Anesthesia Delivery System Part I Flashcards
Which breathing circuit is best for CONTROLLED VENTILATION?
A. Mapleson A
B. Mapleson C
C. Mapleson D
Mapleson D
Components of CIRCLE SYSTEM:
FLURRYS
Fresh gas entry
Low resistance tubing
Unidirectional Valves
Reservoir Bag
Relief Valve
Y-piece
Soda Lime
What law governs the concept of Second Gas effect?
A. Graham’s law
B. Henry’s law
C. Hagen Poiseuille’s Law
GRAHAM’S LAW
The rate of diffusion is inversely proportional to the square root of its molecular weight.
Undersized ETT causes tremdous decrease in flow of gases. This is due to what law?
A. Graham’s law
B. Henry’s law
C. Hagen Poiseuille’s Law
D. Dalton’s law
HAGEN POISEUILLE’S LAW
What is the average velocity of sound in soft tissue?
A. 1,540 m/s
B. 154 m/s
C. 15,400 m/s
1,540 m/s
Pressure from common gas outlet when oxygen flush valve delivers flow:
A. Intermediate pressure
B. low pressure
Intermediate Pressure
Maam Tata accidentally filled the sevo vaporizer with iso, what would happen?
A. Underdose
B. Overdose
C. No changes
OVERDOSE (Vapor Pressure of ISO is higher than SEVO)
One important property of vapor pressure is that as long as any liquid remains in the container, the vapor pressure is independent of the volume of that liquid.
This is what prevents putting the wrong gas cylinder on the wrong hanger yoke:
A. PISS
B. DISS
C. Fail-safe
PISS (Pin Index Safety System)
What is the RATE OF OXYGEN delivery from oxygen flush valve?
A. 35-75 L/min
B. 15 - 35 L/min
35-75L/min
A full air cylinder contains how many liters?
A. 625L
B. 350L
C. 1590L
625L
Which inhaled anesthetics use variable bypass vaporizers?
HISE
Halothane
Isoflurane
Sevoflurane
Enflurane
PSI in full air cylinder
A. 1800 mmHg
B. 690 mmHg
1800
How many liters of oxygen are in a full cylinder?
A. 625 L
B. 315 L
C. 500 L
625L
This Volatile gas is heated to 39 degrees C and pressurized to TWO atmospheres:
A. Desflurane
B. Halothane
C. Isoflurane
Desflurane
(Desflurane Tech 6 Vaporizer)
What is the PSI of full cylinder of carbon dioxide?
A. 838 PSi
B. 8,000 PSi
C. 383 PSi
838 PSi
This prevents transfer of gas from the cylinder with higher pressure to the cylinder with lower pressure:
A. Check valve
B. DISS
C. PISS
D. Oxygen analyzer
CHECK VALVE between cylinders that are double yoked
What are the components included in intermediate pressure?
INTERMEDIATE PRESSURE SYSTEM:
pressure gauges from pipeline
DISS
second stage regulator
flow control valve of manifold
oxygen pressure “fail safe” shut off valve
flush valve
What is the only valves which reduce pressure in the anesthesia work station?
A. flow control valve of manifold
B. “fail safe” shut off valve
C. flush valve
D. Diaphragm valve
Diaphragm Valve
Which property of Oxygen is detected by the fail-safe device?
PRESSURE
Factors that can artificially lower SpO2:
- dyes (ie methylene blue, indocyanine
- Blue nail polish
- Shiver/motion artifact
- Ambient light
- malpositioned sensor
- low perfusion
This is the point where gas prepared within the machine enters the breathing circuit?
A. flowmeter
B. common gas outlet
C. check valves
B. common gas outlet
Every patient ventilated with an ascending bellows anesthesia ventilator receives approximately ___ cm H2O of positive end-expiratory pressure (PEEP):
A. 10 cmH20
B. 2.5 - 3 cmH20
C. 5 cmH20
2.5 - 3 cmH20
TRUE or FALSE
N2O is a vapor and not a gas, therefore, it
does not obey Boyle’s law
TRUE
- Because N2O is a vapor and not a gas, it
does not obey Boyle’s law and the volume of nitrous oxide remaining in the tank cannot be calculated from the tank pressure gauge.
