Respiratory Flashcards
How is asthma defined?
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.
What are environmental exposures and irritants that have a strong role in asthma symptom exacerbations?
allergens or other environmental triggers such as cold air, exercise, tobacco smoke or other air pollutants may launch an inflammatory cascade that induces bronchospasm and airflow limitation
What is airway hyper responsiveness in asthma?
an exaggerated response to these endogenous or exogenous stimuli, and the degree of it generally correlates with he clinical severity of asthma
What is the prevalence of asthma during puberty for boys and girls?
Prior to puberty, asthma shows a higher prevalence in boys compared to girls; however after puberty, prevalence is greater in females
What are the two major environmental factors that influence the development of asthma?
Airborne allergens and viral respiratory infections
Environmental and inflammatory stimuli induce the production of what?
mediators from the airway epithelium which in turn activate and recruit inflammatory cells, consisting of eosinophils, lymphocytes, phagocytic neutrophils and mast cells
What is the dominant feature that leads to clinical symptoms?
Smooth muscle contraction and inflammation, which results in narrowing of the airway and obstruction
Persistent inflammation of the airway leads to what structural changes?
Smooth muscle hyperplasia
Epithelial damage/fibrosis
Mucous production
Angiogenesis (proliferation of blood vessels)
What is the cycle of inflammation that occurs in asthma patients?
- An interplay between genetics and environmental stimuli initiates the cycle.
- The airway epithelium acts as a frontline defense against allergens and other inhaled foreign substances.
- Activation of epithelial cells results in immediate host defense responses that include production of pro-inflammatory cytokines such as interleukin-2, IL-33 and IL-25, which recruit and activate inflammatory cells such as macrophages, neutrophils, eosinophils, lymphocyte T-helper cells, and mast cells.
- Inflammatory cells infiltrate the lungs and release mediators that further augment the inflammatory response in the epithelium, creating a cycle of chronic inflammation.
How do viral respiratory infections affect asthma?
They are one of the most important triggers for asthma exacerbation; may also contribute to the development of asthma
What is atopic-associated asthma?
The genetic predisposition for development of an immunoglobulin E (IgE) - Mediated response to common aeroallergens (strongest identifiable predisposing factor for developing asthma)
What are the signs and symptoms of Asthma?
Cough
Shortness of breath
Tightening of chest
Wheezing
Sputum production
What are the goals of asthma treatment?
Achieve good symptom control
Minimize future risk of asthma-related mortality
Minimize exacerbations, persistent airflow limitation and side-effects of treatment
What needs to be considered to select appropriate pharmacology agents to manage asthma?
Assess asthma severity and current degree of symptom control
Identify asthma triggers
Identify comorbid conditions that may affect management
Assess patient knowledge and skills
What is intermittent asthma?
Daytime symptoms occurring ≤ 2 days/week
Nighttime awakenings from cough ≤ 2 nights/month
Use of short-acting β2-agonists < 2 times/week
No interference with normal activities
Exacerbations requiring oral steroids ≤ 1 time/year
FEV1 and FEV1/FVC spirometry values in normal range
What is persistent asthma (mild or moderate)
More frequent symptoms during daytime
More frequent nighttime awakenings
More frequent use of short-acting β2-agonists
More limitation of normal activities
What are the quick-relief (rescue) medications?
Anticholinergics
Short-acting β2-agonists (SABA)
Oral systemic corticosteroids
How do you determine asthma severity?
Impairment parameters and risk parameters
What are the impairment parameters to determine asthma severity?
Symptoms
Nighttime awakenings
Use of quick-relief medication to control symptoms
Interference with normal activity
Impaired lung function (spirometry)
What are the risk parameters to determine asthma severity?
Number of asthma exacerbations requiring oral systemic corticosteroids in previous year
What are the three types of inhaled drug therapies?
Hydrofluoroalkane inhaler (HFA)- formerly called a metered-dose inhaler (MDI)
Dry-powder inhalers (DPIs)
Nebulizers
What are the four advantages of inhaled drug therapies?
Large surface area for absorption
Rapid symptom relief
Avoidance hepatic first-pass metabolism
Smaller doses required with less systemic effect
What are the disadvantages of inhaled drug therapy?
Without a spacer, only 10-40% of the drug leaving the device is deposited in the lungs
What is the impact of a spacer device on Distribution of Inhaled Medication?
Using a spacer device with an HFA can help reduce the amount of drug that sticks to the back of the throat, improving direction and deposition of medication delivered
