COPD (Therapeutics) Flashcards
How does NICE define COPD?
Characterised by airflow obstruction that is not fully reversible, the airflow obstruction does not change markedly over several months and is usually progressive in the long term
What is COPD predominantly caused by? What can also cause COPD?
Smoking
Occupational exposure
What is classed as an exacerbation?
A rapid and sustained worsening of symptoms beyond normal day-to-day variations
How is airflow obstruction defined?
A reduced FEV1/FVC ratio such that FEV1/FVC is less than 0.7
If FEV1 ≥ 80% of predicted normal…
A diagnosis of COPD should only be made in the presence of respiratory symptoms e.g. breathlessness or cough
What is airway obstruction in COPD caused by?
A combination of airway and parenchymal (functional tissue) damage
This damage is a result of chronic inflammation which differs from that seen in asthma and is usually caused by tobacco smoke
COPD is often…
Undiagnosed
Significant airflow obstruction may be present before a person is even aware of it
COPD may respond to therapies which have little or no impact on…
Airflow obstruction
COPD is now the preferred term for other airflow obstruction conditions previously diagnosed as…
Chronic bronchitis
Emphysema
What is ‘chronic bronchitis’?
Presence of cough and sputum production for at least 3 months in each of 2 consecutive years
Inflammatory process in the bronchi in response to inhaled irritants (usually due to cigarette smoking)
What is ‘emphysema’?
Involves the progressive and destructive enlargement of bronchioles, alveolar ducts and sacs
Leads to loss of surface area available for gas exchange and loss of elastic recoil
What are the 2 types of emphysema?
Centrilobular
Panacinar
What is a COPD diagnosis based on?
History, physical examination and confirmation of the presence of airflow obstruction using spirometry
No single diagnostic test
Early stages of COPD are often…
Asymptomatic
In which patients should a diagnosis of COPD be considered?
Patients over 35 who have a risk factor (generally smoking) and who present with one or more of the following symptoms:
Exertional breathlessness
Chronic cough (productive or unproductive)
Regular sputum production
Frequent winter ‘bronchitis’
Wheeze
Why is it difficult to evaluate sputum production?
Differing patient habits
What does a change in colour or volume of sputum indicate?
Possible exacerbation
For patients in whom a diagnosis of COPD is suspected, they should also be asked about the presence of which factors?
Weight loss Exercise intolerance Waking at night Ankle swelling Fatigue Occupational hazards Chest pain Haemoptysis (blood in mucus)
Patients with a suspected diagnosis of COPD should receive which tests?
Spirometry
A chest radiograph to exclude other pathologies
A FBC to identify anaemia or polycythaemia
BMI calculated
What is the difference in airway obstruction in COPD vs. asthma?
In COPD, airways are permanently damaged and narrowed, therefore symptoms are persistent
In asthma, inflammation of the airways causes constriction, therefore symptoms come and go
What is the difference in reversibility testing in COPD vs. asthma?
In COPD, reversibility following a bronchodilator is only modest
In asthma, expect an increase in lung capacity of ~400ml after using a bronchodilator
What is the difference in cough symptoms in COPD vs. asthma?
Chronic cough with sputum vs. irritating cough
What is the difference in nighttime symptoms in COPD vs. asthma?
Nighttime breathlessness and wheeze that keeps patient awake, not common vs. common
What is the difference in the age groups affected in COPD vs. asthma?
> 35 vs. <35
What is the difference in atopic (genetic) causes in COPD vs. asthma?
Unlikely to be an atopic cause vs. likely
What is the difference in smoking status in COPD vs. asthma?
Nearly all smokers or ex-smokers vs. possibly
Risk of developing COPD is thought to be due to interactions between…
‘Host factors’ and ‘environmental factors’
What are some of the risk factors for developing COPD?
Smoking
Age
Male gender
α1 antitrypsin deficiency
Occupational dusts and chemicals (dependent on intensity and duration of exposure)
Indoor air pollution (burning of open fires of wood, animal dung, coal and agricultural residues)
Existing impaired lung function
Infection (a history of tuberculosis and childhood infections associated with reduced lung function and airway obstruction)
Socioeconomic status (greater smoking prevalence, poorer housing and nutrition)
Nutrition
Asthma
How does smoking contribute to COPD development?
Tobacco smoke causes the releases destructive proteolytic enzymes from inflammatory cells in the lungs, oxidative stress and inactivation of α1 antitrypsin
Dependent on the surrounding context (pack years, age at which smoking was started, maternal smoking and passive smoking )
How does α1 antitrypsin deficiency contribute to COPD development?
