Anaesthetic Machine

Question 1

What is the function of the anaesthetic machine

Answer 1

• deliver gaseous inhalational anaesthesia
• Provide steady flow of anaesthetic gases to patient
• Allows adjustments to be made to rate of flow according to needs

Question 2

What is the anaesthetic machine composed of?

Answer 2

• Gas cylinders (or pipelines)
• Pressure gauge
• Pressure reducing valve
• Flowmeters
• Vaporisers
• Common gas outlet

Question 3

Why was the PIN system designed for cylinders?

Answer 3

• Ensures correct cylinder is connected and to the correct port

Question 4

What is ‘Piped gas’

Answer 4

when gas is stored outisde of the building and pipelines carry the gases from exterior of the building to connect to anaesthetic machine

Question 5

What is the function of an oxygen generator?

Answer 5

• May generate O2 from room air via pressure sieve

Question 6

What is the function of the pressure gauge?

Answer 6

• Shows the pressure of gas in the cylinder and therefore indicates the remaining content

Question 7

What is the pressure gauge unreliable for? Why? And how do you instead measure this cylinder?

Answer 7

• Unreliable for N2O
• Due to being stored part liquid and part gas
• Instead should be weighed

Question 8

Name the two benefits of the pressure reducing valve?

Answer 8

• Safer
• Reduces pressure of gas coming from cylinder making it easier to control
• Avoids damage to patient respiratory tract

Question 9

Where is the pressure reducing valve located?

Answer 9

between cylinder and other parts of machine

Question 10

What kind of trauma can occur without the pressure reducing valve?

Answer 10

Barotrauma

Question 11

What is the function of flowmeters?

Answer 11

• Show level of gas flow supplied to the patient

- Adjust level of gas flow to the patient

Question 12

When might readings be inaccurate?

Answer 12

• Tube is tilted
• Tube is dirty
• Bobbin or ball read from wrong point

Question 13

Where should the bobbin be read from?

Answer 13

the top

Question 14

Where should the ball be read from

Answer 14

the middle

Question 15

What are vaporisers?

Answer 15

• Liquid volatile agent to be mixed with carrier gas

Question 16

What are the two types of vaporiser and which is more common?

Answer 16

• In-circuit

- Out-of-circuit (more common)

Question 17

Name a circuit that uses in-circuit vaporisers?

Answer 17

• Circle circuit

Question 18

How do out-of-circuit vaporisers work?

Answer 18

Fresh gas flow from the machine vaporises the inhalational agent

Question 19

What are modern ‘tec’ vaporisers also known as?

Answer 19

• Compensated vaporisers

Question 20

Why is the modern tec vaporisers used?

Answer 20

• Allow controlled amounts of volatile agent to be delivered
• Adpated to compensate for the variable factors e.g. temperature of agent

Question 21

What is the common gas outlet?

Answer 21

Where gaseous anaesthetic connects to the patient supply (circuit)

Question 22

Name 3 safety features of the anaesthetic machine?

Answer 22

• Pin-index cylinders
• Pipeline connectors
• Oxygen alarm
• Vaporiser key fillers
• Emergency o2 flush

Question 23

What should you do before using the emergency o2 flush?

Answer 23

• Disconnect patient

Question 24

What is the function of the water canister and when is it used?

Answer 24

• Absorbs carbon dioxide

- Used in re-breathing systems

Question 25

Why is scavenging important? (name 2)

Answer 25

• protect personnel

- Minimises exposure to waste gases

Question 26

What is long term exposure to vaporiser gasses linked to ?

Answer 26

• abortions
• kidney/liver failure
• congenital abonormalities

Question 27

What is short term exposure to vaporiser linked to?

Answer 27

• Fatigue
• Headaches
• Nausea
• Irritability

Question 28

How do you minimise the risk when using vaporisers and the anaesthetic machine? Name 5

Answer 28

• Adequate ventilation of workplace
• Effective scavenging system in place
• Sensible working practices
• Passive scavenging
• Active-passive scavenging
• Activated charcoal
• Active system
• Monitor pollution
• Ensure equipment is in order
• Minimise use of masks