Lecture 3: the anesthesia machine Flashcards
Which parts of the anesthesia machine are part of the high pressure system?
- Oxygen cylinder
- Cylinder valve
- Cylinder pressure gauge
- Regulator or reduction valve
Which part of the anesthesia machine are part of the intermediate pressure system?
Oxygen flush/bypass valve
Which parts of the anesthesia machine are part of the low pressure system?
- Flow meter
- Vaporizer
- Common gas outlet
- Common gas inlet
- One-way valves
- Pop-off valve
What are the types of compressed gas in cylinders?
E cylinder
G and H cylinders set up as central supply system
Describe cryogenic liquid supply of oxygen
Large liquid oxygen containers installed at facilities that have a fairly constant demand
How does an oxygen concentrator work?
Increases O2 concentration by absorbing nitrogen onto a molecular sieve and allows O2 and trace gases to pass through resulting in O2 concentration of 90-96%
What is the capacity of an E cylinder?
660 L (2200 PSI)
What is the capacity of a H cylinder?
2900 L (2200 PSI)
What is the function of a gas regulator?
Reduces the gas pressure from the cylinder to a usable level of a constant 50 psi
What is the function of a cylinder pressure gauge?
Allows user to calculate remaining liters in tank or pipeline pressure
What is the function of the oxygen flush valve
Receives O2 from the pipeline inlet or cylinder pressure regulator and directs a high unmetered flow directly to the common gas outlet
What situation should you NEVER use the flush valve?
When connected to a non rebreathing system
What is the minimum L/min flow rate for the flow meter to be set on inorder for a reliable vaporizer output?
500-2000mL/min
No lower than 0.5L/min
What are some of the disadvantages for unidirectional valves?
Increases resistance to breathing
If one or both valves are leaky then the patient will rebreathe CO2
What is the function of the vaporizor?
A device that changes liquid anesthetic agent into its vapor and adds a controlled amount of that vapor to the fresh gas flow going into the patient breathing system
T/F: the vaporizer is specific to a certain substance, meaning that you cannot use one vaporizer for two different anesthetics.
True
How do you calculate the size reservoir bag needed for a patient?
BW (kg) x tidal vol. (mL/kg) x 5
What size reservoir bag would you need for a 35lb dog?
(35 / 2.2) x 10 mL/kg x 5 = 0.795L => 1L
When should you open the pop-off valve?
It must be kept open at all times
What are the top 3 killers of anesthesia?
- Closed pop off valve
- Too little O2
- Too high vaporizer setting
