Asthma in Adults Flashcards
What is asthma?
Chronic inflammatory condition of the airways that causes episodic exacerbations of bronchoconstriction
What is bronchoconstriction?
When the smooth muscles of the airways (the bronchi) contract causing a reduction in the diameter of the airways.
Narrowing of the airways causes an obstruction to airflow going in and out of the lungs.
Caused by parasympathetic nerves
What are typical asthma triggers?
Infection
Night time or early morning
Exercise
Animals
Cold/damp
Dust
Strong emotions
What are presentations suggesting a diagnosis of asthma?
Episodic symptoms
Diurnal variability. Typically worse at night.
Dry cough with wheezing and shortness of breath
A history of other atopic conditions such as eczema, hayfever and food allergies
Family history
Bilateral widespread “polyphonic” wheeze heard by a healthcare professional
Is asthma reversible?
Reversible airway obstruction that typically responds to bronchodilators such as salbutamol
Diagnosis based off of BTS/Sign Guidelines
High probability of asthma clinically: Try treatment
Intermediate probability of asthma: Perform spirometry with reversibility testing
Low probability of asthma: Consider referral and investigating for other causes
BTS guidelines for treatment
Step 1: short-acting inhaled B2-agonist (eg. Salbutamol)
Step 2: add low-dose inhaled corticosteroid
steroid (ICS)
Step 3: add long-acting B2-agonist (eg. Salmeterol). If no benefit, stop this and increase ICS dose; if benefit but inadequate control, continue and increase ICS dose.
Step 4: Trial oral leukotriene receptor antagonist, high-dose steroid, oral B2-agonist
Investigations in chronic asthma
Peak flow: variability >20%
Fractional exhaled nitric oxide (FeNO): >40 ppb in adults or >35 ppb in children
Spirometry: FEV1/FVC <0.7 (obstructive spirometry)
Symptoms
Wheeze
Dyspnoea
Cough (may be nocturnal)
Chest tightness
Diurnal variation (symptoms often worse in the morning)
Signs of normal asthma
Tachypnoea
Hyperinflated chest
Hyper-resonance on chest percussion
Decreased air entry (sign of severe illness: silent chest)
Wheeze on auscultation
Signs of severe asthma
Inability to speak in complete sentences
Respiratory rate >25
Peak flow 33-50% predicted
Signs of life-threatening asthma
Silent chest
Confusion
Bradycardia
Cyanosis
Exhaustion
Diagnosis based off NICE guidelines
First line investigations:
Fractional exhaled nitric oxide
Spirometry with bronchodilator reversibility
If there is diagnostic uncertainty after first line investigations these can be followed up with further testing:
Peak flow variability measured by keeping a diary of peak flow measurements several times per day for 2 to 4 weeks
Direct bronchial challenge test with histamine or methacholine
BTS Stepwise Ladder:
Step One
Add short-acting beta 2 agonist inhaler (e.g. salbutamol) as required for infrequent wheezy episodes.
BTS Stepwise Ladder:
Step Two
Add a regular low dose corticosteroid inhaler.
BTS Stepwise Ladder:
Step Three
Add LABA inhaler (e.g. salmeterol).
Continue the LABA only if the patient has a good response.
BTS Stepwise Ladder:
Step Four
Consider a trial of an oral leukotriene receptor antagonist (i.e. montelukast), oral beta 2 agonist (i.e. oral salbutamol), oral theophylline or an inhaled LAMA (i.e. tiotropium).
BTS Stepwise Ladder:
Step Five
Titrate inhaled corticosteroid up to “high dose”. Combine additional treatments from step 4. Refer to specialist.
BTS Stepwise Ladder:
Step Six
Add oral steroids at the lowest dose possible to achieve good control.
NICE guideline ladder:
Step One
Add short-acting beta 2 agonist inhaler (e.g. salbutamol) as required for infrequent wheezy episodes.
NICE guideline ladder:
Step Two
Add a regular low dose inhaled corticosteroid.
NICE guideline ladder:
Step Three
Add an oral leukotriene receptor antagonist (i.e. montelukast).
NICE guideline ladder:
Step Four
Add LABA inhaler (e.g. salmeterol). Continue the LABA only if the patient has a good response.
NICE guideline ladder:
Step Five
Consider changing to a maintenance and reliever therapy (MART) regime.
NICE guideline ladder:
Step Six
Increase the inhaled corticosteroid to a “moderate dose”.
NICE guideline ladder:
Step Seven
Consider increasing the inhaled corticosteroid dose to “high dose” or oral theophylline or an inhaled LAMA (e.g. tiotropium).
NICE guideline ladder:
Step Eight
Refer to specialist
What additional steps can be taken in the management of asthma?
Each patient should have an individual asthma self-management programme
Yearly flu jab
Yearly asthma review
Advise exercise and avoid smoking
