COPD Flashcards
COPD
chronic obstructive pulmonary disease
COPD definition
COPD is characterised by progressive airflow obstruction, which is not fully reversible and does not change markedly over several months
COPD Epidemiology: Risk of COPD and age?
- risk increases with age
- > 60 years
COPD Epidemiology: FEV1 decline?
- decline in FEV1 of about 30 ml/year after the age of 30, but smoking accelerates this decline
Globally COPD is the —- cause of death (2010)
3rd
How many are affected globally by copd?
3.3 million (5.8%)
In the UK how many people are diagnosed with COPD?
1.2 million
How many GP visits a year in the UK for COPD?
1.4 million
How many acute hospital admissions due to COPD?
1/8
How many deaths per year in the UK due to COPD?
30,000 deaths per year
5th leading cause of death
Economic burden in UK of COPD:
- total cost: 1.9bn
- of the 5 costliest drugs to the NHS, all are respiratory inhalers
COPD is —% of all respiratory disease cost?
29%
How much more likely are you to die from COPD if you are in the most deprived 10% of the population?
10%
Aetiology: 90% of COPD cases
patients who smoke
What is one of the potential causes of corpulmonarae?
right heart failure secondary to lung disease, generally COPD
Aetiology of COPD:
- number of pack years indicates risk of COPD
- cigar and pipe smoking increases risk of COPD to a lesser extent than cigarette smoking
- passive smoking also increases risk of developing COPD
- only 15-20% of those who smoke develop COPD
- occupational exposure to dust, coal mining
- air pollution: COPD is more common in urban areas compared to rural areas
- 1-2% of cases are due to alpha - 1 antitrypsin deficiency
How to calculate pack years?
20 cigarettes a pack (standard)
Number of packs a day * years
Or if not standard
(cigarettes a day/pack size)*years
Decline in lung function with age and smoking
Which inherited condition can cause COPD?
Alpha-1 antitrypsin deficiency
Chronic bronchitis due to smoking:
- symptoms
- is
sputum production for at least 3 months/year for at least 2 consecutive years
Patients are usually breathless
essentially inflammation of the airways
Emphysema
destruction of alveoli distal to terminal bronchioles resulting in loss of elastic supporting tissue
Why does emphysema reduced TLCO?
- reduction in transfer factor as the interstitium is destroyed
- surface area where oxygen diffuses reduced
Are chronic bronchitis and emphysema used interchangeably
yes
COPD patients generally have both chronic bronchitis and emphysema
True or False?
False
Generally one or the other phenotype is predominant
What imaging done for emphysema?
Chest X-ray/ CT
In COPD why might you be hypoxic:
- hypoventilation = type 1 respiratory failure
- emphysema = diffusion impairment
- V/Q mismatch, areas of the lungs in COPD are not being ventilated and hence not perfused
Multiple mechanisms that can affect and cause type 1 respiratory failure in COPD patients
What does alpha-1 antitrypsin do?
- in healthy lungs, protein alpha 1 antitrypsin produced and secreted by liver circulates in lungs.
- Alpha 1 antitrypsin protects the lungs from neutrophil elastase, maintains a balance so that healthy lung tissue is not damaged
- elastase will hydrolyse elastin in lung tissue
COPD Pathophysiology: Emphysema:
- cigarette smoking activates neutrophils in the lungs: neutrophils secreted proteases (elastase, collagenase)
- the proteases are more than alpha 1 antitrypsin.
- neutrophils invade the bronchial mucosa, secrete more proteases, which damage the alveolar sacs leading to a large bullae and therefore emphysema
- reduces surface area for gas exchange
COPD Pathophysiology: Chronic bronchitis:
- patients with chronic bronchitis develop inflammation of the airways with fixed structural changed
- increase number of goblet cells and hypertrophy of goblet cells, hence lungs produce more viscous mucus which is hard to clear.
- mucus acts as a culture medium for infective organisms
- damage to cilia ( due to smoking) affects the host defence mechanisms leads to recurrent respiratory tract infections
- recurrent infections lead to further inflammation of lungs and decreased lung function
pathophysiology of COPD
COPD results in increased
- airway resistance and loss of elastic recoil of the lungs
- airways collapse on inspiration
- causes air trapping and hyperinflation
- increases work of breathing: use of accessory muscles of breathing, pursed lip breathing
- end stage of COPD:
- right heart failure (cor pulmonale)
- pulmonary hypertension
emphysematous lung
COPD risk factors
Diagnosis of COPD
- should be suspected in any individual over the age of 35 years, who presents with symptoms of breathlessness and has a history of cigarette smoking
- spirometry shows FEV1/FVC ratio of less than 70% predicted post administration of a short-acting bronchodilator confirms the diagnosis of COPD
Diagram of COPD
Signs of COPD (11):
- clinical examination may be normal in mild
COPD - tachypnoea with raised respiratory rate
- tremor (over use of beta-2 agonist inhaler)
- pursed-lip breathing and use of accessory
muscles - barrel chest (increased AP diameter of
thoracic cage) - hyperinflation
- wheeze
- signs of cor pulmonale: raised JVP and
ankle oedema - cyanosis
- signs of CO2 retention: CO2 retention flap,
bounding pulse, irritability and confusion - development of type 2 respiratory failure
Symptoms of COPD (5)(3):
- breathlessness on exertion (dyspnoea),
progressively getting worse - chronic productive cough
- frequent lower respiratory tract infections
- progressive weight loss
- peripheral ankle oedema (end stage COPD suggesting cor pulmonale)
- Red Flag symptoms: haemoptysis, chest pain, night sweats