What is COPD?
- COPD is not a single condition but more so an umbrella term for a group of chronic lung conditions characterised by inflammation of the airways that causes irreversible airway obstruction.
- The irreversible nature of COPD is the main differentiating factor from asthma, which is another chronic lung condition but characterised by reversible airway obstruction.
- COPD is a progressive disease meaning that it worsens with time. Therefore, most patients present with symptoms and signs very late in the disease process as it can remain silent for many years.
Some facts about COPD
- COPD is the third leading cause of disease burden in Australia
- Nearly one in 20 Australians 45 years old and over have COPD
- COPD is the fourth leading cause of death in Australian men
- COPD is the sixth leading cause of death in Australian women
- Nearly 500, 000 Australians are living with moderate or severe COPD
- Death from COPD is 10 times higher in Indigenous and Torres Strait Islander populations
What are the risk factors for COPD?
- CIGARETTE SMOKE
- Smoking is by far the biggest cause of COPD in Australia and other developed nations. 10-20% of all smokers will develop airflow obstruction in their lives.
- Air pollution
- Air pollution is more common in India and China than Australia due to the use of biomass fuels in those countries. Smoking remains the number one risk factor for COPD in Australia.
- Occupational and/or household exposure
- Asbestos-exposed workers or people living in houses that used asbestos in building materials during 1920s to 1980s have an increased risk of COPD.
- However, asbestos itself does not cause COPD and is more so associated with lung cancer.
- There is a specific genetic condition called alpha-1-antitrypsin deficiency that increases your risk of COPD. This gene is also associated with liver failure. If you know someone in your family who suffers from this condition, ask your doctor about genetic testing.
- Poorly controlled asthma
- See APA’s Asthma document for further information
- Frequent respiratory tract infections in childhood
What are the different types of COPD?
As said above, COPD is an umbrella term for a number of chronic lung diseases that are characterised by airflow limitation and inflammation. The three different types of COPD are chronic bronchitis, emphysema and chronic obstructive asthma.
- Chronic bronchitis is defined as a persistent cough that produces sputum for at least three months over two consecutive years
- Chronic bronchitis is a diagnosis of exclusion meaning that all other causes of your sputum-producing cough have been ruled out
- Chronic bronchitis is caused by ongoing irritation to your airways by inhaled substances, most often cigarette smoke, but also dust, silicon and certain chemicals
- Chronic bronchitis is characterised by airway inflammation, scarring and narrowing. These three factors all create smaller airways that make it harder for air to get to the lungs for effective gas exchange.
- There are also special cells within your lungs, called goblet cells, that are responsible for producing mucous. Goblet cells both increase in number and become larger in response to lung damage caused by inhaling cigarette smoke. This means that more mucous than normal is produced and the mechanisms in the airways that are responsible for clearing away mucous become overwhelmed and cannot clear it all away.
- Emphysema is defined as an enlargement of the air spaces in the lowest region of the lungs without associated scarring. Emphysema is caused by destruction of the alveoli, the tiny air sacs within the lungs that are responsible for gas exchange.
- When you inhale a nasty substance, such as cigarette smoke, it activates your inflammatory response. There are certain proteins within your lungs that become overactive and are responsible for destroying the elastic tissue in your small airways.
- Without this elastic tissue, your airways collapse and this causes airway obstruction.
Chronic obstructive asthma
- Chronic obstructive asthma differs from normal asthma because the airway obstruction is not completely reversible with bronchodilator medication.
What are the signs and symptoms of COPD?
There are three hallmark features of COPD:
- Shortness of breath
- If early in the disease, you may only experience shortness of breath during exercise.
- As the disease progresses and gets worse, you can start feeling out of breath even at rest.
- A chronic cough which produces mucous
- To meet the definition for chronic bronchitis, the cough must have been present for at least three months in two consecutive years without any other possible cause.
