Learning how a real anesthesia machine is supposed to work? Each of
the following sections explains some learning objectives and how anesthesia
machine functions are simulated in VAM.
Color coding of gases
||You might be in for a surprise when
you work outside the United States!
The color code for oxygen is green in the U.S. but white internationally.
Several countries have their own unique color codes.
The role of the quick-connect & pin-index safety systems in preventing
Cylinder vs. pipeline oxygen supply
What are pressure regulators and how do they work?
Pressure gauge readings
Can a cylinder be empty with the gauge still indicating a positive pressure?
Function of the fail-safe device
Will the fail-safe device always prevent delivery of a hypoxic mixture?
Low pressure alarm
Will a decrease in oxygen pressure always trigger the low pressure alarm?
Low pressure alarm (when the pressure increases, the alarm goes off
and the canister fills, but when the pressure decreases, the canister
will empty, causing the alarm to go off again).
Ventilator drive gas circuit
Will the ventilator function in the absence of a pressurized O2 supply?
Using the oxygen flush
What happens if the oxygen flush is pressed during the inspiratory phase
of mechanical ventilation?
What happens if oxygen flush is pressed during the expiratory phase
of mechanical ventilation?
Should you / can you use the O2 flush for jet ventilation?
Mandatory minimal flow of oxygen
Why you can't turn the oxygen flowmeter to zero when the machine is
The Link-25 system. Does it always safeguard against hypoxia?
Common gas outlet check valve
What could happen if there was no check valve on the common gas outlet.
Contribution of fresh gas flow to the tidal volume
Why high fresh gas flows may contribute significantly to tidal volumes.
Function of inspiratory and expiratory unidirectional valves
Determining the amount of dead space in the circuit.
CO2 absorber function
How to create a non-rebreathing system.
Mechanical Ventilation Systems
The function of the ventilator spill valve (also called the pressure
relief valve or exhaust gas valve).
The function of the proportional flow control valve.
The different locations of the APL (Adjustable Pressure Limiting) valve
in Modulus I and II machines and how this may affect your delivered
tidal volume during mechanical ventilation.
The function & different settings of the APL valve.
Why the increase in compliance of the manual bag with increasing bag
volume may be important.
The Scavenging bag
What is its function?
What happens when it is overinflated?
The positive and negative pressure relief valves
Their function and the reason why they could prevent accidents.
The vacuum adjustment valve
What is the optimal setting ? What if you suction too much or too little