Peak Expiratory Flow

Question 1

How do you measure the peak expiratory flow rate?

Answer 1

Using a peak flow meter

Question 2

What does a peak flow meter do?

Answer 2

• Measures ability to breathe out air and can monitor the degree of obstruction in airways
• (tells the forced vital capacity and is amount of air that can be forcibly exhaled after a deep breath)

Question 3

What can peak expiratory flow meter be used for?

Answer 3

Used to determine lung functionality, and the severity of conditions such as asthma, emphysema, bronchitis and COPD

Question 4

How does PEFR vary?

Answer 4

• varies with age, gender and fitness levels
• peak flow is normally proportional to height
• it dec slowly with age

Question 5

Why do some people have higher than average peak flow readings?

Answer 5

• little narrowing of airways
• good lung health
• high levels of exercise

Question 6

Why do some people have lower than average peak flow readings?

Answer 6

• respiratory airways may be narrowing
• airways might be inflamed
• may be a sign of asthma/asthma getting worse
• COPD may be developing

Question 7

What does a spirometer consist of?

Answer 7

• chamber filled with oxygen that floats on a tank of water
• a disposable mouthpiece is connected to a tube
• tube is connected to a tank and patient breathes in and out

Question 8

What happens when someone breathes in and out when connected to a spirometer?

Answer 8

Breathing in - removes oxygen from the chamber, so it moves down
Breathing out - pushes carbon dioxide in so the chamber moves up

• movement of chamber up and down is recorded using a datalogger + produces a trace

Question 9

Why is soda lime attached to tube?

Answer 9

To absorb CO2 that is breathed out

Question 10

What affect does the soda lime absorbing CO2 that is breathed out do to the gas levels?

Answer 10

• total volume of gas in spirometer will gradually decrease
• volume of CO2 breathed out is the same as volume of oxygen breathed in
• this means as CO2 is removed, the total decrease equals volume of oxygen used by person
• the trace shows a slope that can be used to measure the volume of oxygen used in a certain time

Question 11

Define breathing rate

Answer 11

• at rest, air moves in and out of ur lungs 12 times a minute
• each breath renews air in ur lungs + expels CO2 in your body
• when you exercise, your breathing becomes quicker and deeper
• this supplies more oxygen + removes more CO2

Question 12

What does exercise do to tidal volume?

Answer 12

• tidal volume inc
• to meet oxygen demands of respiring muscles
• so inc CO2 can be expelled

Question 13

What does oxygen do to muscle contraction?

Answer 13

• more oxygen consumption for more aerobic respiration
• more ATP, more energy for muscle contraction