Breathing Circuits and Mask/Chamber Induction

Question 1

a non-precision vaporizer is considered what kind of vaporizer (in or out of circuit)

Answer 1

vaporizer-in-circuit (VIC)

Question 2

what type of vaporizer: O2 flows into breathing circuit from flow meter, circulates before entering vaporizer

Answer 2

Vaporizer-in-Circuit (non-precision vaporizer)

Question 3

how to estimate % of anes gas given when using a non-precision vaporizer ( what factors to look at)

Answer 3

look at respiration rate and depth, if increasing=more gas is passing
or consider room temp, the higher the room temp the more vaporization of gas is occurring

Question 4

a non-precision vaporizer is safe to use w what anes gas

Answer 4

methoxyflurane (bc low VP)

Question 5

a precision vaporizer is considered what kind of vaporizer (in or out of circuit)

Answer 5

vaporizer-out-of-circuit (VOC)

Question 6

what type of vaporizer: O2 flows into vaporizer BEFORE entering breathing circuit

Answer 6

Vaporzier-out-of-circuit (precision vaporizer)

Question 7

a total rebreathing system is used for patients of what size

Answer 7

15 lb or larger

Question 8

in a total rebreathing system, how often is fresh gas added

Answer 8

every time patient inspires

Question 9

in which breathing circuit is pop-off valve closed

Answer 9

total rebreathing (circle system)

Question 10

in which breathing circuit is pop-off valve partially open

Answer 10

partial rebreathing system

Question 11

danger of a total rebreathing system

Answer 11

pressure can build up (watch pressure manometer) which can cause lung damage

Question 12

total rebreathing system O2 flow rate

Answer 12

15ml/kg/min

Question 13

a partial rebreathing system is used for patients of what size

Answer 13

15 lbs or larger

Question 14

O2 flow rate of partial rebreathing system

Answer 14

25-50 ml/kg/min

Question 15

downside of a partial rebreathing system compared to total rebreathing

Answer 15

more O2 used, less cost-efficient

Question 16

a non-rebreathing system is used on animals of what size

Answer 16

less than 15 lbs/ 7 kg

Question 17

O2 flow rate of non-rebreathing system

Answer 17

130-300 ml/kg/min

Question 18

pros of a non-rebreathing system

Answer 18

allows for rapid change in anes depth (more safe bc can quickly be altered if too deep)

Question 19

why non-rebreathing systems used for small patients

Answer 19

less respiratory strength is needed, requires less lung strength, less temp is lost, less dead space

Question 20

how to pressure check a non-rebreathing system

Answer 20

1) close toggle switch (acts like pop-off valve)
2) occlude patient connector and scavenger hose
3) turn on flow meter to fill bag, if it stays inflated for >10 sec = no leak

Question 21

alternative routes of induction (besides injectables)

Answer 21

mask or chamber induction

Question 22

in what cases mask induction and chamber induction is useful

Answer 22

animals w/ underlying disease (avoid injectable drug side effects), fractious, induce/recover quickly, pregnant animals (avoid fetus side effects)

Question 23

mask induction works best w what anes gases

Answer 23

ones w high VP (iso, sevo, halothane) not desflurane bc smell can cause coughing and breath holding

Question 24

mask induction procedure

Answer 24

give 100% O2 for 2-3 min allowing patient to adjust

set vaporizer to .5% iso, gradually increase until at 3-5%

Question 25

mask induction flow rate for <10kg animal v over 10kg

Answer 25

<10kg= 1-3 L/min

over 10 kg= 3-5 L/min

Question 26

downsides of chamber induction

Answer 26

risk of vomiting, may have prolonged stage II (involuntary movements and struggling), more gas is wasted than if mask induction were used

Question 27

when to not use chamber induction

Answer 27

if quick intubation is needed (brachycephalic, unfasted, resp. disease, diaphragmatic hernia)

Question 28

O2 flow rate of chamber induction, iso set to __%

Answer 28

5L/min, 3-5% iso