Airflow Limitation

Question 1

Definition

Answer 1

an abnormal resistance to air flow in the lungs, most commonly with expiration

Question 2

Increasing and Decreasing factors of airflow

Answer 2

INCREASES AIRFLOW

• increased lung volumes
• bronchodilator medications

DECREASES AIRFLOW

• chronic bronchitis
• asthma
• emphysema
• inhaled irritants
• tracheal obstruction

Question 3

Causes

Answer 3

obstruction in the airway 
changes in the airway wall 
- smooth muscle contraction
- inflammation 
- thickening
- hypertrophy of mucous glands and increased mucous production 

changes outside the airway wall

• loss of radial traction due to decreased elastic recoil
• compression

Question 4

Clinical Significance

Answer 4

Unable to rid lungs of air = hyperinflation
Reduced effectiveness of forced expiratory manouevres to clear the airways of secretions
hyperinflation means reduced reserve volumes = reduces tolerance of exercise

Question 5

Dynamic Hyperinflation

Answer 5

Occurs during increased minute ventilation (exercise, exertive activities)
need to be mindful when doing exercises with patients, don’t want to worsen hyperinflation

Question 6

Clinical Features - Subjective

Answer 6

chest tightness
wheeze
breathlessness
reduced exercise tolerance 
difficulty clearing secretions 
* not definitive

Question 7

Clinical Features - Objective

Answer 7

increased work of breathing
pursed lip breathing
hyperinflation - barrel chest
abnormal PFTs - GOLD STANDARD
pattern of breathing - reduced chest expansion
auscultation - hear expiratory wheeze, reduced breath sounds
indrawing of lower ribs

Question 8

Spirometry Interpretation

Answer 8

compare numbers and curve to normative values for their age, gender and height
FEV1/FVC ratio -
- will be reduced in obstructive diseases <80%
- will be preserve in restrictive diseases, however both values will decrease proportionately

Look at values pre and post bronchodilator - do they improve after? - indicative of asthma

Question 9

Effects of disease on lung volumes

Answer 9

Obstructive

• FRC and TLC increases due to increased RV
• not functional RV, just means more air left in the lungs
• reduces the ERV and inspiratory volumes
• unable to generate adequate expiratory flow

Restrictive
- all volumes are reduced

Question 10

Physio Management

Answer 10

not much - usually irreversible

Education - mechanisms, self-management, pursed lip breathing, dyspnoea relief positions