- A whistling sound you make when breathing out that can be heard by the doctor using a stethoscope placed over your chest.
There are also some signs and symptoms that are classically associated with chronic bronchitis and with emphysema respectively. In reality, people with COPD will have both chronic bronchitis and emphysema although one usually does predominate over the other. You may hear the terms blue bloaters and pink puffers which refers to the clinical features of a person with predominantly chronic bronchitis or emphysema respectively.
How is COPD diagnosed?
- The gold standard for COPD diagnosis is a special lung function test called Your doctor will order a spirometry test if they are suspicious that you may have COPD due to your history and symptoms such as:
- Being a current or past smoker
- Having a chronic cough that produces phlegm/ mucous
- Being short of breath either with exercise or at rest
- Being exposed to other nasty chemicals, either in your workplace, the natural environment or your home
- A spirometer is a large tube that is connected to a monitoring machine. Your doctor will ask you to take a big breath in, and then breathe out as forcefully and rapidly as you can into the spirometer mouthpiece until you cannot breathe out anymore. The spirometer can measure both the time it takes you to fully exhale as well as the volume of air exhaled. It is the best measure of airflow obstruction.
- The criteria you must meet to be diagnosed with COPD is very specific. A diagnosis of COPD is made if a special ratio, known as the FEV1-to-FVC ratio, is less than 0.7 and not improved after the administration of a bronchodilator medication. The cut-off for an improvement with a bronchodilator is defined as a 12% and greater than 200mL increase in either FEV1 and or FVC. Therefore, if your results do not improve by this specific amount, it is confirmed that your airflow limitation is irreversible and a diagnosis of COPD is made.
What are the stages of COPD?
- The GOLD Criteria is commonly used to determine the severity of COPD. There are four stages according to the GOLD criteria which range from mild to very severe. The GOLD criteria is based on the FEV1-to-FVC ratio as calculated by spirometry testing (see above).
- GOLD Stage 1 – Mild: FEV1 > 80% predicted
- GOLD Stage 2 – Moderate: 50% < FEV1 < 80% predicted
- GOLD Stage 3 – Severe: 30% < FEV1 <50% predicted
- GOLD Stage 4 – Very Severe: FEV1 < 30% predicted
- It is important to stage COPD because the severity of COPD will determine the treatment and management of your condition.
How is COPD managed?
- The current treatment guidelines for COPD focus on:
- Controlling symptoms
- Improving lung function and health status
- Preventing exacerbations
- Reducing hospital admission
- A common management plan for COPD is known as COPD-X
- Confirm diagnosis and assess severity
- Optimise lung function
- Prevent deterioration
- Develop a support network and a self-management plan
- Manage eXacerbations appropriately
- The most important thing you can do to prevent worsening of COPD is stop smoking. The cessation of smoking is the single most clinically effective way at stopping the progression of COPD. At any stage of COPD, stopping smoking improves your breathing, reduces coughing and chest tightness, and reduces inflammation. Stopping smoking is an incredibly challenging thing to do but it will improve your health significantly and is worth the challenge.
- Click here to read more about COPD and smoking
- If you feel ready to quit, click here to read more about the different quitting methods and where to go for support during your journe
- A comprehensive pulmonary rehabilitation This includes specific exercises and activities set by a physiotherapist, engaging in regular physical activity, promoting healthy behaviours, adhering to medication and psychological support. The diagram below is an example of an exercise you may be asked to do to improve your COPD. It is called Bubble PEP (Positive Expiratory Pressure) which is used to help clear the build-up of mucous in your lungs. As the name suggests, it requires you to blow down the tube into the container of water and blow bubbles to hold the airways open. This allows air to flow more easily in and out of your lungs, and to help move mucous out of the lungs into the airways to be removed.
