Lung Function Flashcards
Define tidal volume (Vt)
The amount of air inhaled or exhaled with each breath
Define expiratory reserve volume (ERV)
The volume of air that can be voluntarily expelled after completing a normal, quiet respiratory cycle
Define inspiratory reserve volume (IRV)
The volume of air that can be inhaled above the Tidal volume
Define vital capacity (VC)
Tidal volume plus expiratory and inspiratory reserve volumes
Define residual volume (RV)
Air left in lungs after maximum exhalation
Define total lung capacity (TLC)
Total volume of the lungs = vital capacity + residual volume
What is the normal values for tidal volume?
500 mls for males
500 mls for females
What is the normal values for expiratory reserve volume?
1000 mls for males
700 mls for females
What is the normal values for inspiratory reserve volume?
3300 mls for males
700 mls for females
What is the normal values for residual volume?
1200/6000 ml for males
1100/4200 ml for females
What is the normal values for vital capacity?
4800 mls for males
3100 mls for females
What is the equation for vital capacity?
Tidal volume + inspiratory reserve volume + expiratory reserve volume
What is the normal values for total lung capacity?
6L for Males
4.5 L for females
What is the equation for total lung capacity?
Vital capacity + residual volume
What is respiration rate?
The number of breaths per minute
What is the normal values for respiration rate?
12 to 18 in a normal resting adult
What is eupnea?
Quiet breathing
What is used in eupnea?
The diaphragm and external and internal intercostal muscles
What is hypernea?
Forced breathing
What is used in hypernea?
Accessory muscles are used
What is minute ventilation?
The volume of air brought into the lungs every minute
What is the normal values for minute ventilation?
6L for a 70 kg male
What is the equation for minute ventilation?
Tidal volume x respiration rate
What does ones tidal volume depend on?
It depends on their height
What can peak expiratory flow rate be used for?
For the monitoring and progression of asthma
What is peak flow rate?
The maximum speed of expiration, as measured with a peak flow meter
What is PEFR?
Peak expiratory flow rate
List some obstructive disorders.
Asthma
Chronic obstructive pulmonary disease = chronic bronchitis or emphysema or both together
Cystic fibrosis
Lung cancer/tumours
What are PFTs?
Pulmonary function tests
What are pulmonary function tests used for?
They are used to diagnose and monitor pulmonary diseases
What is FVC?
Forced vital capacity
What if FEV1?
Forced Expiratory Volume after 1second
What three things indicate obstructive disorders?
Normal or slightly low Forced vital capacity
Low Forced Expiratory Volume after 1 second
Low ratio, E.g. 40-50%
List some restrictive disorders.
5
Pulmonary fibrosis
Damage to rib cage
Skeletal disorder e.g. scoliosis
Muscular disorder e.g. muscular dystrophy
Pulmonary edema
What three things indicate restrictive disorders?
Very low FVC
Low FEV1
High or normal ratio e.g 90% (as both are low so ratio can be high)
How do you find the FEV1/FVC ratio?
Put FEV1 over FVC
How do you find FVC from a graph?
Find the point where the graph plateaus and then go across to the y axis to find your answer in Litres
How do you find FEV1 from a graph?
Go to one second on the x axis and go up to your graph, then go across to the y axis to find your answer in Litres
