Asthma introduction and overview Flashcards
What is the definition of asthma?
“Asthma is an inflammatory disorder of the airways characterized by paroxysmal or persistent symptoms such as dyspnea, chest tightness, wheezing, sputum production and cough, associated with variable airflow limitation and airway hyper-responsiveness to endogenous or exogenous stimuli. Inflammation and its resultant effects on airway structure and function are considered to be the main mechanisms leading to the development and maintenance of asthma.”
What age groups do we mostly see asthma in?
It is mostly a pediatric disease, with most patients being diagnosed by 5 years of age.2,3,4
Around 50% of children will exhibit symptoms by 2 years of age. It is more common in boys. Approximately 30% of children with asthma will get better by early adulthood and 70% will become symptom-free. Chronic disease persists in about 30% to 40% of patients, 20% or less develop severe chronic disease.
What is the preferred diagnosis of children aged 1 to 5 years of age for asthma?
Documentation by trained health care provider of wheeze and other signs of airflow obstruction with documented improvement with SABA +/- oral corticosteroids
Alternatively - convincing caregiver report of wheezing or other symptoms of airflow obstruction with symptomatic response to a 3-month trial of a medium dose of ICS and as needed SABA or symptomatic response to SABA
How are children 6 to 17 years diagnosed with asthma preferably? Alternatively?
Preferred: Spirometry showing reversible airflow obstruction
FEV1/FVC <LLN (<0.8-0.9)
AND increase in FEV1 after a bronchodilator or after a course of controller therapy of >12%
ALTERNATIVELY
Peak expiratory flow
>20% increase after a bronchodilator or after a course of controller therapy
OR
Positive challenge test
Methacoline Pc20 <4mg/ml or PD20 <0.5umol (100 mcg)
OR
Exercise challenge with >10-15 % decrease in FEV1 post exercise
What is the preferred diagnostic criteria for adults (18 years and older), and an alternative?
Preferred: Spirometry showing reversible airflow obstruction
FEV1/FVC <LLN (<0.75 to 0.8)
AND increase in FEV1 after a bronchodilator OR after a course of controller therapy of >12 % and a minimum of >200ml
OR
Peak expiratory Flow
60L/min (minimum >20%) increase after a bronchodialator or after a course of controller therapy
OR
Diurnal variation >8% based on twice daily readings; >20% based on multiple daily readings
OR
Positive challenge test
Methacholine PC2 <4mg/min or PD20 <0.5umol (100mcg)
How long should each of the following types of inhalers be held before spirometry?
1. SABA
2. Ipratropium
3. LABA (Salmeterol/formoterol)
4. Ultra-LABA (Indacaterol, olodaterol, vilanterol
5. LAMA (Glycopyrronium, tiotripium, aclidinium, and umeclidinium
- SABA - 4 to 6 hours
- Ipratropium - 12 hours
- LABA (Salmeterol/formoterol) - 24 hours
- Ultra-LABA (Indacaterol, olodaterol, vilanterol) - 36 hours
- LAMA (Glycopyrronium, tiotripium, aclidinium, and umeclidinium) - 36-48 hrs
What are symptoms of chronic ambulatory asthma?
Symptoms: episodes of dyspnea, chest tightness, coughing, wheezing, or a whistling sound when breathing. These often occur in association with exercise but may also occur spontaneously or in association with known allergens
SIGNS: expiratory wheezing on auscultation, dry hacking cough, or signs of atopy (allergic rhinitis and/or eczema) may be present
What are the signs and symptoms of acute asthma?
Symptoms:
1. The patient is anxious in acute distress and complains of severe dyspnea, shortness of breath, chest tightness, or burning.
The patient is only able to say a few words with each breath.
Symptoms are unresponsive to usual measures (inhaled β2-agonist administration).
SIGNS:
Signs include expiratory and inspiratory wheezing on auscultation (breath sounds may be diminished with very severe obstruction), dry hacking cough, tachypnea, tachycardia, pale or cyanotic skin, hyperinflated chest with intercostal and supraclavicular retractions, hypoxic seizures if very severe, normal or slightly elevated temperature.
Aside from symptom control, as is often described, what are also other very important facets to consider when describing asthma control?
- severity of symptoms
- impact on quality of life
- Exacerbations
- lung function
- and inflammatory marks for adults with moderate to severe asthma
What needs to be assessed when looking at asthma patients to determine how well controlled it is?
When assessing your asthma patients, you need to know how well it is controlled (via symptoms); are there any treatment issues (inhaler technique, attitudes towards their asthma and medications); and assess for comorbidities (allergies, reflux, sleep apnea, etc., anything that can affect asthma control).
You can have good control of asthma but still be at high risk of exacerbations.
Describe each of the following characteristics of asthma control and what is considered good control:
1. Day time symptoms
2. Nighttime symptoms
3. physical activity
4. Exacerbations
5. Absence from work or school due to asthma
6. need for reliever (Saba or Bud/form)
7. FEV1 or PEF
8. PEF diurnal variation
9. Sputum eosinophils
What are 4 criteria that indicates a person is a risk of an asthma exacerbation?
- Any hx of previous severe asthma exacerbation (requiring any of the following: Systemic steroids, ED visit, or hospitalization)
- poorly controlled asthma as per CTS criteria
- Over use of SABA (defined as use of more than 2 inhalers of SABA in a year)
- Curren smoker
What is the difference between severe asthma and uncontrolled asthma?
Severe asthma
Asthma which requires treatment with high-dose inhaled corticosteroids (ICS) and a second controller for the previous year, or systemic corticosteroids for 50% of the previous year to prevent it from becoming “uncontrolled”, or which remains “uncontrolled” despite this therapy.
Uncontrolled Asthma
Asthma that is defined at a minimum of any one of those mentioned below:
Poor symptom control as per Canadian Thoracic Society asthma control criteria or other standardized questionnaires:
Asthma Control Questionnaire (ACQ) consistently ≥ 1.5 is poor control.
Asthma Controlled Test (ACT) ≤20, or child Asthma Controlled Test (cACT) ≤20 is poor control.
Frequent severe exacerbations: two or more courses of systemic corticosteroids (3 days each) in the previous year.
Serious exacerbations: at least one hospitalization, intensive care unit (ICU) stay or mechanical ventilation in the previous year.
Airflow limitation: after appropriate bronchodilator withhold forced expiratory volume in one second (FEV1) <80% of personal best (or < the lower limit of normal (LLN), in the face of reduced FEV1/forced vital capacity (FVC) defined as less than the LLN)
