Vapor pressure is dependent on _____ and ____ only. _______ does not matter.
temperature and liquid
pressure
Ideal anesthetic properties (6)
- non-flammable and non-explosive at RT
- vaporizable at RT
- stable with long shelf life
- stable with soda lime, plastics, and metals
- environmentally friendly
- cheap and easy to make
Biological properties of ideal anesthetic: (6)
- non irritating, pleasant to inhale
- low blood: gas solubility
- high oil: gas solubility
- min effects on body systems
- no biotransformation
- non-toxic
Isoflurane:
- vapor pressure
- blood:gas
238 mmHg
1.4
Sevoflurane:
- vapor pressure
- blood:gas
160
0.6
Desflurane
vapor pressure
blood:gas
670
0.47
Maximum agent concentration:
vapor pressure/ barometric pressure
The _____ effect increases vaporizer output.
pumping
The _______ effect decreases vaporizer output.
pressurizing
Greater PUMPING effect when: (4)
- low agent in vaporizer
- low FGF
- low dial setting
- high and frequent pressure fluctuations
Greater PRESSURIZING effect with: (3)
- high FGF
- large pressure fluctuations
- low vaporizer settings
Vaporizer equation:
Exam: fraction or percent?
Methods of regulating concentration (2):
concentration calibrated (variable bypass)
measured flow (copper kettle)
Methods of vaporization: (3)
- flow over
- bubble through
- injection
Vaporizer classifications: (3)
ReST
TEMPERATURE COMPENSATION
- mechanical thermocompensation
- computerized thermocompensation
- supplied heat
SPECIFICITY
- agent specific
RESISTANCE
- plenum (out of circuit)
- low resistance (in circuit)
________ _____ are found in mechanical vaporizers.
Bi-metallic strips
Bi-metallic strips:
________ at cooler temperatures which increase flow.
________ at warmer temperatures which decrease flow.
Contract
Expand
Output is relatively constant from ____ to ____ºC.
20 - 35
Purposes of vaporizer manifold: (2)
- where vaporizers mounted on machine
- passageway for FGF
Vaporizer port valves are ____ way valves that are ball and spring loaded. The ball is pressed against its seat until the vaporizer is turned on.
2
Characteristics of a copper kettle:
- ______ flow
- temperature or non temperature compensated?
- single or multiple agents?
- in or out of circuit?
- MEASURED FLOW
- bubble through
- non temperature compensated
- multiple agent
- out of circuit
EXAM
Does all the gas pass through the copper kettle?
no
EXAM
Current vaporizers: (5)
- variable bypass
- measured flow
- flow over temperature compensated
- agent specific
- out of circuit
Desflurane vaporizer type is ______.
Characteristics : (7)
- heat
- temp
- pressure
- specific
- in or out of circuit
Tec 6
- electrically heated
- constant temp
- pressurized
- injection
- thermostatically/electromechanically coupled
- agent specific
- out of circuit
