1
Q
Definition of VA agent
A
liquid at room temperature
2
Q
What is the vaporizer used today?
A
temperature compensated concentration-calibrated variable bypass vaporizer
3
Q
what is saturated vapor pressure?
A
in a closed container at normal atmosphere and RT a potent VA is in liquid form -> some molecules escape to enter gas/vapor form -> equilibrium established between liquid and vapor phase
4
Q
What concentration of VA do we aim for?
A
MAC, typically administered at 1.2-1.3 MAC
5
Q
What is the splitting ratio?
A
vaporizing chamber flow rate:bypass pathway flow rate
6
Q
What are the issues with simple variable bypass?
A
- high flows result in inadequate vaporization (wiking)
- temperature issues
- accuracy of concentration with mechanical control knobs
7
Q
Why are vaporizers temperature compensated?
A
- heat of vaporization- E required to promote vaporization -> cooling of liquid anesthetic -> slow vaporization
- now temperature compensated so no reduction in output
8
Q
What is the Ohmeda Tec 6 vaporizer?
A
- heats DES to 39 C -> 2 atm
- stable SVP
- fresh/diluent gas separate from vaporing chamber
