COPD Flashcards
what is COPD?
limited airflow that isn’t fully reversible
both emphysema & chronic bronchitis (both progressive, co-exist)
PROGRESSIVE airflow limitation
abnormal inflammatory response of lungs to noxious particles / gases
what is the primary cause of COPD?
cigarette smoking
what are the causes of COPD?
tobacco smoke
air pollution
occupational exposure
a-1 antitrypsin deficiency (destroy alveolar walls)
what are the pathological changes of COPD?
- hypertrophy of mucus-secreting glands
- hyperplasia of goblet cells (psudostratified ciliated columnar)
- ciliary dysfunction
- breakdown of elastin (destruction of alveolar wall & structure)
- formation of larger air spaces & reduced total SA for gas exchange (bullae)
- vascular bed changes –> pulmonary hypertension
what is emphysema?
elastin breakdown & subsequent loss of alveolar integrity –> permanent destructive enlargement of airspaces DISTAL to terminal bronchioles
what is chronic bronchitis?
excessive mucus secretion & impaired removal of secretions (from ciliary dysfunction)
why does COPD lead to increased airway resistance?
- luminal obstruction of airways by mucus (slow moving, thick, ciliary dysfunction)
- narrowing small bronchioles - normally kept open by outward pull (radical traction) by elastin
- decreased elastic recoil –> reduced expiratory force –> air trap (increase residual volume)
what leads to hyperinflation?
expiratory flow limitation (decreased elastic recoil, narrowing small bronchioles, luminal obstruction)
what predisposes patient to hypoxia?
airway narrowing & destruction of lung parenchyma
especially during exercise
what is hypoxia from?
airways narrowing & pulmonary vasculature changes
what does progressive hypoxia causes?
pulmonary vasoconstriction & vascular SM thickening
with subsequent pulmonary hypertension + RH failure (cor pulmonale)
what is a typical history of COPD?
gradual onset
usually present in older people with long history of smoking
what are the symptoms of COPD?
- cough (usually initial)
- frequent morning cough (constant through progression)
- usually productive cough (sputum produced)
- SoD (dyspnoea) - usually on exertion, progress to at rest
physical examinations of COPD patients
- tachypnoea
- use of accessory muscles of respiration
- barrel chest
- hyper-resonance on percussion
- reduced intensity (distant) breath sounds
- reduced air entry (poor air movement)
- wheezing
what causes tachypnoea?
increase RR to compensate for hypoxia & hypoventilation
what are the accessory muscles of respiration?
SCM
scalene
pec minor
why use the accessory muscles of respiration?
difficulty moving air in & out of lungs
how can you tell if a patient is using accessory muscles of respiration?
tracheal tug
intercostal recession
subcostal recession
nasal flare
what is barrel chest?
increase A-P diameter of chest
why will patient present with barrel chest?
hyperinflation (decreased elastic recoil --> limited expiratory flow rate) air trapping (secondary to incomplete expiration)
why will there be hyper-resonance on percussion?
hyperinflation & air trapping
why will there be reduced intensity (distant) breath sounds?
caused by barrel chest, hyperinflation & air trapping
why will there be reduced air entry (poor air movement)?
secondary to loss of lung elasticity & lung tissue breakdown
what are late features of COPD?
- central cyanosis
- flapping tremors
- signs of RH failure