The ______ is designed to ensure that only an N2O tank may hang in an N2O hanger yoke.
A. DISS
B. PISS
PISS
TRUE or FALSE
The ‘fail-safe’ valve prevents administration of a hypoxic mixture.
TRUE
An oxygen failure cutoff valve is present in the gas line supplying each of the flowmeters except oxygen.
Controlled by oxygen supply pressure, the valve shuts off (or proportionally decreases) the supply pressure of all other gases (nitrous oxide, and in some machines air) as the oxygen supply pressure
decreases.
Contemporary potent inhaled volatile anesthetics exist in the liquid state at temperatures below ___
A. 20C
B. 10C
C. 30C
20C
When a volatile liquid is in a closed container,
molecules escape from the liquid phase into the vapor phase until the number of molecules in the vapor phase is constant and in equilibrium with the liquid phase.
- Vapor pressure is independent of atmospheric pressure and is dependent only on the temperature and physical characteristics of the liquid.
This is defined as that temperature at which the
vapor pressure equals atmospheric pressure
A. Critical temperature
B. Boiling point
B. Boiling point
This is the amount of energy that is consumed by a given liquid as it is converted to a vapor:
A. latent heat of vaporization
B. critical temperature
C. boiling point
A. latent heat of vaporization
The amount of energy that is consumed by a given liquid as it is converted to a vapor is referred to as the latent heat of vaporization.
It is more precisely defined as the number of calories required to change 1 g of liquid into vapor without a temperature change.
____ is the number of calories required to increase the temperature of 1 g of a substance (a solid, liquid, or gas) by 1°C.
A. latent heat of vaporization
B. critical temperature
C. boiling point
D. specific heat
D. specific heat
The concept of specific heat is important to the design, operation, and construction of vaporizers because it is applicable in two ways.
First, the specific heat value for an inhaled anesthetic is important because it indicates
how much heat must be supplied to the liquid to maintain a constant temperature when heat is being lost during vaporization
Second, manufacturers select vaporizer component materials that have a high specific heat to minimize temperature changes associated with vaporization.
When two gases, one of high and another of low critical temperature are mixed in a container, the critical temperature of the gas with a high critical temperature will decrease to a lower level(pseudo critical temperature)and the mixture will remain as a gas above this pseudo critical temperature.
Poynting effect
TRUE or FALSE
The saturated vapor pressure (SVP) of a potent volatile anesthetic depends on the ambient temperature
TRUE
For example, at 20°C the SVP of isoflurane is 238
mmHg, whereas at 35°C the SVP is almost double, at 450 mmHg.
Variable bypass vaporizers incorporate a mechanism to compensate for variations in
ambient temperature.
If a vaporizer has been tipped, it should be withdrawn from clinical use until it has been purged for ____ using a high FGF rate from the machine’s flowmeters.
A. 20 - 30 minutes
B. 5 - 10 minutes
C. 30 minutes - 1 hour
A. 20 - 30 minutes
in the case of Tec 6:
The design of the GE Tec 6 and the Aladin cassette vaporizer systems has essentially eliminated the dangers of tipping.
What is the most common cause of vaporizer leak?
Vaporizer leaks do occur and can potentially result in patient awareness during anesthesia or in contamination of the operating room environment.
A loose filler cap is the most common source of vaporizer leaks.
TRUE or FALSE
It is imperative that only nonferrous, MRI-compatible equipment be used.
NON-FERROUS vaporizer can be used in an MRI suite.
What is the boiling point of DESFLURANE?
A. 22.8 C
B. 20 C
C. 28 C
A. 22.8 C
The vapor pressure of desflurane is three to four times that of other contemporary inhaled anesthetics, and it boils at 22.8°C which is
slightly above normal room temperature
TRUE or FALSE
Misfilling Desflurane with contemporary vaporizer would result to hypoxic gas mixture.
TRUE
Because desflurane’s SVP at room temperature is near 1 atm, misfilling contemporary vaporizers with desflurane could theoretically result in both
desflurane overdose and creation of a hypoxic gas mixture
This safety feature cuts off N2O if the O2 supply fails?
