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Flashcards in Cicuits Deck (23)
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1

How do non-rebreathing circuits operate

Rely on high FGF to flush expired CO2 from system do it cannot be re-breathed

2

Ayre’s t-piece features (3)

Small animals <10kg
High FGFR
Suitable for IPPV

3

Ayre’s t-piece circuit factor

2.5-3

4

Bain features (4)

larger patients >10kg
Double tubing
High FGFR
Suitable for IPPV

5

Bain circuit factor

2.5-3

6

Check specific to Bain

Check that inner tube not detached from system

7

Magill features (3)

patients >10kg
Lower FGFR than t-piece and Bain
Not suitable for prolonged IPPV

8

Magill circuit factor

1-1.5

9

Parallel lack features (3)

For patients >10kg
More economical than Bain for large patients
- lower FGFR
Not suitable for prolonged IPPV

10

Mini-lack features (3)

For patients <10kg
Lower FGFR
Not suitable for prolonged IPPV

11

Parallel and mini-lack circuit factor

1-1.5

12

Advantages of non-rebreathing circuits (6)

Simple construction
Inexpensive
No soda lime
Lower resistance than RB
- some good for small patients
Inspired gas volume comparable to vaporiser setting
Volatile agent concentration can be altered rapidly

13

Disadvantages of NRB circuits (4)

High FGFR
High volatile agent consumption
Expired moisture and heat loss
- cold inspired gas
Different FGFR required for different circuits

14

Re-breathing circuit features (3)

Requires lower FGFR
Higher resistance
- unsuitable for small patients
Allows conservation of heat and moisture

15

Circle features (7)

High resistance
Soda lime absorbs CO2
For patients <10kg
- more economical than Bain/lack
Preserves exhaled heat and moisture
Less pollution
Cost efficient re. O2 and VA

16

Circle FGFR

100ml/kg/min ~15mins
10ml/kg/min after ~15mins

17

Humphrey ADE features (6)

Adjustable lever and detachable SLC allows use as RB or NRB
Adjustable level allows IPPV
Can use SLC to act as circle
Suitable for wide range of patient weights
Economical
- can be run at low FGFR
Preserves expired heat and moisture

18

Soda lime checks and when should be changed and how

Checked regularly for
- cracks
- exhaustion
Changed at 2/3 exhausted
Gloves and mask worn to change

19

Advantages of RB circuits (4)

Lower FGFR
Economical
- lower O2 and VA consumption
Expired heat and moisture conserved
Less pollution than other systems

20

Disadvantages of RB circuits (5)

Expensive to buy
Higher resistance
Soda lime must be changed regularly
Changes in vaporiser level slow to alter depth
N2O cannot be used in low-flow closed systems

21

Circuit safety checks (6)

Correct assemble
Kinks and damage
Contamination of tubing or bag
Leak test
APL valve open
Check soda lime

22

Reason for use of induction chamber

For small mammals where restrain difficult or overly stressful

23

Features of induction chamber (5)

Airtight
Transparent to allow monitoring
Durable material
Inlet for VA / outlet for waste gas
High risk of environmental pollution