ANESTHESIA EQUIPMENT: PRINCIPLES AND APPLICATIONS, 3RD EDITION — COMPLETE
REVIEW QUESTION BANK
, TABLE OF CONTENTS
Anesthesia Equipment: Principles and Applications, 3rd Edition
Complete Original Review Question Bank - All 27 Chapters
Chapter Chapter Title
PART I - GASES AND VENTILATION
1 Medical Gases: Storage and Supply
2 The Anesthesia Machine and Workstation
3 Anesthesia Vaporizers
4 Breathing Circuits
5 Waste Anesthetic Gases and Scavenging Systems
6 Anesthesia Ventilators
7 Humidification and Filtration
PART II - SYSTEM MONITORS
8 Respiratory Gas Monitoring
9 Monitoring Ventilation
PART III - PATIENT MONITORS
10 Capnography
11 Pulse Oximetry
12 Hemodynamic Monitoring
13 Temperature Monitoring
PART IV - OTHER EQUIPMENT
14 Airway Equipment
15 Preventing Transmission of Infectious Diseases
16 Infusion Pumps
PART V - VIGILANCE, ALARMS, AND ERGONOMICS
17 Vigilance, Alarms, and Integrated Monitoring Systems
18 Ergonomics of the Anesthesia Workspace
PART VI - SPECIAL CONDITIONS
19 Closed-Circuit Anesthesia
20 Anesthesia Delivery in the MRI Environment
21 Anesthesia at High Altitude
Anesthesia in Difficult Locations and in Developing
22
Countries
PART VII - SAFETY, STANDARDS, AND QUALITY
23 Hazards of the Anesthesia Delivery System
24 Electrical and Fire Safety
25 Machine Checkout and Quality Assurance
Risk Management and Medicolegal Aspects of Anesthesia
26
Equipment Use
27 Standards and Regulatory Considerations
PART I — Gases & Ventilation
Chapter 1 — Medical Gases: Storage and Supply
Question 1
During the workstation checkout, the central oxygen pipeline is functioning, but the mounted backup E-
cylinder contains only 250 psi. Which action best protects against an unexpected pipeline failure?
A. Open the cylinder and leave it open throughout the case
B. Rely on pipeline oxygen because its pressure is normal
C. Remove the cylinder and operate without a backup source
D. Replace the cylinder with one containing an adequate oxygen reserve
Correct Answer: D
Rationale: The mounted oxygen cylinder provides an independent emergency source if pipeline oxygen
becomes unavailable. A cylinder containing only 250 psi provides a very limited reserve and should be
replaced before anesthesia begins.
Page 2 of 366
,Why the other options are less appropriate:
A. Leaving the cylinder open can unintentionally consume the reserve.
B. Normal pipeline function does not eliminate the need for backup oxygen.
C. Operating without an immediately available reserve increases risk.
Equipment Pearl: Verify reserve-cylinder pressure during every pre-use workstation check.
Exam Strategy: Before anesthesia begins, correct deficiencies in essential backup systems rather than
planning around them.
Keyword: Oxygen reserve
Question 2
A clinician needs to estimate the amount of oxygen remaining in an E-cylinder. Which parameter is most
useful when the cylinder temperature is stable?
A. Cylinder pressure
B. Cylinder color
C. Cylinder orientation
D. Pipeline flow rate
Correct Answer: A
Rationale: Oxygen is stored primarily as a compressed gas. As oxygen is consumed, cylinder pressure
decreases approximately in proportion to the amount remaining, provided temperature does not change
substantially.
Why the other options are less appropriate:
B. Color aids identification but not quantity determination.
C. Orientation does not indicate oxygen content.
D. Pipeline flow does not indicate cylinder contents.
Equipment Pearl: Oxygen-cylinder contents can generally be estimated from pressure.
Exam Strategy: For compressed oxygen, pressure is the key quantity indicator.
Keyword: Cylinder pressure
Question 3
A nitrous oxide cylinder has been used for several cases, yet its pressure remains close to 745 psi. Which
explanation is most accurate?
A. The cylinder is necessarily still completely full
B. The pressure gauge is malfunctioning
C. Liquid nitrous oxide continues to vaporize and maintain near-constant pressure
D. Nitrous oxide is supplied from the hospital pipeline into the cylinder
Correct Answer: C
Rationale: Nitrous oxide exists as both liquid and vapor inside the cylinder. As vapor is removed, more liquid
vaporizes, maintaining relatively constant vapor pressure until the liquid portion is nearly exhausted.
Why the other options are less appropriate:
A. Considerable nitrous oxide may already have been consumed.
B. A stable pressure is expected while liquid remains.
D. Cylinders are not automatically refilled from pipeline systems.
Equipment Pearl: Nitrous oxide pressure does not reliably indicate cylinder fullness while liquid remains.
