E2 L1: 6/2 - Compressed Gases & vaporizers (Jen)

1. Main supply reaches the daily average 2. Main supply not at normal operating pressure 3. Reserve supply being used 4. Reserve supply has dropped to 1-day supply 5. Reserve supply has ↓ pressure 6. Humidity of medical air unsuitable #24

6 pipeline alarm system conditions.

1. Marking 2. Labeling 3. Storing 4. Maintenance 5. Transportation 6. Disposition # 7

6 things the department of transportation is responsible for re: e-cylinders.

1. Store in designated secure areas (not OR) 2. Adequate ventilation 3. Signs: no smoking, no combustibles in area of cylinder 4. Not exposed to corrosive chemicals/fumes 5. Nitrous secured/locked up to prevent access & abuse 6. Stored upright in bins or chained to the wall 7. Wrapping and drapes undesirable #14

7 must haves for cylinder storage.

A vaporizer is a device that changes a liquid anesthetic agent into a vapor for inhalation. We must add a controlled amount of that vapor to fresh gas flow in a breathing system. #27

A _____ is a device that changes a liquid anesthetic agent into a vapor for inhalation. We must add a controlled amount of that vapor to ____ in a breathing system.

Pipeline systems includes the central supply system and transports gases to specific locations, branches, and terminal units. #17

Pipeline systems includes the _____ supply system and transports gases where?

True Sometimes when those pressure relief valves break, there can be a leak and you can actually hear the gas coming out. The cylinder will start to move! It's not enough pressure to make it explode, but as it starts venting, it becomes a mobile type of weapon and can cause injury to people and property. #13

T/F If the cylinder leaks, it becomes a mobile type weapon.

False The relationship b/t pressure, remaining volume, and pressure reading on the gauge is different b/t different types of gases. #2

T/F The relationship b/t pressure, remaining volume, and pressure reading on the gauge is the same b/t non-liquefied and liquified compressed gases.

False 3AL/3ALM (aluminum) cylinders are MRI-compatible. 3AA gas cylinder = steel or steel carbon fiber. This can cause death if taken into MRI. #8

T/F Type 3AA medical gas cylinders are MRI-compatible.

False Most vaporizers are calibrated to sea level, but it is your responsibility to acquaint yourself with the vaporizers at your facility! You have to read the manual or look at your particular machine because there can be variations based on different altitudes and barometric pressures across the country. #27,28

T/F All vaporizers are calibrated at sea level and are affected by barometric pressure changes.

False O2 = non-liquefied; pressure and volume have linear relationship. Therefore, we could tell how much volume is left from the pressure. N2O = Liquefied; non linear relationship. Therefore, we cannot determine the volume remaining. ** As pressure ↓, we have no way of knowing the N2O volume until the tank is about 95% empty. #3-6

T/F From the pressure gauge on O2 and N2O tanks, we can tell how much volume we have left.

False Just because you hear a low-pressure alarm does not mean you're not getting gas through the pipeline; it just means that we've had a change in the pressure. #23

T/F If you have a low pipeline pressure alarm system, you must supplement your gas because you won't be receiving enough.

True This can happen if you force the the cylinder (or is it port, tubing). It will break the entry way allowing for the wrong gas to fit into the pin index. They are other safety mechanism that prevent harm to patient in case this were to happen. #10

T/F It is possible to put a wrong gas into the pin index.

False If cylinder valve has no holes, then it should be impossible to attach to yoke/regulator with pins. **SHOULD be impossible. if you force it though... #16

T/F It is still possible to attach to yoke/regulator with pins if cylinder valve has no holes.

False The pipeline supply source must be in a secured area, but it can be above or underground; it can also inside or outside the facility. #18

T/F The pipeline supply sources must be in a secured area underground inside the facility.

False The reserve and central supplies are in different areas with different routing, because if you have a problem with the routing of the pipelines, you're screwed either way. #18

T/F The reserve and central supplies are located in the same place. Rationale?

True These pipelines also have to be identified every 20 feet per regulation standards. #19

T/F There are different pipeline supply systems for each type of gas.

