Dr Gas Vet’s first post in a helpful series all about the veterinary anaesthetic machine
Originally published on the Vet Anaesthesia Tips blog 29/7/2016: The Anaesthetic Machine: Made Simple. Scroll down to find links to the whole series.
This is the beginning of a series of blogs about the anaesthetic machine. My aim is to provide a basic and simple understanding of how your anaesthetic machine works.
How does your anaesthetic machine work?
Anaesthetic machines can be very confusing, especially if you only use them occasionally or if you are faced with a new machine. A thorough understanding of the basic elements of an anaesthetic machine should make it possible for you to easily set up, test and troubleshoot any machine.
When I talk about the ‘anaesthetic machine’ I don’t include breathing systems. These should be considered separately from the machine itself. Hence, I do not include soda lime canisters, APL valves or expiratory/inspiratory valves here. These may be permanently attached to your anaesthetic machine, but they are actually part of a rebreathing CIRCLE system.
Understanding that these elements are part of a breathing system rather than the machine itself makes life much easier when it comes to attaching a breathing system, especially a non-rebreathing (e.g. Bain) system!
The basic elements…
The basic elements that should be present in any anaesthetic machine are:
- A gas supply (cylinders and/or pipeline)
- Pressure gauges (for gas supply)
- Pressure-reducing valves (for gas supply)
- Oxygen failure warning device
- Pressure relief valve
- Oxygen flush system
- Common gas outlet
- Gas scavenging system (not technically part of the anaesthetic machine itself, but important to mention)
The above elements are listed in order from a gas supply (highest pressure), to the common gas outlet where a patient’s breathing system is attached (lowest pressure).
I will go through each of these elements separately over the next few months.
I will attach photos and videos to illustrate my blogs as we go along. But it’s a great idea to have a look at the anaesthetic machines in your practice as we go; to identify each element and understand how it works.