Exam Strategy: Liquefied gas + stable pressure = think liquid-vapor equilibrium.
Keyword: Vapor pressure
Question 4
Which method provides the best estimate of the amount of nitrous oxide remaining in a cylinder?
A. Measuring outlet pressure alone
B. Observing the flowmeter
C. Checking the color code
D. Weighing the cylinder and subtracting its tare weight
Correct Answer: D
Page 3 of 366
,Rationale: Because nitrous oxide pressure remains relatively constant while liquid is present, cylinder weight is
the most useful indicator of remaining contents. Subtracting tare weight estimates the mass of nitrous oxide
present.
Why the other options are less appropriate:
A. Pressure does not closely track contents until the liquid is gone.
B. Flow indicates current delivery, not total reserve.
C. Color identifies gas type, not quantity.
Equipment Pearl: The tare weight represents the weight of the empty cylinder and valve assembly.
Exam Strategy: Nitrous oxide = determine quantity by weight, not gauge pressure.
Keyword: Tare weight
Question 5 — Supply Data Interpretation
Gas Source Observed Pressure Condition
Oxygen pipeline 50 psi Connected
Oxygen E-cylinder 1,900 psi Closed
Nitrous oxide pipeline 49 psi Connected
Nitrous oxide cylinder 745 psi Available
Which conclusion is best supported by the data?
A. Pipeline oxygen pressure is dangerously low
B. The oxygen cylinder is nearly depleted
C. The oxygen pipeline and backup cylinder appear adequately supplied
D. The nitrous oxide cylinder is definitely completely full
Correct Answer: C
Rationale: An oxygen pipeline pressure around 50 psi is expected, while an oxygen cylinder near 1,900 psi
contains a substantial reserve. The data therefore indicate an adequate primary and backup oxygen supply.
Why the other options are less appropriate:
A. Approximately 50 psi is expected pipeline pressure.
B. 1,900 psi represents substantial cylinder contents.
D. Nitrous oxide pressure alone cannot establish fullness.
Equipment Pearl: Pipeline and cylinder pressures operate at very different pressure ranges.
Exam Strategy: Compare each pressure with the expected value for that specific source.
Keyword: Supply pressure
Question 6
What is the primary purpose of the pressure regulator connected to a high-pressure oxygen cylinder?
A. Reduce high cylinder pressure to a safer working pressure
B. Increase oxygen concentration
C. Liquefy oxygen before administration
D. Generate pipeline pressure when the cylinder is closed
Correct Answer: A
Rationale: Oxygen cylinders may contain pressures near 2,000 psi. The regulator reduces this very high and
variable pressure to a lower, more stable pressure suitable for downstream anesthesia-machine components.
Why the other options are less appropriate:
B. Oxygen concentration is not changed by pressure regulation.
C. The regulator does not liquefy oxygen.
D. A closed cylinder cannot supply gas to the regulator.
Equipment Pearl: Pressure regulators protect downstream equipment from cylinder pressure.
Exam Strategy: Cylinder → regulator → intermediate-pressure system.
Keyword: Pressure regulator
Question 7 — Cylinder-Yoke Sketch
Page 4 of 366
,What is the function of the two index pins shown?
A. Reduce cylinder pressure
B. Prevent attachment of the wrong gas cylinder
C. Measure cylinder contents
D. Prevent reverse flow into the pipeline
Correct Answer: B
Rationale: The pins form part of the Pin Index Safety System. Their gas-specific arrangement corresponds with
holes in the cylinder valve and helps prevent incorrect cylinder interchange.
Why the other options are less appropriate:
A. Pressure reduction occurs at the regulator.
C. Pressure gauges or weight estimate contents.
D. The pins do not function as check valves.
Equipment Pearl: Oxygen commonly uses PISS positions 2 and 5.
Exam Strategy: Small cylinder + yoke + pins = Pin Index Safety System.
Keyword: Pin Index Safety System
Question 8
Which safety system is primarily associated with gas-specific pipeline connections?
A. Bodok sealing system
B. Pin Index Safety System
C. Cylinder pressure regulator
D. Diameter Index Safety System
Correct Answer: D
Rationale: The Diameter Index Safety System uses gas-specific connector dimensions to reduce the risk of
attaching a pipeline hose to the wrong medical gas outlet.
Why the other options are less appropriate:
A. The Bodok seal is associated with cylinder-yoke sealing.
B. PISS is associated with small cylinders.
C. Regulators modify pressure rather than identify gas.
Equipment Pearl: PISS = cylinders; DISS = pipeline connections.
Exam Strategy: Identify the physical location before choosing the safety system.
Keyword: Diameter Index Safety System
Question 9 — Block Chain
Page 5 of 366
,If full cylinder pressure is appearing in the intermediate-pressure system, which component should be
suspected first?
