Asthma or COPD lecture

Question 1

What is the relationship between asthma and patient age?

Answer 1

Asthma onset is often associated with childhood - most common in families history of atopy or asthma.
Symptoms increase with exposure to allergen or triggers
Sometimes childhood asthma can resolve.

There is a second peak in asthma diagnosis from 40-49.

1 in 11 children has asthma
1 in 12 adults have asthma.

Question 2

How does age affect the rates of COPD?

Answer 2

COPD risk increases most significantly with smoking risk.
Risk is higher at any age group for smokers than non smokers
Diagnosis tends to increase with age, particularly for smokers - presumed been smoking for longer. And uncommon family history suggests no genetic link
Uncommon to have symptoms before age 35years.

Question 3

How can the symptoms be used to differentiate between asthma and COPD?

Answer 3

Both will present with cough, wheeze and breathlessness.
Porudctive sputum is uncommon in asthma and common in COPD.
Asthma usually intermittent, return to normal between triggers such as exercise.
COPD, chronic and progressive decline with no relief, predictable end point.
Asthma common for symptoms to vary by day to day, common to wake up breathless or wheezing. Both are uncommon in COPD.

Question 4

What are some of the risk factors for COPD?

Answer 4

Main risk factor is smoking
Indoor pollution
Outdoor pollution
Passive smoke exposure
Occupational - e.g brick making
Genetic - A1ATD. (2% of cases)
Low birth weight
Low socioeconomic status
Childhood infection
Asthma

Question 5

What is the genetic link behind COPD?

Answer 5

2% of cases are caused by a alpha 1 antitrypsin deficiency.
A1AT is a protein made in the liver to protect the lungs, inhibits neutrophil elastase activity protecting the lungs from protease induced damage.
Decreased A1AT means the lungs are more vulnerable to damage from cigarettes smoke so asthma is more likely.
Autosomal recessive condition

Question 6

What are the risk factors for asthma?

Answer 6

Family history - inherited genetic and epigenetic changes
Environmental triggers - dust, smoke, pollen.
Obseity - systemic inflammation, increased leptin (inflammatory marker)
Childhood respiratory infections

Question 7

In industrialised countries what tend to be the trigger for asthma?

Answer 7

Isocyanates in paints in varnishes
Cerelea flours/grain dust - bakers lung
Welding fumes
Wood dust
Animal hair and secretion
Aldehydes
Latex proteins
Persulfate salts
Solder flux
Seafood.

Question 8

In developing countries what tends to trigger asthma attacks?

Answer 8

Cleaning agents
Thermal degradation products e.g burning rubber and plastic
Latex proteins
Isocynates
Cereal flours nad grain dust
Agriculture products
Metallic products
Solvent petroleum derivatives
Wood dust.

Question 9

What is the Chest x-ray of an asthmatic like?

Answer 9

Tends to be normal
May be hyperexpanded

Question 10

What is the chest x-ray of a COPD patient like?

Answer 10

Hyperinflation
Loss of heigh and convexity of the hemidiaphragm
Hence are able to see 6 or more anterior or 10 or more posterior ribs above the diaphragm on the midclavicular line.

Question 11

Why is the steroid sensitivity different between asthma and COPD?

Answer 11

Asthma is normally eosinophil dominated
COPD is normally neutrophil dominated.
Eosinophil pathology is more vulnerable to steroids.

Question 12

What are the features of neutrophilic asthma?

Answer 12

Very severe and persistent
Frequent exacerbations
Characterised by fixed airway obstruction
Can be associated with comorbidities such as respiratory infections, obesity, GERD and obstructive sleep apnoea.

Question 13

What are the features of eosinophilic COPD?

Answer 13

Tends to only be in COPD exacerbations and inflammation (30% of cases)
Patients tend to have higher eosinophil levels over time
May indicate co-development of asthma or initial misdiagnosis
As more eosinophils becomes more effectively managed by steroids.

Question 14

How does spirometry indicate COPD?

Answer 14

Obstructive spirometry.
Reduced FEV1/FVC ratio - norm below 0.7 is indicative (may need to be higher in younger patients or lower threshold in older patients)
Larger decrease in FEV1 than FVC but both do decrease due to airflow obstruction
Abnromal lung function - between symptoms

Question 15

How can spirometry be used to diagnose asthma?

Answer 15

Obstructive spirometry
Reduced FEV1/FVC to below 0.7
Bronchodilator reversibility increase in FEV1 of 12% or more or 200ml volume with beta 2 agonist or corticosteroid is positive.
Variable peak expiratory flow of 20% or more can indicate asthma.
FeNO test - elevated FeNO is a sign of inflammation. Below 25ppb is considered normal.

Question 16

What is meant by an ACO phenotype?

Answer 16

Asthma COPD overlap - a type of chronic obstructive airway disease with shared asthma and COPD features.
Tends to be poorly identified, worse outcomes and greater disease burden than patients with COPD or asthma.

Question 17

What is the sliding scale of a ACO phenotype?
Asthma COPD overlap phenotype

Answer 17

Asthma favoured by genetics, IgE, allergens, TH2 cytokines, eosinophils.
COPD favoured by environment and early life inlufnces - emphysema, Th1 cytokines, smoke exposure, neutrophils
Overal tends to shown - airway hyperresponsiveness, bronchodilator responsiveness and mucus hypersecretion

Question 18

What tends to be the graphic of a person with ACO phenotype?

Answer 18

Over 40yrs old
Past or current smoker
Atopy present
GERD
Exercise very limited
Very frequent exacerabtions - more than just COPD alone.

Question 19

What treatment tends to be offered for patients with an ACO phenotype?

Answer 19

First line: ICS +/or LAMA +/or LABA
Smoking cessation
Pulmonary rehabilitation.