lec 4+5 Obstructive pulmonary disease Flashcards
Cause and results of Obstructive pulmonary disease:
Anatomic obstruction: Asthma
Loss of elastic recoil: emphysema
result:
-Normal or increased Total lung capacity (because of loss of elastic recoil)
- slightly Decreased **Forced vital capacity (max air you can breathe out)
-Forced expiratory volume (FEV1)** is decreased significantly
Emphysema is:
-permanent enlargment of air spaces distal to the terminal bronchioles in the acinus.
-Acinus : bronchiole, alveolar duct, alveolus
basically, destruction of acni wall but without fibrosis
Types of emphysema and their pathogenisis :
(simple)
Centriacinar
Panacinar
pathogenisis:
1) protease- Antiprotease imbalance
2) Oxidant- Antioxidant imbalance
what is Protease-antiprotease imbalance:
-Protease, elastase and oxidase from inflam cells damage elastic tissue and collagen
-a decrease in antiproteases can produce acini wall damage—-emphysema
can be genetic deficiency or smoking
1) Centriacinar emphysema
-involves proximal acinus
-more severe in upper lobes
-more in male smokers and chronic bronchitis patients.
-presence of bulla is common
2)panacinar emphysema:
-Involves entire acinus
-more severe in lower zones and bases
-more genetic: so a1 antitrypsin deficiency
3)Distal emphysema:
paraseptal
-involves pleural surface and connective tissue of septa
-more in upper lobe and subpleural
-adjacent to fibrosed area
-prescence of multiple bulla
very similar to centriacinar
4)Irregular emphysema
-common but asymptomatic.
-acinus is unlikely involved.
-associated with scarring of healed inflammation.
Conditions related to emphysema:
-enlargment of air spaces w/o destruction of walls
-bullous emphysema : any type with formation of subpleural air filled cysts
Morphology of emphysema:
Destruction of alveolar walls
collapse of adjacent spaces
diminished blood vessles in septa
later—- pulmonary hypertension
Clinical course of emphysema:
-decreased FEV1/FVC ration
-dyspnea is first symptom
-insidious then progressive dyspnea
-tachypnea and hyperventilation (pink puffer)
-Blue bloater (in chronic bronchitis)
-Decreased O2 level and increased CO2 level— cyanosis
Signs of chronic bronchitis:
on level of bronchi
-Productive cough for 3 months, for 2 years consistently
-simple chronic bronchitis—- mucoid sputum , but is not enough to obstruct airflow in early stage
Hypersecretion of mucus is a result of:
1) hypertrophy and hyperplasia of mucus glands
2) increase in goblet cells by metaplasia
3) recurrent infections
Reid index:
-measure of degree of chronic bronchitis
-Thickness of submucosal mucus secreting glands vs thickness between epithelium and cartialage.
<0.4 normally
Morphology of chronic bronchitis:
-Edematous congested mucus
-luminal thick mucus
Microscopic:
-non eosinophillic cell infiltrate
-squamous metaplasia and dysplasia
-inc in mucus glands, and goblet cells
PURE emphysema vs PURE bronchitis:
Bronchitis:
-inflammation and mucus hypersecretion in large airways
-airway obstruction in small airways
Emphysema: Acini wall damage and loss of elastic recoil
Blue bloater vs pink puffer:
Blue bloater (COPD):
* chronic cough
* purulent sputum
* hemoptysis
* cyanosis
* obesity
* secondary polycythemia vera
* hypercapnia
Pink puffer (emphysema):
* minimal cough
* hyperventilation and tachypnea
* cachexia
Bronchiectasis is:
chronic necrotizing inflammation of bronchi AND bronchioles with destruction of the muscle and elastic tissue in the wall.
-leads to PERMANENT enlargment of bronchioles
predisposing conditions of bronchiectasis:
1)Bronchial obstruction
-localized (F.B or tumor)
-generalized (asthma, bronchitis)
2)congenital
-cystic fibrosis
-Immunodeficiency
-kartagners syndrome
3)post necrotizing supparative inflammation
important
Pathogenisis of bronchiectasis:
-Obstruction of bronchus wall+ infection
-continous dialation and exudate accumilation
Asthma is :
A CHRONIC inflammatory process of wheezing (small airway obstruction during expiration)
chest tightness, cough early in the morning or at night
important
Morphology of bronchiectasis:
-more in lower lobes and bilateral
-occurs in distal bronchial tree
-wall shows:
acute and chronic inflam cells
squamous metaplasia of lining
fibrosis
Clinical picture of bronchiectasis:
VERYYYY SIMILAR TO CHRONIC BRONCHITIS
-chronic cough
-purulent sputum
-hemoptysis
-CLUBBING
-core pulmonale
Summary of bronchiectasis:
-irreversibly dialated thick walled bronchi
-honeycombing, tram-line, cystic, signet ring sign can all be seen in imaging
-the vicious cycle and p.aeuroginosa contributes to severity of disease
