What is COPD?

COPD is characterized by airflow obstruction that is chronic, progressive and irreversible. It has two variants depending upon part of lung that is damaged.

Chronic bronchitis (abnormality of airways)
Emphysema (abnormality of alveoli)

(Alveoli are tiny sacs of air in lungs where exchange of gases take place during the process of breathing in and out)

Emphysema:

Emphysema is destruction of walls of alveoli leading to permanent enlargement of alveoli. This damage affects exchange of gases thus leading to the development of respiratory symptoms of COPD.

Chronic bronchitis:

It is defined as cough with sputum that is present for 3 months in each of 2 consecutive years with no other identifiable cause of sputum production. There is enlargement of mucus glands that are normally present in airways. Due to enlargement of these glands, there is excessive production of mucus that obstructs airways and creates resistance.

COPD can be genetic but is not contagious.

COPD classification on the basis of causes of COPD

COPD-G

COPD can be genetic . The best documented genetic risk factor for COPD is mutation in SERPINA-1 gene that leads to hereditary deficiency of Alpha-1 anti-trypsin (AATD). Few other gene mutations are also thought to be involved in causing COPD but there is no strong evidence for those genetic mutations. These include genes encoding matrix metalloproteinase 12 (MMP-12), Glutathione S- transferase, the alpha-nicotinic acetylcholine receptor, and hedgehog interacting protein (HHIP).

COPD-D

COPD due to abnormal lung development because of early life events (i.e. low birth weight, pre mature birth, maternal smoking during pregnancy, passive smoking exposure during infancy)

COPD-C

COPD due to

Active cigarette smoking ( > 20 pack years )
Second hand Cigarette smoking
Vaping
E-cigarette
Cannabis

COPD-P

COPD due to exposure to

Household pollution
Air pollution
Wildfire smoke
Occupational hazards (organic and inorganic dust, fumes, pesticides and chemicals).

COPD-I

Severe infections like HIV, Tuberculosis and chronic pseudomonas can lead to development of COPD.

COPD-U

COPD due to unknown cause.

COPD-A

COPD and asthma. Asthma may also be a risk factor for the development of chronic airflow obstruction leading to COPD. There is 12-fold higher risk of developing COPD in asthmatics over time compared to those without asthma.

Diagnostic criteria:

Diagnosis of COPD should be considered in any patient who has shortness of breath, chronic cough or sputum production and history of exposure to risk factors along with irreversible airflow obstruction measured on spirometry (FEV1/FVC ratio < 0.7) post bronchodilation, that is mandatory.

What Are the Early signs of COPD?

Early signs of COPD include but not limited to the following:

Shortness of breath / Dyspnea

It is the most characteristic symptom of COPD. Shortness of breath gets worse with exercise, progresses over time and is persistent. Patients describe this symptom as a sense of increased effort to breathe, chest heaviness, air hunger, or gasping. Initially shortness of breath occurs only during physical activity or exertion.

Wheeze
Chronic cough

Chronic cough is often the first symptom of COPD and is frequently discounted by the patient as an expected consequence of smoking and /or environmental exposures. Initially cough may be intermittent but subsequently it may be present every day, often throughout the day. Cough may be with or without sputum. Patients might experience episodes of syncope (loss of consciousness) during prolonged attacks of coughing.

Sputum production

COPD patients commonly raise small quantities of tenacious sputum with coughing. Sputum production can be intermittent with periods of flare up interspersed with periods of remission. Large volume of sputum production reflects underlying bronchiectasis. Yellow sputum may indicate bacterial infection.

Fatigue

Tiredness or exhaustion is one of the most common and distressing symptom experienced by people with COPD. This fatigue is described as a feeling of general tiredness or as a feeling of being drained of energy. Fatigue affects patient ‘s ability to perform activities of daily living and quality of life.

History of risk factors

Risk factors are tobacco smoke, smoke from home cooking and heating fuels, occupational dusts vapors, fumes, gases and other chemicals. Developmental abnormalities, genetic factors, low birth weight, prematurity, childhood respiratory infections.

Additional clinical features in severe disease

Weight loss, muscle mass loss and anorexia are common problems in patients with severe COPD. These symptoms can be a sign of other diseases like tuberculosis or lung cancer in COPD patients. Ankle swelling may indicate involvement of heart in COPD. Depression and anxiety are also common.

What are the Stages of COPD?

There are 4 stages of COPD. Staging /grading of COPD is done on basis of FEV1 value that is obtained from spirometry.

