Small Animal Anaesthesia

Question 1

Bag choice

Answer 1

3x tidal volume (equivalent to maximum lung capacity)

Question 2

T piece

Answer 2

<10kg
Non-rebreathing
Tidal volume: 15
Circuit factor: 2.5

Question 3

Bain

Answer 3

10-30kg
Non-rebreathing
Circuit factor: 2.5
Relies on high FGF
Can be used for IPPV
(Uncommon)

Question 4

Lack or mini lack

Answer 4

Standard >10kg, mini 2-10kg
Distinguishing feature is 2 parallel tubes
Circuit factor: 1 (more O2 efficient)
Non-rebreathing
Not suitable for prolonged IPPV

Question 5

Circle

Answer 5

> 10kg
Suitable for IPPV
Soda lime must be changed regularly
Rebreathing

Question 6

Humphrey ADE circle

Answer 6

All patients (remove soda lime if smaller)
Non-rebreathing/rebreathing

Question 7

Calculations for non-rebreathing systems

Answer 7

FGF = MV x CF
MV = TV x RR
TV = 10ml/kg
RR = 20

Question 8

Calculating FGF for rebreathing systems

Answer 8

5-10ml/kg/minute
(>10ml may be necessary if used as low flow circuit)

Question 9

Leak test prior to anaesthetic

Answer 9

Plug the “patient end” using hand/finger
Turn oxygen on
Close APL Valve
Allow reservoir bag to fill (so no creases are visible)
Turn oxygen off
Watch bag for creases appearing (they shouldn’t)
Open APL valve and empty bag with finger still plugging patient end