Obstructive Lung Disease Flashcards
What is characteristic about obstructive lung disease?
Airflow limitation
What is FEV1?
The forced expiratory volume of air exiting the lung in the first second
What is FVC?
The final total expired
What is normal FEV1?
3.5-4 litres
What is normal FVC?
About 5L
What happens to FEV1 in obstructive lung disease?
It is reduced
What happens to FVC in obstructive lung disease?
It may be reduced
What are the most common obstructive airway diseases?
Asthma
Chronic Bronchitis
Emphysema
What happens in peak expiratory flow in obstructive lung diseases?
It may also be reduced
What is emphysema?
A destruction of the alveolar wall
An increase in the alveolar space causing exhalation to be more difficult
Loss of elasticity
Is the mechanism of obstruction for chronic bronchitis, emphysema and asthma the same?
No they all have different mechanisms
Although all of their most component is airway obstruction
What does COPD stand for?
Chronic Obstructive Pulmonary Disease
What does the person physically have to do to measure FEV1 and FVC?
Take in a deep breath and blow out their lungs as much air as fast as possible
What is the predicted FVC based on?
Age
Sex
Height
What is normal range of PERF?
80-100% normal
What is a moderate fall in PERF?
50-80%
What is a marked fall in PERF?
<50%
In bronchial asthma what Type of hypersensitivity is present?
Type 1
What are the most common causes of both emphysema and chronic bronchitis?
Smoking
Atmospheric Pollution
Occupation: exposure to dust
Which gender is more affected by chronic bronchitis and emphysema?
Male
What is chronic bronchitis defined clinically as?
Cough productive of sputum most days in at least 3 consecutive months for 2 or more consecutive years
What are the 3 forms of emphysema?
Centriacinar
Panacinar
Periacinar
What does pan-acinar wipe out surface area by?
By area
What does centri-acinar wipe out surface area by?
By number
What is a bulla?
An emphysematous space greater than 1cm
Is COPD reversible?
No generally considered to be irreversible
What is ‘ura bleb’?
Term used to describe bulla spaces underneath the plura
What can ‘bleb’ lead to?
Spontaneous pneumothorax
How does smoking contribute to COPD?
Contributes to a protease-antiprotease imbalance by inducing anti-elastase deficiency and negatviely affecting elastin synthesis repair mechanisms
What do neutrophils and macrophages release that can cause lung damage?
Enzymes (elastases) which can lead to the degradation of lung tissue
How is the maintenance of alveolar tissue maintained in a healthy individual?
Repair mechanisms of anti elastases and elastin synthesis
What is there a loss of in emphysema? (think guy ropes)
Alveolar attachments
What are the normal values of pulmonary gas exchange of oxygen?
Normal PaO2 - 10.5 -13.5 kPa
What are the normal values of pulmonary gas exchange of carbon dioxide?
Normal PaCO2 4.8 - 6.0 kPa
What are the values in Type 1 respiratory failure?
PaO2 , 8 kPa (PaCO2 normal or low)
What are the values in Type 2 respiratory failure?
PaCO2 > 6.5 kPa
What are the 4 normal states associated with HYPOXAEMIA?
Ventilation/Perfusion imbalance
Diffusion impairment
Alveolar hypoventilation ( not enough air getting in)
Shunt
What can the obstruction of airways be made worse by?
Inflammation
Mucous
In the UK how many people are diagnosed with COPD?
900,000
How common a cause of death is COPD in UK?
6th
How common a cause of death is COPD in the world?
5th
How can COPD affect the daily lives of those that live with it?
Climbing stairs Gardening housework Dressing Sleep disturbance Can all be affected
What is the main cause of COPD?
Smoking
What % of smokers develop COPD?
20%
Is weight loss a bad symptom?
Yes - often indicates severe disease
What are the specific features that should be included in the past medical history of a COPD patient?
Asthma as a child
Respiratory diseases
Ischaemic heart disease
What are the specific features that should be included in the drug history of a COPD patient?
List of current inhales, doses
Previous medications and effects on breathing
What are the specific features that should be included in the personal and social history of a COPD patient?
Occupation
Smoking history, age started, stopped smoking, cigarettes/day, pack years
Does COPD change markedly over several months?
No
In obstructive lung disease why is FEV1 reduced?
Because in 1 second the amount of air getting out is more affected due to the obstructed airways
Is the mechanism for all obstructive airway diseases the same?
No the mechanism for obstruction is different in each case
Where is there inflammation in chronic bronchitis?
Inflammation of the bronchial tubes
Alot of what is produced in chronic bronchitis?
Mucous
In chronic bronchitis what are the morphological changes in the large airways?
Mucous gland hyperplasia
Goblet cell hyperplasia
Inflammation and fibrosis is a minor component
In chronic bronchitis what are the morphological changes in the small airways?
Goblet cells appear
Inflammation and fibrosis in long standing disease
What is goblet cell hyperplasia?
Increased numbers of goblet cells
What is fibrosis?
The thickening and scarring of connective tissue
What is the most common form of emphysema?
Centriacinar
What part of the lung is predominantly destroyed in centriacinar emphysema?
Upper half of the lungs
What part of the lung is predominantly destroyed in panacinar emphysema?
The lower half of the lungs
What is ventilation?
The amount of air moved in and out of the lungs
What is chronic (hypoxic) Cor Pulmonale?
Pulmonary heart disease
Enlargement and failure of the right ventricle as a response to increased vascular resistance or high blood pressure i the lungs
i.e the heart has to work harder to get blood through the pulmonary circulation
In the UK how many are diagnosed with COPD?
900,000
What % of COPD patients are diagnosed?
50%
What is 85% of COPD causation due to?
Tobacco smoke
What is the other 15% of COPD causation due to?
Passive smoking Chronic asthma Maternal smoking Air pollution Occupation
What is FEV1 in mild COPD?
<80%
What is FEV1 in moderate COPD?
50-80%
30-50%
What is FEV1 in severe COPD?
<30%
When might you start suspecting COPD?
Age 35 or over Current or former smoker Chronic cough Exertional Breathlessness Sputum production Frequent winter bronchitis Wheezing Chest tightness
When examining what might be noticed in a COPD patient?
Reduced chest expansion
Prolonged expiraiton/wheeze
Hyperinflated chest
What are the signs of respiratory failure?
Cyanosis
Use of accessory muscles of expiration
Pursed lip breathing
Peripheral Oedema
What confirms the diagnosis for COPD?
Spirometry
What are the baseline tests for COPD?
Spirometry CXR ECG Full blood count BMI
What is the management treatment for COPD?
Smoking cessation
Inhalers
Long term Oxygen Therapy
What treatment is given to extreme COPD patients?
Long term O2 therapy
Why is smoking cessation advisable for COPD patients?
Because smoking highly contributes to COPD
What inhaled therapy is available for COPD patients?
Short acting Bronchodilators
Long Acting Bronchodilators
High Dose inhaled corticosteroids
When is long term oxygen given?
When PaO2 <7.3 kPa
When is long term oxygen given if the patients has nocturnal hypoxia, peripheral oedema or pulmonary hypertension?
7.3-8kPa
