APEX ANESTHESIA MACHINE ASSESSMENT
COMPREHENSIVE QUESTIONS AND VERIFIED ACCURATE
SOLUTIONS (DETAILED & ELABORATED) | GET IT 100%
ACCURATE!! 2025 TEST!!
CORE DOMAINS
Pressure Systems and Components
Cylinder and Pipeline Supply
Safety Systems (PISS, DISS, Fail-Safe)
Leak Testing and Pre-Use Checkout
Breathing Circuits and Ventilation
Scavenging and Waste Gas Management
Monitors and Alarms
Oxygen Flush and Flowmeters
Vaporizers and Anesthetic Delivery
INTRODUCTION
This comprehensive assessment is designed for anesthesia providers and
students preparing for the APEX Anesthesia Machine examination. It
covers the essential components, safety systems, and operational
principles of the modern anesthesia machine. Each question is
accompanied by a verified, detailed rationale to reinforce understanding of
machine function, troubleshooting, and patient safety. Topics include
pressure system boundaries, cylinder specifications, leak testing
procedures, and safety mechanisms such as the Pin Index Safety System
(PISS) and Diameter Index Safety System (DISS). This resource serves as
a focused review for achieving accuracy on the 2025 APEX assessment.
SECTION ONE: QUESTIONS 1–100
1. How many pressure systems are there in the anesthesia machine?
A) One
B) Two
C) Three
D) Four
, C) Three
RATIONALE: The anesthesia machine contains three distinct pressure
systems: the high pressure system (from the cylinder to the cylinder
regulators), the intermediate pressure system (from the pipeline to the
flowmeter valves), and the low pressure system (from the flowmeter tubes
to the common gas outlet). Understanding these systems is critical for
troubleshooting machine issues and performing proper leak tests .
2. What are the components of the high pressure system?
A) Flowmeter tubes, vaporizers, common gas outlet
B) Hanger yoke, yoke block with check valves, cylinder pressure gauge,
cylinder pressure regulators
C) Pipeline inlets, pressure gauges, oxygen flush valve
D) Scavenger system, ventilator, breathing circuit
B) Hanger yoke, yoke block with check valves, cylinder pressure
gauge, cylinder pressure regulators
RATIONALE: The high pressure system begins at the cylinder and ends
at the cylinder regulators. The hanger yoke secures the cylinder, the check
valves prevent reverse gas flow, the pressure gauge displays cylinder
pressure, and the regulators reduce cylinder pressure to a usable level (45
psi for tanks vs. 50 psi for pipeline) .
3. Where does the high pressure system begin and end?
A) Begins at the pipeline; ends at the flowmeter valves
B) Begins at the cylinder; ends at the cylinder regulators
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the ventilator; ends at the scavenger
B) Begins at the cylinder; ends at the cylinder regulators
RATIONALE: The high pressure system starts at the compressed gas
cylinder (where pressures can exceed 1900 psi for oxygen) and ends at the
cylinder pressure regulator .
4. What is the gas pressure in the high pressure system?
,A) 15 psi
B) 45 psi
C) 50 psi
D) Cylinder pressure
D) Cylinder pressure
RATIONALE: The pressure in the high pressure system is equal to the
cylinder pressure, which can be as high as 1900-2200 psi for a full oxygen
E-cylinder .
5. Where does the intermediate pressure system begin and end?
A) Begins at the cylinder; ends at the cylinder regulators
B) Begins at the pipeline; ends at the flowmeter valves
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the vaporizer; ends at the breathing circuit
B) Begins at the pipeline; ends at the flowmeter valves
RATIONALE: The intermediate pressure system begins at the pipeline
and ends at the flowmeter valves. It receives gas at 50 psi from the hospital
pipeline or 45 psi from the cylinder after the regulator .