MILD FEV1 > 80 %

MODERATE 50% < FEV1 < 80 %

SEVERE 30%< FEV1 < 50%

VERY SEVERE FEV1 < 30%

Modified MRC Dyspnea Scale

mMRC dyspnea scale grades dyspnea / shortness of breath on basis of patient’s severity of complaint. There are 4 grades/ stages of dyspnea / shortness of breath.

GRADE O I only get breathless with strenuous exercise.

GRADE 1 I get short of breath when hurrying on level or walking up a slight hill.

GRADE 2 I walk slower than people of the same age on the level because of breathlessness, or I have to stop for breath when walking on my own pace on the level.

GRADE 3 I stop for breath after walking about 100 meters or after a few minutes on the level.

GRADE 4 I am too breathless to leave the house or I am breathless when dressing or undressing.

Only one box should be selected to grade breathlessness.

Is asthma a form of COPD?

Asthma and COPD may show similarities in symptoms but are 2 different diseases. Both have different causes, pattern, course and treatment.

Some major differences of asthma and COPD are :

COPD

Symptoms are persistent
Slowly progressive
Irreversible symptoms
Smoking and other Risk factors present
Two variants ( chronic bronchitis and emphysema)
Later ages
Spirometry shows irreversible obstruction

ASTHMA

Variable airflow obstruction
Symptoms vary widely from day to day
Symptoms worse at night/ early morning
Allergy, rhinitis, eczema, food allergy present
Family history
Early age
Spirometry shows reversible obstruction

Is bronchiectasis COPD?

No. Let’s explain it a little more:

BRONCHIECTASIS

Bronchiectasis is abnormal permanent dilatation of airways called bronchi.
Causes are genetic, immune defect or infection
Large volumes of sputum
Bacterial infection is commonly present
Chest Xray / CT scan shows airways dilatation and mucus plugs
COPD can lead to development of bronchiectasis later through vicious cycle of airways inflammation and repeated infections.

COPD

Smoking is the main cause along with other risk factors
Small amount of tenacious sputum
Bacterial infection less common and only during flare ups
Chest xray / CT scan shows hyper inflated lungs

Does COPD cause heart failure?

COPD can lead to right sided heart failure that is also called Cor Pulmonale.

Chronic lung conditions like COPD leads to long standing low oxygen level in blood (i.e. hypoxia) and high carbon dioxide level in blood (i.e. hypercapnia). Both hypoxia and hypercapnia lead to pulmonary hypertension (i.e. raised pressure of vessels in lungs) which in turn lead to the development of right sided heart failure which in medical terms is called Cor-pulmonale.

Patients often present with their first episode of ankle swelling during a flare-up of their COPD. Cor -pulmonale is a marker of poor prognosis in COPD, with a five-year survival rate of ~50%. Long-term oxygen therapy is the main treatment in patients with cor-pulmonale and improves survival.

Signs of right heart failure/ cor-pulmonale

Ankle swelling
Breathlessness on lying flat on bed
Visible neck vein ( JVP)
Bluish discoloration of skin ( cyanosis)

Investigations for right heart failure

Chest Xray (COPD changes i.e. hyperinflated lungs and prominent vessels of lungs)
ECHO (it will show enlarged right side of heart, impaired heart valves on right side)
Blood gases (low oxygen level i.e. below 8kPa and raised carbon dioxide level i.e. above 6kPa)

Management

Long term oxygen at home ( LTOT)
Di-uretics (medicines that increase urine output )
Always elevate legs while sitting
Salt restriction (<3 g/day) and fluid restriction (1.5 to 2 L/day)

COPD, a death sentence?

Yes, COPD can be a death sentence if its not controlled with regular daily medications, smoking abstinence and timely referral to emergency in case of flare ups.

COPD can lead to life threatening Respiratory Failure. It has following signs and symptoms:

Respiratory rate >24 breaths per minute
Use of accessory muscles of breathing
Sudden change in mental status
High level of carbon dioxide in blood (>60 mmHg)
Acidosis (pH ≤7.25)

This is an emergency that needs to be addressed timely and quickly.

Investigations

Blood gases (ABGs)
Chest Xray

Management

Bronchodilators
Controlled oxygen
No- invasive ventilation (BiPAP)
Invasive ventilation (mechanical ventilator)

Prevention

How can one prevent flare up of COPD?

Regular use of medications
Proper follow ups with chest physician
Careful use of oxygen therapy at home (only if advised by physician)
Vaccinations (influenza, pneumococcal, COVID-19, RSV vaccine, zoster vaccine and dTaP vaccine)
Pulmonary rehabilitation
Abstinence from smoking

COPD (Chronic Obstructive Pulmonary Disease)