Spirometry

Question 1

Spirometry Parameters

Answer 1

FVC - Forced vital capacity. Total volume exhaled
FEV1 - Volume exhaled in 1 second
FEV1/FVC - Forced expiratory ratio. Used to diagnose restrictive or obstructive pathology.

Question 2

Interpretation of Spirometry

Answer 2

Review FEV1/FVC as well as FVC.
- Possible restriction - Normal FEV1/FVC with low FVC
- Obstruction - Low FEV1/FVC, Normal FVC
- Mixed - Low FEV1/FVC, Low FVC

Ratios relating to predicted %
- FEV1/FVC of 0.7 of predicted is normal.
- FEV1 > 0.8 of predicted is normal
- FVC > 0.8 of predicted is normal.

Reversibility - Post 200microg salbutamol
- Increase in FEV1 and/or increase in FVC by 12%

Question 3

Contraindications to Spirometry

Answer 3

Haemoptysis (Possible TB)
Pneumothorax
Unstable Angina
Recent MI
Aneurysms (Thoracic, Cerebral, Abdominal)
Recent Eye surgery
Regular bronchodilators not witheld.