TEST TWO Flashcards
(35 cards)
Modern vaporizers are accurate over a wide range of temperatures and fresh gas flows. TRUE/FALSE
TRUE
Measure of the volatility of the liquid anesthetic in the carrier gas
SVP
The amount of calories required to convert 1 g of liquid to vapor without temperature change in the remaining fluid
Heat of vaporization
A substances _________ ______ is the quantity of heat required to raise the temperature of one gram (1 ml) of a substance by one degree C.
Specific heat SH
Factors potentially affecting vaporizer output (4)
FGF
temperature
Carrier gas composition
Ambient pressure
Increasing contact area between gas and liquid in a vaporizer increases efficiency of __________. (Baffles spiral tracks or wicks)
Vaporization
3 characteristics of modern vaporizers include:
Agent specificity (keyed filling port required)
Temperature compensation
Flow-over
Safety feature that only allows one vaporizer on at a time
Vaporizer interlock
The basic operating premise of variable-bypass vaporizers states that FGF enters the vaporizer and splits into carrier gas (much less than ___%) and bypass gas (____%)
Carrier gas <20%
Bypass gas 80%
Depends on the ratio of resistances to their flow (determined by concentration dial)
The “splitting ratio” of the two flows
Output is relatively constant over a wide range of flows. (_____ ml/mon to ___ L/min)
250 ml/min to 15 L/min
Describes the affect on vaporizer output from intermittently fluctuating pressure in the breathing system
“Pumping Effect”
ASTM established standards (1988) that included FGF limits (____ L/min), __________ rotation for concentration increase, concentration __________ of vaporizers, and _________ effects.
FGF limits 15 L/min
Unidirectional rotation
Concentration calibration of vaporizers
Temp/pressure effects
Hazards associated with vaporizers include: (4)
Using the wrong agent
Tipping
Overfilling
Empty vaporizer
Safety features of vaporizers include: (4)
Agent-specific keyed fillers
Secured vaporizers
Interlocks
Counterclockwise rotation of dial for increase in %
Compared to newer vaporizers (tec 6, 7 etc), _________ vaporizers require FGF close to ___ L/m, and are more affected by pumping.
Tec 5; 5 L/m
Desflurane is heated to ______ C. (Above boiling point) as large amounts are vaporized and overpressurized to _____ mmHg.
Heated to 39 degrees C
Overpressurized to 1300 mmHg
Electronic control mechanism in the _________ ________ is in the anesthesia machine
Aladdin cassette
This type of vaporizer CAN be tipped
Aladdin cassettes
These vaporizers may be tipped as long as in the “T” setting
Vapor 2000 vaporizers
If wrong agent is used, discard contents of vaporizer and run ___ liters oxygen flow until no agent detected. (About ____ min)
5 L O2 flow
About 20 min
What are the two factors affecting resistance in the circuit?
Width and length of the tubing
Any breathing circuit creates resistance to gas flow, INCREASES/DECREASES work of breathing such that a spontaneously breathing pt under anesthesia should ALWAYS/SOMETIMES be assisted.
INCREASES work of breathing
Pts should ALWAYS be assisted under anesthesia
What are the advantages of rebreathing?
- Cost reduction
- Increased warmth and humidity of inspired gases
- decrease of OR contamination