COPD Flashcards
What cormobidities are associated with COPD?
CVD Lung cancer Osteoporosis i.e. due to having to take corticosteroids Muscle weakness Cachexia
What is COPD? What causes the obstruction?
Progressive, partially reversible disorder due to airway obstruction caused by chronic bronchitis or emphysema which can be accumpanied with airway hypersensitivity (FEV1/FVC <0.7)
Chronic bronchitis
- inflammation and thickening of the bronchioles
- cough and chronic sputum production on most days for 3 months of the past 2 years
Emphysema
-enlarged airways distal to terminal bronchioles (damaged alveoli)
Causes of obstruction:
- Disrupted alveolar attachments= emphysema
- Mucosal inflammation + Fibrosis
- Mucus hypersecretion
What happens to airways in COPD patients during the expiratory phase?
Degredation of protein and elastin scaffolding due to inflammation and cigarette smoke which normally acts to keep airways patent during expiration
Therefore:
-early collapse of airways during expiration in COPD
Why do COPD patients have “gas trapping”? What is the consequence of this?
Unable to completely expire (due to increased resistance to expiration) before inspiration triggered
Eg. Leads to gas trapping and high residual volume
What are the 2 main phenotypes of COPD? How might patients present differently for the different phenotypes?
Chronic bronchitis= BLUE BLOATER
- chronic sputum production (3+ months for more than 2 consecutive years)
- increased risk of infective exacerbation due to sputum production providing environment for bacteria
- other causes of chronic cough been excluded
- cyanosis due to hypoxaemia
- peripheral oedema due to cor pulmonale
- prolonged expiration
- obese
Emphysema= PINK PUFFER
- breakdown of alveolar tissue leading to enlarged airspaces distal to terminal bronchioles w/o obvious fibrosis
- breathless and hypoxic
- increased minute ventilation
- pink skin + pursed lips
- accessory muscle use and tri-podding
- cachexic
- hyperinflation of chest= barrel chested
What is required for patient to be diagnosed with COPD? How is FEV1 used to grade the severity of COPD?
Spirometric diagnosis of AIRWAY OBSTRUCTION
-FEV1/FVC < 0.7
>80%= mild 50-80%= moderate <50%= severe <30%= very severe
H/O progressive symptoms of:
- SOB
- Chronic cough
- Expiratory wheeze
What is the criteria for asthma patients for be classified as having asthma-COPD overlap syndrome?
When asthma patients develop partially reversible airway obstruction over time
What is the pathophysiology of COPD?
Exposure to noxious particles and gases Consequences: -tissue damage -muco-ciliary dysfunction -chronic inflammation -airway hyper responsiveness -bronchospasm
LEADS TO AIRWAY OBSTRUCTION
How does cigarette smoke lead to tissue damage and inflammation?
Triggers alveolar macrophages which produce chemotactic factors ( IL-8 and LTB4) to recruit neutrophils
Neutrophils secrete proteases which target bacterial infection
Deficiency in protease inhibitors (alpha anti-trypsin deficiency) leads to:
- alveolar wall destruction= emphysema
- mucus hypersecretion= chronic bronchitis
What factors exacerbation mucociliary dysfunction associated with COPD? What are the implications of mucociliary dysfunction?
Tissue damage + inflammation
Increased mucus viscosity
Mucus hypersecretion
Leads to bacterial colonisation due to reduced mucociliary transport of mucus
What are the causes of COPD?
Smoking
Occupations exposure
- industrial dusts
- cotton textile industry
Indoor air pollution and biomass exposure:
Genetics:
-alpha-1 antitrypsin deficiency= inability to neutralise neutrophil proteases
What is the most affective way to improve lung function in COPD patients? What are the possible obstacles?
Smoking cessation i.e. lung function will improve with cessation at all stages of disease
Nicotine dependency
Initial productive unpleasant cough due to re-activating of muco-ciliary escalator
How can the clinical presentation of a COPD patient provide evidence of which type of COPD they have? What are the associated characteristics for both?
BLUE BLOATERS= chronic bronchitis
- overweight
- cyanotic
- elevated Hb
- cor pulmonale= RHF
- peripheral oedema
- rhonchi= low-pitch sound which can be heard in airways
- wheezing due to inflamed airways
PINK PUFFERS= emphysema
- older
- thin (cachexic)
- severe dyspnea
- quiet chest
- CXR w/ hyperinflation and flattened diaphragms
What are the signs and symptoms of COPD?
SOB
- worse on exercising
- MRC breathless scale
Chronic cough w/ sputum
-try to quantify the amount of sputum production per day
Expiratory wheeze
Weight loss
Nocturnal + early morning symptoms
-asthma overlay
Barrel chest
Cyanosis
Abnormal posture
Resp distress
Chronic hypoxaemia signs
- RHF
- signs of cor pulmonale
Why can RHF and cor pulmonale be associated with COPD?
Chronic hypoxaemia can lead to pulmonary circulation shutting down as lung tries to shunt BF away from non-functioning part of lung BUT most of lung affected meaning there is gross vasocontriction:
- leads to increase BV in peripheral circulation which increases the blood return to the right side of the heart
- pulmonary hypertension
THEREFORE= right sided heart failure