COPD Flashcards
What causes COPD?
COPD is caused by long-term exposure to substances that can irritate and damage your lungs, such as smoking or certain types of fumes, dust and chemicals at work.
COPD primary cause and risk factors
Primarily caused by cigarette smoke •Associated to active and passive smoking •High risk of developing COPD with continued long term smoking •Other risk factors include: •Occupational exposure •Air pollution •Genetic susceptibilities also have been identified
Diagnosing COPD
•Based on history of smoking or exposure to other noxious inhalation agents •FEV1/FVC ratio of less than 70% •Healthy ratio should be 80% or higher •FEV1: forced expiratory volume in 1 second •FVC: maximum amount of air that can be forcibly exhaled in one breath
Emphysema
•is a lung condition that causes shortness of breath.
In people with emphysema, the air sacs in the lungs (alveoli) are damaged.
Over time, the inner walls of the air sacs weaken and rupture — creating larger air spaces instead of many small ones
Emphysema continued…
•Begins with destruction of alveolar septa
(alveoli, alveolar walls & alveolar capillaries)
•Tobacco smoke and pollution stimulate
inflammation which over time causes
alveolar destruction & loss of elasticity of the
bronchi.
•This eliminates portions of the pulmonary
capillary bed & increases the volume of air in
the alveoli
Destruction of Alveolar
Alveolar destruction produces large air spaces within the lung tissue • These areas are not effective in gas exchange due to loss of respiratory membrane where gases cross between air and blood
Emphysema - Reduced gas exchange results in?
ventilation-perfusion mismatch • Leads to hypoxaemia & hypercapnia •Hypoxaemia: Low arterial blood oxygen levels (PaO2) •Normal PaO2: 80 – 100 mmHg •Hypercapnia: Increased carbon dioxide in the arterial blood •Normal PaCO2: 35 – 45 mmHg
Pathophysiology of Emphysema
- Tobacco smoke/Air pollution
- Inflammation of the airway
- Infiltration of inflammatory cells & release of neutrophils,
macrophages, lymphocytes, leukotrienes, interleukins - Breakdown in lung elastic tissue
- Destruction of alveolar septa & loss of elasticity of bronchial
walls - Airway obstruction, Air trapping, loss of surface area for gas
exchange - Dyspnoea, Cough, Hypoxaemia, Hypercapnia
Manifestations of Emphysema
Dyspnoea • initially on exertion & then on rest •Wheezing • may occur during exertion & exacerbations •Minimal coughing • Usually occurs in the morning •No sputum • or small amounts of mucous sputum
Manifestations of Emphysema contd.
Barrel chest • alveoli over distended, air trapped, flattened diaphragm •Chest breather •relying on intercostal & accessory muscles (ribs become fixed in inspiratory position) •Hypoxaemia & hypercapnia •later in disease •Weight loss & anorexia
Chronic Bronchitis
inflimmation and irritation of the bronchiol tubes
Chronic Bronchitis patho
•Inflammation caused by inspired irritants
•Infiltration of neutrophils, macrophages &
lymphocytes into the bronchial wall
•Continual bronchial inflammation causes
bronchial oedema & increases the size and
number of mucous glands & goblet cells in the
airway epithelium
•More mucous is produced & Ciliary function is
impaired
what is Chronic Bronchitis…
Thick, mucous is produced which
cannot be cleared due to impaired ciliary
function
•Increases the risk for infection and injury
•Infection exacerbations complicated by
bronchospasm, dyspnoea & productive
cough
Pathophysiology of Chronic Bronchitis
- Tobacco smoke/Air pollution
- Inflammation of the airways
- Infiltration of inflammatory cells & release of neutrophils,
macrophages, lymphocytes, leukotrienes, interleukins - Continuous bronchial irritation & inflammation
- Bronchial oedema, hypersecretion of mucous, bacteria
buildup of airways - Airway obstruction, air trapping, loss of surface area for gas
exchange - Dyspnoea, cough, hypoxaemia, hypercapnia
Chronic Bronchitis - Effects
Initially affects only the larger bronchi
• Eventually all airways are involved
•As airways become narrowed, expiratory airway
obstruction results
•Airways collapse, gas is trapped in the lungs
•Ventilation-perfusion mismatch occurs
•Hypoventilation, Hypoxaemia & hypercapnia
