I. Pathophysiology
- chronic inflammation of the lungs
- symptoms:
- main: difficulty in exhalation due to airway limitation
- other: productive coughs
- spirometry levels:
- low FEV1: obstructive, restrictive
- low FVC: restrictive
- low FEV1/FVC: obstructive
- GOLD classification
- stage 1: mild airway limitation ; FEV1/FVC <70% ; FEV1 > 80% of the predicated value
- macro main aspects: chronic bronchitis and emphysema
- chronic bronchitis: inflammation causing elevated mucus production, bronchoconstriction,
small airway fibrosis
- emphysema: destruction of alveolar sac septa causing reduction of gaseous exchange
- overall: loss of elasticity and gaseous exchange, bronchoconstriction, mucus production,
tissue swelling, septa destruction
= less compliance, more resistance
- micro main aspects:
- inflammation: increase leukocyte/lymphocyte levels
> release of elastase, MMPs, proteinase-3, cysteine proteinase, plasminogen activator
> collagen and elastin fiber destruction -> loss of elasticity, firmness, tissue
> M3 parasympathetic receptor activation (leads to bronchoconstriction):
> mucus production due to hyperplasia/metaplasia of mucous cells
> smooth muscle contraction
- note on elastase: usually destroyed by anti-proteases but here it is resistance
- destruction relies on alpha 1 antitrypsin (AAT - produced by liber)
II. Goals of Treatment
- curative: none
- preventive: escalation from GOLD stages; prevent secondary symptoms and side effects
- palliative: improve quality of life/ability to breathe/bronchodilation