A. Flowmeter
B. Common gas outlet
C. Pressure regulator
D. Hanger-yoke retaining screw
Correct Answer: C
Rationale: The pressure regulator is responsible for reducing high cylinder pressure before gas enters the
intermediate-pressure system. Failure of this component can expose downstream structures to excessive
pressure.
Why the other options are less appropriate:
A. The flowmeter regulates and displays flow downstream.
B. The common gas outlet does not reduce cylinder pressure.
D. The retaining screw secures the cylinder mechanically.
Equipment Pearl: Follow gas flow sequentially when troubleshooting workstation problems.
Exam Strategy: Locate the first device designed to prevent the abnormal condition.
Keyword: Intermediate pressure
Question 10
Gas is leaking from the junction between an E-cylinder valve and the anesthesia-machine yoke. Which
component should be inspected first?
A. Bodok seal
B. Oxygen analyzer
C. Scavenging interface
D. Flow-control valve
Correct Answer: A
Rationale: The Bodok seal provides a gas-tight connection between the cylinder valve and hanger yoke. A
missing, damaged, or improperly positioned seal can produce a substantial gas leak.
Why the other options are less appropriate:
B. The analyzer measures oxygen concentration.
C. Scavenging is downstream from the cylinder system.
D. The flow-control valve is not located at the yoke junction.
Equipment Pearl: A small yoke leak can rapidly deplete an emergency cylinder.
Page 6 of 366
, Exam Strategy: Leak at cylinder-yoke junction = inspect the seal.
Keyword: Bodok seal
Question 11
Why is using two sealing washers at a cylinder-yoke connection potentially dangerous?
A. It increases oxygen concentration above 100%
B. It increases cylinder temperature
C. It causes the regulator to generate pipeline pressure
D. It may prevent proper engagement of the Pin Index Safety System
Correct Answer: D
Rationale: Stacking washers increases the separation between the cylinder valve and yoke. This can reduce
effective engagement of the index pins and potentially defeat an important gas-specific safety mechanism.
Why the other options are less appropriate:
A. Washer number does not change oxygen concentration.
B. It does not inherently raise temperature.
C. Regulators do not generate pressure.
Equipment Pearl: Only the correct sealing washer arrangement should be used.
Exam Strategy: Anything that physically separates the valve from the yoke can compromise pin indexing.
Keyword: Multiple-washer hazard
Question 12
Following replacement of a hospital pipeline section, the oxygen outlet produces normal pressure. What
additional verification is most important before patient use?
A. Confirm that the outlet is painted the expected color
B. Confirm the flowmeter bobbin rises
C. Confirm that the delivered gas is actually oxygen
D. Confirm that nitrous oxide is also available
Correct Answer: C
Rationale: Normal pressure and correct fittings do not prove gas identity. Pipeline cross-connections can
deliver an unintended gas through a correctly labeled outlet, so composition should be verified following
suspected alterations.
Why the other options are less appropriate:
A. Color alone cannot establish internal pipeline contents.
B. Flow demonstrates gas movement, not gas identity.
D. Nitrous oxide availability does not confirm oxygen purity.
Equipment Pearl: An oxygen analyzer is a critical downstream defense against pipeline misconnections.
Exam Strategy: Correct pressure ≠ correct gas.
Keyword: Pipeline cross-connection
Question 13 — Mermaid Diagram
If a major failure occurs upstream of the wall outlet, which source offers the most immediate independent
oxygen backup?
A. Nitrous oxide pipeline
B. Scavenging reservoir
C. Carbon dioxide absorber
D. Mounted oxygen cylinder
Correct Answer: D
Rationale: A properly filled oxygen cylinder mounted on the workstation is independent of the central pipeline
and provides an immediate alternate oxygen source following pipeline interruption.
Why the other options are less appropriate:
A. Nitrous oxide does not provide adequate oxygenation.
Page 7 of 366
,B. Scavenging removes waste gases.
C. The absorber removes carbon dioxide.
Equipment Pearl: Backup systems should not depend on the same infrastructure as the failed primary
source.
Exam Strategy: Pipeline failure → think independent cylinder supply.
Keyword: Backup oxygen
Question 14
What is the greatest immediate danger if a compressed-gas cylinder falls and its valve is completely sheared
off?
A. The gas becomes chemically unstable
B. The cylinder may become a high-velocity projectile
C. The oxygen concentration drops to zero
D. The cylinder automatically connects to nearby pipeline fittings
Correct Answer: B
Rationale: High-pressure gas contains substantial stored energy. If a valve is broken off, rapidly escaping gas
can propel the cylinder with tremendous force, creating a serious mechanical hazard.
