COPD

Question 1

Define COPD

Answer 1

Chronic Obstructive Pulmonary Disease

COPD is a chronic slowly progressive disorder characterised by fixed or partially reversible airway obstruction, unlike ‘reversible’ asthma.

Question 2

COPD Epidemiology

Answer 2

Presentation tends to be in middle age and onwards, but heavily related to smoking (smoking is response for 90%) causing centriacinar emphysema. α-1-antitrypsin deficiency is a genetic condition that can be responsible for COPD and panacinar emphysema.

Question 3

COPD Pathogenesis

Answer 3

COPD results in two findings: chronic bronchitis (clinical) and emphysema (pathological).

As the disease progresses CO2 levels rise and the drive to respiration switches from CO2 to low oxygen levels (hypoxemia). If supplementary oxygen corrects hypoxaemia the drive to respiration may also be removed, provoking respiratory failure.

Question 4

Emphysema Overview

Answer 4

Emphysema

• Pathological finding of destruction of lung tissue with dilatation of distal alveoli.
• This causes hyperinflation, loss of elastic recoil, gas trapping and increased work of breathing, causing SoB.

Question 5

Chronic Bronchitis Overview

Answer 5

Chronic bronchitis

• Defined as a productive cough lasting 3/12 for ≥2 years.
• It is a result of chronic irritation of the airways leading to decreased numbers of ciliated cells, more goblet cells and squamous metaplasia.
• There is a greater degree of mucin production to protect the mucosa from damage induced by smoke.

Question 6

COPD Clinical Presentation

Answer 6

Presentation is usually a mixture of the pink puffer and blue bloater syndromes

• Pink puffer (emphysema)
  
  • Thin, anxious hypoxic patient with Type I respiratory failure (=no CO2 retention).
• Blue bloater
  
  • Large, quiet hypoxic patent with Type II respiratory failure (= CO2 retention) develops right heart failure and floats out. (chronic bronchitis)

Signs are hyper-inflated chest, wheeze, cyanosis, oedema (cor pulmonale), lip pursing from prolonged expiration.

Question 7

COPD Diagnosis

Answer 7

• Spirometry is required to make the diagnosis; the presence of a post-bronchodilator FEV1/FVC <0.70 confirms the presence of persistent airflow limitation and thus COPD

Question 8

COPD Investigations

Answer 8

• Respiratory function tests
  * FEV1/FVC ratio < 70%, lower FEV1 and FVC near normal (obstructive pattern)
• CXR - hyperinflation with loss of lung markings and a small heart
• CT - confirm emphysematous bullae
• ABGs - confirm respiratory failure type I or II.

Question 9

COPD Severity Assessment

Answer 9

Based on spirometry findings: postbronchodilator FEV1

Mild = 60-80% predicted
Moderate = 40-59% predicted
Severe < 40% predicted

Question 10

Mild COPD Impact on ADLs and Complications

Answer 10

ADL Impact

• few symptoms
• no effect on daily activities
• breathless on moderate exertion

Complications
- no

Question 11

Moderate COPD Impact on ADLs and Complications

Answer 11

ADL Impact

• increasing dyspnoea
• breathless on the flat
• increasing limitation of daily activities

Complications
- exclude complications: consider sleep apnoea if there is pulmonary hypertension

Question 12

Severe COPD Impact on ADLs and Complications

Answer 12

ADL Impact

• dyspnoea on minimal exertion
• daily activities severely curtailed

Complications

• severe hypoxaemia (PaO2 less than 60 mm Hg or 8 kPa)
• hypercapnia (PaCO2 more than 45 mm Hg or 6 kPa)
• pulmonary hypertension
• heart failure
• polycythaemia

Question 13

COPD Management

Answer 13

1) Non-pharmacological / Ongoing measures for all patients
2) Pharmacology for Patients with Symptoms
3) Pharmacology for Patients with >2 exacerbations
4) Long term O2 therapy

Question 14

1) Non-Pharmacological COPD Management

Answer 14

1) Assist with smoking cessation
2) Maintain up-to-date immunisations
3) Pulmonary rehabilitation

Question 15

2) Pharmacology for COPD Patients with Symptoms

Answer 15

1) SABA PRN
2) Add LABA or LA-anticholinergic
3) Use both LABA and LA-anticholinergic
4) Consider adding theophylline

Question 16

3) Pharmacology for COPD Patients with >2 exacerbations

Answer 16

1) Add IHC (Inhaled Corticosteroids)
2) If all meds are used as single agents
- – LA-anticholinergic and combo LABA + IHC inhaler

Question 17

Short Acting Bronchodilators in COPD

Answer 17

β2 agonists (salbutamol or turbutaline)

Anticholinergics (iptratropium bromide)

Question 18

Long Acting Bronchodilators in COPD

Answer 18

β2 agonists (eformoterol or salmeterol)
Anticholinergics (tiotropium bromide spiriva)
Theophyline

Question 19

Inhaled Corticosteroids used in COPD

Answer 19

Budesonide or flutacasone propionate

Question 20

COPD Management for Acute Exacerbations

Answer 20

Bronchodilators
- salbutamol, tubutaline or ipratropium (inhaled)
Corticosteroids
- Prednisolone (oral) or hydrocortisone (IV)
Antibiotics
- Amoxycillin or doxycycline (oral)
Oxygen therapy
- Sats between 88-92%
Ventilatory support

Question 21

COPD Complications

Answer 21

• Pneumonia
  * With Haemophilus influenzae - due to increased mucin production but decreased mucocillary escalator
  • Pneumothorax
    
    • Due to rupture of bullae - can occur if dilation of airways cause sub pleural cystic spaces
  • Secondary pulmonary HTN
    
    • Leading to for pulmonale