False Vapor pressure is NOT influenced by barometric pressure. It is dependent only on liquid and temperature. #29,31

T/F Vapor pressure is influenced by barometric pressure and is dependent only on liquid and temperature.

Temp regulations on a cylinder is between 20-130˚F (-7 - 54˚C). #13

Temp regulations on a cylinder is between ____ and ____.

Terminal unit is the point where piped gas is accessed by the user through hose connections. Ex: In the ICU, the wall connector for oxygen flowmeter, hose-station outlet. #25

The ____ is the point where piped gas is accessed by the user through hose connections.

The conical depression fits the retaining screw on the yoke. #9

The ______ fits the retaining screw on the yoke.

The port of the medical gas cylinder is the point of exit for the gas. **make sure the port is facing the anesthesia machine b/c this is the port of exit for the gas. #9

The ______ of the medical gas cylinder is the point of exit for the gas.

A safety relief valve is a spring-loaded mechanism to allow venting of gas. Most commonly used; found on the e-cylinders we use. If pressure ↑, it allows gas to vent and then re-closes/seals back up after the pressure is normalized (back to Patm) inside the cylinder. However, leaks can still occur. #11

What is a safety relief valve on an e-cylinder? How does it work?

Apparatus used to connect cylinder to the back of the anesthesia machine. #9

What is a yoke?

Saturated VP is the pressure of the gas phase above this liquid when it contains all the vapor it can hold at a given temperature. Saturated vapor concentration is the concentration of what's in the gas form above the liquid. #29

What is saturated vapor pressure? What is saturated vapor concentration?

PISS: Two holes on the cylinder valve positioned in an arch which receives the pin of the yoke/pressure regulator that corresponds to that assigned gas's pin configuration. Found underneath the port. **safety mechanism to make sure right cylinder connects to the anesthesia machine. However, if you push too hard, you can possibly break the pins and incorrectly connect the cylinder. #16

What is the PISS?

Low-pressure Alarms #17

What is the most frequently reported alarm in pipeline system?

There is a certain diameter for these hoses for each gas. So, it is gas specific. **O2: 1/2 in. Other gases: 3/8 in. Ex. Oxygen hose won't screw onto N2O outlet because it won't fit. #26

What is the safety mechanism in the DISS system that prevents you connecting the wrong gas to wrong outlet?

The quick connectors have a main male part that will fit in a specific female outlet. These female parts have specific configurations that prevent the wrong male part from connecting. If it's not aligned, the quick connector won't work. #26

What is the safety mechanism in the quick connector system that prevents you connecting the wrong gas to wrong outlet?

1. Made of bronze or brass 2. Screws into the neck of the cylinder 3. Purpose: - allows refilling and discharge of gas at stem - controls pressure → prevents it from getting too high. #8

What is the valve of the medical gas cylinder made off? Where does it screw into? Purpose of the valve? (2)

Left: DISS Right: Quick connector #26

What type of system is being used in the pictures?

The reserve supplies should be used for emergencies or failure of the primary supply only. If the pipelines fail or lose pressure, then we use the e-cylinders on the back of the anesthesia workstation. #18

When are reserve pipeline supplies used? E-cylinders?

DISS (diameter index safety system) system. #25

Connection into the anesthesia machine (station outlet) uses the ____ system.

Cylinder handle: - purpose: opens/closes cylinder - aka cylinder wrench - turns counter-clockwise to open - each machine requires one to be readily used #9

Cylinder handle: - purpose? - another name? - turns which direction? - how many?

Cylinder safety: - Keep connections tight. - No adaptors should be used to change the size of connections. - Markings and labels should never be altered - No dragging, dropping, or sliding - Valve is closed at all times - Prevent cylinder falls by properly securing. #13

Cylinder safety: - Keep _____ tight. - No _____ should be used to change the size of connections. - Markings and labels? - How to handle? - Valve open or closed? - How to prevent falls?

The vapor pressure of a liquid is the equilibrium pressure of the vapor above its liquid form. In other words... it is the pressure of the vapor resulting from evaporation of the liquid in a closed system at a constant temperature. #29

Define vapor pressure of a liquid.