α1 antitrypsin is a protein produced mainly in the liver
Its role is to protect the lungs from neutrophil elastase
Lack of α1 antitrypsin results in early and accelerated development of panlobular emphysema
Risk is exponentially higher in smokers
Who does α1 antitrypsin deficiency predominantly affect?
People of Northern European origin
On which factors is COPD graded?
FEV1% Breathlessness (using MRC scale) Symptoms BMI Hypoxia Smoking status Exercise capacity
Which tool is used to assess dyspnoea in COPD?
MRC dyspnoea scale
Which tool is used to assess prognosis in COPD?
BODE index (BMI, airflow obstruction, dyspnoea and exercise capacity) This a 10-point score that assesses disease outcome
What is always the number one strategy in COPD management?
Smoking cessation
Even with a FEV1% <25, smoking cessation will increase life expectancy
What are the treatment aims in patients with chronic COPD?
Stop smoking Improve symptoms Prevent acute infective exacerbations Reduce rate of disease progression Maintain nutritional intake, BMI>20 Increase quality of life
Describe the basic pharmacological treatment steps in COPD.
Step 1 - SABA or SAMA as required
Step 2 - if no asthmatic features/features suggesting steroid responsiveness, offer LABA + LAMA
If such features are present, offer LABA + ICS
Step 3 - LAMA + LABA + ICS
What is the maintain of treatment in COPD?
SABA/LABA/LAMA and ICS if indicated
What are some additional add on therapies that can be used in COPD if control is not stable or maintained?
Mucolytics
Oxygen
Methylxanthines
Oral steroids
When is at home nebulised therapy and spacer devices used?
In patients who remain breathless but who are stable
Home nebulisers are much more common in COPD
What effect do bronchodilators have on FEV1?
Little or no effect
Name 4 LABA’s.
Salmeterol
Formoterol
Indacaterol
Olodaterol
What should be prescribed alongside long term oral corticosteroids?
Bone protective agents
Calcium/vitamin D and biphosphonate as 1st line for all patients over 65
Name 2 mucolytics.
Carbocisteine
Mecysteine
How do mucolytics work?
Facilitate expectoration by reducing sputum viscosity
What course of antibiotics is given prophylactically in COPD?
Azithromycin 250mg TDS
What conditions must be met for a patient to be eligible for prophylactic antibiotics?
Non-smoker Optimised inhaler therapy Up to date vaccinations Continue to have one or more symptoms Baseline LFT's and ECG (QT interval) Review at 3 and 6 months for benefit
What is Roflumilast?
Anti-inflammatory drug with similar actions to theophylline
Only approved by NICE for clinical trial use
What is Indacaterol?
A LABA
When is oxygen therapy used?
Acute exacerbations
Long term if the patient has an FEV <30% and is symptomatic, or if the patient has polycythaemia or cor pulmonale
If patients O2 saturation <92% or is chronically breathless to the point it affects every day life
What is LTOT?
Long term oxygen therapy
>15 hours daily
Cylinders or concentrator
What is a major contraindication in oxygen therapy?
Smoking
What concentrations of oxygen are used in oxygen therapy?
24-28% (much lower than asthma where it is 40-60%) to prevent a reduction in respiratory drive
What combination therapies are available for COPD?
LABA plus ICS (e.g. Seretide and Symbicort)
Triple therapy LABA/LAMA/ICS
When is surgery considered as an option in COPD?
Very severe COPD despite maximal medical therapy
What surgery options are there in treating COPD?
Breathlessness can be improved by,
Bullectomy (i.e. removal of bullae - thin walled, air-filled spaces in the lungs)
Lung volume reduction (i.e. removal of areas of poorly functioning lung)
Transplantation
How is the severity of COPD assessed?
1) Define level of obstruction using GOLD 1-4 scale from mild to very severe
2) Establish the severity of symptoms using the modified MRC scale or the COPD assessment test (CAT) which is more comprehensive and looks at symptoms other than breathlessness
3) Use these indicators of symptoms and severity to give an ABCD score, do this by matching the number of exacerbations that have led to hospital admission within the last year to their mMRC or CAT score
What is the ABCD score then used for?
Selecting a treatment option
Note that patients are escalated and deescalated depending on their ABCD score, which is not fixed but is variable over time as COPD is a chronic and declining condition
What should COPD patients have each year and why?
Flu (influenza) and pneumococcal vaccines
To avoid winter infections
What must a COPD patients BMI be maintained between and why?
