Breathing Systems Pt. 1 (Exam II)

Question 1

This type of circuit is characterized by no reservoir bag and no rebreathing.

Answer 1

Open Circuit

Question 2

This type of circuit is defined by a reservoir bag and complete rebreathing. This circuit is also dependent on fresh gas flow.

Answer 2

Closed Circuit

Question 3

This type of circuit is characterized by a reservoir bag with no rebreathing.

Answer 3

Semi-open Circuit

Question 4

This type of circuit is characterized by a reservoir bag and partial rebreathing.

Answer 4

Semi-closed Circuit

Question 5

What component of the anesthesia machine is indicated by 1 on the figure below?

Answer 5

Common (Fresh) gas inlet

Question 6

What component of the anesthesia machine is indicated by 2 on the figure below?

Answer 6

Pressure gauge

Question 7

What characteristics are necessary for unidirectional valves?

Answer 7

• Must open widely w/ little pressure
• Must close rapidly w/ no backflow
• Metal disc w/ low resistance & high competence.

Question 8

What anesthesia breathing system component directs respiratory gas flow in the correct direction?

Answer 8

Inspiratory/Expiratory valves

Question 9

Which valve opens on inspiration, closes on exhalation, and prevents backflow of exhaled gas?

Answer 9

Inspiratory valve

Question 10

Where is a mask supposed to fit on a patient’s face?

Answer 10

Inbetween the interpupillary line and the groove between the mental process and alveolar ridge.

Question 11

What size is the connection that fits the mask to the Y-piece of the machine.

Answer 11

22mm female connector.

Question 12

What are the general benefits of connectors/adapters on the airway portion of the anesthesia machine?

Answer 12

• extends distance between patient and breathing system
• change angle of connection
• allow flexibility

Question 13

What are the general disadvantages of connectors/adapters on the airway portion of the anesthesia machine?

Answer 13

• increased resistance
• increased dead space
• additional points of failure/disconnection

Question 14

How long is breathing tubing?
How much internal volume does it typically have?

Answer 14

• 1 meter long
• 400-500 mL/m of length

Question 15

What type of flow is typically present in corrugated breathing tubing?

Answer 15

Turbulent due to corrugation

Question 16

Does adding longer tubing increase dead space?

Answer 16

Interestingly no it does not

Only adds dead space if bidirectional air flow is occurring.

Question 17

What adds dead space?

Answer 17

• Y-piece attached to patient due to unidirectional gas flow

Question 18

At what pressure should a circuit pressure check be done?

Answer 18

30 cmH₂O

Question 19

What is required for dead space?

Answer 19

Bidirectional gas flow

Includes anatomic dead space, ETT, and Y-piece.

Question 21

Which valve opens on exhalation & prevents rebreathing?

Answer 21

Expiratory valve

Question 22

What shape do breathing/reservoir bags have?

Answer 22

Ellipsoidal

Question 23

What volume do breathing bags have?

Answer 23

3L for adults

(0.5 - 6L range)

Question 24

What is the minimum pressure of a breathing bag?

Answer 24

30 cmH₂O

Question 25

What is the max pressure of breathing bags?

Answer 25

40 - 60 cmH₂O

Question 26

Plastic bags have ____ the distending pressure of rubber bags.

Answer 26

twice

Question 27

What functions does the breathing/reservoir bag serve?

Answer 27

- Reservoir for gasses & O₂ - Manual ventilation - Assistance w/ spontaneous ventilation - Protection from excessive positive pressure - Visual/tactile monitoring of ventilation - Protection from excessive pressure

Question 28

Where is the preferred location for the fresh gas inlet?

Answer 28

Between CO₂ absorbent and inspiratory valve

Question 29

What is the purpose of the APL (adjustable pressure limiting) Valve?

Answer 29

- Permits gas to leave the circuit to the scavenging system - Controls pressure in the breathing system

Question 30

Turning the APL valve in a clockwise motion will ______ pressure.

