Test 1 part VII (AM) Flashcards
Adjusts the ratio of vaporizing chamber flow to bypass flow and guarantees a constant vaporizer output over a wide range of temperatures (bimetallic strip or expansion element).
Temperature Compensating Valve
Constructed of metals with high thermal conductivity (copper, bronze) to minimize heat loss
Temperature Compensating Valve
If the temperature of the liquid anesthetic decreases, the temperature element will _____ FGF into the vaporizing chamber to offset the decrease in vapor pressure.
Increase
What is the purpose of the baffles and wicks?
Increase surface area and turbulence to cause 100% saturation.
________ is required to guarantee a consistent vaporizer output!!
Full Saturation
How do variable bypass (AKA flowover, temp-compensated) vaporizers work?
Fresh gas flows through either the vaporizing chamber or the bypass chamber. A small portion of the Fresh gas flows through the vaporizing chamber, over a series of baffles and wicks to get 100% saturation. The fully saturated concentration of flowover gas is diluted with the balance of bypass flow.
What is the splitting ratio?
Carrier flow:bypass flow
some fresh gas encounters the anesthetic
while the rest bypasses the anesthetic liquid.
Flows less than ____ mL or greater than ____ L can reduce vapor output
Less than 200 mL; greater than 15 L
Why does Desflurane need a special vaporizer?
It’s high VP
The Tec 6 is a dual-circuit vaporizer, heated to ____ degrees and pressurized to ___ atm.
39 degrees, 2 atm
How does the Tec 6 Injector (AKA Injector Vaporizer) work?
The fresh gas flow never bypasses or flows over liquid desflurane. There is no contact between them. An appropriate amount of desflurane vapor is injected into the FGF right before the vaporizer outlet.
What are the hazards of vaporizers?
- Incorrect agent administration
- Tipping (increase vaporizer output)
- Overfilling
- Reliance on breath-by-breath gas analysis
- Leaks (esp loose filler cap)-only detected when vaporizer turned on
- Electronic failures
What are the two most common reasons for an increase in inspired CO2?
- The absorbent granules have been exhausted (soda lime)
- The unidirectional valves are faulty
What should you do if inspired CO2 of more than 1-3 mmHg is detected on the capnograph?
Increase FGF to 5-8 L/min (converts the system to semi-open and rebreathing of exhaled gases is minimized).
What should you do if elevated inspired CO2 persists in spite of the higher FGF?
The unidirectional valves are likely to be incompetent.