Pathophysiology of COPD Flashcards
Goal of therapy
reduce symptoms
prevent progression & exacerbation
reduce mortality
Therapies
Smoking cessation - NRT
Exercise & diet changes
DRUG THERAPIES
Influenze & pneumococcal vaccination
Drug therapy options
BRONCHODILATORS
ANTICHOLINERGICS
SHORT ACTING BRONCHODILATORS
function
Ease INTERMITTENT COPD symptoms
LONG ACTING BRONCHODILATORS
function
Prevent breathing problems
Step-up therapy for PERSISTENT symptoms
ANTICHOLINERGICS
mechanism
M3 antagonists
- block Ach-M3 receptor binding
ANTICHOLINERGICS
function
BRONCHODILATION
Prevent bronchospasm
reduce mucus production
SHORT ACTING BRONCHODILATORS examples
Anticholinergics - ipratropium
B2-agonists - salbutamol
LONG ACTING BRONCHODILATORS examples
Anticholinergics - tiotropium
B2-agonists - salmeterol
B2 AGONISTS mechanism
Bind B2AR receptor (GPCR)
- Activate AC via Gs protein
- cAMP»_space;
- PKA»_space;
- PKA phosphorylates target proteins - BRONCHODILATION
BRONCHODILATORS
ANTICHOLINERGICS & B2AR agonists
COPD
persistent airflow limitation associated with enhanced chronic inflammation in the airways
COPD symptoms
chronic & progressive dyspnoea, cough, sputum production
VARIABLE day-to-day
Compare asthma & COPD daily variability
Asthma has more daily variability
State COPD classifications
CHRONIC BRONCHITIS
EMPHYSEMA
CHRONIC BRONCHITIS
+ Symptoms
+ Characteristics
chronic cough with sputum production
INFLAMMATION & EXCESS MUCUS
> Narrowed bronchioles
EMPHYSEMA
+ Symptoms
+ characteristics
Chronic cough, SOB
INFLAMMATION
> alveolar membrane destruction
> reduced elasticity
> FEWER, ENLARGED ALVEOLI
Risk factors
SMOKING, pollution, occupation
AAT deficiency
Describe COPD pathogenesis following exposure to risk factors
Neutrophils & macrophages accumulate in alveoli
> release granules containing ELASTAASE & MMP
> Damage & elastic tissue destruction
How smoking causes inflammation
CHEMOATTRACTANTS & ROS
NEUTROPHIL ELASTASE effects
TISSUE DAMAGE
Consequences of inflammation in the lungs:
Thickens bronchiole walls
Bronchioles collapse during expiration
Mucus»_space; in lumen
> AIRWAY OBSTRUCTION
AIR TRAPPING
During EXPIRATION - lack of elasticity ALVEOLAR CLOSURE - DYSPNOEA << exercise capacity
Relate smoking & inflammatory effects
> > neutrophils, macrophages, cytokines, mediators & proteases
> > ELASTASES, MMP, ROS
«_space;INFLAMMATION & TISSUE DAMAGE
Common causes of COPD exacerbations
SMOKING
viral & bacterial infections
Describe the process of a spirometry test
BRONCHODILATOR administered
> SPIROMETRY
> results compared to age-related normal parameters
Limited airflow is indicated by post-bronchodilator FEV/FVC ___
FEV/FVC <0.7
