COPD

Question 1

COPD

Answer 1

is a non-reversible, long term deterioration in air flow through the lungs caused by damage to lung tissue. This lung damage is almost always the result of smoking. The damage to the lung tissues causes an obstruction to the flow of air through the airways making it more difficult to ventilate the lungs and making them prone to developing infections.
Unlike asthma, this obstruction is not significantly reversible with bronchodilators such as salbutamol. Patients are susceptible to exacerbations during which there is worsening of their lung function. Exacerbations are often triggered by infections and these are called infective exacerbations.
COPD, or chronic obstructive pulmonary disease, is a progressive disease that makes it hard to breathe. Progressive means the disease gets worse over time. COPD can cause coughing that produces large amounts of a slimy substance called mucus, wheezing, shortness of breath, chest tightness, and other symptoms.
COPD is an umbrella term encompassing the older terms chronic bronchitis and emphysema. In the vast majority of cases, COPD is caused by smoking. Some patients with more mild disease may just need to use a bronchodilator occasionally whereas other patients may have several hospital admissions a year secondary to infective exacerbations.

Question 2

Presentation of copd

Answer 2

• Suspect COPD in a long term smoker presenting with chronic shortness of breath, cough, sputum production, wheeze and recurrent respiratory infections, particularly in winter.
• Always consider differential diagnoses such as lung cancer, fibrosis or heart failure. COPD does NOT cause clubbing. It is unusual for it to cause haemoptysis (coughing up blood) or chest pain. These symptoms should be investigated for a different cause.

Question 3

MRC: medical research council dyspnoea scale.

Answer 3

This is a 5 point scale that NICE recommend for assessing the impact of their breathlessness:

Grades:

Grade 1 – Breathless on strenuous exercise
Grade 2 – Breathless on walking up hill
Grade 3 – Breathless that slows walking on the flat
Grade 4 – Stop to catch their breath after walking 100 meters on the flat
Grade 5 – Unable to leave the house due to breathlessness

Question 4

Diagnosis COPD

Answer 4

Diagnosis is based on clinical presentation plus spirometry.

Spirometry will show an “obstructive picture”. This means that the overall lung capacity is not as bad as their ability to quickly blow air out of their lungs. The overall lung capacity is measured by forced vital capacity (FVC) and their ability to quickly blow air out is measured by the forced expiratory volume in 1 second (FEV1). Being able to blow air out is limited by the damage to their airways causing airway obstruction. Therefore in COPD:

FEV1/FVC radio <0.7
The obstructive picture does not show a dramatic response to reversibility testing with beta-2 agonists such as salbutamol during spirometry testing. If there is a large response to reversibility testing them consider asthma as an alternative diagnosis.

Question 5

Severity

Answer 5

The severity of the airflow obstruction can be graded using the FEV1:

Stage 1: FEV1 >80% of predicted
Stage 2: FEV1 50-79% of predicted
Stage 3: FEV1 30-49% of predicted
Stage 4: FEV1 <30% of predicted

Question 6

Other investigations

Answer 6

Chest xray to exclude other pathology such as lung cancer.
Full blood count for polycythaemia or anaemia. Polycythaemia (raised haemoglobin) is a response to chronic hypoxia.
Body mass index (BMI) as a baseline to later assess weight loss (e.g. cancer or severe COPD) or weight gain (e.g. steroids).
Sputum culture to assess for chronic infections such as pseudomonas.
ECG and echocardiogram to assess heart function.
CT thorax for alternative diagnoses such as fibrosis, cancer or bronchiectasis.
Serum alpha-1 antitrypsin to look for alpha-1 antitrypsin deficiency. Deficiency leads to early onset and more severe disease.
Transfer factor for carbon monoxide (TLCO) is decreased in COPD. It can give an indication about the severity of the disease and may be increased in other conditions such as asthma.

Question 7

Long term support

Answer 7

It is essential for people to stop smoking. Continuing to smoke will progressively worsen their lung function and prognosis. They can be referred to smoking cessation services for support to stop.

Patients should have the pneumococcal and annual flu vaccine.

Step 1 treatment should be short acting bronchodilators: beta 2 agonists (salbutamol or terbutaline) or short acting antimuscarinics (ipratropium bromide).
Step 2 if they do not have asthmatic or steroid responsive features they should have a combined long acting beta agonist (LABA) plus a long acting muscarinic antagonist (LAMA). Anoro ellipta, ultibro breezhaler and duaklir Genuair.

If they have asthmatic or steroid responsive features they should have a combined long acting beta agonist (LABA) plus an inhaled corticosteroid (ICS). If these don’t work then they can step up to a combination of a LABA, LAMA and ICS. “Trimbo” and “Trelegy Ellipta” are examples of LABA, LAMA and ICS combination inhalers.

Question 8

Severe cased of COPD options

Answer 8

Nebulisers (salbutamol and/or ipratropium)
Oral theophylline
Oral mucolytic therapy to break down sputum (e.g. carbocisteine)
Long term prophylactic antibiotics (e.g. azithromycin)
Long term oxygen therapy at home.

Long term oxygen therapy is used for severe COPD that is causing problems such as chronic hypoxia, polycythaemia, cyanosis or heart failure secondary to pulmonary hypertension (cor pulmonale). It can’t be used if they smoke as oxygen plus cigarettes is a significant fire hazard.