9.2 and 9.5 Assessment of Pulmonary Function

Question 1

What are the contraindications for assessing pulmonary function

Answer 1

Less then 6 weeks post eye, thoracic or abdominal surgery 
Aneurysms 
Unstable cardiac function 
Haemoptysis of unknown cause 
Pneumothorax 
Diarrhoea 
Suspected PE 
Infectious diseases - TB 
Recent rib fracture

Question 2

What is spirometry?

Answer 2

A measurement of airflow and lung vital capacity during forced expiratory manoeuvre from full inspiration

Question 3

What factors effect flow and volume

Answer 3

Elastic properties of the lung and chest wall
Expiratory muscle strength and effort
airway calibre and resistance to flow in airways

Question 4

what is FEV1

Answer 4

volume expired in teh first second of forced maximal expiration initiated after maximal expiration

Question 5

What is FVC

Answer 5

Maximum volume of air which can be expired with maximal force (after maximal inspiration) during a forced manoeuvre

Question 6

What is FEV1/FVC ratio

Answer 6

FEV1 expressed as a percentage of FVC

Question 7

what is PEF

Answer 7

Maximal expiratory flow achieved during the forced expiratory manoeuvre

Question 8

What is FET

Answer 8

Forced expiratory time -time required to perform the forced expiratory manoeuvre

Question 9

What happens in obstructive lung disorders and whta are some examples

Answer 9

Airflow is reduced as a result of airway narrowing. there is a reduction in maximum expired flows
Bronchitis: airway lumen narrowed by mucous
Asthma: reactive airways caused by airway thickening/inflammation
COPD/emphysema: loss of elastic recoil

Question 10

What happens in restrictive disorders

Answer 10

There is a reduction in FVC

Question 11

How do you assess obstruction in spirometry?

Answer 11

FEV1/FVC ratio to detect obstruction and FEV1 as the severity

Question 12

How do you assess restriction in spirometry

Answer 12

FVC with confirmation by TLC

Question 13

When is bronchodilator reversibility seen?

Answer 13

When there is a 12% of greater improvement in FEV1 and an increase of at least 200mL

Question 14

What are the methods of provocation testing?

Answer 14

Manniotol challenge
Methacholine
Exercise
Eucapnic hyperventilation

Question 15

How does body plethysmography work?

Answer 15

At FRC a shutter is closed and the patient gently inhales and exhales against the closed shutter for 3 seconds. The expansion and decompression of the air in the lungs causes small volume and pressure changes in the lungs and the machine.
FRC is derived from the mouth pressure and box pressure

Question 16

what are the types of restrictive lung diseases?

Answer 16

Intrapulmonary and extra pulmonary

Question 17

What are exampled of intrapulmonary restrictive lung diseases?

Answer 17

Interstitial lung diseases 
Pneumoconioses (asbestosis)
Pulmonary oedema 
Drugs such as amioderone, bleomycin and methotrexate
Sarcoidosis, rheumatoid arthritis
Parenchymal lung tumours 
Lobectomy or pneumonectomy 
Pneumonia

Question 18

What are examples of extrapulmonary restrictive lung disease?

Answer 18

Pleural effusion
Thoracic cage deformity (scoliosis)
Neuromuscular disorders
Obesity and pregnancy

Question 19

What will cause decrease in TlCO (transfer factor for the lung of CO)

Answer 19

anything that:
reduces ability of CO to bind to Hb
reduces ability of CO to cross the membrane
reduces the amount of blood in the pulmonary capillaries

Question 20

What will cause an increase in TlCO

Answer 20

Anything that:
Increases the number of Hb binding sites
increases the amount of blood in pulmonary capillaries