Chronic obstructive pulmonary disease (COPD)

Question 1

What is COPD?

Answer 1

COPD is a preventable & treatable disease state characterised by airflow limitation that is not fully reversible.

• emphysema
• chronic bronchitis.

airflow limitation =

• usually progressive
• associated with an abnormal inflammatory response of the lungs to noxious particles or gases.

Question 2

What two factors are important in the overall condition & prognosis of COPD pts?

Answer 2

• comorbidities
• COPD exacerbations

Question 3

Explain the aetiology / risk factors of chronic obstructive pulmonary disease (COPD)

Answer 3

Bronchial and alveolar damage is caused by environmental toxins (e.g. cigarette smoke)

RARE CAUSE: a1 antitrypsin deficiency

• Though this is rare, consider it in young patients, who have never smoked, presenting with COPD type symptoms (and may have accomopanying symptoms of cirrhosis)

Chronic Bronchitis

• Narrowing of the airways resulting in bronchiole inflammation (bronchiolitis)
• Bronchial mucosal oedema
• Mucous hypersecretion

Squamous metaplasia

Emphysema

• Destruction and enlargement of alveoli
• Leads to loss of elasticity that keeps small airways open in expiration
• Progressively larger spaces develop called bullae (diameter > 1cm)

Question 4

Summarise the epidemiology of chronic obstructive pulmonary disease (COPD)

Answer 4

Very Common (8% prevalence)

Presents in middle age or later

More common in males - this may change because there has been a rise in female smokers

Question 5

Recognise the presenting symptoms of chronic obstructive pulmonary disease (COPD)

Answer 5

• Chronic cough
• Sputum production
• Breathlessness
• Wheeze
• Reduced exercise tolerance

Question 6

Recognise the signs of chronic obstructive pulmonary disease (COPD) on physical examination

Answer 6

Inspection

• Respiratory distress
• Use of accessory muscles
• Barrel-shaped over-inflated chest
• Decreased cricosternal distance
• Cyanosis

Percussion

• Hyper-resonant chest
• Loss of liver and cardiac dullness

Auscultation

• Quient breath sounds
• Prolonged expiration
• Wheeze
• Rhonchi - rattling, continuous and low-pitched breath sounds that sounds a bit like snoring.
  
  • They are often caused by secretions in larger airways or obstructions.
• Sometimes crepitations

Signs of CO2 retention

• Bounding pulse
• Warm peripheries
• Asterixis

LATE STAGES:

• signs of right heart failure (cor pulmonale)
• Right ventricular heave
• Raised JVP
• Ankle oedema

Question 7

Identify appropriate investigations for chronic obstructive pulmonary disease (COPD) and interpret the results

Answer 7

• Spirometry and Pulmonary Function Tests
  
  • Shows obstructive picture
  • Reduced PEFR
  • Reduced FEV1/FVC
  • Increased lung volumes
  • Decreased carbon monoxide gas transfer coefficient
• CXR
  
  • May appear NORMAL Hyperinflation (> 6 anterior ribs, flattened diaphragm)
  • Reduced peripheral lung markings
  • Elongated cardiac silhouette
• Bloods FBC -
  
  • increased Hb and haematocrit due to secondary polycythaemia ABG - may show hypoxia, normal/raised PCO2
• ECG and Echocardiogram
  
  • check for cor pulmonale
• Sputum and Blood Cultures -
  
  • useful in acute infective exacerbations a1 antitrypsin levels
  • • useful in young patients who have never smoked

Question 8

Generate a management plan for chronic obstructive pulmonary disease (COPD)

Answer 8

STOP SMOKING

• Bronchodilators
• Short acting beta 2 agonists (e.g. salbutamol)
• Anticholinergics (e.g. ipratropium bromide)
• Long acting beta 2 agonists (if > 2 exacerbations per year)
• Steroids
  
  • Inhaled beclamethasone considered in all patients with FEV1 < 50% of predicted OR > 2 exacerbations per year
  • regular oral steroids should be avoided if possible
• Pulmonary rehabilitation
• Oxygen therapy -
  
  • Only for those who stop smoking
  • indicated if: PaO2 < 7.3 kPa on air during a period of clinical stability
  • PaO2: 7.3 - 8 kPa and signs of secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema or pulmonary hypertension

Treatment of Acute Exacerbations

• 24 % O2 via Venturi mask
  
  • Increase slowly if no hypercapnia and still hypoxic (do an ABG)
• Corticosteroids
• Start empirical antibiotic therapy if evidence of infection
• Respiratory physiotherapy
  
  • to clear sputum
• Non-invasive ventilation may be necessary in severe cases

Prevention of infective exacerbations: pneumococcal and influenza vaccination

Question 9

Identify the possible complications of chronic obstructive pulmonary disease (COPD) and its management

Answer 9

• Acute respiratory failure
• Infections
• Pulmonary hypertension
• Right heart failure
• Pneumothorax (secondary to bullae rupture)
• Secondary polycythaemia

Question 10

Summarise the prognosis for patients with chronic obstructive pulmonary disease (COPD)

Answer 10

High morbidity

3 year survival of 90%

• if < 60 yrs, FEV1 > 50%

predicted 3 year survival of 75%

• if > 60 yrs, FEV1: 40 - 49% predicted