Anaesthetic machines

Question 1

If gauge registers 6,850 kPa how many litres of O2 remain?

Answer 1

Vused = Pused/Pfull x Vfull
Vused = 6850/13700 x 680 = 340 L

Question 2

How many literes does a full E sized cylinder contain

Answer 2

680l

Question 3

Should APL valve be open or close when not giving IPPV

Answer 3

FULLY OPEN

Question 4

Name non rebreathing systems

Answer 4

Lack (incl. MiniLack)
T-piece (various versions)
Bain

Question 5

Equation for calculating FGF using circuit factor

Answer 5

MRV = resp rate x tidal volume (10-20 ml/kg)
FGF = MRV x “circuit factor”

Question 6

Circuit factor of lack

Answer 6

0.8-1

Question 7

Circuit factor of Tpiece

Answer 7

2.5-3.5

Question 8

Circuit factor of bain

Answer 8

1-3.5

Question 9

Calculate FGF required for 10 kg dog taking 20 breaths/min & using a Lack

Answer 9

20 breaths/min x 15 ml/kg x 10 kg x 1 = 3L/min

Question 10

Calculating FGF using ml/kg/min

Answer 10

Lack 150-200ml/kg/min
T-piece 400-600ml/kg/min
Bain 200-600ml/kg/min

Question 11

Calculate FGF required for a 10 kg dog using a Lack

Answer 11

200 ml/kg/min x 10 kg= 2 L/min

Question 12

When should I use a parallel lack

Answer 12

Patients 10 kg & over
Not suitable for prolonged IPPV

Question 13

When should I use a MiniLack system

Answer 13

Patients 10 kg & less
Not suitable for prolonged IPPV

Question 14

Jackson Rees modification of a T piece has what benefits?

Answer 14

Allows observation of respiration
Allows more control during IPPV

Question 15

Do T pieces have an APL valve

Answer 15

No

Question 16

What is a mapleson D tpiece

Answer 16

Adaptation to facilitate scavenging
Includes closed reservoir bag & APL valve

Question 17

When should I use a T-piece (Modified/basic/Mapleson D)

Answer 17

Patients up to 10 kg
Suitable for IPPV

Question 18

Difference between coaxial bane and lack

Answer 18

COAXIAL BAIN -fresh gas passes up INner tube and expired gas out via outer tube
COAXIAL LACK -fresh gas passes up outer tube and expired gas out via inner tube

Question 19

When should I use a T-piece (Modified/basic/Mapleson D)

Answer 19

Patients 10 kg & above
Suitable for IPPV

Question 20

T/F Rebreathing systems are suitable for small patients

Answer 20

False! They are unsuitable as there is a greater resistance