)
–FEV1/FVC
–Peak expiratory flow (PEF)
•Increased in airway resistance
Pathophysiology of Asthma
Diagnosis of Asthma
Lung Function Tests
•Spirometry
–FEV
1/FVC ratio of less than 70%
•Bronchodilator reversibility (BDR)
–Offer a BDR test to patients with obstructive spirometry
–improvement in FEV
1of 12% or more, together with an increase
in volume of 200ml or more is considered as a positive test
•Peak expiratory flow variability
–Regard a value of more than 20% variability as a positive test
Diagnosis of Asthma
Airway inflammation measures
•Fractional exhaled Nitric Oxide [FeNO]
–FeNOlevel of 40parts per billion (ppb) or more as a positive test
for adults (aged 17 yearsand over)
–FeNOlevel of 35ppb or more as a positive test for children and
young people (aged 5to16 years)
Airwayhyperreactivitymeasures
•Direct bronchial challenge test with histamine or methacholine
–Regard a PC
20value of 8mg/ml or less as a positive test
{PC
20 -provocative concentration causing a 20% drop in FEV1}
Diagnosis of Asthma
Other supportive investigations
•FBC –Elevated eosinophil count
•CXR –Normal initially
How to check the peak flow variability easily?
•Do the Peak Flow assessment before and after
salbutamol nebulisation
Classification of Asthma
Old Classification
•Intermittent Asthma
•Mild persistent Asthma
•Moderate persistent Asthma
•Severe persistent Asthma
New Classification
•Controlled Asthma
•Partially controlled Asthma
•Uncontrolled Asthma
New classification
Level of Asthma Control
Characteristic Controlled
(All of the following)
Partly controlled Uncontrolled
Daytime symptomsTwice or less/weekMore than twice/weekThree or more
Features of partly
controlled asthma
present in any
week
Limitations of
activities
None Any
Nocturnal symptoms
/awakening
None any
Need for
reliever/rescue
treatment
Twice or less/weekMore than twice /week
Lung function Normal <80% predicted
Aims of Asthma Management
•Minimal (ideally no) chronic symptoms, including nocturnal
•Minimal (infrequent) exacerbations
•No emergency visits
•Minimal (ideally no) use of as-required β2-agonist
•No limitations on activities, including exercise
•PEF circadian variation <20% and (Near) normal PEF
•Minimal (or no) adverse effects from medicine
Medications to treat asthma can be classified as;
•Relievers
–They are used on as needed basis, that act quickly to
reverse bronchoconstriction and its symptoms
•Controllers
–They are medications taken daily on a long term basis
to keep asthma under clinical control chiefly through
their the anti inflammatory effect.
Brittle Asthma
•Chaotic variations in lung function despite taking
appropriate therapy
•The most effective therapy is subcutaneous epinephrine
Pregnancy and Asthma
•Severity during pregnancy
•1/3 -improve
•1/3 -unchanged
•1/3 -worse
•Poor control can have adverse effect to fetus
•short-acting β2-agonists, ICSs, theophylline,leukotrienemodifiers
(montelukast) are not associated with fetal abnormalities
•Acute exacerbation should be treated aggressively to avoid fetal
hypoxia
•During labour-no special indication for LSCS other tan Obsindication
Asthma and Covid-19
•Advise patients with asthma to continue taking their prescribed asthma
medications, particularly ICS oral corticosteroids (OCS) if prescribed
•Make sure that all patients have a written asthma action plan
•Where possible, avoid use of nebulizers due to the risk of transmitting infection
to other patients and to healthcare workers
•Avoid spirometry in patients with confirmed/suspected COVID-19
•Follow infection control recommendations if other aerosol-generating
procedures are needed
•Follow local health advice about hygiene strategies and use of personal
protective equipment, as new information becomes available in the country or
region
Discharge plan
•Minimum 7 days course of oral steroids along with
continuation of bronchodilator therapy
•Short acting β2 agonist can be used as needed
•Initiate or continue inhaled glucocorticosteroids
•Factors precipitated the exacerbation should be identified an
strategies for future avoidance implemented
•Satisfactory inhaler and peak flow meter techniques should be
assessed and confirmed
•Providing a short course of oral steroid to be on hand for
subsequent exacerbations
•Written action plan-according to the PEFR
•If <400l/min-2-4 fold increase inhaled steroids
•If <300l/min-take oral steroids
•If<200l/min-hospital admission
•The follow-up appointment should be arranged within few
days
Discharge plan
What are the clinical and social significance of
asthma?
1. T/F regarding Bronchial Asthma?
1.Associated with Type 1 hypersensitivity reaction
2.Basophils, mast cells and eosinophils play an important
role
3.Irreversible airway obstruction occurs
4.Common among developing countries than developed
countries
5.Socio-economic consequences of asthma is not significant
when comparing to the clinical significance
2. T/F regarding discharge plan of asthma patient;
1.Can be discharged while on regular salbutamol
nebulization
2.Ensure the patient has oral corticosteroids
3.Review and correct the inhaler technique
4.Risk factor assessment should be done only during the
clinic review
5.Plan of next clinic review should be arranged
3. T/F regarding asthma and pregnancy;
1.1/3
rd
of the patients develop frequent exacerbations
2.Leukotriene receptor antagonists are contraindicated
3.Oral corticosteroids can be given during breat feeding
4.LSCS is contraindicated
5.Mepolizumab (anti-interleukin 5) is safe