Why the other options are less appropriate:
A. The chemical identity of the gas does not change.
C. This does not describe the principal mechanical danger.
D. Cylinders cannot self-connect to pipelines.
Equipment Pearl: Even an apparently empty cylinder should be handled and secured carefully.
Exam Strategy: High pressure + damaged valve = projectile risk.
Keyword: Projectile hazard
Question 15
Why should petroleum-based oils or grease never be applied to an oxygen-cylinder valve?
A. They decrease cylinder pressure
B. They block the Pin Index Safety System
C. They change oxygen into ozone
D. They may ignite violently in a high-pressure oxygen environment
Correct Answer: D
Rationale: Oxygen strongly supports combustion. Hydrocarbon contamination combined with high-pressure
oxygen and a heat source can cause rapid ignition or fire.
Why the other options are less appropriate:
A. Oil does not simply reduce pressure.
B. Its principal danger is combustion rather than indexing failure.
C. It does not convert oxygen into ozone.
Equipment Pearl: Oxygen itself is not flammable, but it greatly accelerates combustion.
Exam Strategy: Oxygen + hydrocarbon + heat = fire hazard.
Keyword: Oxygen fire hazard
Question 16 — Pressure Trend Graph
Page 8 of 366
,Which interpretation is correct?
A. Oxygen pressure stays constant until the cylinder is empty
B. Oxygen pressure rises as gas is removed
C. Oxygen-cylinder pressure generally decreases as contents are consumed
D. Oxygen content can only be estimated by weight
Correct Answer: C
Rationale: Oxygen is stored as compressed gas, so cylinder pressure progressively falls as oxygen is withdrawn,
assuming relatively stable temperature.
Why the other options are less appropriate:
A. Constant-pressure behavior is more characteristic of liquefied gases while liquid remains.
B. Pressure normally decreases.
D. Pressure is useful for estimating compressed-oxygen contents.
Equipment Pearl: Temperature changes can alter pressure without changing the amount of gas present.
Exam Strategy: Progressive linear-like pressure fall = compressed-gas behavior.
Keyword: Pressure depletion
Question 17
Which cylinder-storage practice most effectively reduces the risk of valve trauma?
A. Store all cylinders horizontally in traffic areas
B. Remove valve-protection features before storage
C. Place cylinders next to heat-producing equipment
D. Secure cylinders in an appropriate rack or restraint system
Correct Answer: D
Rationale: Cylinders should be mechanically secured to prevent falling, rolling, and damage to the valve
assembly. Valve damage under high pressure can produce serious injury.
Why the other options are less appropriate:
A. Loose cylinders can roll and be struck.
B. Valve protection should not be unnecessarily removed.
C. Heat increases cylinder pressure and risk.
Equipment Pearl: Cylinder safety includes both pressure control and physical restraint.
Exam Strategy: Storage questions usually prioritize securing the cylinder and protecting its valve.
Keyword: Cylinder restraint
Page 9 of 366
, Question 18
A full oxygen cylinder is moved from a very cold storage room into a much warmer operating suite. Its
measured pressure increases slightly without any added gas. What best explains this observation?
A. Gas pressure rises as temperature increases in a fixed-volume cylinder
B. The regulator has generated additional oxygen
C. The cylinder has absorbed oxygen from the room
D. Oxygen has become a liquid
Correct Answer: A
Rationale: In a fixed-volume container, increasing gas temperature increases molecular kinetic activity and
therefore increases pressure. The amount of oxygen may remain unchanged.
Why the other options are less appropriate:
B. Regulators do not generate oxygen.
C. A sealed cylinder does not absorb atmospheric oxygen.
D. Warming does not cause oxygen liquefaction.
Equipment Pearl: Always consider temperature when interpreting cylinder pressure.
Exam Strategy: Same gas quantity + warmer temperature = higher pressure.
Keyword: Pressure-temperature relationship
Question 19 — Nitrous Oxide Graph
What causes the long pressure plateau?
A. Pipeline nitrous oxide continuously refills the cylinder
B. A regulator maintains pressure inside the cylinder
C. Liquid nitrous oxide vaporizes as gaseous nitrous oxide is withdrawn
D. Cylinder pressure is independent of physical state
Correct Answer: C
Rationale: While liquid nitrous oxide remains, vapor removal is followed by additional evaporation from the
liquid phase, maintaining approximately constant vapor pressure.
Why the other options are less appropriate:
A. The cylinder is not refilled by the pipeline.
B. The regulator does not maintain pressure inside the cylinder.
D. Pressure behavior is directly related to liquid-vapor equilibrium.
Equipment Pearl: Once all liquid has vaporized, nitrous oxide cylinder pressure begins to fall more rapidly.
Exam Strategy: Plateau → liquefied gas.
