Anesthesia machine and breathing circuits (E1)

Question 1

What are the 4 subsystems of the breathing machine?

Answer 1

High pressure system
Low pressure system
Breathing system
Scavenging system

Question 2

T/F E cylinders are bigger than H cylinders?

Answer 2

FALSE; E cylinders hold 660L of O2, while H cylinders hole 6900 L

Question 3

What are some safety features of gas cylinders?

Answer 3

Color coding
Pin-index safety system
Bull-nose or threaded outlets
Diameter index safety system

Question 4

What does the pressure regulator do?

Answer 4

Reduces the pressure of the gas being administered to 50-55 psi

Question 5

What is the oxygen flush valve? When would it be used?

Answer 5

Valve located between pressure regulator and flowmeter.
Use when the pressure in the circuit increases and could lead to bronchotrauma, or when the concentration of inhalant in circle system will decrease and lead to light plane of anesthesia

Question 6

What are the components of the high pressure system? What is the pressure of the gas at the end of it?

Answer 6

Gas source, pressure regulator, pressure gauge, and oxygen flush valve
50-55 psi

Question 7

What is the flow meter?

Answer 7

Controls the rate of gas delivery to vaporizer and to the patient’s breathing circuit; first part of low pressure system

Question 8

T/F Each gas needs its own flowmeter

Answer 8

TRUE

Question 9

Where should the O2 flowmeter be?

Answer 9

Always the last one in the circuit

Question 10

What is the vaporizer?

Answer 10

Adds a specific amount of volatile liquid anesthetic to the oxygen/gas mixture

Question 11

What are the two types of vaporizers and which one is more commonly used?

Answer 11

Vaporizer in circuit

Vaporizer out of circuit (Winner)

Question 12

What is the common gas outlet?

Answer 12

Leads from the anesthesia machine to the breathing circuit

Question 13

What are the components of the low pressure system?

Answer 13

Flowmeter, Vaporizer, and common gas outlet

Question 14

What are the two different breathing systems?

Answer 14

Rebreathing system (Most common)
Non-rebreathing system

Question 15

What are the qualifications for using standard vs pediatric circuits in rebreathing?

Answer 15

Standard: >15 kg
Pediatric: 7-15 kg

Question 16

For non-rebreathing systems what are the flow rates for induction, recovery, or changes in depth? What about maintenance?

Answer 16

50-100 ml/kg/min

20-40 mL/kg/min

Question 17

How do you calculate tidal volume?

Answer 17

10-15 mL/kg x Patient’s weight in Kg

Question 18

How do you determine the appropriate size of the reservoir bag?

Answer 18

5-6 X Patients tidal volume

Question 19

What is the non-rebreathing system ideal for?

Answer 19

Patients less than 7 kg

Question 20

What are the recommended flow rates for partial rebreathing and no rebreathing?

Answer 20

Partial: 150-200 mL/kg/min

No: 400-600 mL/Kg/min

Question 21

What are the different types of breathing circuits in a non-rebreathing system?

Answer 21

Bain Circuit

Modified Jackson Rees

Question 22

T/F A non-rebreathing system constains CO2 absorbent

Answer 22

FALSE

Question 23

What is the purpose of a waste scavenging system?

Answer 23

Direct waste gas from the breathing system out of the immediate workspace and into the atmosphere

Question 24

How do you calculate a time constraint?

Answer 24

Volume of the circuit / Oxygen flow rate

Question 25

How many time circuits does it take to have a 99.9% change in the system?

Answer 25

5

Question 26

What % change occurs after 1 time constraint?

Answer 26

63.2%

Question 27

What are the two types of scavenging systems?

Answer 27

Active: uses a vacuum or fan-blower system
Passive: Open to atmospheric pressure