COPD patho Flashcards
What is COPD
Chronic obstructive pulmonary disease
- characterised by chronic obstruction of lung airflow that interferes with normal breathing, not fully reversible.
includes both chronic bronchitis and emphysema
What is chronic bronchitis?
it involves a productive cough for at least 3 months for 2 or more years with mucus
what is emphysema?
it involves damage to the alveolar walls over time, til they lose elasticity, difficulty exhaling.
Lower FEV1 to FVC ratio in view of difficulty exhaling air out.
TLC( total lung capacity) is higher due to air trapping.
List the causes of COPD:
long term exposure to tobacco smoke
indoor air pollution
occupational exposure to noxious gases
exposure to fumes form burning fuel ( indoor air pollution)
Genetic factors alpha 1 antitrypsin deficiency emphysema
What tests should you conduct to diagnose COPD?
Spirometry with pre and post bronchodilator
CXR
CT scan
ABG
What sounds are expected from bronchitis?
Rales( fine crackles) - indication of mucus build up.
What is FVC
Forced vital capacity
What is FEV1
Forced expiratory volume in 1 second
How does emphysema form?
When exposed to irritants such as cigarette smoke,
it triggers an inflammatory reaction, attracts immune cells that release inflammatory chemical and proteins that break down structural proteins- collagen( gives alveoli elasticity.
SO alveoli is no longer elastic anymore.
What happens to a COPD airway walls during exhalation as compared to a normal airway?
COPD:thin alveolar walls are weak and collapse during exhalation, thus trapping air.
normal: air travel out at a higher velocity= lower pressure. Strong healthy airway full of elastic will not collapse, allow air to fully escape.
Does emphysema patients have difficulty breathing?
yes, surface area to volume ratio has decreased and thus affects the gaseous exchange.
What is Alpha 1 antitrypsin ?
it is a protease inhibitor to protect against unintended damage to the alveoli
How does alpha 1 antitrypsin defiency puts patients at risk for COPD?
In a healthy being, macrophages always let out proteases to help clear debris, but they break down proteins and damages tissues.
the alpha 1 antitrypsin helps to protect from these unintended damage.
Deficiency: no protection hence the proteases damages the air sacs, alveoli on lung surface can rupture and cause a pneumothorax.
Signs and symptoms of emphysema
1) Dyspnea, SOB due to air trapping and diminished gas exchange.
2) weightless
3) Hypoxemia
4) cough with small amount of sputum.
5) barrel shaped chest- flattened diaphragm due to air trapping and hyperventilation
6) pursed lip breathing- increase pressure in airway- prevents airway from collapsing
consequence of emphysema?
hypoxic vasoconstriction - reduced blood flow to lungs
- cause pulmonary hypertension
- cor pulmonae ( right heart failure)