Keyword: Liquid-vapor equilibrium
Question 20
Why are bulk oxygen systems useful in large hospitals?
Page 10 of 366
REVIEW QUESTION BANK
, TABLE OF CONTENTS
Anesthesia Equipment: Principles and Applications, 3rd Edition
Complete Original Review Question Bank - All 27 Chapters
Chapter Chapter Title
PART I - GASES AND VENTILATION
1 Medical Gases: Storage and Supply
2 The Anesthesia Machine and Workstation
3 Anesthesia Vaporizers
4 Breathing Circuits
5 Waste Anesthetic Gases and Scavenging Systems
6 Anesthesia Ventilators
7 Humidification and Filtration
PART II - SYSTEM MONITORS
8 Respiratory Gas Monitoring
9 Monitoring Ventilation
PART III - PATIENT MONITORS
10 Capnography
11 Pulse Oximetry
12 Hemodynamic Monitoring
13 Temperature Monitoring
PART IV - OTHER EQUIPMENT
14 Airway Equipment
15 Preventing Transmission of Infectious Diseases
16 Infusion Pumps
PART V - VIGILANCE, ALARMS, AND ERGONOMICS
17 Vigilance, Alarms, and Integrated Monitoring Systems
18 Ergonomics of the Anesthesia Workspace
PART VI - SPECIAL CONDITIONS
19 Closed-Circuit Anesthesia
20 Anesthesia Delivery in the MRI Environment
21 Anesthesia at High Altitude
Anesthesia in Difficult Locations and in Developing
22
Countries
PART VII - SAFETY, STANDARDS, AND QUALITY
23 Hazards of the Anesthesia Delivery System
24 Electrical and Fire Safety
25 Machine Checkout and Quality Assurance
Risk Management and Medicolegal Aspects of Anesthesia
26
Equipment Use
27 Standards and Regulatory Considerations
PART I — Gases & Ventilation
Chapter 1 — Medical Gases: Storage and Supply
Question 1
During the workstation checkout, the central oxygen pipeline is functioning, but the mounted backup E-
cylinder contains only 250 psi. Which action best protects against an unexpected pipeline failure?
A. Open the cylinder and leave it open throughout the case
B. Rely on pipeline oxygen because its pressure is normal
C. Remove the cylinder and operate without a backup source
D. Replace the cylinder with one containing an adequate oxygen reserve
Correct Answer: D
Rationale: The mounted oxygen cylinder provides an independent emergency source if pipeline oxygen
becomes unavailable. A cylinder containing only 250 psi provides a very limited reserve and should be
replaced before anesthesia begins.
Page 2 of 366
,Why the other options are less appropriate:
A. Leaving the cylinder open can unintentionally consume the reserve.
B. Normal pipeline function does not eliminate the need for backup oxygen.
C. Operating without an immediately available reserve increases risk.
Equipment Pearl: Verify reserve-cylinder pressure during every pre-use workstation check.
Exam Strategy: Before anesthesia begins, correct deficiencies in essential backup systems rather than
planning around them.
Keyword: Oxygen reserve
Question 2
A clinician needs to estimate the amount of oxygen remaining in an E-cylinder. Which parameter is most
useful when the cylinder temperature is stable?
A. Cylinder pressure
B. Cylinder color
C. Cylinder orientation
D. Pipeline flow rate
Correct Answer: A
Rationale: Oxygen is stored primarily as a compressed gas. As oxygen is consumed, cylinder pressure
decreases approximately in proportion to the amount remaining, provided temperature does not change
substantially.
Why the other options are less appropriate:
B. Color aids identification but not quantity determination.
C. Orientation does not indicate oxygen content.
D. Pipeline flow does not indicate cylinder contents.
Equipment Pearl: Oxygen-cylinder contents can generally be estimated from pressure.
Exam Strategy: For compressed oxygen, pressure is the key quantity indicator.
Keyword: Cylinder pressure
Question 3
A nitrous oxide cylinder has been used for several cases, yet its pressure remains close to 745 psi. Which
explanation is most accurate?
A. The cylinder is necessarily still completely full
B. The pressure gauge is malfunctioning
C. Liquid nitrous oxide continues to vaporize and maintain near-constant pressure
D. Nitrous oxide is supplied from the hospital pipeline into the cylinder
Correct Answer: C
Rationale: Nitrous oxide exists as both liquid and vapor inside the cylinder. As vapor is removed, more liquid
vaporizes, maintaining relatively constant vapor pressure until the liquid portion is nearly exhausted.
Why the other options are less appropriate:
A. Considerable nitrous oxide may already have been consumed.
B. A stable pressure is expected while liquid remains.
D. Cylinders are not automatically refilled from pipeline systems.
Equipment Pearl: Nitrous oxide pressure does not reliably indicate cylinder fullness while liquid remains.
