Asthma

Asthma is a heterogeneous disease, usually characterized by chronic airway
inflammation.
It is defined by the history of respiratory symptoms such as wheeze, shortness of
breath, chest tightness and cough that vary over time and in intensity, together with
variable expiratory airflow limitation.
Definition of Asthma
GINA 2014GINA 2014 © Global Initiative for Asthma

• Asthma is one of the most common chronic diseases in the world.
• It is estimated that around 300 million people in the world currently have
asthma.
• The socioeconomic impact is enormous, poor control leads to days lost
from work.
© Global Initiative for Asthma

 The pathophysiology of asthma is complex and involves the following
components:
• Airway inflammation
• Intermittent airflow obstruction
• Bronchial hyperresponsiveness

o ATOPY
• Relationship between atopy & asthma is well established.
• Sensitisaton & allergen exposure demonstrated by skin prick reactivity &
elevated serum IgE.
o ASPIRIN SENSITIVE ASTHMA
• Result in inhibition of cyclo- oxygenase enzyme, leads to production of
asthmogenic cysteinyl leukotrienes.
o EXERCISE INDUCE ASTHMA
• Hyperventilation result in water loss from pericellular lining of respiratory
mucosa triggers mediator release.
Global Initiative for Asthma

Factors influencing the development of
asthma
HOST FACTORS
•Genetic
•Obesity
•Sex
ENVIOURMENTAL FACTORS
•Allergen
•Infections
•Occupational sensitizer
•Tobacco smoking
•Outdoor/indoor pollution
•Diet
•Drugs

A history of respiratory symptom that vary over
time and intensity
Diagnosis of asthma
Variable expiratory airflow limitation

Criteria for making diagnosis of Asthma
GINA 2014
A HISTORY OF VARIABLE RESPIRATORY
SYMPTOMS
More than one type of symptom.
Symptoms often worse at night or in the early
morning
Symptoms vary over time and in intensity
Symptoms are triggered by various factors.

EVIDENCE OF VARIABLE AIRFLOW LIMITATION
Confirm presence of airflow limitation
Document that FEV1/FVC is reduced (at least once, when FEV1 is low)
Confirm variation in lung function is greater than in healthy individuals
•Excessive bronchodilator reversibility (increase in FEV1 >12%
and >200mL)
• Excessive diurnal variability for 1-2 weeks, twice-daily PEF monitoring
(daily amplitude x 100/daily mean, averaged)
• Significant increase in FEV1 or PEF after 4 weeks of controller
treatment
• If initial testing is negative:
• Repeat when patient is symptomatic, or after withholding
bronchodilators

 Physical examination in people with asthma
Often normal
The most frequent finding is wheezing on
auscultation, especially on forced expiration
 Wheezing may be absent during severe asthma
exacerbations (‘silent chest’)

Other investigations
• Chest xray
• Often normal.
• Hyperinflation in acute asthma.
• Lobar collapse if large bronchi occulded.
• Measurement of allergic status
• Total IgE or allergen specific IgE or skin prick test required.
• Blood eosinophilia
• Sputum eosinophilia.

GINA 2014, Box 1-1 © Global Initiative for Asthma

 Decreased probability that symptoms are due to asthma if:
 Isolated cough with no other respiratory symptoms
 Chronic production of sputum
 Shortness of breath associated with dizziness, light-headedness
or peripheral tingling
 Chest pain
 Exercise-induced dyspnea with noisy inspiration (stridor)

• Diagnosis
– Demonstrate variable expiratory airflow limitation
• Risk assessment
– Low FEV1 is an independent predictor of exacerbation risk
• Monitoring progress
– Measure lung function at diagnosis, 3-6 months after starting
treatment
(to identify personal best), and then periodically
– Consider long-term PEF monitoring for patients with severe asthma or
impaired perception of airflow limitation
The role of lung function in asthma
GINA 2014

• The long-term goals of asthma management are
1. Symptom control: to achieve good control of symptoms and maintain
normal activity levels
2. Risk reduction: to minimize future risk of exacerbations, fixed airflow
limitation and medication side-effects
Goals of asthma management
GINA 2014

The control-based asthma management cycle
GINA 2014, Box 3-2

Treating modifiable risk factors
• Encourage avoidance of tobacco smoke
• For patients with confirmed food allergy:
– Appropriate food avoidance
– Ensure availability of injectable epinephrine for anaphylaxis
• Physical activity
– Encouraged because of its general health benefits.