6. What are the components of the intermediate pressure system?
A) Flowmeter tubes, vaporizers, common gas outlet
B) Pipeline inlets, pressure gauges, ventilator power inlet, oxygen pressure
failure system, oxygen second stage regulator, oxygen flush valve,
flowmeter valves
C) Hanger yoke, cylinder pressure gauge, cylinder regulators
D) Scavenger system, breathing circuit, ventilator
B) Pipeline inlets, pressure gauges, ventilator power inlet, oxygen
pressure failure system, oxygen second stage regulator, oxygen flush
valve, flowmeter valves
RATIONALE: The intermediate pressure system includes pipeline
inlets, pressure gauges, ventilator power inlet, oxygen pressure failure
, system, oxygen second stage regulator, oxygen flush valve, and flowmeter
valves .
7. Where does the low pressure system begin and end?
A) Begins at the cylinder; ends at the cylinder regulators
B) Begins at the pipeline; ends at the flowmeter valves
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the vaporizer; ends at the scavenger
C) Begins at the flowmeter tubes; ends at the common gas outlet
RATIONALE: The low pressure system begins at the flowmeter tubes
and ends at the common gas outlet. This system operates at slightly above
atmospheric pressure .
8. What are the components of the low pressure system?
A) Pipeline inlets, pressure gauges, flowmeter valves
B) Hanger yoke, cylinder pressure gauge, cylinder regulators
C) Flowmeter tubes (Thorpe tubes), vaporizers, check valves (if present),
common gas outlet
D) Scavenger system, ventilator, breathing circuit
C) Flowmeter tubes (Thorpe tubes), vaporizers, check valves (if
present), common gas outlet
RATIONALE: The low pressure system includes flowmeter tubes,
vaporizers, check valves (if present), and the common gas outlet .
9. What is the gas pressure in the low pressure system?
A) 50 psi
B) 45 psi
C) Cylinder pressure
D) Slightly above atmospheric pressure
D) Slightly above atmospheric pressure
RATIONALE: The low pressure system operates at slightly above
atmospheric pressure, allowing for precise gas delivery and mixing .
COMPREHENSIVE QUESTIONS AND VERIFIED ACCURATE
SOLUTIONS (DETAILED & ELABORATED) | GET IT 100%
ACCURATE!! 2025 TEST!!
CORE DOMAINS
Pressure Systems and Components
Cylinder and Pipeline Supply
Safety Systems (PISS, DISS, Fail-Safe)
Leak Testing and Pre-Use Checkout
Breathing Circuits and Ventilation
Scavenging and Waste Gas Management
Monitors and Alarms
Oxygen Flush and Flowmeters
Vaporizers and Anesthetic Delivery
INTRODUCTION
This comprehensive assessment is designed for anesthesia providers and
students preparing for the APEX Anesthesia Machine examination. It
covers the essential components, safety systems, and operational
principles of the modern anesthesia machine. Each question is
accompanied by a verified, detailed rationale to reinforce understanding of
machine function, troubleshooting, and patient safety. Topics include
pressure system boundaries, cylinder specifications, leak testing
procedures, and safety mechanisms such as the Pin Index Safety System
(PISS) and Diameter Index Safety System (DISS). This resource serves as
a focused review for achieving accuracy on the 2025 APEX assessment.
SECTION ONE: QUESTIONS 1–100
1. How many pressure systems are there in the anesthesia machine?
A) One
B) Two
C) Three
D) Four
, C) Three
RATIONALE: The anesthesia machine contains three distinct pressure
systems: the high pressure system (from the cylinder to the cylinder
regulators), the intermediate pressure system (from the pipeline to the
flowmeter valves), and the low pressure system (from the flowmeter tubes
to the common gas outlet). Understanding these systems is critical for
troubleshooting machine issues and performing proper leak tests .
