Equipment Flashcards
Charles Law
Heat (Temp) goes up, Volume goes up.
Gay-Lussacs
Heat (temp) goes up, pressure goes up!
What is the only gas law not effected by temperature?
Boyle’s law
What is temperature measured in?
Kelvin equation is (K = Degree Celsius + 273)
How to convert F to C?
C = F -32/1.8
Solubility info for DES
BG: 0.42 MAC 6.3 Vapor Pressure 660
Solubility info for SEVO
BG: 0.60 MAC 1.8 Vapor Pressure 185
Solubility info for ISO
BG: 1.4 MAC: 1.1 Vapor Pressure: 250
Boyles Law
Pressure goes up, Volume goes down (inverse relationship) Think of bagging Susan boyle…
Oxygen cylinder info… What law?
Full cylinder = 660 L (volume) 2000 psi (pressure) Correlates linearly Boyles law
O2 cylinder should be changed when?
Nitrous oxide cylinder info What law?
95-90 % liquid Critical temp is 36.5 degrees c… Pressure in tank does not correlate until all liquid is consumed, same with boyles law. Full = 1590 L Pressure = 750psi When pressure drops below 745, change it out. Is almost out
What 5 places does oxygen flow to on machine?
Flush valve Oxygen supply fail safe alarm Fail-safe valve Flow meters Pneumatically powered devices (vent)
Nitrous only supply flow goes through what?
Fail-safe valve, cannot flow without assistance of o2 pressure.
Bourden gauge principle… Info on gauge itself…
Think of the party blow up kazoo thing… Higher pressure required to open the device the farther it goes. bends back and forth, can become fatigued over time and break. (Heavy metal case and plate glass help provide safety measures in the event of breakage)
Fail-safe valve What does do?
Is the o2 pressure cutoff valve. If psi drops below 25, it stops the flow of all gases. (Does NOT prevent delivery of hypoxic mixture technically)
Flow meters…
Tapered glass tubes that are larger at the top, this allows for constant pressure with variable flow.
High flow rates…. What kind of flow, and what is the major flow rate factor?
Turbulent flow (1-15 ml). Density is the major factor. Co2 and Nitrous have similar densities
Low flow rates… What type of flow? What is major flow factor?
Laminar flow (0-1 L) Viscosity is major factor (O2 and Helium have similar viscosities)
Oxygen flush valve rate(volume)? Psi (pressure)
40-60 psi 30-70 L/min (Bypasses on/off switch as well)
Common gas outlet size? Has a check valve that does what?
15mm. Prevents retrograde gas flow
Vaporizers… What system? What is the significance of this system?
Variable bypass system. This delivers a constant FRACTION … Allows change in flow rates without a change in concentration. See picture in cc
What law does vaporizer output regulation follow?
Dalton’s law
How many ccs of gas for every cc of liquid?
200
How long will sevo last 100 cc when given at 3L/min at 2%?
333 minutes
What volatile agent does NOT utilize a variable bypass method?
Des Vapor pressure around 690 makes this impossible Des vaporizer heats it to 39 C… This increases vapor pressure to about 1500…. Then pressure sensors determine fgf, then output is calculated.
Co2 absorber… Can be what 2 substances?
Amsorb or sodalime
Chemical reaction to eliminate co2 is what (absorber)?
CO2+ Ca(OH)2. -> CaCO3 + H2O Sodalime uses NaOH or KOH as catalyst Exothermic rx in all 3 phases (liquid, gas, and solid)
CO2 absorber …. 1000 gm canister can absorb how much CO2? Is what percent airspace? What indicates exhaustion?
200 L of CO2 50% airspace, 50% absorbent Ethyl violet indicates exhaustion
What do unidirectional valves do?
Prevent rebreathing of CO2. (are disk valves)
Reservoir bag highlights…
Buffers high insp. and exhaled gas flows, Shock buffer, Means of delivering positive pressure **volume should EXCEED inspiratory capacity**
Where does deadspace end?
At the Y piece of the circuit
What is single most important factor in reducing anesthetic air pollution?
Air turnover (10 x hr or more required)
Vent Class: Volume affected by leak?
delivers fixed volume If there is a leak, less volume is delivered, so it IS affected by leak
Vent class: Pressure affected by leak?
delivers a fixed amount of pressure is NOT affected by leak
Vent class: Jet PSI? TV obtained?
From narrow cath in trachea Oxygen PSI is 25-30 TV 400-700 ish
High frequency ventilation - What is the major difference?
Gas transport by DIFFUSION rather than convection
A good analogy for a leak….?
Think of it as a disconnect, still only delivers a set volume
Inspiration… where can gas go?
All valves are off, can’t get out.
What is fresh gas flow coupling?
When fresh gas flows ass to the tidal volume (vent doesn’t see this, so actual volume delivered can be much higher)…
What are the two types of capnography?
Side stream (sample brought to machine).. most commonly use Main stream (analyzer positioned in gas flow)
How does capnography work? (what law?)
infrared light is STRONGLY absorbed by CO2, Beer-Lambert law - mass spectrometry, chemical indicators
How exactly does the beer-lambert law work?
think of a giant glass of milk with one person on one side and one person on the otherside with a flashlight. Shinging through, can’t see the light at first (means lots of milk), but the more water you fill it with, (as the milk spills out and becomes less concentrated) you start to see a little light… so on and so forth…. think of the milf as CO2, if it can’t see the infared light, there’s ALOT of CO2.
What is single most important factor in reducing anesthetic air pollution?
Air turnover (10 x hr or more required)
Vent Class: Volume affected by leak?
delivers fixed volume If there is a leak, less volume is delivered, so it IS affected by leak
Vent class: Pressure affected by leak?
delivers a fixed amount of pressure is NOT affected by leak
Vent class: Jet PSI? TV obtained?
From narrow cath in trachea Oxygen PSI is 25-30 TV 400-700 ish
High frequency ventilation - What is the major difference?
Gas transport by DIFFUSION rather than convection
A good analogy for a leak….?
Think of it as a disconnect, still only delivers a set volume
Inspiration… where can gas go?
All valves are off, can’t get out.
What is fresh gas flow coupling?
When fresh gas flows ass to the tidal volume (vent doesn’t see this, so actual volume delivered can be much higher)…
What are the two types of capnography?
Side stream (sample brought to machine).. most commonly use Main stream (analyzer positioned in gas flow)
How does capnography work? (what law?)
infrared light is STRONGLY absorbed by CO2, Beer-Lambert law - mass spectrometry, chemical indicators
How exactly does the beer-lambert law work?
think of a giant glass of milk with one person on one side and one person on the otherside with a flashlight. Shinging through, can’t see the light at first (means lots of milk), but the more water you fill it with, (as the milk spills out and becomes less concentrated) you start to see a little light… so on and so forth…. think of the milf as CO2, if it can’t see the infared light, there’s ALOT of CO2.
What happens during phase 1?
Fresh gas flows rushes past sampling line, C02 concentration almost drops to 0, dead space gas at end of phase 1.
What happens during phase II?
Called Expiratory upstroke…
Exiting gas contains CO2 (causes rapid upstroke), an obstruction here may produce a decrease in the overall slope