Non-liquefied compressed gases have a linear relationship. This is Boyle's Law. (P1/V1) = (P2/V2) So, pressure ↑ = volume ↑ (and vice versa) Significance: if we know the pressure, we can determine how much volume is left. **Oxygen: 1900PSI and 660L. #3

Do non-liquefied gases have a [linear or opposite] relationship b/t pressure and volume? What law is this? Why is it significant?

Yes. E-cylinders have a pressure relief devices that vents to atmospheric pressure if the pressure or temp in the cylinder gets too high. This prevents it from exploding! #11

Does a cylinder have a way to vent itself in case of pressure and temperature changes?

Fusible Plug: - Good for really high temps (ex. fire). - Plug melts at high temp to allow gas to escape - Non-re-closing **Explosion is still possible depending if gas is flammable. However, the cylinder won't be a projectile! #11

Fusible Plug pressure relief device. - good for what scenario? - how does it work? - re-closing or non-re-closing?

Gov't regulations of cylinder: FDA is responsible for gas purity. Dept of Labor/OSHA is responsible for employee & cylinder safety. #7

Gov't regulations of cylinder: Food and Drug administration is responsible for _____. Dept of labor/OSHA is responsible for ______.

They have a parallel relationship. So, ↑temp = ↑VP #29

How are temperature and vapor pressure related?

By adding a low temperature to the non-liquefied gas. #2

How can you force a non-liquefied into a liquefied compressed gas?

Compressed gases are measured via PSIG. It depends on the type of gas--liquified or non-liquified. #2

How compressed gases are read depends on what?

The potential dangers of volatile anesthetics are lessened because we dilute or we mix the volatiles with fresh gas flow. This will not only help carry the vapor to the patient, but prevents us from giving toxic levels. #27

How does the anesthesia machine lessen the potential dangers of volatile anesthetics?

Oxygen: 1/2 in. (larger) Other gases: 3/8 in. (smaller) This is a safety mechanism to prevent the wrong gas from being connected. #21

How does the outer diameter of oxygen pipes differ from other gases? Why?

Each facility requires 2 supply banks. Each bank has a 2-day supply. So, there is a total of 4 days worth! #18

How many supply banks does each facility have? What is included in a bank?

We need to look at the whole picture and give them what they need so that they are appropriately anesthetized for anesthesia. This is not the same for everybody. #28

How much volatile gas do we need to give the patient for adequate anesthesia?

Area alarm systems are checked daily and tested monthly. This includes the ICUs and ORs. #23

How often are area pipeline alarm systems assessed? What units do this type of alarm system include?

1. Open slowly and slightly prior to installation to clean out the valve port 2. Check pressure gauge 3. Open away from patient, yourself and others 4. Face the valve away from people 5. Check for leaks (If leaking, get another one!) #15

How should you open the gas cylinder? (5)

A = Sealing Washer B = PISS C = Gas Cylinder D = Anesthesia Machine hanger-yoke assembly E = Cylinder Valve #15

Identify A-E

A = Sealing washer. Prevents leaks as the gas is escaping from the cylinder to the machine. B = Port. Where gas exits the cylinder. C = Pin-index. Safety mechanism for gas identification. #15

Identify and explain the parts.

In order to qualify for medical air, the air systems need to dehumidify. We don't want humidified air coming through those lines; that's why we sometimes have to use humidifiers on our anesthesia circuits. #20

In order to qualify for medical air, the air systems need to do what?

In the US, pipeline pressures are 380 kPa, approx 55 PSI. #17

In the US, pipeline pressures are ____ KPA or approximately ____ PSI.

Intake locations for medical air must be free of contaminants. #20

Intake locations for medical air must be free of _____.

Partial/empty and full cylinders must be tagged and stored separately. #14

JCAHO guidelines for empty and partially empty cylinders.

