L18 Asthma and COPD Flashcards
Risk factors of asthma?
Signs/Symptoms of Asthma
Symptoms of Asthma: Cough, Wheeze, Shortness of Breath, Chest Tightness
Signs of Asthma: Hyperexpansion of chest cavity, prolonged expiratory time, expiratory wheezing, use of respiratory muscles
What allows asthma to be differentiated from COPD?
Asthma’s reversibility w/ broncho dilator allows it to be differentiated from COPD
What is Atopy and what is its significance?
Atopy is the tendency to produce an exaggerated immunoglobulin E immune response to otherwise harmless substances in the environment
- Presence of atopy makes asthma more likely than COPD
- Determines sensitivity to indoor allergens
- Serologic testing:
– IgE- elevations indicate the presence of allergic sensitization
– radioallergosorbent test (RAST)
• Allergen skin testing– Guides interventions to reduce exposure
Pathology of Asthma?
Reduction in airway luminal diameter
- excessive mucus production
- thick basement membrane
- airway inflammation
- bronchial hyper-responsiveness
Interactions between CD4 T Cells and B Cells => IgE Synthesis
Airway obstruction caused by some combination of
– Airway smooth-muscle constriction
– Inflammation of the bronchi
– Abnormal smooth-muscle contractility or Excess smooth-muscle mass
– Eosinophil influx
Th1 versus Th2 Phenotype of Asthma?
Asthma Treatment?
Reduction in bronchial inflammation when treated => still too many goblet cells
relaxation of airway smooth muscle (bronchodilators)
suppression of airway inflammation (anti-inflammatory drugs)
newer medication (dual effects)
– leukotriene modifiers
– Anti IgE therapy
drug combinations– inhaled corticosteroids combined with long-acting β-adrenergic agonists
Characteristics of COPD?
COPD is Chronic airflow obstruction due to chronic bronchitis and/or pulmonary emphysema
Primarily caused by cigarette smoking
Some patients with asthma develop poorly reversible airflow limitation
– indistinguishable from patients with COPD
– for practical purposes are treated as asthma
Diagnosis of COPD?
Diagnosis of COPD considered in any patient who has the following symptoms:
– cough
– sputum production or
– dyspnoea or
– history of exposure to risk factors for the disease (tobacco smoking++)
The diagnosis is confirmed with spirometry
Assessment of COPD severity
– spirometry
– functional dyspnoea
– body mass index = weight (Kg)/ height2 (m)
COPD Pathology? (4 Compartements impacted)
COPD => pathological changes in 4 different compartments of the lungs:
- central airways
- peripheral airways
- lung parenchyma
- pulmonary vasculature
Physiological Abnormalities in COPD
Physiological abnormalities in COPD
– mucous hypersecretion
– ciliary dysfunction
– airflow limitation
– hyperinflation
– gas exchange abnormalities
– pulmonary hypertension: destroys capillary beds => secondary hypertension from increased PVR
Smoking’s Contribution to COPD
Smoking is the main risk factor for COPD + Other inhaled noxious particles and gases
Oxidative stress from free radicals in tobacco smoke => Imbalance of proteinases and anti-proteinases in the lungs
– Free radicals impair activity of anti-proteases
– ⇑ Proteases enzymes damages the lungs
Inflammatory response in the lungs
Irritation of the mucous membrane
– bronchitis
– Increased mucous secretion
– ball and valve obstruction
Chornic Bronchitis Pathogeneis?
known as “blue bloaters”
bronchi inflammation => eventual fibrosis/scarring
Pathogenesis
• inflammation of the wall of bronchi and bronchioles
• increased mass of mucous glands=> excessive production of mucus and sputum
• Airways become narrowed => ⇓ airflow
Clinical Diagnostic Criteria fro Chornic Bronchitis
Cough + sputum (productive cough) for 3 months/year over 2 years