A. DISS
B. PISS
C. Fail-safe valve
C. Fail-safe valve
Which of the following flowmeters is situated nearest to the gas outlet?
A. Nitrous oxide
B. Oxygen
C. Air
D. None of the above
B. Oxygen
Variable bypass vaporizers should be located:
A. Between the common gas outlet (upstream) and the flowmeters (downstream)
B. Between the flowmeters (upstream) and the common gas outlet (downstream)
C. Between the gas pipeline and the flowmeters
D. Inside the circle system
B. Between the flowmeters (upstream) and the common gas outlet (downstream)
TRUE or FALSE
The LPC leak test checks the integrity of the anesthesia machine from the flow control valves to the common gas outlet
TRUE
LPC = leak test from FLOW CONTROL VALVE to CGO(common gas outlet)
It evaluates the portion of the machine that is downstream from all safety devices except the oxygen analyzer.
As per ASA recommendation, it is mandatory to perform the appropriate low-pressure system leak test:
A. every day
B. every 2 days
C. once a week
D. every 12 hours
A. every day
It is the only machine safety device that continually evaluates the integrity of the LPC:
A. oxygen analyzer
B. DISS
C. PISS
D. fail-safe device
A. oxygen analyzer
Other machine safety devices, such as the oxygen
supply pressure failure cutoff (“fail-safe”) valve, the oxygen supply pressure failure alarm, and the N2O/O2 proportioning system, are all upstream from the flow control valves.
The oxygen analyzer is the ONLY monitor that detects problems downstream from the flow control valves.
What is “Plan B” in the standard ASA pre-anesthesia checkout procedure?
PLAN B means:
The availability of two critical items to include in the checkout of the anesthesia workstation. These are the functionally tested SIRB and a full auxiliary tank of oxygen that should be readily available.
This test is performed to evaluate the integrity of the breathing system from the common gas outlet to Y-piece:
A. LPC test
B. oxygen analyzer test
C. circle system test
The circle system tests evaluate the integrity of the circle breathing system, which spans from the
machine common gas outlet to the Y-piece.
What is the most common identified medical-gas delivery system malfunctions inside the OR?
A. Breathing circuit malfunction
B. Vaporizer leaks
C. Ventilator malfunction
D. Gas tanks or gas lines leaks
BREATHING CIRCUIT malfunction
As per BARASH, authors identified the most common malfunctions in the breathing circuit (39%), followed by vaporizers (21%), ventilators (17%), gas tanks or gas
lines (11%), and the anesthesia machine itself (7%).
NIOSH recommended maximum exposure for Halogenated agent ALONE is:
A. 2 ppm
B. 25 ppm
C. 20 ppm
A. 2 ppm
- The NIOSH recommendations have never promulgated into law and therefore are not
enforceable.
Which of the following DOES NOT significantly contribute to the operating room atmosphere contamination?
A. failure to turn off gas flow control
B. poorly fitting masks
C. flushing the circuit
D. filling anesthetic vaporizers
E. use of cuffed tracheal tubes
E. use of cuffed tracheal tubes - DOES not contribute.
- Uncuffed tracheal tubes CONTRIBUTES to the contamination.
The two major causes of waste gas contamination in the operating room are the anesthetic technique and equipment issues. Regarding the anesthetic technique, the following factors cause operating room atmosphere contamination:
(1) failure to turn off gas flow control valves at the end of an anesthetic
(2) poorly fitting masks
(3) flushing the circuit
(4) filling anesthetic vaporizers
(5) use of uncuffed tracheal tubes
(6) use of breathing circuits such as the Jackson-Rees, which are difficult to scavenge
Barash | 9th edit
Scavenging systems FIVE components:
READ
Which of the following is the MOST critical component of the standard scavenging system?
A. gas-collecting assembly
B. transfer means
C. scavenging interface
D. gas-disposal assembly tubing
E. active or passive gas-disposal assembly
C. scavenging interface
The scavenging interface is the most critical component of the system because it protects the breathing circuit or ventilator from excessive positive or negative pressures.
The direction of the bellows movement during the ____ phase determines the bellows classification:
A. Inspiratory phase
B. Expiratory phase
B. Expiratory phase
