COPD & Respiratory Failure

Question 1

What is COPD?

How can exacerbations be reduced?

Answer 1

• Fixed airway obstruction, with little-to-no response to inhaled steroids.
• Characterised by persistent respiratory symptoms and airflow limitation due to airway and / or alveolar abnormalities, usually caused by significant exposure to noxious particles or gases.
• Exacerbations ar reduced with steroids.
• Management is based on symptoms control.
• FEV declines, inexrably.

Question 2

What are the types of inhaler therapy used in COPD?

Broadly speaking, what is their mechanism of action?

Answer 2

• There are 3 kinds
  
  • LABA - Salmeterol, Fomoterol
  • LAMA - Triotropium
  • ICS - Beclomethasone, Fluticasone, Budesonide
• Bronchodilators relax smooth muscle, improve airflow and improve breathlessness.
• Inhaled steroids reduce inflammation, and so exacerbation.

Question 3

Describe the stepwise pharmacological management of COPD.

Answer 3

• LABA or LAMA
• • ICS
• • LABA or LAMA (whatever wasn’t used in first step)
• Usually:
  
  • Prednisolone
  • Aminophylline
  • Oygen
  • Nebulisers

Question 4

What are the stimulatory and inhibitory factors in the development of pathology associated with COPD?

Answer 4

• There must be a host factor which modifies the initial noxious stimulus.
  
  • Not everyone who smokes gets lung inflammation and people who don’t smoke get lung inflammation.

Question 5

Describe the pathophysiology of COPD.

Answer 5

• Alveolar walls become obliterated.
• The larger alveolar sacs are not good for gas exchange.
• They also cause hyperinflation of the lungs and for this reason the chest is hyper-resonant upon percussion.

Question 6

What are the treatment goals in COPD?

Answer 6

• Reduce the symptoms
  
  • ​Improve symptoms, exercise tolerance and health status.
• Reduce the risk
  
  • ​Disease progression, exacerbation and mortality.

Question 7

Dscribe the prognosis of a COPD patient.

Answer 7

• Disease progression
• Rate of decline according to FEV%

Question 8

What are the clinical features of COPD?

Answer 8

• Chronic cough +/- phlegm
• Chronic SOB
• Colds ‘go to the chest’

Question 9

Describe the use of pulmonary function tests in COPD.

Answer 9

• Spirometry
  
  • ​Obstructive = FEV/FVC <0.70
  • Predicted FEV:
    
    • <30% = very severe
    • 30-50% = severe
    • 50-80% = moderate
    • >80% = mild
• Lung volumes
  
  • ​Gas trapping causes increased residual volume, increased total lung capacity; RV/TLC.
• Gas transfer
  
  • ​Decreased TLCO
  • Decreased VA
  • Decreased KCO
• Oxygen saturation and desaturation
  
  • ​Prescribe O₂ to maintain between 88-92%

Question 10

Describe the use of imaging in the diagnosis of COPD.

Answer 10

• CXR is specific, but not sensitive.
• CT is very sensitive, but carries ‘risk’.
• Neither should be the main driver for the diagnosis.
• Imaging is variable with emphysema, but poorly corelated with FEV.
• Extensive emphysema can exist with normal FEV.
• Severe FEV can co-exist with minimal emphysema on CT.
• Useful in advanced disease to review non-COPD disease - bronchiectasis, fibrosis, cancer.

Question 11

What are the goals of COPD assessment?

Answer 11

To determine:

• The level of airflow limitation
• The impact of disease on the patient’s health status
• The risk of future events (exacerbations, hospital admissions, or death)

In order to guide therapy.

Question 12

Describe group A management of COPD.

Answer 12

Question 13

Describe group B management of COPD.

Answer 13

Question 14

Describe group C management of COPD.

Answer 14

Question 15

Describe group D management of COPD.

Answer 15

Question 16

How is treatment escalated based on symptoms and risk in COPD?

Answer 16

• Go to the right along the x axis if the patient is more breathless.
• Go up the y axis if they have greater risk.
• You should escalate in this order.

Question 17

What oral medications can be used to treat inflammation in COPD patients?

Answer 17

• Leukotriene-receptor antagonist
  
  • Montelukast
  • Roflumilast
• Theophyllines
  
  • ​Phyllocontin
  • Uniphyllin

Question 18

What oral medications can be used to treat infection in COPD patients?

Answer 18

• Maintenance ABx
  
  • Azithromycin, Clarithromycin
  • ?Tetracyclines, ?Co-trimoxazole

Question 19

For what infections might a COPD patient commonly require oral ABx therapy?

Answer 19

• Pseudomonas
• Haemophilus influenzae
• COPD-bronchiectasis overlap syndrome
• Chronic bronchial sepsis

Question 20

What can COPD patients be given to manage breathlessness?

Answer 20

• Concurrent palliative care
• Opiates
• Benzodiazepines - oral, sublingual
• Furosemide

Question 21

What are the 4 pillars of management of COPD?

Answer 21

• Pulmonary rehabilitation
• Oxygen therapy
• Palliative care
• Anticipatory care planning (ACP)

Question 22

Describe the prescription of oxygen therapy for COPD patients.

Answer 22

Question 23

What are the common comorbidities of COPD?

Answer 23

• Cardiovascular disease
• GORD
• Micro-aspiration
• Frailty
• Anxiety and depression
  
  • Require psychosocial care

Question 24

What is type 1 respiratory failure?

What are the causes and the treatment options?

Answer 24

• PaO₂ <8kPa
• Causes:
  
  • Infection
  • Airway disease
  • Sepsis
• Treatment:
  
  • High flow O₂ therapy
  • Intubation
  • CPAP

Question 25

What is type 2 respiratory failure?

What are the causes and the treatment options?

Answer 25

• PaO₂ <8kPa AND PaCO₂ >8kPa
• Causes:
  
  • Ventilatory failure
  • Classic decompensated COPD
• Treatment:
  
  • NOT high flow O₂; usually NOT intubation
  • Non-invasive ventilation - BiPAP