This document summarizes different types of vaporizers used in breathing systems. It discusses plenum vaporizers that are located outside the breathing system and have high resistance, and those located inside the breathing system with low resistance like the Goldman and OMV vaporizers. It also describes temperature compensation methods, potential problems like leaks, and safety features of various vaporizer models including anti-spill mechanisms and pressure relief valves.

1. Vaporizers Dr C. Thorpe

2. Classification Location Inside breathing system Low resistance E.g. Goldman, OMV. Outside Breathing system Plenum vaporizer, high resistance.

3. Plenum vaporizers Tec 2 8 sevo

4. Temperature compensation Vaporization causes cooling Which affects vapour pressure of volatile. 2 methods Bimetallic strip Ether filled bellows Case material characteristics

5. Problems and safety features Anti spill (tec 5) Selectatec system –potential for leaks

6. Problems and safety features Back pressure from minute volume dividers Pressure can contaminate bypass channel. Avoided by Tec 3 – long inlet port into vapour chamber A Downstream flow restrictors B Bypass channel & vapour chamber of equal volume

7. Plenum vaporizers A B 8 sevo

8. Problems and safety features Thymol- need for cleaning and servicing Pressure relief valve Agent specific filling system Colour coding

9. Desflurane Tec 6 FGF outlet a HEAT sump Shut off valve Regulator Control valve Fixed Restrictor Sump 39C 2Bar

10. Desflurane Tec 6 Does not function until at correct temp 5-10 mins warm up required Alarms Back up 9V battery Specific filling port