Spirometry

Question 1

When is spirometry indicated for use?

Answer 1

• Diagnose or manage asthma
• Detect respiratory disease in patients presenting with symptoms of breathlessness
• Distinguish respiratory from cardiac disease as the cause
• Measure bronchial responsiveness in patients suspected of having asthma
• Diagnose + differentiate between obstructive lung disease + restrictive lung disease
• Follow natural history of disease in respiratory conditions
• Assess of impairment from occupational asthma
• Conduct pre-operative risk assessment before anaesthesia or cardiothoracic surgery
• Measure response to treatment of conditions which spirometry detects (i.e.: bronchodilators)
• Diagnose the vocal cord dysfunction

Question 2

What are contraindication of spirometry (when should it not be performed)?

Answer 2

• Haemoptysis of unknown origin
• Pneumothorax
• Unstable cardiovascular status (angina, recent myocardial infarction, etc.)
• Thoracic, abdominal, or cerebral aneurysms
• Cataracts or recent eye surgery
• Recent thoracic or abdominal surgery
• Nausea, vomiting, or acute illness
• Recent or current viral infection
• Undiagnosed hypertension

Question 3

What is Spirometry?

Answer 3

A method of assessing lung function by measuring the volume of air that the patient can expel from the lungs after a maximal inspiration, & how fast they can expel it

Question 4

Describe the procedure of Spirometry.

Answer 4

• Patient asked to take the deepest breath possible, and then exhale into the sensor as hard + long as possible
• During test: use a soft nose clip (prevent air escaping)

Question 5

What are the limitations of Spirometry?

Answer 5

• Highly dependent on patient co-operation & effort (normally needed to repeat 3x for reproducibility)
• Only children old enough/ people able to comprehend & follow instructions (need patient co-operation)
• No unconscious/sedated patients
• Can’t always be used as a diagnostic tool, better at monitoring for sudden decrease in FEV1
  (e.g.: asthma may be normal apart from during an attack)

Question 6

What is an Incentive Spirometry device?

Answer 6

A device which provides visual feedback on inspiratory effort and volume

Question 7

What must be encouraged when using incentive spirometer?

Answer 7

Diaphragmatic excursion

Question 8

What must the patient do when using an incentive spirometer?

Answer 8

The patient should take a slow deep breath in watching the indicator and aiming to achieve a set target

Question 9

Why would spirometry be performed?

Answer 9

• At diagnosis
• To reconsider the diagnosis, for people who show an exceptionally good response to treatment
• To monitor disease progression

Question 10

What parameters are most commonly measured in spirometry?

Answer 10

• Vital capacity (VC)
• Forced vital capacity (FVC)
• Forced expiratory volume (FEV) – at timed intervals of 0.5, 1.0 (FEV1), 2.0, and 3.0 seconds
• Results usually given in both raw data (litres, litres per second) and percent predicted