Chronic Obstructive Pulmonary Disease Flashcards
General characteristics of COPD
Treatable disease characterized by respiratory sxs and airflow limitation
When does an airway disease become COPD?
When it is irreversible
Clinical subtypes of COPD
Chronic bronchitis
Emphysema
Chronic obstructive asthma
How does a chronic bronchitis pt look?
Blue bloater due to cyanosis and overweight body habitus
Hypoxemia and respiratory acidosis
Cor pulmonale from pulm HTN
How does an emphysema pt look?
Pink puffers because of pursed-lip breathing, skin colo and thin body habitus
When does a pt have chronic bronchitis?
Chronic productive cough for 3 or more months, during 2 consecutive yrs with no other cause
Structural changes in chronic bronchitis
Mucous gland enlargement and hypersecretion
Bronchial squamous metaplasia
Loss of ciliary transport
Pathophysiology of chronic bronchitis
Inflammation of the bronchial wall and infiltration of the sub-mucosal layer by NEUTROPHILS
Also may be due to chronic bacterial colonization and airway hyper-reactivity
When is the obstruction for chronic bronchitis?
Inspiratory and expiratory
What results from the impeded ventilation in chronic bronchitis?
Hypoxemia and hypercapnia
Pathophysiology of emphysema
Pathologic enlargement of the air spaces distal to the terminal bronchioles due to destruction of the alveolar walls (might be due to too much elastase or too little antitrypsin)
What is neutrophil elastase?
Protease enzyme secreted by neutrophils and macrophages during inflammation
Destroys bacteria and host tissue (like elastin)
What is alpha-1 antitrypsin?
Inhibitor of neutrophil elastase (so in a deficiency there is a breakdown of lung structure by elastase)
Structural changes in emphysema
Reduced alveolar surface area available for gas exchange
Decreased elastic recoil
Loss of alveolar supporting structure leads to airway narrowing
When is the obstruction in emphysema?
Mostly exhalation
Hypoxemia and emphysema
Not usually significant until later disease severity (due to destruction of the capillary bed that results in reduced diffusing capacity for CO)
Differences between asthma and COPD
Inflammatory disorder of the airways mostly due to EOSINOPHILS
Airway hyperreactivity- increased secretions, mucosal edema, constriction of bronchial SM-obstruction
Reversible!
Risk factors for COPD
Cigarette smoking (most common) Environment/occupation Second hand smoke exposure Airway hyper-responsiveness (asthma) Genetic: alpha-1 antitrypsin deficiency
Why does cigarette smoking lead to COPD?
It stimulates elastase enzymatic activity to cause changes in the structures
Causes release of cytotoxic oxygen radicals from WBCs in lung tissue
Amt and duration will contribute to severity
Examples of environmental exposures
Air pollution, coal miners, grain handlers, metal molders, workers exposed to dust, cooking with biomass fuels
What is alpha-1 antitrypsin deficiency?
Hereditary syndrome resulting in early onset of emphysema (when its younger age-<45)
Process of lung destruction is accelerated in smokers with this
Classic presentation of COPD
Dyspnea, chronic cough and sputum production (5th or 6th decade of life)
Common comorbidities of COPD
CVD, DM, renal insufficiency, osteoporosis, psych illness, cognitive dysfunction
What physical exam findings might be seen in COPD?
Tripod positioning, cyanosis, tobacco staining of the fingers, JVD, accessory muscle use, pursed lip breathing
Lungs: barrel chest, prolonged expiration, increased resonance on percussion, decreased breath sounds/wheezes/crackles
S3 gallop, RV lift
Hepatomegaly
Peripheral edema
What is the use of pursed lip breathing?
Ordinary breathing allows for early bronchial collapse on exhalation
This breathing achieves resistance to outflow at the lips so it raises the intrabronchial pressure to keep them open and expel the air easier