• Occupational asthma
– Remove sensitizers as soon as possible. Refer for expert advice, if
available
• Avoid medications that may worsen asthma
– Always ask about asthma before prescribing NSAIDs or beta-blockers
GINA 2014, Box 3-9

• Before starting initial controller treatment
– Record evidence for diagnosis of asthma, if possible
– Record symptom control and risk factors, including lung function
– Consider factors affecting choice of treatment for this patient
– Ensure that the patient can use the inhaler correctly
– Schedule an appointment for a follow-up visit
Initial controller treatment
GINA 2014, Box 3-4 (2/2) © Global Initiative for Asthma

• After starting initial controller treatment
– Review response after 2-3 months, or according to clinical urgency
– Adjust treatment (including non-pharmacological treatments)
– Consider stepping down when asthma has been well-controlled for 3
months

Stepwise management - pharmacotherapy
*For children 6-11 years, theophylline is not recommended, and preferred Step 3 is medium dose ICS
**For patients prescribed BDP/formoterol or BUD/formoterol maintenance and reliever therapy
GINA 2014, Box 3-5, Step 1

Step 2 – low-dose controller + as-needed
inhaled SABA

Step 3 – one or two controllers + as-needed
inhaled reliever

Step 4 – two or more controllers + as-needed
inhaled reliever

Step 5 – higher level care and/or add-on
treatment

Low, medium and high dose inhaled
corticosteroids
Adults and adolescents (≥12 years)
– Most of the clinical benefit from ICS is seen at low doses
– High doses are arbitrary, but for most ICS are those that, with prolonged use, are
associated with increased risk of systemic side-effects
Inhaled corticosteroid Total daily dose (mcg)
Low Medium High
Beclometasone dipropionate (CFC) 200–500 >500–1000 >1000
Beclometasone dipropionate (HFA) 100–200 >200–400 >400
Budesonide (DPI) 200–400 >400–800 >800
Ciclesonide (HFA) 80–160 >160–320 >320
Fluticasone propionate (DPI or HFA) 100–250 >250–500 >500
Mometasone furoate 110–220 >220–440 >440
Triamcinolone acetonide 400–1000 >1000–2000 >2000
GINA 2014, Box 3-6 (1/2)

• How often should asthma be reviewed?
– 1-3 months after treatment started, then every 3-12 months
– During pregnancy, every 4-6 weeks
– After an exacerbation, within 1 week
• Stepping up asthma treatment
– Sustained step-up, for at least 2-3 months if asthma poorly controlled
– Short-term step-up, for 1-2 weeks, e.g. with viral infection or allergen
– Day-to-day adjustment
• For patients prescribed low-dose ICS/formoterol maintenance and
reliever regimen
Reviewing response and adjusting
treatment
GINA 2014

 Stepping down asthma treatment
• Aim
– To find the lowest dose that controls symptoms and exacerbations,
and minimizes the risk of side-effects

Consider
Step-
down
Symtoms
controlled for
≥ 3 months
Stable lung
functions for≥
3 months
No RTI
Not pregnant
Not travelling
Prepare for step-down
•Record the level of symptom control and
consider risk factors
•Make sure the patient has a written
asthma action plan
•Book a follow-up visit in 1-3 months

Written asthma action plans
GINA 2014, Box 4-2 (1/2)

