Medical Gas Systems Flashcards
What are two sources of gas for the anesthesia machine?
pipeline, ecylinder
What is the DISS system? What’s it for?
Diameter Index Safety System, pipeline gases
What are properties of the DISS system? (4)
non interchangeable connections for medical gas
connection is: body, nipple, nut
can only fit together w/ the right connections
every anesthesia machine uses it
What is the PISS system? What’s it for?
Pin Index Safety System, gas cylinders
What are the properties of the PISS system? (3)
series of pins to connect gas cylinders to matching yoke
each gas has unique pin combo
prevents wrong incorrect connections
What are the pin indexes for the following gases?
air O2 N2O CO2 Entonox
air 1,5 O2 2,5 N2O 3,5 CO2 1,6 Entonox 7
What is the link proportioning system?
A safety system, a fail safe mechanism that prevents hypoxic mixture of gas. If you turn on N2O, the system will also turn on O2. The ratio can never drop below 3:1, or at least room air concentration of O2.
What is a MAC of N2O?
105%
What does MAC mean?
minimum alveolar concentration, end expiration concentration of anesthetic required to suppress movement to surgical stimuli in 50% of subjects
Do electronic flow meters have a link proportioning system?
Yes, it is internalized
What are the US system’s color codes for the following gases?
O2 N2O Air N2 He Vacuum Waste
O2 green N2O blue Air yellow N2 black He brown Vacuum white Waste purple
How many L of O2 and at what pressure is a full e-cylinder?
660 L, 2000 psi
How many L of N2O and at what pressure is a full e-cylinder?
1590 L, 745 psi
True or false, pressure determines the fullness of a tank of N2O?
False (weighing the tank does, because as long as liquid remains in tank, pressure will read 745 psi)
How much does a full ecylinder of N2O weigh?
20.7 lbs
How much does an eyclinder with no liquid N2O weigh?
14.2 lbs
How much does an eyclinder tank weigh empty?
12.9 lbs
What formula is used to estimate how much time you have left in an ecylinder?
psi in tank/(200 x L/min flow of O2) = hours remaining of gas
Who specifies the purity of medical gases?
US Pharmacopoeia
Who establishes the requirements for manufacturing, filling, qualification etc.?
Department of Transportation
What permanent markings are found on ecylinders? (8)
date, serial numbers, test markings, cylinder specification, type of material, service/working pressure, neck ring ID, retest markings (q5 years, q10 years if a star), + means over filled by 10%
Whats a diamond label on ecylinder indicate?
denotes hazard class
What is in charge of the labeling system for gas cylinders?
Compressed Gas Association (CGA)
How do you properly use a cylinder tag?
When first opened, rip off portion of tag that says FULL, then when empty rip off portion that says IN SERVICE. Leaves EMPTY label behind signaling it needs to be refilled.
What are 7 safe handling procedures for cylinders?
never stand upright without support
never leave empty on the machine
never leave plastic tape on port while installing cylinder
never rely on cylinder color for identification
never oil valves - fire risk
new cylinders should be cleared of dust/debris by briefly cracking the cylinder away from self and others
when cylinder is in use make sure it is fully open to ensure delivery of adequate gas