Clinical Anaesthetic Machines & Equipment

Question 1

What is the purpose of anaesthetic machines?

Answer 1

to deliver anaesthetic gases/vapours and oxygen to the patient

Question 2

What does the oxygen flush do?

Answer 2

Pure Oxygen comes out when used, comes through common gas outlet as the anaesthetic agent
- delivers pure oxygen

Question 3

What is the purpose of the oxygen flush button?

Answer 3

to quickly flush all anaesthetic agent OUT OF THE SYSTEM

Question 4

What is an oxygen concentrator/generator?

Answer 4

filters air & concentrates air
Creates up to 95% Oxygen through a concentrator

Question 5

What does a pressure gauge do?

Answer 5

measures pressure of gas in cylinder or pipeline

Question 6

What is the pipeline pressure?

Answer 6

400-500 kPa (4-5 Bar)

Question 7

In Europe, how much pressure is in a new cylinder?

Answer 7

137 BAR/13,700 kPa

Question 8

What does the regulator/reducing valve do?

Answer 8

• reduces pressure of gas in cylinder to a level suitable for the patient
• regulates pressure & keeps it constant
• allows fine and accurate control of gas flow

Question 9

What does a flowmeter do?

Answer 9

measures gas flow in litres per minute

Question 10

flowmeters are specifically calibrated for…

Answer 10

the density & viscosity of each gas

Question 11

Each gas MUST have its own

Answer 11

flowmeter

Question 12

The bobbin in a flowmeter floats on a

Answer 12

column of gas

Question 13

What does a vaporiser do?

Answer 13

allows controlled vaporisation of volatile agents

Question 14

Vaporisers MUST NOT BE…

Answer 14

TILTED! (by greater than 15 degs)

Question 15

What should you do if you tilt a vaporiser more than 15 degrees?

Answer 15

Flush it properly, do NOT attach to patient!

Question 16

Each anaesthetic agent vaporiser has a different way of filling so…

Answer 16

you cannot accidentally mix the gases inside the same vaporiser

Question 17

When do you use the oxygen flush button?

Answer 17

in emergencies only to flush all anaesthetic out of the system

Question 18

Why do you need to use the oxygen flush button w/ extreme caution?

Answer 18

it will rapidly overinflate the lungs of your patient and cause barotrauma

Question 19

if you need to push the flush button, what is the proper way of doing it while there is a patient undergoing an anaesthetic procedure?

Answer 19

• disconnect p
• cap end of system
• flush into the scavenging system
• reconnect into system
• turn off anaesthetic agent
• P now only receives O2

Question 20

Why should you never use the O2 flush to fill the reservoir bag?

Answer 20

Can easily lead to pneumothorax

Question 21

How fast does the rate of O2 flush through the system?

Answer 21

35 L/min (600 ml/sec)

Question 22

What is the common gas outlet?

Answer 22

For connection of breathing systems

Question 23

When attaching to the common gas outlet, what is important to do to secure it?

Answer 23

“Push & Twist” to lock it in so that it does not disconnect from system

Question 24

What gas(es) come out at the outlet?

Answer 24

Oxygen +/- anaesthetic agent

Question 25

ETT may be manufactured…

Answer 25

with or without a cuff

Question 26

Why should you use a cuff on an ETT?

Answer 26

It ensures a good seal between the tube & the tracheal mucosa and is important to preventing regurgitated material from entering the lungs

Question 27

All ETT have a…

Answer 27

14 mm connector that connects them to the breathing system

Question 28

The connector on an ETT must be connected to the breathing system by a…

Answer 28

“push and twist” movement to prevent accidental disconnection between the ETT and the breathing system

Question 29

How do you measure an ETT for an individual patient?

Answer 29

From the end that goes into the trachea, place the tube in a fashion that runs from the thoracic inlet to the tip of the nose.

Question 30

What is important to remember about the markings on ETT tubes for measuring?

Answer 30

They are the same size no matter what tube you are using

Question 31

What species should only use ETT tubes without cuffs?

Answer 31

Birds b/c they have complete tracheal rings and the cuff when expanded could rupture the trachea.

Question 32

Why do we inflate the cuff on an ETT?

Answer 32

• to prevent oral secretions/blood/regurge from entering the lungs
• protects those in the room from inhalant anaesthetics so go straight into the scavenging system

Question 33

How MUCH should you inflate the cuff on an ETT?

Answer 33

just enough that you no longer hear air escaping around the edges of the tube

Question 34

What are the potential consequences of overinflating the ETT cuff?

Answer 34

Pressure necrosis or tracheal rupture

Question 35

What are the advantages of an ETT?

Answer 35

• Protect airway from regurgitation (if cuff inflated)
• Essential in brachycephalic dogs / pigs /wild animals / ruminants
• Less atmospheric pollution from anaesthetic gases of the workplace
• Allows control of ventilation
• Necessary for IPPV

Question 36

What are potential disadvantages of using an ETT?

Answer 36

• could intubate the oesophagus
• intubation of the main stem bronchus
• kinking of ETT allowing no inhalation or exhalation to occur
• damage to the larynx, trachea, laryngeal spasm
• undiscovered disconnection

Question 37

What equipment do you require for intubation?

Answer 37

Laryngoscope w/ range of blade sizes
Mouth gag & light source
Lidocaine spray (cats)
KY Jelly/Lube
Swabs/empty syringe/bandage

Question 38

If you are anticipating a difficult intubation, what instrument could be used to assist you?

Answer 38

A bougie with the ETT railroaded over it

Question 39

What are the 5 main things to keep in mind when using an ETT?

Answer 39

• ensure cleanliness of the tube
• always check cuff & connector by leak testing
• check length against the patient
• use widest possible
• insert gently

Question 40

What is the typical dosing of lidocaine in a cat

Answer 40

2 mg/kg

Question 41

How long does it take for lidocaine to work as a splash block for laryngeal spasm in a cat?

Answer 41

20-30 sec