Exam Strategy: Liquefied gas + stable pressure = think liquid-vapor equilibrium.
Keyword: Vapor pressure
Question 4
Which method provides the best estimate of the amount of nitrous oxide remaining in a cylinder?
A. Measuring outlet pressure alone
B. Observing the flowmeter
C. Checking the color code
D. Weighing the cylinder and subtracting its tare weight
Correct Answer: D
Page 3 of 366
,Rationale: Because nitrous oxide pressure remains relatively constant while liquid is present, cylinder weight is
the most useful indicator of remaining contents. Subtracting tare weight estimates the mass of nitrous oxide
present.
Why the other options are less appropriate:
A. Pressure does not closely track contents until the liquid is gone.
B. Flow indicates current delivery, not total reserve.
C. Color identifies gas type, not quantity.
Equipment Pearl: The tare weight represents the weight of the empty cylinder and valve assembly.
Exam Strategy: Nitrous oxide = determine quantity by weight, not gauge pressure.
Keyword: Tare weight
Question 5 — Supply Data Interpretation
Gas Source Observed Pressure Condition
Oxygen pipeline 50 psi Connected
Oxygen E-cylinder 1,900 psi Closed
Nitrous oxide pipeline 49 psi Connected
Nitrous oxide cylinder 745 psi Available
Which conclusion is best supported by the data?
A. Pipeline oxygen pressure is dangerously low
B. The oxygen cylinder is nearly depleted
C. The oxygen pipeline and backup cylinder appear adequately supplied
D. The nitrous oxide cylinder is definitely completely full
Correct Answer: C
Rationale: An oxygen pipeline pressure around 50 psi is expected, while an oxygen cylinder near 1,900 psi
contains a substantial reserve. The data therefore indicate an adequate primary and backup oxygen supply.
Why the other options are less appropriate:
A. Approximately 50 psi is expected pipeline pressure.
B. 1,900 psi represents substantial cylinder contents.
D. Nitrous oxide pressure alone cannot establish fullness.
Equipment Pearl: Pipeline and cylinder pressures operate at very different pressure ranges.
Exam Strategy: Compare each pressure with the expected value for that specific source.
Keyword: Supply pressure
Question 6
What is the primary purpose of the pressure regulator connected to a high-pressure oxygen cylinder?
A. Reduce high cylinder pressure to a safer working pressure
B. Increase oxygen concentration
C. Liquefy oxygen before administration
D. Generate pipeline pressure when the cylinder is closed
Correct Answer: A
Rationale: Oxygen cylinders may contain pressures near 2,000 psi. The regulator reduces this very high and
variable pressure to a lower, more stable pressure suitable for downstream anesthesia-machine components.
Why the other options are less appropriate:
B. Oxygen concentration is not changed by pressure regulation.
C. The regulator does not liquefy oxygen.
D. A closed cylinder cannot supply gas to the regulator.
Equipment Pearl: Pressure regulators protect downstream equipment from cylinder pressure.
Exam Strategy: Cylinder → regulator → intermediate-pressure system.
Keyword: Pressure regulator
Question 7 — Cylinder-Yoke Sketch
Page 4 of 366
,What is the function of the two index pins shown?
A. Reduce cylinder pressure
B. Prevent attachment of the wrong gas cylinder
C. Measure cylinder contents
D. Prevent reverse flow into the pipeline
Correct Answer: B
Rationale: The pins form part of the Pin Index Safety System. Their gas-specific arrangement corresponds with
holes in the cylinder valve and helps prevent incorrect cylinder interchange.
Why the other options are less appropriate:
A. Pressure reduction occurs at the regulator.
C. Pressure gauges or weight estimate contents.
D. The pins do not function as check valves.
Equipment Pearl: Oxygen commonly uses PISS positions 2 and 5.
Exam Strategy: Small cylinder + yoke + pins = Pin Index Safety System.
Keyword: Pin Index Safety System
Question 8
Which safety system is primarily associated with gas-specific pipeline connections?
A. Bodok sealing system
B. Pin Index Safety System
C. Cylinder pressure regulator
D. Diameter Index Safety System
Correct Answer: D
Rationale: The Diameter Index Safety System uses gas-specific connector dimensions to reduce the risk of
attaching a pipeline hose to the wrong medical gas outlet.
Why the other options are less appropriate:
A. The Bodok seal is associated with cylinder-yoke sealing.
B. PISS is associated with small cylinders.
C. Regulators modify pressure rather than identify gas.
Equipment Pearl: PISS = cylinders; DISS = pipeline connections.
Exam Strategy: Identify the physical location before choosing the safety system.
Keyword: Diameter Index Safety System
Question 9 — Block Chain
Page 5 of 366
,If full cylinder pressure is appearing in the intermediate-pressure system, which component should be
suspected first?