Answer 30

increase

Question 31

Turning the APL valve in a counterclockwise motion will ______ pressure.

Answer 31

decrease

Question 32

How many turn are required to go from fully open to fully closed on the APL valve?

Answer 32

1-2 clockwise turns

Question 33

What is the purpose of the side/center tube located in the absorbent cannister?

Answer 33

Returns gas to the patient

Question 34

What is the chemical formula for soda lime?

Answer 34

Ca(OH)₂

Question 35

What is the chemical reaction that occurs with soda lime in a CO₂ absorbent cannister?

Answer 35

CO₂ + Ca(OH)₂ → CaCO₃ + H₂O + heat

Question 36

What are the components of soda lime?

Answer 36

- Calcium hydroxide (80%) - Sodium & potassium hydroxide (5%) - Water (15%)

Question 37

When does soda lime become exhausted?

Answer 37

When all hydroxides become carbonates

Question 38

How much CO₂ can soda lime absorb?

Answer 38

19% of its weight 100g can absorb 26L of CO₂

Question 39

What absorbent has greater absorption capacity and is used in submarines and spacecraft?

Answer 39

Lithium Hydroxide

Question 40

Which absorbent is responsible for compound A & CO formation?

Answer 40

Calcium Hydroxide Lime

Question 41

What is Litholyme?

Answer 41

Lithium chloride

Question 42

What are the benefits of Litholyme (Lithium chloride) ?

Answer 42

- No compound A formation - No reaction with inhaled anesthetic agents - Low exothermic reactivity, and low risk of fire - Better for environment

Question 43

What absorbent has **no** color indicator?

Answer 43

Spira-Lith (Anhydrous LiOH)

Question 44

What are the benefits of Spira-Lith?

Answer 44

- Large reaction surface area - ↓ temperature production - Long duration - Cheap

Question 45

At what pH do absorbents undergo color change?

Answer 45

10.3 pH > 10.3 (absorbent is colorless & fresh) pH < 10.3 (exhausted & purple absorbent)

Question 46

What dyes are used in CO₂ absorbents?

Answer 46

- Ethyl Violet - Ethyl orange - Cresyl yellow

Question 47

What is the purpose of the mesh located in CO₂ absorbents?

Answer 47

Maximize absorption and minimize resistance

Question 48

What will excess liquid water do inside a CO₂ absorbent cannister?

Answer 48

- ↓ surface area - ↓ absorbent efficiency

Question 49

Approximately how much of a CO₂ absorbent cannister's volume is gas?

Answer 49

½

Question 50

What is channeling and its consequence?

Answer 50

- Small passage ways allowing gas to flow through a defined route - Decreases functional absorptive capacity

Question 51

How can channeling be minimized?

Answer 51

- Circular baffles - Permanent mounting - Prepackaged cylinders - Avoiding over packing

Question 52

Which gasses produced the most CO? The least?

Answer 52

Desflurane ≥ Enflurane > Isoflurane > Halothane = Sevo

Question 53

Why should sevoflurane use with dessicated strong base absorbents (baralyme, LiOH) be avoided?

Answer 53

High risk of fire

Question 54

What component of the anesthesia machine is indicated by 3 on the figure below?

Answer 54

Inspiratory Unidirectional Valve

Question 55

What component of the anesthesia machine is indicated by 4 on the figure below?

Answer 55

APL valve

Question 56

What component of the anesthesia machine is indicated by 5 on the figure below?

Answer 56

Expiratory Unidirectional Valve

Question 57

What component of the anesthesia machine is indicated by 7 on the figure below?

Answer 57

Reservoir Bag

Question 58

What component of the anesthesia machine is indicated by 8 on the figure below?

Answer 58

Absorbent Cannisters

Question 59

A unidirectional valve is broken. Is the attached inspiratory limb considered dead space?

Answer 59

Yes, now bidirectional gas flow is occurring. If valve is fixed then the limb will not be considered dead space again.