20 and 25
A lower BMI has demonstrated higher mortality
How often should COPD patients be reviewed?
At least annually and care must be under a multi-disciplinary team
What is an ‘acute exacerbation’?
A progressive decline in disease with symptomatic decline and breathlessness as FEV1% reduces
Can be infective or non-infective
Why are URTI and LRTI’s common in COPD patients?
Due to lung degradation and used of steroids
When should antibiotics be used?
In infectious exacerbations only Also given if 2 or more of the following are increased, Breathlessness Sputum volume Sputum purulence
What is antibiotic choice dependent on?
Local policy
Lab sensitivity patterns
Previous Rx (resistance)
What are some of the typical pathogens seen in infectious COPD exacerbations?
Haemophilus influenzae
Streptococcus pneumoniae
Which antibiotics are 1st line in treatment of an infectious exacerbation in COPD?
Amoxicillin
Tetracycline
Doxycycline
Clarithromycin
Which antibiotics are 2nd line in treatment of an infectious exacerbation in COPD?
Broad spectrum cephalosporin
Macrolide
What is the length of antibiotic treatment of an infectious exacerbation in COPD?
5 day course in the community
7-14 day course in hospital
What can be given alongside antibiotics to treat exacerbations?
Nebulised salbutamol
Ipratropium
Theophylline
Oral corticosteroid
Why are oral corticosteroids used in COPD exacerbations?
To reduce inflammation and give symptom relief
What is O2 saturation maintained at?
88-92% (vs. 94-98% in asthma)
What are the monitoring requirements for a COPD patient in hospital?
Pulse oximetry/ABG's (blood pH, O2, CO2, cyanosis, hypoxia) HR/RR CRP WCC Theophylline levels (if cont. >24 hours) Serum K+ Glucose Hydration C&S Sputum purulence ECG and ECHO Jugular venous pressure (JVP) RCC
Why are each of these monitoring requirements necessary?
Blood pH ~7.4 - prevent acidosis CO2 - hypercapnia HR/RR - tachycardia/ponea WCC - infection K+ - nebulised SABA C&S - infection ECG and ECHO - cor pulmonale JVP - cor pulmonale RCC - polycythaemia
What is hypercapnia?
A patient with chronic COPD will have a change in respiratory drive
Healthy adults take a breath when CO2 levels increase
A COPD patient is used to high CO2 levels so adapts to take a breath when O2 levels drop
This is hypercapnia and many COPD patients are chronically hypoxic
How does hypercapnia impact on how we treat patients?
This hypoxia affects how we administer oxygen to patients
A high O2 concentration removes the patients drive to take a breath and so oxygen can be fatal in COPD patients
Can lead to respiratory failure if not adjusted to hypercapnic patient
What other 2 complications does hypercapnia drive?
Cor pulmonale
Polycythaemia
What is cor pulmonale?
Right heart failure
Due to pulmonary hypertension and blood flow resistance in the damaged pulmonary vasculature due to structural alterations and remodelling
In addition, hypoxia (secondary to hypercapnia) means an increased oxygen demand and polycythaemia means viscous blood which is more difficult to pump
What are some of the symptoms of cor pulmonale?
Peripheral oedema
Hepatomegaly (abnormal enlargement of the liver)
Raised JVP
How is cor pulmonale treated?
Diuretics are used to reduce oedema
O2 is used to reduce hypoxia
What is polycythaemia?
An increased number of RBC’s in response to chronic hypoxia
An increase in RBC’s, also means an increase in haematocrit and blood viscosity
How is polycythaemia treated?
O2 to reduce hypoxia
Venesection used to remove blood
What is pulmonary rehabilitation?
Incorporates a programme of physical training (physiotherapy), disease education, nutritional, psychological and behavioural intervention
Who should pulmonary rehabilitation be offered to?
Patients who consider themselves to be functionally disabled with COPD (usually MRC grade 3 or above)
What does ‘self-care’ involve in relation to COPD?
Patients should be encouraged to respond promptly to the symptoms of an exacerbation at home by,
Starting oral corticosteroid therapy if their increased breathlessness interferes with activities of daily living
Starting antibiotic therapy if their sputum is purulent
Adjusting their bronchodilator therapy to control their symptoms
Should always contact a HCP if symptoms do not improve
What is a ‘rescue’ or ‘self-care pack’?
A pack with a course of antibiotics and oral corticosteroids for patients who are at risk of having a COPD exacerbations to keep at home
