What does FEV stand for and what is its definition?
- Forced Expiratory Volume in one second
- The amount of air expeled In one second when you try and blow out as hard as you can or…
- FEV1 - Forced Expiratory Volume in 1 second:
–VOLUME of gas forcibly exhaled from full inspiration in 1 second
What does FVC stand for and what is it?
- FVC = Forced Vital Capacity
- FVC - Forced Vital Capacity:
–Total VOLUME of gas forcibly exhaled from full inspiration
What does PEFR stand for and what is it?
- PEFR = Peak Expiratory Flow Rate
- PEFR–The maximum flow RATE generated during a forced expiration from full inspiration.
Not including obstructive airway disease, List THREE factors which affect the peak expiratory flow readings ?
- Age
- Sex
- Height
- Others = Race, smoking history, respiratory muscle strength and effort, time of day, effort made by patient in performing the test
What are 2 reasons to perform a PEFR on a patient?
- Screening for airflow obstruction
- Monitoring of asthma and response to treatment
- Aid assessment of acute asthma attack
What are the FEV1 and FEV1/FVC criteria for diagnosing Obstructive disease?
- FEV1: <80% predicted
- FEV1/FVC: < 0.7 (70%)
- ↓ FEV1 AND FEV1/FVC ratio
What is the gradation of severity of airflow obstruction for COPD? (Mild, moderate, sever, life threatening)
- Mild → FEV1% of predicted capacity = >80%
- Moderate → FEV1% of predicted capacity = 50-79%
- Severe → FEV1% of predicted capacity = 30-49%
- Very severe → FEV1% of predicted capacity = <30%
What are the current British Thoracic Society PEFR percentages to aid the classification of patients with moderate, severe and life threatening acute asthma attacks?
PEFR (% best or predicted)
- Moderate → 50-75%
- Severe → 33 - 50%
- Life threatening → < 33%
At what ages are lung function tests unreliable (i.e. PEF and spirometry)?
<5yrs old
Name 2 pulmonary restrictive lung disorders?
- Pulmonary fibrosis
- Pneumoconiosis
- Asbestosis
- Pulmonary oedema
- Parenchymal tumours
- Lobectomy or pneumonectomy
Name 2 extra pulmonary restrictive lung diseases?
- Chest wall deformities and Kyphosis
- Obesity
- Pregnancy
- Neuromuscular disorders
- Rheumatoid arthritis
Name 2 obstructive lung diseases?
- Asthma
- COPD
- Bronchiectasis
- Cystic fibrosis
- Lung cancer
- Post-tuberculosis
- Obliterative Bronchioloitis
What would happen to a patients FEV1/FVC in an obstructive disease, and in a restrictive disease?
- FEV1/FVC in Obstructive → Reduced
- FEV1/FVC in Restrictive → Normal or increased
What would happen to a patients FVC in an obstructive disease, and in a restrictive disease?
- FVC in Obstructive → normal or reduced
- FVC in restrictive → Decrease
What would happen to a patients FEV1 in an obstructive disease, and in a restrictive disease?
- FEV1 in restrictive → Reduced or normal
- FEV1 in obstructive → Reduced
What do the lines on a graph for an obstructive restrictive and normal exhilation over time look like?
What are the FEV1, FVC and FEV1/FVC criteria for diagnosing restrictive disease?
- FEV1: Normal (>80%) or mildly ↓
- FVC: <80% predicted
- FEV1/FVC: > 0.7 (70%)
What are 3 clinical features that differentiate between COPD and Asthma?
- Smoking → almost all COPD smoke, variable in Asthma
- Age → COPD > 35yrs, asthma can start in childhood
- Chronic productive cough → Cough is common in COPD and is variable in asthma
- Breathlessness → Chronic and progressive in COPD, variable in asthma
How many PEF (peak expiratory flow) and spirometry’s should you do in a session with a patient?
3 of each
