COPD: Aetiologies, Symptoms, Aids to Diagnosis and Management Flashcards
What is the definition of COPD?
COPD is characterized by progressive airflow obstruction which is not fully reversible and does not change markedly over several months.
How does COPD prevalence change with age?
COPD increases with age, particularly in individuals over the age of 60 years.
What is the rate of decline in FEV1 after the age of 30, and how does smoking affect this decline?
After the age of 30, there is a decline in FEV1 of about 30 ml/year. Smoking accelerates this decline.
What is the primary cause of COPD?
Cigarette smoking is the primary cause of COPD in approximately 90% of cases.
How is the risk of developing COPD associated with smoking?
The risk of developing COPD is associated with the number of pack years of smoking. Higher pack years indicate a greater risk.
Does cigar and pipe smoking increase the risk of COPD?
Yes, cigar and pipe smoking increase the risk of COPD, although to a lesser extent than cigarette smoking.
Does passive smoking contribute to the development of COPD?
Yes, passive smoking (exposure to second-hand smoke) also increases the risk of developing COPD.
What percentage of smokers develop COPD?
Only 15-25% of individuals who smoke develop COPD.
Besides smoking, what other factors can contribute to COPD?
Occupational exposure to dusts (e.g., coal mining), air pollution (more common in urban areas), lower socioeconomic status, and α-1 antitrypsin deficiency (1-2% of cases) can also contribute to COPD.
What is the definition of chronic bronchitis?
Chronic bronchitis is characterized by sputum production for at least 3 months per year for at least 2 consecutive years.
What is emphysema?
Emphysema is a condition characterized by the destruction of alveoli distal to the terminal bronchiole, resulting in the loss of elastic supporting tissue.
How does emphysema affect gas exchange?
Emphysema affects gas exchange by destroying the interstitium. This destruction leads to a reduction in the transfer factor (TLCO), which is responsible for the efficient exchange of gases.
How does α-1 antitrypsin contribute to lung protection?
In healthy lungs, α-1 antitrypsin protects the lung from neutrophil elastase, maintaining a balance that prevents damage to healthy lung tissue.
How does cigarette smoking affect the lung’s defense mechanism?
Cigarette smoking activates neutrophils in the lungs, leading to an increased release of proteases that overwhelm α-1 antitrypsin, causing damage to the lung tissue.
What is the impact of neutrophil invasion and proteases in the lungs?
Neutrophils invading the bronchial mucosa release proteases such as elastase and collagenase, which damage alveolar sacs. This damage can lead to the formation of large bullae and contribute to the development of emphysema.
How does chronic bronchitis affect the airways?
In chronic bronchitis, there is inflammation of the airways along with structural changes. There is an increase in goblet cells and hypertrophy of goblet cells, leading to the production of viscous mucus that is difficult to clear.
What are the consequences of mucus accumulation in chronic bronchitis?
The thick mucus acts as a culture medium for infective organisms and impairs the host defense mechanisms. This can lead to recurrent respiratory tract infections and further inflammation of the lungs, causing a decline in lung function.
How does COPD affect airway resistance and lung function?
In COPD, there is an increased airway resistance and loss of elastic recoil of the lungs. Airways tend to collapse on expiration, resulting in air trapping and hyperinflation. This increased work of breathing can lead to the use of accessory muscles and the adoption of pursed-lip breathing.
What are the consequences of end-stage COPD?
In end-stage COPD, patients may develop right heart failure (cor pulmonale) due to the increased pulmonary vascular resistance. They may also develop pulmonary hypertension, which further complicates the cardiopulmonary status.
How is COPD diagnosed?
A 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. Confirmation is made by spirometry, which shows an FEV1/FVC ratio of less than 70% predicted post administration of a short-acting bronchodilator.
What is a common symptom of COPD?
Breathlessness on exertion (dyspnea) is a common symptom of COPD. It tends to progressively worsen over time.
