Anaesthetic Machine Flashcards
What is the function of the anaesthetic machine
- deliver gaseous inhalational anaesthesia
- Provide steady flow of anaesthetic gases to patient
- Allows adjustments to be made to rate of flow according to needs
What is the anaesthetic machine composed of?
- Gas cylinders (or pipelines)
- Pressure gauge
- Pressure reducing valve
- Flowmeters
- Vaporisers
- Common gas outlet
Why was the PIN system designed for cylinders?
- Ensures correct cylinder is connected and to the correct port
What is ‘Piped gas’
when gas is stored outisde of the building and pipelines carry the gases from exterior of the building to connect to anaesthetic machine
What is the function of an oxygen generator?
- May generate O2 from room air via pressure sieve
What is the function of the pressure gauge?
- Shows the pressure of gas in the cylinder and therefore indicates the remaining content
What is the pressure gauge unreliable for? Why? And how do you instead measure this cylinder?
- Unreliable for N2O
- Due to being stored part liquid and part gas
- Instead should be weighed
Name the two benefits of the pressure reducing valve?
- Safer
- Reduces pressure of gas coming from cylinder making it easier to control
- Avoids damage to patient respiratory tract
Where is the pressure reducing valve located?
between cylinder and other parts of machine
What kind of trauma can occur without the pressure reducing valve?
Barotrauma
What is the function of flowmeters?
- Show level of gas flow supplied to the patient
- Adjust level of gas flow to the patient
When might readings be inaccurate?
- Tube is tilted
- Tube is dirty
- Bobbin or ball read from wrong point
Where should the bobbin be read from?
the top
Where should the ball be read from
the middle
What are vaporisers?
- Liquid volatile agent to be mixed with carrier gas
What are the two types of vaporiser and which is more common?
- In-circuit
- Out-of-circuit (more common)
Name a circuit that uses in-circuit vaporisers?
- Circle circuit
How do out-of-circuit vaporisers work?
Fresh gas flow from the machine vaporises the inhalational agent
What are modern ‘tec’ vaporisers also known as?
- Compensated vaporisers
Why is the modern tec vaporisers used?
- Allow controlled amounts of volatile agent to be delivered
- Adpated to compensate for the variable factors e.g. temperature of agent
What is the common gas outlet?
Where gaseous anaesthetic connects to the patient supply (circuit)
Name 3 safety features of the anaesthetic machine?
- Pin-index cylinders
- Pipeline connectors
- Oxygen alarm
- Vaporiser key fillers
- Emergency o2 flush
What should you do before using the emergency o2 flush?
- Disconnect patient
What is the function of the water canister and when is it used?
- Absorbs carbon dioxide
- Used in re-breathing systems
Why is scavenging important? (name 2)
- protect personnel
- Minimises exposure to waste gases
What is long term exposure to vaporiser gasses linked to ?
- abortions
- kidney/liver failure
- congenital abonormalities
What is short term exposure to vaporiser linked to?
- Fatigue
- Headaches
- Nausea
- Irritability
How do you minimise the risk when using vaporisers and the anaesthetic machine? Name 5
- 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
