Asthma Flashcards
What is asthma?
Chronic inflammatory disease of the respiratory system characterized by bronchial hyperresponsiveness, episodic exacerbations (asthma attacks), and reversible airflow obstruction
What is the pathophysiology of asthma?
Inflammatory disease driven by T-helper type 2 (Th2-cell). Three processes occurr:
1) Bronchial hyper-responsiveness
2) Mainly in terminal bronchioles, inflammation and expression of Th2-cells.production of cytokines (IL-3, IL-4, IL-5, IL-13) → activation of eosinophils and induction of cellular response (B-cell IgE production) → bronchial submucosal edema and smooth muscle contraction → bronchioles collapse
3) Bronchial obstruction
What are the clinical features of asthma?
(Mild to moderate) Persistent, dry cough End-expiratory wheezes Dyspnea Chest tightness Chronic allergic rhinitis Hyper-resonance chest sound
(Severe) Severe dyspnea Pulsus paradoxus Hypoxemia Accessory muscle use Increased risk of pulmonary infection Silent chest
How is asthma diagnosed?
(>17 years) Assess for occupational asthma
all patients should have spirometry with a bronchodilator reversibility (BDR) test
all patients should have a FeNO test
(5-16 years) spirometry with a bronchodilator reversibility (BDR) test
a FeNO test should be requested if there is normal spirometry or conflicting results
(< 5 years) clinical judgement
What results indicate a positive in spirometry, FeNO and BDR?
(FeNO, adults) >= 40 parts per billion (ppb) is considered positive
(FeNO, children) >= 35 parts per billion (ppb) is considered positive
(Spirometry) FEV1/FVC ratio less than 70% is obstructive
(BDR) positive test is indicated by an improvement in FEV1 of 12% or more
What is the treatment of asthma?
(Newly-diagnosed asthma) Short-acting beta agonist (SABA)
(Not controlled on previous step OR Newly-diagnosed asthma with symptoms >= 3 / week) SABA + low-dose inhaled corticosteroid (ICS)
(Step 3) SABA + low-dose ICS + leukotriene receptor antagonist (LTRA)
(Step 4) SABA + low-dose ICS + long-acting beta agonist (LABA)
(Step 5) SABA +/- LTRA + Switch ICS/LABA for a maintenance and reliever therapy with low does ICS (MART)
(Step 6) SABA +/- LTRA + medium-dose ICS MART
(Step 7) SABA +/- LTRA + one of the following options:
increase ICS to high-dose or additional drug (for example, a long-acting muscarinic receptor antagonist or theophylline)
What is maintenance and reliever therapy?
ICS and LABA combinations in which the LABA has a fast-acting component (for example, formoterol)
What is the treatment for mild acute asthma?
short-acting beta-2 agonist
What is the treatment for excercise-induced asthma?
hort-acting beta-2 agonist prior to exercise
What is the treatment for severe acute asthma?
(Medication) Short-acting beta-2 agonist (SABA)
Short-acting muscarinic antagonists (SAMA) like ipratropium bromide
Oral corticosteroid
Intravenous magnesium sulfate
(Oxygen/ventilation) Supplemental oxygen and/or helium-oxygen mixture (heliox)
Noninvasive ventilation (NIV
(Intubation)