What is a characteristic symptom of chronic bronchitis?
A chronic productive cough is a characteristic symptom of chronic bronchitis, which is a form of COPD.
What are some other symptoms associated with COPD?
Other symptoms of COPD include frequent lower respiratory tract infections, progressive weight loss (in some cases), peripheral (ankle) edema (seen in end-stage COPD suggesting cor pulmonale), and red flag symptoms such as hemoptysis, chest pain, and night sweats.
Can clinical examination be normal in mild COPD?
Yes, clinical examination may be normal in mild COPD.
What is a common sign of COPD?
Tachypnea (raised respiratory rate) is a common sign of COPD.
What is a potential tremor associated with COPD?
Tremor can occur if a person is overusing a β-2 agonist inhaler.
What are some respiratory-related signs of COPD?
Pursed-lip breathing and the use of accessory muscles can be observed in individuals with COPD. Hyperinflation of the chest and a barrel-shaped chest (increased anteroposterior diameter of the thoracic cage) are also common signs.
What respiratory sound may be heard in COPD?
Wheezing is often present in individuals with COPD.
What are signs of right heart failure (cor pulmonale)?
Signs of cor pulmonale may include a raised jugular venous pressure (JVP) and ankle edema.
What are some signs of CO2 retention in COPD?
Signs of CO2 retention may include a CO2 retention flap (flapping tremor of the outstretched hands), bounding pulse, irritability, and confusion.
What can be a consequence of advanced COPD?
Advanced COPD can lead to the development of type 2 respiratory failure.
What spirometry findings indicate obstruction in COPD?
In COPD, spirometry will show reduced FEV1 (forced expiratory volume in 1 second) and an FEV1/FVC (forced vital capacity) ratio less than 70%.
What is the criterion for reversibility to a bronchodilator in COPD?
There is no significant reversibility to a bronchodilator in COPD if, 20 minutes after inhaling 200 mcg of salbutamol, the FEV1 does not increase by at least 15% of the baseline value or by more than 200 ml. In asthma, there is typically reversibility.
What changes in lung volumes are observed in COPD?
In COPD, there is an increase in total lung capacity (TLC) and residual volume (RV) due to air trapping.
How is the transfer factor or diffusing capacity affected in COPD?
The transfer factor or diffusing capacity (TLCO/DLCO) is reduced in COPD.
What do the abbreviations TLC and RV stand for?
TLC stands for total lung capacity, which is the maximum volume of air the lungs can hold, and RV stands for residual volume, which is the volume of air remaining in the lungs after maximal expiration.
Why is it important to determine the extent of breathlessness in COPD?
The extent of breathlessness correlates with the severity of COPD. Determining baseline measurements of breathlessness helps assess prognosis and the impact of treatment.
What is the mMRC Dyspnoea Scale?
The mMRC Dyspnoea Scale is a tool used to assess the severity of breathlessness in COPD. It ranges from 0 to 4, with higher numbers indicating greater levels of dyspnea.
What are the different levels of dyspnea on the mMRC Dyspnoea Scale?
The levels on the mMRC Dyspnoea Scale are as follows:
0: Dyspnea with strenuous exercise.
1: Dyspnea when hurrying or walking up a slight hill.
2: Walks slower than others of the same age due to dyspnea or has to stop for breath when walking at own pace.
3: Stops for breath after walking 100 yards or after a few minutes.
4: Too dyspneic to leave the house or breathless when dressing.
Severity of COPD:
How does the GOLD guideline define the severity of COPD?
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) defines the severity of COPD as mild, moderate, severe, and very severe based on spirometry values when the FEV1/FVC ratio is less than 70%.
What are the different severity categories of COPD according to GOLD?
According to GOLD, the severity categories of COPD are as follows:
Mild: FEV1 ≥ 80%
Moderate: FEV1 50-79%
Severe: FEV1 30-49%
Very Severe: FEV1 ≤ 30%