week 1 restrictive Flashcards
(44 cards)
What is bronchial asthma?
A heterogeneous group of diseases characterized by chronic airway inflammation, variable expiratory airflow obstruction, and symptoms such as wheezing, dyspnea, chest tightness, and cough that vary over time and in intensity.
What are the two main types of asthma based on prior sensitization to allergens?
Atopic (Extrinsic) Asthma
Non-atopic (Intrinsic) Asthma
What is the immunological mechanism in atopic asthma?
Type I (IgE-mediated) hypersensitivity reaction.
What are the common environmental triggers in atopic asthma?
Dust, pollen, animal dander, and certain foods.
What are the key features of atopic asthma?
Childhood onset
Positive family history
Positive skin test (wheal and flare)
Increased serum IgE
Associated with atopic diseases (e.g., allergic rhinitis, eczema)
What are the key features of non-atopic asthma?
Triggered by viral infections or irritants (e.g., SO₂, NO₂, O₃)
Normal serum IgE
Negative skin test
No associated atopy
No age preference
Less family history involvement
What is the pathogenesis of airway remodeling in atopic asthma?
Chronic inflammation leads to structural changes in the bronchial wall, known as airway remodeling.
List features of airway remodeling in asthma.
Thickened airway wall
Sub-basement membrane fibrosis
Increased vascularity
Increased submucosal gland size and number
Goblet cell hyperplasia
Smooth muscle hypertrophy/hyperplasia
What is the pathogenesis of drug-induced (aspirin-sensitive) asthma?
COX inhibition → Increased leukotriene synthesis → Bronchoconstriction. Common in patients with nasal polyps and rhinitis.
What triggers occupational asthma?
Fumes (epoxy), organic dusts (wood, cotton), gases (toluene), and chemical exposures after repeated contact.
What are the gross pathological features in fatal asthma?
Hyperinflated lungs
Airways occluded by thick mucus plugs
What microscopic findings are seen in asthma sputum/bronchoalveolar lavage?
Curschmann spirals – Whorls of shed epithelium in mucus
Charcot-Leyden crystals – Eosinophil protein crystalloids
Eosinophils
What are the clinical features of an asthma attack?
Dyspnea, expiratory wheezing, chest tightness, and cough (with or without sputum), worse at night or early morning.
What is status asthmaticus?
A severe, prolonged asthma attack that does not respond to standard therapy and can lead to respiratory failure.
What spirometry findings are seen during an asthma attack?
FEV1 < 30%
Decreased FEV1:FVC ratio
May be normal between attacks with residual deficits
What lab findings may support asthma diagnosis?
Eosinophilia in CBC
ABG: Hypoxemia, hypercapnia, respiratory acidosis
Sputum: Curschmann spirals, Charcot-Leyden crystals
What are the treatment options for asthma?
Avoid triggers
Bronchodilators
Leukotriene blockers
Long-term: Inhaled corticosteroids
How is parenchymal restrictive lung disease characterized?
Normal FEV1:FVC
Reduced DLCO
Increased A-a gradient
How is extra-parenchymal restrictive lung disease characterized?
Normal FEV1:FVC
Normal DLCO
Normal A-a gradient
What are the two main categories of restrictive lung disease?
Parenchymal and Extra-parenchymal.
What characterizes parenchymal restrictive lung diseases on spirometry and gas exchange?
Normal FEV1:FVC, reduced DLCO, increased A-a gradient.
What characterizes extra-parenchymal restrictive lung diseases?
Normal FEV1:FVC, normal DLCO, and normal A-a gradient.
Give examples of extra-parenchymal causes of restrictive lung disease.
Chest wall disorders, kyphoscoliosis, neuromuscular diseases (e.g., myasthenia gravis), obesity, pleural disorders (effusions/pneumothorax).
What structures make up the lung interstitium?
Basement membranes, collagen, elastin, fibroblasts, and mononuclear inflammatory cells.
