COPD Flashcards
Individual disorders in COPD includes?
- Emphysema
- Chronic bronchitis
- Asthma
- Bronchiectasis
Emphysema is defined by ?
irreversible enlargement of the airspaces DISTAL to the terminal bronchiole associated with destruction of their walls without any obvious fibrosis
Definition of COPD
“a common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities caused by exposure to noxious particles or gases.”
While asthma is distinguished from chronic bronchitis and emphysema by??
The presence of reversible bronchospasm
COPD and smoking?
Overall, 35% to 50% of heavy smokers develop COPD
conversely about 80% of COPD is attributable to smoking.
Emphysema epidemiology ??
- 4th leading cause of morbidity and mortality in the united state
- commoner in Women, African-Americans
- Associated with heavy cigarettes smoking
Classification of emphysema ?
Based on anatomic distribution within the lobule:
- Centriacinar
- Panacinar
- paraseptal (distal acini)
- irregular
Features of centriacinar emphysema ?
- Seen predominantly in heavy smokers
- Often associated with bronchitis affecting the apical lobes
- Distal alveoli are spared
- proximal respiratory bronchioles affected often with inflammation
Features of Panacinar enlargement ?
- Uniform enlargement from respiratory bronchioles to terminal alveoli
- Associated with a1 anti-trypsin deficiency
- tends to occur more commonly in the lower zones and in the anterior margins of the lung and it is usually most severe at the lung bases
Features of paraseptal emphysema (distal acini) ?
- Seen in *^pleural surfaces**
- Normal proximal acini
- Distal alveoli is affected
- Seen in Cases of spontaneous pneumothorax
- more severe in the upper half of the lungs.
Irregular emphysema?
- the acinus is irregularly involved,
- Associated with scarring
- Airspace enlargement with fibrosis
- clinically induced insignificant
Most common form of Emphysema is the?
Centriacinar emphysema (>95%)
Heavy smokers with COPD are at risk of having what type of emphysema?
Centriacinar Emphysema
α1-antitrypsin deficiency is associated with ?
Panacinar emphysema
Pathogenesis of emphysema
A) There’s activation of inflammatory cells (macrophages, CD8, CD4, T lymphocytes and neutrophils) reach release variety of mediators (leukotrienes B4, IL8, TNF) that sustain inflammatory process and lead to destruction of alveoli wall
B) Proteaseantiprotease hypothesis
C) imbalance of antioxidants and oxidants
Deficiency of antiprotease alpha 1 antitrypsin enables?
Unchecked destruction of elastic tissue thus emphysema results
80% of them will develop Panacinar emphysema
Clinical features of emphysema ?
Pink puffers - Well oxygenated but over ventilated
Dyspnea with prolonged expiration
Cough or wheezing
Expectoration
Weight
- Sits forward in a hunched over position and breaths through pursed lips
Diagnosis or emphysema ??
On examination, patient is barrel chested
Expiratory airflow limitation Pulmonary function tests show: decreased FEV1 (at 1sec) using a spirometer - Key to diagnosis
Morphological features of emphysema ?
Gross;
- Enlarged Lung with apical bullae or bleb
Histology;
Abnormally large alveoli with thin septa, having focal Centriacinar fibrosis and lots of inflammatory cells
Treatment of emphysema
- Bronchodilators
- Sterioids
- Surgery: bullectomy/ lung volume reduction
- lung transplantation
- substitution therapy with alpha 1- AT
Complications of emphysema ?
- Cor Pulmonale
- congestive heart failure
- right sided heart failure
Lung collapse secondary to pneumothorax - Death from respiratory acidosis
- coma
Chronic bronchitis is defined as?
Persistent cough with sputum production for at least 3 months in at least 2 consecutive years, in the absence of any other identifiable cause
Chronic bronchitis is common among?
Habitual smokers
Dwellers of smog-Kaiden cities
Pathogenesis of chronic bronchitis
- Long standing irritation from inhaled tobacco smoke and dust from grain, cotton and silica
- Activation of mediators of inflammation within the large airway (proteases, elastase, cathepsin and matrix metalloproteinases) from neutrophils
- Then, mucus hypersecretion in the large airways and hypertrophy of submucosal glands in the trachea and bronchi
- As chronic bronchitis persists, there’s a marked increase in goblet cells of small airway
- leading to excessive mucus production that contributes to airway obstruction