Written asthma action plans – medication
options
Increase inhaled reliever
•Increase frequency as
needed
•Adding spacer for pMDI
may be helpful
Early and rapid increase in inhaled
controller
•Up to maximum ICS of 2000mcg
BDP/day or equivalent
•Options depend on usual
controller medication and type of
LABA
Add oral corticosteroids
•prednisolone 1mg/kg/day up to 50mg,
usually 5-7 days
•Tapering not needed if taken for less than 2
weeks

• The aim of asthma management is control of the disease.
Complete control of asthma is defined as:
– no daytime symptoms
– no night-time awakening due to asthma
– no need for rescue medication
– no asthma attacks
– no limitations on activity including exercise
– normal lung function (in practical terms FEV1 and/or PEF>80%
predicted or best)
– minimal side effects from medication.

Assessment of asthma
Asthma control -
two
domains
Treatment issues
Comorbidities
Assess symptom control over the last 4 weeks
Assess risk factors for poor outcomes,
including low lung function.
Check inhaler technique and adherence
Ask about side-effects
Think of rhinosinusitis, GERD, obesity, OSA,
depression, anxiety
These may contribute to symptoms and poor
quality of life

GINA assessment of asthma control
GINA 2014, Box 2-2B

Assessment of risk factors for poor asthma
outcomes
Risk factors for exacerbations include:
• Ever intubated for asthma
• Uncontrolled asthma symptoms
• Having ≥1 exacerbation in last 12 months
• Low FEV1 (measure lung function at start of treatment, at 3-6 months
to assess personal best, and periodically thereafter)
• Incorrect inhaler technique and/or poor adherence
• Smoking
• Obesity, pregnancy, blood eosinophilia
GINA 2014, Box 2-2B
• Smoking
Risk factors for fixed airflow limitation include:
• No ICS treatment, smoking, occupational exposure, mucus
hypersecretion, blood eosinophilia
• Smoking
Risk factors for fixed airflow limitation include:
• No ICS treatment, smoking, occupational exposure, mucus
hypersecretion, blood eosinophilia
Risk factors for medication side-effects include:
• Frequent oral steroids, high dose/potent ICS, P450 inhibitors

“Acute or sub-acute worsening of symptoms and lung function compared with
the patient’s usual status”
Acute exacerbation of Asthma

Classifying Severity of Asthma
Exacerbations

Clinical CourseInitial PEF (or
FEV1)
Symptoms and
Signs
• Usually cared for at home
• Prompt relief with inhaled
SABA
• Possible short course of oral systemic corticosteroids
PEV 70%
predicted
Dyspnea only with
activity
Mild
• Usually requires office or ED visit
• Relief from frequent inhaled SABA
• Oral systemic corticosteroids; some symptoms last
for 1–2 days after treatment is begun
PEF 40–69%
predicted
Dyspnea interferes
with limits of usual
activity
Moderate
• Usually requires ED visit and likely hospitalization
• Partial relief from frequent inhaled SABA
• Oral systemic corticosteroids; some symptoms last
for > 3 days after treatment is begun
• Adjunctive therapies are helpful
PEF < 40%
predicted
Dyspnea at rest;
interferes with
conversation
Severe
• Requires ED/hospitalization; possible ICU
• Minimal or no relief from frequent inhaled SABA
• Intravenous corticosteroids
• Adjunctive therapies are helpful
PEF < 25%
predicted
Too dyspneic to
speak; perspiring
Subset: Life-
threatening

Evaluation of Asthma Exacerbation
Severity

Subset: Respiratory
Arrest Imminent
SevereModerateMild
Symptoms
While at restWhile at restWhile walkingBreathlessness
Sits uprightPrefers sittingCan lie down
WordsPhrasesSentencesTalks in
Drowsy or confusedUsually agitatedUsually agitatedMay be agitatedAlertness
Signs
Often > 30/minuteIncreasedIncreasedRespiratory rate
Paradoxical
thoracoabdominal
movement
UsuallyCommonlyUsually notUse of accessory
muscles; suprasternal
retractions
Absence of wheezeUsually loud;
throughout
inhalation and
exhalation
Loud; throughout
exhalation
Moderate, often
only and expiratory
Wheeze
Bradycardia>120120–100<100Pulse/minute

