Spirometry practical Flashcards
what is spirometry
method of assessing lung function by measuring the specific lung volumes that the patient can expel form the lungs
why perform spirometry
measure lung function to help make a definitive diagnosis
confirm presence/absence of airway obstruction
assess severity of airflow obstruction in COPD and asthma
detect airflow obstruction in smokers who may have few or no symptoms
monitor disease progression
assess response to therapy
perform pre-operative assessment
additional uses of spirometry
make a diagnosis and assess severity in a range of other respiratory conditions
distinguish between obstruction and restriction as causes of breathlessness
screen workforces in occupational environments
perform pre-employment screening in certain professions
inspiratory reserve volume
the amount of air a person can inhale forcefully after normal tidal volume inspiration
vital capacity
the total amount of air exhaled after maximal inhalation
inspiratory capacity
The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration
tidal volume
the amount of air that moves in or out of the lungs with each respiratory cycle
expiratory reserve volume
The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration.
total lung capacity
the volume of air in the lungs upon the maximum effort of inspiration
residual volume
the amount of air that remains in a person’s lungs after fully exhalin
functional residual capacity
the volume remaining in the lungs after a normal, passive exhalation
diseases associated with airflow obstruction
COPD such as chronic bronchitis and/or emphysema
asthma
cystic fibrosis
post-tuberculosis
lung cancer
FEV1
4L
FVC
5L
FEV1/FVC
0.8
obstructive FEV1,FVC and FEV1/FVC
1.8L
3.2L
0.56
pulmonary diseases associated with a restrictive defect
fibrotic lung diseases
pneumoconiosis
pulmonary oedema
parenchymal lung tumours
extra pulmonary diseases associated with a restrictive defect
thoracic cage deformity
obesity
pregnancy
neuromuscular disorders
restrictive diseases lung volumes
all lung volumes reduced
reduced FVC and FEV1
FVC reduced more than FEV1
so ratio is normal to high, >0.8
spirometry restrictive disease
FEV1= 1.9L
FVC= 2L
FEV1/FVC= 0.95
withholding medications before performing spirometry
short acting B2 agonists for 6 hours
long acting B2 agonists for 12 hours
what else should be withheld before spirometry
caffeine and cigarette smoking for 30 minutes