A. Flowmeter
B. Common gas outlet
C. Pressure regulator
D. Hanger-yoke retaining screw
Correct Answer: C
Rationale: The pressure regulator is responsible for reducing high cylinder pressure before gas enters the
intermediate-pressure system. Failure of this component can expose downstream structures to excessive
pressure.
Why the other options are less appropriate:
A. The flowmeter regulates and displays flow downstream.
B. The common gas outlet does not reduce cylinder pressure.
D. The retaining screw secures the cylinder mechanically.
Equipment Pearl: Follow gas flow sequentially when troubleshooting workstation problems.
Exam Strategy: Locate the first device designed to prevent the abnormal condition.
Keyword: Intermediate pressure
Question 10
Gas is leaking from the junction between an E-cylinder valve and the anesthesia-machine yoke. Which
component should be inspected first?
A. Bodok seal
B. Oxygen analyzer
C. Scavenging interface
D. Flow-control valve
Correct Answer: A
Rationale: The Bodok seal provides a gas-tight connection between the cylinder valve and hanger yoke. A
missing, damaged, or improperly positioned seal can produce a substantial gas leak.
Why the other options are less appropriate:
B. The analyzer measures oxygen concentration.
C. Scavenging is downstream from the cylinder system.
D. The flow-control valve is not located at the yoke junction.
Equipment Pearl: A small yoke leak can rapidly deplete an emergency cylinder.
Page 6 of 366
, Exam Strategy: Leak at cylinder-yoke junction = inspect the seal.
Keyword: Bodok seal
Question 11
Why is using two sealing washers at a cylinder-yoke connection potentially dangerous?
A. It increases oxygen concentration above 100%
B. It increases cylinder temperature
C. It causes the regulator to generate pipeline pressure
D. It may prevent proper engagement of the Pin Index Safety System
Correct Answer: D
Rationale: Stacking washers increases the separation between the cylinder valve and yoke. This can reduce
effective engagement of the index pins and potentially defeat an important gas-specific safety mechanism.
Why the other options are less appropriate:
A. Washer number does not change oxygen concentration.
B. It does not inherently raise temperature.
C. Regulators do not generate pressure.
Equipment Pearl: Only the correct sealing washer arrangement should be used.
Exam Strategy: Anything that physically separates the valve from the yoke can compromise pin indexing.
Keyword: Multiple-washer hazard
Question 12
Following replacement of a hospital pipeline section, the oxygen outlet produces normal pressure. What
additional verification is most important before patient use?
A. Confirm that the outlet is painted the expected color
B. Confirm the flowmeter bobbin rises
C. Confirm that the delivered gas is actually oxygen
D. Confirm that nitrous oxide is also available
Correct Answer: C
Rationale: Normal pressure and correct fittings do not prove gas identity. Pipeline cross-connections can
deliver an unintended gas through a correctly labeled outlet, so composition should be verified following
suspected alterations.
Why the other options are less appropriate:
A. Color alone cannot establish internal pipeline contents.
B. Flow demonstrates gas movement, not gas identity.
D. Nitrous oxide availability does not confirm oxygen purity.
Equipment Pearl: An oxygen analyzer is a critical downstream defense against pipeline misconnections.
Exam Strategy: Correct pressure ≠ correct gas.
Keyword: Pipeline cross-connection
Question 13 — Mermaid Diagram
If a major failure occurs upstream of the wall outlet, which source offers the most immediate independent
oxygen backup?
A. Nitrous oxide pipeline
B. Scavenging reservoir
C. Carbon dioxide absorber
D. Mounted oxygen cylinder
Correct Answer: D
Rationale: A properly filled oxygen cylinder mounted on the workstation is independent of the central pipeline
and provides an immediate alternate oxygen source following pipeline interruption.
Why the other options are less appropriate:
A. Nitrous oxide does not provide adequate oxygenation.
Page 7 of 366
,B. Scavenging removes waste gases.
C. The absorber removes carbon dioxide.
Equipment Pearl: Backup systems should not depend on the same infrastructure as the failed primary
source.
Exam Strategy: Pipeline failure → think independent cylinder supply.
Keyword: Backup oxygen
Question 14
What is the greatest immediate danger if a compressed-gas cylinder falls and its valve is completely sheared
off?
A. The gas becomes chemically unstable
B. The cylinder may become a high-velocity projectile
C. The oxygen concentration drops to zero
D. The cylinder automatically connects to nearby pipeline fittings
Correct Answer: B
Rationale: High-pressure gas contains substantial stored energy. If a valve is broken off, rapidly escaping gas
can propel the cylinder with tremendous force, creating a serious mechanical hazard.