Treatment of Asthma Exacerbations
• Asthma treatment algorithms begin with an assessment of the severity of a patient's baseline
asthma.
• Most instances of uncontrolled asthma are mild and can be managed successfully by patients at
home with the telephone assistance of a clinician

More severe exacerbations require evaluation and management in an urgent care or
emergency department setting

Mild Exacerbations
• Many patients respond quickly and fully to an inhaled short-acting 2-
agonist alone
• However, an inhaled short-acting 2-agonist may need to be continued at
increased doses, eg, every 3–4 hours for 24–48 hours
• In patients not taking an inhaled corticosteroid, initiation of this agent
should be considered
• In patients already taking an inhaled corticosteroid, a 7-day course of oral
corticosteroids (0.5–1.0 mg/kg/d) may be necessary

Moderate Exacerbations
o Main goal:
 correction of hypoxemia through the use of supplemental oxygen
 Reversal of airflow reduction by continuous administration of an inhaled
short-acting 2-agonist and the early administration of systemic
corticosteroids
 Reduction of recurence of obstruction
• Serial measurements of lung function
• It may reduce the rate of hospital admissions for asthma exacerbations
• The post-exacerbation care plan is an important aspect of management

Severe Exacerbations
• All patients with a severe exacerbation should immediately receive
 oxygen
(To maintain an SaO2 > 90% or a PaO2 > 60 mm Hg)
 high doses of an inhaled short-acting 2-agonist
(higher doses, 6–12 puffs every 30–60 minutes of SABA)
 systemic corticosteroids
• .

• Ipratropium bromide reduces the rate of hospital admissions when added to
inhaled short-acting 2-agonists in patients with moderate to severe asthma
exacerbations
• Intravenous magnesium sulfate (2 g I/V over 20 minutes) produces a detectable
improvement in airflow.
• Repeat assessment should be made after the initial dose of inhaled bronchodilator
and after three doses (60–90 minutes after initiating treatment)

• Follow up all patients regularly after an exacerbation, until symptoms and
lung function return to normal
– Patients are at increased risk during recovery from an exacerbation
• At follow-up visit check:
– The patient’s understanding of the cause of the flare-up
– Modifiable risk factors, e.g. smoking
– Adherence with medications, and understanding of their purpose
– Inhaler technique skills
– Written asthma action plan
Follow-up after an exacerbation
GINA 2014, Box 4-5

Indication of assissted ventilation in acute severe
asthma
Coma
Respiratory arrest
Deterioration of ABGs despite optimal therapy
•PaO2 < 8 kPa(60 mmHg) and falling
•PaCO2 >6 kPa (45 mmHg) and rising
•pH low and falling
Exhaustion, confusion , drowsiness.

INHALED
CORTICOSTERIODS
DOSE
Beclomethasone 40 0r 80mcg/puff
Fluticosone 50,100,or
250mcg/puff
SHORT ACTING β2
AGONIST
Albuterol (MDI) 90 mcg/puff,
200puff/ canister
2 puff 5 mins before exercise
Albuterol
(nebulizer)
1.25mg/3ml
2.5mg/3ml
5mg/3ml
1.25-5mg in 3 ml of saline every 4-8 hr
ANTICHOLINERGIC
Ipratropium 17 mcg/puff 2-3 puff every 6 hour
0.25mg/ml 0.25mg every 6 hour.
LONG ACTING β2
AGONIST
Salmeterol 50mcg/blister Every 12 hourly
Formetrol 12mcg/single
capsule
Every 12 hourly

Asthma

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