Changes

==Plenum Vapourisers==

==Plenum Vaporisers==

===''Temperature Compensated (TEC) Vapourisers''===

===''Temperature Compensated (TEC) Vaporisers''===

These vapourisers prevent the fall in vapour that may otherwise occur as evapouration and cooling of the liquid. This is achieved by changing the splitting ratio with temperature, so that as temperature falls more gas flows through. TEC vapourisers are used for Isoflurane.

These vaporisers prevent the fall in vapour that may otherwise occur as evaporation and cooling of the liquid. This is achieved by changing the splitting ratio with temperature, so that as temperature falls more gas flows through. TEC vaporisers are used for Isoflurane.

===''Measured Flow Vapourisers''===

===''Measured Flow Vaporisers''===

These vapourisers are used for Desflurane, as it has a very low boiling point and would not stay as a liquid in conventional vapourisers. These vapourises are electrically heated to maintain the agent chamber at a constant temperature allowing the agent to remain liquified.  

These vaporisers are used for Desflurane, as it has a very low boiling point and would not stay as a liquid in conventional vaporisers. These vaporises are electrically heated to maintain the agent chamber at a constant temperature allowing the agent to remain liquified.  

To prevent the incorrect agent being used in the incorrect vapouriser a key-indexed filling system has been designed so that each agent has a specific key that will only fit in the appropriate vapouriser. Sevoflurane and desflurane are sold such that the bottles will only fit into the filler ports on the appropriate vapouriser.  

To prevent the incorrect agent being used in the incorrect vaporiser a key-indexed filling system has been designed so that each agent has a specific key that will only fit in the appropriate vaporiser. Sevoflurane and desflurane are sold such that the bottles will only fit into the filler ports on the appropriate vaporiser.  

Position of vapourisers on the backbar is important, especially if there is more then one vapouriser present. The more volatile anaesthetic agent should be places closer to the flowmeter.

Position of vaporisers on the backbar is important, especially if there is more then one vaporiser present. The more volatile anaesthetic agent should be places closer to the flowmeter.

 

==Vapouriser In-Circuit Machines==

==Vapouriser In-Circuit Machines==

Komesaroff and Stephens' anaesthetic machines are both examples of a vapouriser in-circuit machine. They are essentially a circle breathing system with one or more draw-over vapourisers within the circuit. They are economical due to very low required gas flows but disadvantages include possible overdosing and performance of vapouriser may be contaminated by water vapour.

Komesaroff and Stephens' anaesthetic machines are both examples of a vapouriser in-circuit machine. They are essentially a circle breathing system with one or more draw-over vapourisers within the circuit. They are economical due to very low required gas flows but disadvantages include possible overdosing and performance of vapouriser may be contaminated by water vapour.