Why the other options are less appropriate:
A. The chemical identity of the gas does not change.
C. This does not describe the principal mechanical danger.
D. Cylinders cannot self-connect to pipelines.
Equipment Pearl: Even an apparently empty cylinder should be handled and secured carefully.
Exam Strategy: High pressure + damaged valve = projectile risk.
Keyword: Projectile hazard
Question 15
Why should petroleum-based oils or grease never be applied to an oxygen-cylinder valve?
A. They decrease cylinder pressure
B. They block the Pin Index Safety System
C. They change oxygen into ozone
D. They may ignite violently in a high-pressure oxygen environment
Correct Answer: D
Rationale: Oxygen strongly supports combustion. Hydrocarbon contamination combined with high-pressure
oxygen and a heat source can cause rapid ignition or fire.
Why the other options are less appropriate:
A. Oil does not simply reduce pressure.
B. Its principal danger is combustion rather than indexing failure.
C. It does not convert oxygen into ozone.
Equipment Pearl: Oxygen itself is not flammable, but it greatly accelerates combustion.
Exam Strategy: Oxygen + hydrocarbon + heat = fire hazard.
Keyword: Oxygen fire hazard
Question 16 — Pressure Trend Graph
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,Which interpretation is correct?
A. Oxygen pressure stays constant until the cylinder is empty
B. Oxygen pressure rises as gas is removed
C. Oxygen-cylinder pressure generally decreases as contents are consumed
D. Oxygen content can only be estimated by weight
Correct Answer: C
Rationale: Oxygen is stored as compressed gas, so cylinder pressure progressively falls as oxygen is withdrawn,
assuming relatively stable temperature.
Why the other options are less appropriate:
A. Constant-pressure behavior is more characteristic of liquefied gases while liquid remains.
B. Pressure normally decreases.
D. Pressure is useful for estimating compressed-oxygen contents.
Equipment Pearl: Temperature changes can alter pressure without changing the amount of gas present.
Exam Strategy: Progressive linear-like pressure fall = compressed-gas behavior.
Keyword: Pressure depletion
Question 17
Which cylinder-storage practice most effectively reduces the risk of valve trauma?
A. Store all cylinders horizontally in traffic areas
B. Remove valve-protection features before storage
C. Place cylinders next to heat-producing equipment
D. Secure cylinders in an appropriate rack or restraint system
Correct Answer: D
Rationale: Cylinders should be mechanically secured to prevent falling, rolling, and damage to the valve
assembly. Valve damage under high pressure can produce serious injury.
Why the other options are less appropriate:
A. Loose cylinders can roll and be struck.
B. Valve protection should not be unnecessarily removed.
C. Heat increases cylinder pressure and risk.
Equipment Pearl: Cylinder safety includes both pressure control and physical restraint.
Exam Strategy: Storage questions usually prioritize securing the cylinder and protecting its valve.
Keyword: Cylinder restraint
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, Question 18
A full oxygen cylinder is moved from a very cold storage room into a much warmer operating suite. Its
measured pressure increases slightly without any added gas. What best explains this observation?
A. Gas pressure rises as temperature increases in a fixed-volume cylinder
B. The regulator has generated additional oxygen
C. The cylinder has absorbed oxygen from the room
D. Oxygen has become a liquid
Correct Answer: A
Rationale: In a fixed-volume container, increasing gas temperature increases molecular kinetic activity and
therefore increases pressure. The amount of oxygen may remain unchanged.
Why the other options are less appropriate:
B. Regulators do not generate oxygen.
C. A sealed cylinder does not absorb atmospheric oxygen.
D. Warming does not cause oxygen liquefaction.
Equipment Pearl: Always consider temperature when interpreting cylinder pressure.
Exam Strategy: Same gas quantity + warmer temperature = higher pressure.
Keyword: Pressure-temperature relationship
Question 19 — Nitrous Oxide Graph
What causes the long pressure plateau?
A. Pipeline nitrous oxide continuously refills the cylinder
B. A regulator maintains pressure inside the cylinder
C. Liquid nitrous oxide vaporizes as gaseous nitrous oxide is withdrawn
D. Cylinder pressure is independent of physical state
Correct Answer: C
Rationale: While liquid nitrous oxide remains, vapor removal is followed by additional evaporation from the
liquid phase, maintaining approximately constant vapor pressure.
Why the other options are less appropriate:
A. The cylinder is not refilled by the pipeline.
B. The regulator does not maintain pressure inside the cylinder.
D. Pressure behavior is directly related to liquid-vapor equilibrium.
Equipment Pearl: Once all liquid has vaporized, nitrous oxide cylinder pressure begins to fall more rapidly.
Exam Strategy: Plateau → liquefied gas.
Keyword: Liquid-vapor equilibrium
Question 20
Why are bulk oxygen systems useful in large hospitals?
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