- Proper education is also a huge part of COPD management. You should be educated by your GP about how to correctly use your inhaler medications (discussed below in Medications) and discuss whether you would benefit from using a spacer (see APA’s document on Respiratory Disease Management for more information). This education is crucial because it is thought that as many as nine out of 10 people are not using their inhalers correctly. Proper use of your inhaler is necessary to ensure the right amount of medicine reaches your lungs and to minimise side effects of the medication
There are many different types of medications you may prescribed if you have COPD. The type and dose of medications depends on the severity of your condition which will be assessed by your doctor. Similarly to asthma, management with medications is a step-by-step process but there are some important differences compared to asthma treatment.
- Short-acting b– agonists
- Work in the short-term by dilating the airways
- Used for relief of intermittent symptoms of COPD and for people who have chronically mild COPD but frequent acute exacerbations
- Prescribed on an as needed basis rather than on a regular schedule
- Ventolin, salbutamol
- Short-acting muscarinic antagonists
- Similar use as short-acting b- agonists but have a different mechanism of action to dilate the airways
- Tiotropium bromide
- Long-acting muscarinic antagonists
- Have the same mechanism of action as short-acting forms but are used in patients with COPD who have more severe regular symptoms but at a lower risk of having acute exacerbations
- Ipratropium bromide
- Long-acting b– agonists
- Work in the same way as short-acting forms but are used for patients who have chronic severe symptoms but less risk of acute exacerbations
- Salmeterol, formoterol
- Inhaled corticosteroids (ICS)
- Function by reducing inflammation in the airways
- Used in patients who have frequent acute exacerbations of COPD
- Most often used as a duel therapy with a long-acting muscarinic antagonist because studies have shown ICS are not very beneficial as a single therapy
- Fluticasone, budesonide
Notes on medications:
- Inhaled corticosteroids generally try to be avoided in COPD sufferers, who often are older, because in older patients they can have severe side effects including cataracts, diabetes and osteoporosis.
- Two muscarinic antagonists cannot be used together.
- Always follow your doctor’s advice and prescriptions when it comes to medications
- Long-term oxygen is indicated for patients with severe COPD who have very low oxygen levels within their blood, known as hypoxaemia.
- Oxygen is only prescribed when all other medical therapies have failed to manage the patient’s COPD.
- For patients with normal oxygen levels whilst awake, oxygen may only be prescribed during sleep when the oxygen levels drop overnight, known as nocturnal hypoxaemia.
- Oxygen may also be prescribed to patients only during exercise when the oxygen demands increase to meet the demands of the body during physical activity.
- The flow rate of oxygen and the selection of equipment is made on an individual basis. See the table and information below to learn more about the different oxygen devices.
- CPAP stands for continuous positive airway pressure and is a therapy used to help patients with COPD who suffer from obstructive sleep apnoea.
- Obstructive sleep apnoea is the most common sleep-related breathing disorder and is characterised by intermittent airflow limitation during sleep that stops you breathing.
- CPAP is a machine that creates an increased pressure in your throat to hold it open so that your airway does not collapse. This allows you to keep breathing normally rather than your breathing being on-and-off throughout the night. The same amount of pressure is delivered to your airways through the machine during inhalation and exhalation.
- Click here to read more about CPAP
- BiPAP stands for bilevel positive airway pressure and is similar to CPAP in that it is a machine that helps patients who suffer from sleep apnoea. Rather than CPAP, which provides the same amount of pressure continuously as you breathe in and out, a BiPAP machines provides a higher amount of pressure when you breathe in compared to when you breathe out. It is important to speak to your doctor about what machine would suit your condition best.
- Click here to read more about BiPAP
- Infections are a very common cause of acute exacerbations of COPD. It is advised all patients with COPD have the following vaccinations to prevent exacerbations:
What are the complications of COPD?
- The most important complication of COPD is heart failure.
- This is so common that there is a medical term, known as cor pulmonale, which means heart disease caused specifically by a chronic lung condition.
- Most of the deaths from COPD are ultimately caused by heart failure.
Useful additional resources