Breathing Systems and Scavenging

Question 1

Two types of patient breathing systems are

Answer 1

re-breathing and non-rebreathing

Question 2

Hoses for re-breathing (2)

Answer 2

circle and universal F

Question 3

Hoses for non-rebreathing

Answer 3

Mapleson A-F (bain/modified mapleson D and Mapleson F most common)

Question 4

What is anatomic dead space?

Answer 4

airway structures that do not participate in gas exchange (oral cavity, larynx, trachea, bronchi)

Question 5

what is mechanical dead space?

Answer 5

portion of anesthesia circuit where bidirectional flow is occurring (rebreathing of exhaled gases)

Question 6

T/F: breathing tubes in a circle system constitute mechanical dead space

Answer 6

False - the flow is unidirectional so there is no rebreathing

Question 7

Which is not an advantage of a re-breathing system?
A) saves money
B) decreases environmental pollution
C) lower resistance due to valves
D) patient breathes warm, humidified gases

Answer 7

C - the resistance is increased due to valves, and this is a disadvantage

Question 8

Which system has more potential for leaks?

Answer 8

re-breathing because more components

Question 9

The ______ is a shared connection between rebreathing and non-rebreathing systems

Answer 9

fresh gas inlet

Question 10

T/F: the pop-off or adjustable pressure limiting valve should always be closed.

Answer 10

FALSE should always be open

Question 11

When should you close the APL/pop off valve?

Answer 11

1) leak checking machine before use

2) administering IPPV (manual or mechanical positive pressure ventilation)

Question 12

Most commonly used in a CO2 absorber

Answer 12

soda lime

Question 13

T/F: purple soda lime means it is exhausted/

Answer 13

False - it just means it is actively producing heat and water from the reaction between CO2 and soda lime

Question 14

3 patient signs of CO2 absorbent exhaustion.

Answer 14

1) increased RR
2) increased HR and BP
3) red MM (CO2 induced vasodilation)

Question 15

3 functions of reservoir bag.

Answer 15

1) inspiratory reserve for patient
2) administer IPPV
3) allow anesthetist to monitor ventilation

Question 16

You need to choose a reservoir bag for a 40kg dog. What size bag do you use?

Answer 16

~15ml/kg x 6
so 15ml x 40 kg x 6
= 3600ml
always round up
Use a 4L bag

Question 17

Typical O2 flow rates for small animals < 50kg?

Answer 17

Induction and recovery - 50-100ml/kg/min

Maintenance - 20-50ml/kg/min

Question 18

Typical O2 flow rates for large animals?

Answer 18

induction and recovery - 20-50ml/kg/min

Maintenance - 10-20ml/kg/min

Question 19

2 things not present in non-rebreathing system

Answer 19

soda lime canister and unidirectional valves

Question 20

Which breathing system would you use for a small patient <3kg?

Answer 20

non-rebreathing

Question 21

Which breathing system requires a higher gas flow rate?

Answer 21

non-rebreathing

Question 22

approximate oxygen flow rate in a non-rebreathing system?

Answer 22

~300ml/kg/min

Question 23

Most common ETT in vet med?

Answer 23

Murphy

Question 24

Which ETT would you use in avian patients?

Answer 24

Cole

Question 25

What aspect of ETT has the largest effect on gas flow?

Answer 25

radius

Question 26

A _____ (instrument) makes intubation safer and easier.

Answer 26

Laryngoscope

Question 27

An example of an active waste gas scavenging system?

Answer 27

piped vacuum

Question 28

F air canister is what kind of scavenging system?

Answer 28

passive

Question 29

F air canister must be discarded when it has gained ____.

Answer 29

50g

Question 30

What gas does an Fair canister not absorb?

Answer 30

N2O