2. What are the components of the high pressure system?
A) Flowmeter tubes, vaporizers, common gas outlet
B) Hanger yoke, yoke block with check valves, cylinder pressure gauge,
cylinder pressure regulators
C) Pipeline inlets, pressure gauges, oxygen flush valve
D) Scavenger system, ventilator, breathing circuit
B) Hanger yoke, yoke block with check valves, cylinder pressure
gauge, cylinder pressure regulators
RATIONALE: The high pressure system begins at the cylinder and ends
at the cylinder regulators. The hanger yoke secures the cylinder, the check
valves prevent reverse gas flow, the pressure gauge displays cylinder
pressure, and the regulators reduce cylinder pressure to a usable level (45
psi for tanks vs. 50 psi for pipeline) .
3. Where does the high pressure system begin and end?
A) Begins at the pipeline; ends at the flowmeter valves
B) Begins at the cylinder; ends at the cylinder regulators
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the ventilator; ends at the scavenger
B) Begins at the cylinder; ends at the cylinder regulators
RATIONALE: The high pressure system starts at the compressed gas
cylinder (where pressures can exceed 1900 psi for oxygen) and ends at the
cylinder pressure regulator .
4. What is the gas pressure in the high pressure system?
,A) 15 psi
B) 45 psi
C) 50 psi
D) Cylinder pressure
D) Cylinder pressure
RATIONALE: The pressure in the high pressure system is equal to the
cylinder pressure, which can be as high as 1900-2200 psi for a full oxygen
E-cylinder .
5. Where does the intermediate pressure system begin and end?
A) Begins at the cylinder; ends at the cylinder regulators
B) Begins at the pipeline; ends at the flowmeter valves
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the vaporizer; ends at the breathing circuit
B) Begins at the pipeline; ends at the flowmeter valves
RATIONALE: The intermediate pressure system begins at the pipeline
and ends at the flowmeter valves. It receives gas at 50 psi from the hospital
pipeline or 45 psi from the cylinder after the regulator .
6. What are the components of the intermediate pressure system?
A) Flowmeter tubes, vaporizers, common gas outlet
B) Pipeline inlets, pressure gauges, ventilator power inlet, oxygen pressure
failure system, oxygen second stage regulator, oxygen flush valve,
flowmeter valves
C) Hanger yoke, cylinder pressure gauge, cylinder regulators
D) Scavenger system, breathing circuit, ventilator
B) Pipeline inlets, pressure gauges, ventilator power inlet, oxygen
pressure failure system, oxygen second stage regulator, oxygen flush
valve, flowmeter valves
RATIONALE: The intermediate pressure system includes pipeline
inlets, pressure gauges, ventilator power inlet, oxygen pressure failure
, system, oxygen second stage regulator, oxygen flush valve, and flowmeter
valves .
7. Where does the low pressure system begin and end?
A) Begins at the cylinder; ends at the cylinder regulators
B) Begins at the pipeline; ends at the flowmeter valves
C) Begins at the flowmeter tubes; ends at the common gas outlet
D) Begins at the vaporizer; ends at the scavenger
C) Begins at the flowmeter tubes; ends at the common gas outlet
RATIONALE: The low pressure system begins at the flowmeter tubes
and ends at the common gas outlet. This system operates at slightly above
atmospheric pressure .
8. What are the components of the low pressure system?
A) Pipeline inlets, pressure gauges, flowmeter valves
B) Hanger yoke, cylinder pressure gauge, cylinder regulators
C) Flowmeter tubes (Thorpe tubes), vaporizers, check valves (if present),
common gas outlet
D) Scavenger system, ventilator, breathing circuit
C) Flowmeter tubes (Thorpe tubes), vaporizers, check valves (if
present), common gas outlet
RATIONALE: The low pressure system includes flowmeter tubes,
vaporizers, check valves (if present), and the common gas outlet .
9. What is the gas pressure in the low pressure system?
A) 50 psi
B) 45 psi
C) Cylinder pressure
D) Slightly above atmospheric pressure
D) Slightly above atmospheric pressure
RATIONALE: The low pressure system operates at slightly above
atmospheric pressure, allowing for precise gas delivery and mixing .
