What are the features of spirometry?
quick non-invasive diagnostic test for age 5+ exhales + inhales into spirometer exhales fast + long as possible from full inspiration measure exhaled air v in L FEV1, FVC, FEV1/FVC % measured
Why do spirometry?
aids in diagnosis of obstructive + restrictive lung disorders
monitors severity
monitors progression
assesses responses to medication/interventions
pre operative assessment
prognosis
Describe history
family, medical, medication, 🚬, symptoms, occupation
What are the diff clinical examinations?
respiratory rate, listen to chest/breath sounds, observation, cyanosis, clubbing, BMI
What are the diff diagnostic tests?
lung function, pulse oximetry, cardiac, blood, imaging
How do you perform spirometry?
- determine height, age, gender
- seated wear nose clippers
- blow into spirometer
- blow fast + long as possible
- 3 measurements recorded (guidlelines ATS/ERS + ARTP/BTS)
- measures exhaled air v
- volitional
- repeated after bronchodilator to see improvement
Why measure FVC?
indication of lung size in L
to calculate FEV1/FVC ratio
Why measure FEV1?
forced expiratory volume in 1 min in L
to calculate FEV1/FVC ratio
What factors affect spirometry values?
age, gender, height
What are common causes of airway obstruction?
COPD : emphysema, bronchitis
asthma
cystic fibrosis
What’s the affect of airway obstruction on spirometry values?
↓FEV1/FVC <70%
↓FEV1
normal FVC
Why do you need high quality measurements?
so diagnostic tests performed correctly
facilitates accurate results
so correct diagnosis/management - medication/therapy, surgery, occupation
How do you get high quality measurements?
performed by skilled trained operators - clinical physiologists
equipment calibrated
infection control
test contraindications
