Gas systems and Vaporizers Flashcards
Thermal conductivity
a measure of speed with which heat flow through a substance
*higher thermal conductivity, the better the substance conducts heat
PISS for Oxygen
2-5
Isoflurane (20°C)
240 mmHg
Critical temp of O2
- 118.6°C
- bc ambient/room temp (20C) is above oxygens CT, it CANNOT be stored as liquid, no matter how much pressure we apply.
- HOWEVER, the main supply of oxygen in a hospital is in liquid oxygen stores. The containers are insulated from the outside and the temp is kept at -160C.
- ie: ambient temp is below O2’s CT, so if you apply enough pressure, you can make it a liquid.
Enflurane Vapor pressure (20°C)
172 mmHg
Changes in altitude
Increase altitude, decrease barometric pressure
decrease altitude, increase barometric pressure
Gas/tank color blue
Nitrous oxide
Latent heat of vaporization
Number of calories required to change one gram of liquid into vapor without a temperature change
- the energy comes from the liquid itself or an outside source
Halothane (20°C)
244 mmHg
Changes in altitude
Increased altitude, decreased barometric pressure, increased concentration of inhaled gas put out through vaporizer
Safe handling of cylinders
- never stand cylinder upright without support
- never leave empty cylinders on the machine
- lever leave the plastic tape on the port while installing the cylinder
- never rely only on the cylinder’s color for id of contents
- never oil valves
- “crack” the valve first to remove particles of dust or other crap.
- valve should always be fully open when a cylinder is in use
gas/tank color yellow
air
Vaporization
Conversion of a liquid to a gas
molecules combard the surface of the liquid and the walls of the contaner creating a vapor pressure
Dependent on:
- vapor pressure
- temperature
- amount of carrier gas used
Cylinder tag
Gas/tank color brown
Helium
Nitrous oxide:
liters
pressure
1590 L
750 psi
copper kettle
- measured flow, bubble through
- dedicated flowmeter for kettle
- gas comes up through central tube inside vaporizer to the loving cup
- flow of gas is then directed down toward the liquid (bubble through)
- highly concentrated vapor then exits the vaporizer and is diluted into the fresh gas flow