Week 2 - Respiratory - Obstructive Airways Disease Flashcards
(31 cards)
Define Obstructive Airway Disease
- Airflow obstruction or limitation, causing difficulty during expiration
- Examples:
- Chronic obstructive pulmonary disease
(COPD) - Asthma
List the common symptoms of Obstructive Airway Disease
- Dyspnoea
- Increased work of breathing (use of
the accessory muscles) - A decreased forced expiratory volume in one second (FEV1)
- Decreased FEV1/forced vital capacity (FVC) ration
Define the Pathophysiology of Asthma
Hypersensitivity reaction (immunological processes), leading to inflammation
What are the principal characteristics of Asthma
- Airway inflammation (oedema)
- Airway hyper-responsiveness (bronchial smooth muscle spasm, thickening of airway walls)
- Mucus hypersecretion (thick mucus, impaired mucociliary function)
What happens to the airways in Asthma
- Thick mucus
- Mucosal oedema (inflammation)
- Smooth muscle spasm causing obstruction of small airways occurs in asthma
- Breathing becomes laboured and expiration is difficult due to the airway restrictions
Define Exacerbations
Events that require urgent action to prevent a serious outcome, such as hospitalization or death from asthma.
What triggers acute exacerbations
- Allergens
- Infections
- Occupational exposures
- Tobacco smoke or from treatment non-adherence.
What are the symptoms of exacerbations of Asthma
- Bronchoconstriction
- Expiratory wheezing
- Dyspnoea
- Cough
- Prolonged expiration
- Tachycardia and tachypnoea (increased ventilatory rate)
- The accessory muscles of ventilation
What is the first long term goals for Asthma management
- Maintain asthma control & maintain lung function
- The most important element of regular asthma management > reduction of inflammation
- A stepwise approach recommended:
- Education, avoidance of triggers
- Pharmacotherapy
- Inhaled corticosteroids and
- Bronchodilator therapy
What is the second long term goals for Asthma management
- Prevent morbidity & mortality
- Acute asthma episodes > life threatening
- Maintain a patent (open) airway
- Administration of oxygen
- Rapid-acting bronchodilators E.g. salbutamol
- Systemic steroids for moderate to severe attacks > decrease inflammatory responses in the lungs
Define Sympathetic Nervous System
- Autonomic nervous system responsible for “fight or flight” responses.
- It increases heart rate, dilates airways, and prepares the body for action in stressful situations.
Define Parasympathetic Nervous System
- Autonomic nervous system responsible for “rest and digest” functions.
- It slows the heart rate, increases digestion, and promotes relaxation.
What receptors has sympathetics effects
- Adrenergic Receptors
- Alpha and Beta
- Beta 1 - Increase heart rate
- Beta 2 - Brochodilation
- Alpha 1 - Urinary Retantion
- Beta 1 - Increases Contractility
- Beta 1 - Atrioventricular conduction
What receptors has parasympathetics effects
Cholinergic Receptors
- M3 and M2 - Mucus Secretion
- M2 - Brochoconstriction
- M2 - Decrease Heart Rate
Explain the mechanism of action of Brochodilators
- β2 -adrenergic receptors control bronchial smooth muscle of the airway.
- When these receptors are stimulated by sympathomimetic agents (e.g. salbutamol) > leads to
bronchodilation (smooth muscle relaxation)
What receptor is Salbutamol and what is it for?
- Short-acting β2 receptor agonists
- Act very quickly, last for a short duration in the lungs
- Used for quick relief of bronchospasm
What receptor is Salmeterol and what is it for?
- Long-acting β2 receptor agonists
- A longer duration of action/used to control symptom
What is an example of non-selective adrenergic agonist
- Ephedrine
- Stimulate the β2 recpetors in the lung but can also stimulate the β1-receptors in the heart
- May be dangerous to use in a client with COPD who also suffers from heart disease.
What are reliever medications of Asthma
- Relax bronchial smooth muscle
- Rapid bronchodilation
- Acute relief of symptoms
- Administered on an as-needed basis.
- E.g. Salbutamol ad Iprotropium (Combivent)
What are preventer medication of Asthma
- Treat inflammation + overall asthma control
- Examples:
- Inhaled corticosteroids such as budesonide
Define Chronic Obstructive Pulmonary Disease (COPD)
- A preventable, progressive, chronic disease characterised by irreversible
obstruction of the airways - Immunological processes leads to the airway inflammation and lung damage
What is the cause of COPD
- Exposure to noxious particles or gases
- Most common = cigarette smoke
- Other risks: inhaled noxious particles
E.g. occupational exposure and air pollution.
Define COPD Pathophysiology
COPD is Pathophysiologically characterised by:
Chronic bronchitis:
- airway inflammation and remodelling
Emphysema:
- destruction of alveolar tissue, and a decrease in elastic recoil
- Commonly the coexistence of both
What is Emphysema
Destruction of alveolar tissue, and a decrease in elastic recoil
