|Video: Adult Asthma|
Overview Asthma is one of the most common respiratory diseases. It is generally accepted that asthma is associated with affluent Westernised lifestyle, with the prevalence being higher in more developed countries. The prevalence increasing significantly since 1960. Asthma is more common in children than adults and affects boys more than girls, with most patients being symptomatic by age 3 years. Between 30-80% of children become asymptomatic around the time of puberty.
Asthma is one of the most common causes of presentation to the emergency department. It implies reversible airway constriction (peak flows vary by >20%) +/- wheeze, dyspnoea or cough. Airway obstruction occurs due to a combination of:
- Inflammatory cell infiltration
- Mucus hypersecretion with mucus plug formation
- Smooth muscle contraction
Mast cells and Eosinophils play a major role. This page will mainly focus on adult asthma
Asthma: Condition of bronchial hyperactivity and smooth muscle hypertrophy leading to a chronic inflammatory condition of the airways associated with widespread bronchospasm that is reversible.
Acute cough: Condition for less than 3 weeks, most commonly caused by acute upper respiratory infection but also may be caused by congestive heart failure, pneumonia, and pulmonary embolism.
Chronic cough: Condition for longer than 3 to 8 weeks (case definitions vary). Smoker – chronic obstructive pulmonary disease. Nonsmoker with a normal chest radiograph and not taking an ACE inhibitor, it may be due to postnasal drip, gastroesophageal reflux disease (GERD), or asthma.
Signs and Symptoms
|Asthma Triad CDE: Cough, Dyspnea, Expiratory wheeze|
Clinical Presentation Patients may present because of an asthma exacerbation due to a recent respiratory infection. This is often the case for children. Asthma is clinically characterised by having a expiratory wheeze. Some patients may have a completely normal examination and a lung spirometry has to be performed +/- exercising to check for exercise induced asthma.
- Cystic Fibrosis
- Foreign body aspiration
- Pulmonary Embolism
- Congestive heart failure
- Heart Failure
|Remember The three most common causes of chronic cough in immunocompetent nonsmokers who are not taking ACE inhibitors are postnasal drip, asthma, and gastroesophageal reflux disease.|
- Spirometry – shows <80 FEV/FVC ratio. Broncho-reversibility testing FEV >12% (or 200ml).
- Chest X-Ray – normal or hyperinflation
- Full blood count – normal or shows eosinophilia (allergy)
|Clinical triad CDE|
|Airflow reversibility 12% FEV1/FVC OR 200ml|
|Day-to-day peak flow variability|
|Watch Asthma Pathophysiology|
Asthma is a chronic lung disease, which can be controlled but not cured. Management of asthma include:
- Pharmacological – involves administration of a reliever and a preventer, depending on patients severity, co-morbidities, allergies and compliance
- Non-pharmacological interventions – Education and developing a asthma action plan is critical for preventing emergency admission and for controlling asthma.
|Remember Treatment of asthma is a stepwise process based on frequency of symptoms and response to prescribed medications.|
Step 1 – mild intermittent and exercise-induced asthma
- SABA for quick relief
Step 2 – mild persistent
- SABA + Low dose inhaled Corticosteroids (ICS)
Step 3 – moderate persistent
- LABA + Low does ICS which can gradually be increased
- SABA is used for quick relief
Step 4-6 – severe persistent
- LABA + moderate to high dose ICS
- SABA is used for quick relief
- Oral corticosteroids can be used it very severe
- An imunomodulator is considered in patents with allergies (Montelukast)
- Asthma action plan (Aimed to reduce emergency visits following acute exacerbations)
- Altering therapy
- What to do and how long to do it
- Allergen avoidance
- Dietary intervention
- Complementary medicine
- Smoking cessation
Sometimes people with asthma can have exacerbations. It can be mild, moderate, severe or life threatening. During an exacerbation if their SABA (ventolin) does not help people present to emergency for help.
- Acute Mild/moderate asthma
- Acute Severe asthma
- Life-threatening asthma
Complications and Prognosis
- Moderate – severe exacerbations
- treat with oxygen, fluids, SABA and ICS.
- Airway remodelling
- Gastrointestinal candidiasis secondary to inhaled corticosteroids
- Dysphonia secondary to inhaled corticosteroids
- Acute asthma
- Life threatening asthma
|Side note Smoking: