L 50. COPD Flashcards
What is COPD?
An inflammatory disease of the airways in response to an exposure to a particle or gas.
Is airflow obstruction reversible in COPD?
It is a progressive disease, so some can be reversed but not all.
2 main components of the COPD disease
- Chronic bronchitis (mucus producing cough most days for 2 years or more)
- Emphysema (damage and destruction of alveolar cells causing shortness of breath)
How is COPD gotten? (lol)
Genetics + environment
What environ factors help to get COPD?
Smoking and pollution (e.g air particulates)
In lower income countries, … factors had a greater impact than … factors
In lower income countries, environmental factors had a greater impact than behavioural factors.
(e.g bad air is worse than smoking)
COPD risk factors
Environment: occupational (farming, textiles, industry) and pollution (inside and outside home)
What is the trend with NZ smoking rates?
Trending downwards (less people smoking)
Risk factors for smoking x6
Media, social influences, friends/parents who smoke, low self esteem, taking part in risk activities, access and affordability.
What is the overall prevalence of COPD?
0.95%
COPD epidemiology x4
- Prevalence increases with age
- Rates higher for women <65 and men >65
- Higher mortality rates for elderly men
- Hospitalisation and mortality rates increase with increasing deprivation.
- Highest hospitalisation in māori and pacifika
Barriers identified for COPD management
- Access to care
- Inattention to culturally accepted practises
- Sporadic/poor quality care
- Inadequate provision of health care ifnormation
How to address inequities for COPD care
- Audits of care providing
- Systematic approach to health literacy and COPD education for whānau
- Providers need to support staff to develop Cultural safety skills to engage with māori and their whānau (about COPD)
- Assess patients using a māori model of health
Pathogenesis of COPD
Production of inflammatory mediators and oxidants by airway epithelium and macrophages
Accumulation of immune cells (more macrophages, neutrophils, CD4 and CD8 cells)
What type of CD4 cells are involved in COPD pathogenesis?
Th1 cells
What role do macrophages play in COPD pathogenesis? x3
Macrophages release:
- Proteases (cause tissue destruction, mucus hypersecretion)
- TGF beta (fibroblasts to release CTGF - connective tissue growth factor)
- Oxidants (goblet cell hyperplasia, decrease in HDAC2 gene causing steroid resistance)
What role do neutrophils play in COPD pathogenesis? x2
- An increase in number of neutrophils correlates with a decline in airway function
- Neutrophils also release proteases
What role do CD8 cells play in COPD pathogenesis?
They kill alveolar cells (directly or by inducing apotosis)
What role do Th1 and Th17 cells play in COPD pathogenesis?
Th1 and Th17 are pro-inflammatory.
Requirements to get COPD
An inappropriate inflammatory response to noxious airway irritants in genetically susceptible individuals.
Define noxious
Toxic, harmful
How does smoking impact COPD pathogenesis?
Cigarette smoking impairs innate immune responses, therefore increasing susceptibility to infection (along with other methods of damaging health)
What is the deal with eosinophils and COPD pathogenesis
15-40% of cases are based on Th2 biased eosinophilic inflammation.
COPD is usually more neutrophils and Th1 based, but there is a small subset that is Th2
Exacerbations of COPD can be triggered by…
Symptoms of exacerbations
Triggers: infection, pollutants
Symptoms: worsening symptoms overall, often increased airway inflammation
Features of COPD x4
- Early changes in airways (fibrosis and vascular smooth muscle proliferation)
- Air trapping, dyspnoea, FEV1 decline, irreversible destruction.
- Enhanced parasympathetic activity causing hyperresponsiveness to irritants. (DRUG TARGET)
- Gas exchange abnormalities, pulmonary hypertension.
What is fibrosis?
Formation/thickening of scar tissue, usually as a result of injury.
What is dyspnoea?
Breathlessness
What are some other impacts of COPD?
Accelerated ageing, Cachexia, increased CVD risk, osteoporosis, depression and anxiety
Define cachexia?
Weakness and wasting of the body due to severe chronic illness
What % of COPD patients have comorbidities?
94% have at least 1 comorbidity.
How is COPD diagnosed? x3
Symptoms (cough, sputum or dyspnoea)
Pulmonary function testing
Imaging (e.g chest x-ray)
Management of COPD … x5
Smoking cessation Pharmacological options Nutrition and exercise Pulmonary rehabilitation!!!! (physio) Surgery
Asthma vs COPD
There may be differences, it can also be considered as a continuum. Stupid 2 slides.
