Module 3 Medical Gas Supply Flashcards
Regulates design, performance, labeling, testing, transportation, filling and storage, construction of medical gas cylinders
The Dept. of Transportation
Regulatory Agency)(Mandatory to Follow
Regulates medical devices.
-Can recall devices at any time and stop shipment orders
FDA
Regulatory Agency)(Mandatory to follow
P.I.S.S. of Oxygen
2-5
P.I.S.S. Nitrous Oxide
3-5
P.I.S.S. Air
1-5
Adiabatic Compression
Fire Hazard
Recompression of high pressure gas in the cylinder yoke, when cracking open, heats up to 1000f can ignite dust, grease , oil
FYI:
- Open cylinders slowly
- Don’t allow valves, regulators, gauges & fittings to come in contact with oil, greases, lubricants, rubber or combustible substance
- No aluminum o2 compressors, only brass
Adiabatic Expansion
AKA Joule-Thompson effect
Icing Effect
Icing over cylinder, due to expansion of high pressure gas to low pressure atmosphere through leaks from improper seals of cylinder to yoke or leaks around the valve stem
P.I.S.S. Nitrogen
1,4
Name the most common gas cylinder size utilized in the hospital and with the anesthesia machine _______.
E.
FYI:
Cylinder sizes range from A-H, A being the smallest while H the largest.
True or False:
A gas stored partially in liquid form in a cylinder, such as nitrous oxide, will drop its cylinder volume in proportion to a drop in cylinder pressure.
False.
Simple:
Nitrous oxide will read full until 75% of the tank is utilized this is because typically the liquid has evaporated at this point. The liquid form of nitrous oxide is what makes the gauge read more full than it really is.
Details:
A gas stored partially in liquid form will show a constant pressure reading even as the contents of the tank are being utilized and gas volume is falling. This will continue until all of the liquid has evaporated, at which time the pressure will drop in direct proportion to the rate at which the gas is withdrawn. (usually drop quickly-signifying your tank is about empty).
-400Liters will gauge begins to fall
- Nitrous oxide
- Carbon dioxide
True or False:
A non liquified gas will show a steady decline in pressure until the cylinder is empty.
True.
Cylinder volume is proportionate to a drop in cylinder pressure
FYI:
- oxygen
- helium
- Nitrogen
- Air
True of False:
The cylinder color is the best method to ID cylinder content.
False.
Cylinder labels are the best method to ID contents. Color is useful to ID the contents from a far/ to use for sorting purposes.
How often must gas cylinders be inspected and tested?
At least every 5 years.
Special circumstances, every 10 years.
Describe what is inspected at least every 5 years on a gas cylinder.
- internal and external visual check for corrosion/ outside for deformity (dents)
- Leaks and retention of structural strength
FYI: this is done by imposing 1.66x their service pressure (max pressure to which the cylinder can be filled at 70 degrees) upon a cylinder.
Ex. 1.66 Xs normal. Ex O2 E cylinder 2200psi x 1.66= 3154psi
Hydrostatic Test
A test to determine strength of cylinder and if there are any leaks.
Water if filled to 5/3 or 1.66x service pressure and left for 30 seconds. Part of a DOT requirement every 5-10 years.
- If pressure drops and water is rising in barrette (there is usually an inside leak)
- Pressure drops water drops= high pressure leak and O ring needs replacement
*more to come for this card
A type of cylinder that is is MRI safe
Aluminum Cylinder
Pressure Relief Valve VS. Pressure relief Device (AKA safety release)
Valve:
Spring loaded device designed to re close & prevent discharge of cylinder contents after normal pressures are restored
more prone to leaking than the pressure relief device
Device:
vents the contents of the cylinder to atmosphere if pressure increases too much
Pressure/Safety Release Device: Rupture Disk
when predetermined pressure is reached from improper filling, the disc ruptures & contents dc’d
(air, CO2, He, N2O, O2)
Pressure/Safety Release Device: Fusible Plug
thermally operated .Metal alloy, has low melting point, high pressures caused by high temps 212F- will cause venting When pressure increases from high temp, fusible material turns soft & extrudes from holder
(N2, air)
Conical Depression
Do not mix up with safety relief device
-Placed above the safety relief device on “E” tanks. Receives the retaining screw of the yoke
D.I.S.S.
Diameter index safety system.
Lock and key “holes” so that wrong gas cannot be hooked up to wrong gas line.
Bourdon Gauge
Tells us the pressure in our tanks.
Details:
closed coiled tube connected to the cylinder in which pressure is to be sensed. As the pressure increases the tube will uncoil, while a reduced pressure will allow the tube to coil more tightly
Hazards of gas cylinders
-Incorrect tank (despite PISS)
-Incorrect Contents
-Incorrect Valves
-Wrong color
-Wrong label
-Inoperable/damaged valves
-Suffocation (lrg. amount of nitrous oxide leaking out quickly can displace atmosphere and cause this)
-Fires
-Explosions (rapid escape of contents or rocketing of tank)
-Contamination
-Theft of N2O (substance abuse)
Overfilled
-Thermal injury (frostbite reported with recreational use of N2O)
Pipeline
-primary source for the anesthesia gas machine
Oxygen Cylinder:
Service Pressure:_____
Capacity:_____
Color:_____
Service Pressure: 2000
Capacity: 660L
Color: Green
Nitrous Oxide:
Service Pressure:_____
Capacity:_____
Color:_____
Service Pressure: 750
Capacity: 1590L
Color: blue
Air:
Service Pressure:_____
Capacity:_____
Color:_____
Service Pressure: 1900
Capacity: 625L
Color: Yellow
How long will a cylinder last if pipeline oxygen is no longer in use?
Maintaining mechanical ventilation in the absence of pipeline oxygen can use an entire E cylinder of oxygen (approximately 600 L) in an hour or less
Describe the storage, handling, and utilization of a gas cylinder.
-Use only one washer, or PISS system will be defeated.
-Do not oil valve.
-Protect the valve when transporting.
-To installCheck & remove labels
Hold valve away from face, and “crack” valve
-Place in hanger yoke
-Observe for appropriate pressure and lack of audible leak.
-Leave cylinders on machine CLOSED.
-Don’t leave empty cylinders on the machine
The cylinder pressure regulator converts high, cylinder pressure to a constant pressure of approximately 45 psi, why is this?
it is intentionally slightly less than pipeline pressure, to prevent silent depletion of cylinder contents if a cylinder is inadvertently left open after checking its pressure
Pipeline gas working pressure
50 psi; which is therefore the “normal working pressure” of the anesthesia delivery system.
True of False:
Piped medical gasses are sterile
False.
Bateria, water, and foreign material get in pipes.