Liquified compressed gas pressure depends on vapor pressure (VP). **It is not an indication of remaining volume; not a linear relationship. It means when one gas molecule leaves the cylinder to be used, another molecule from the liquid takes its place. So, it will maintain pressure until it's basically empty; it has to be over 95% empty before you see pressure change on the gauge. #5

Liquified compressed gas pressure depends on ______. What does this mean?

Manual shut offs are visible and accessible at all times. Service shut offs are in a locked box and not accessible to us. #22

Main difference b/t manual shut off valves and service shut off valves?

A = Oxygen (non-liquefied) - has a linear relationship b/n pressure and volume. As pressure ↓, volume ↓. We change the tank at 500PSI (25% of 1900 PSI) B = N2O (liquified) - does not have a linear relationship b/n pressure and volume. So, as volume ↓, we don't see a change in pressure (until the tank is practically empty). We weigh the tank to determine how much is left. # 4 & 6

Which gas is identified as A and B What is happening with the pic?

Quick connections are more prone to leaks. #25

Which is more prone to gas leaks--DISS system or quick connections?

Volatiles are very potent. So, we need a way to get an appropriate level and to measure how much our patients getting. Hence, the vaporizers. #28

Why are vaporizers necessary for volatiles?

Warning signs for nitrous absolutely have to be posted because if there's a leak, people inhaling the nitrous can become unconscious and die from asphyxiation and hypoxemia. #20

Why are warning signs necessary for nitrous?

PISS system used on cylinders require different arrangements for each type of gas to avoid placing the wrong gas cylinder to the wrong slot on the anesthesia machine. #10

Why does every gas have a different pin arrangement?

A study by Ehrenwerth et al. noted that cylinders may have irregularities or faulty construction when they come to us. As the CRNA, it is also your responsibility to inspect the cylinder; you run the risk of being sued if something were to happen to a patient/staff d/t your negligence and failure to inspect the cylinder before use. #13

Why should facilities and CRNAs inspect the cylinders before use?

21% oxygen (room air) b/c there is no extra oxygen flow! #27

With the ether drip method, how much fresh gas flow is present?

Liquefied compressed gases become liquid at ambient temp and at a pressure range of 25-1500 PSI. Examples: • Nitrous oxide • Carbon Dioxide (insufflation) #5

____ gases become liquid at ambient temp and at a pressure range of ____. 2 Examples.

Nitrous (N2O) must be secured and is generally supplied by a manifold cylinder system, because the regulators can be prone to freezing. This special system prevents that from happening. #20

_____ must be secured and is generally supplied by a manifold cylinder system. Why?

Liquid oxygen must be in constant use in order to be cost effective. (FYI: pressure increases can make the liquid oxygen boil which will cause it to vent/evaporate into the atmosphere. So, we lose that oxygen essentially.) #18

_____ oxygen must be in constant use.

Medical air uses either a manifold or compressor pipeline system. #20

_____ uses either a manifold or compressor pipeline system.

Pounds per square inch gauge is the difference between measured pressure and atmospheric pressure. #2

_________ is the difference between measured pressure and atmospheric pressure.

1. Main supply into building 2. One at each riser 3. One at each branch (except if branch is to an anesthetizing area or ICU) #22

3 mandatory locations of manual shut off valves.

Non-re-closing 1. Rupture or Frangible Disk = not ideal 2. Fusible Plug Re-closing 3. Safety Relief Valve = most common #11

3 types of pressure relief devices. Which is most common? Which is not ideal for OR use?

Pipeline alarm systems must be: 1. audible 2. visible 3. labeled for gas and area 4. Personnel must know what to do if the alarm sounds. #23,24

4 requirements for pipeline alarm systems.

1. Analgesia 2. Delirium 3. Surgical 4. Respiratory cessation #28

4 stages of anesthesia.

1. Body 2. Valve 3. Port 4. Conical Depression 5. Handle 6. Pressure/safety Relief Device 8-11

6 components of medical gas cylinder.

Non-liquefied Compressed Gas #2

Are the e-cylinders on the back of the anesthesia machine considered liquefied or non-liquefied compressed gases?

B/c E-cylinder use is not enough, we have a pipeline/central gas supply to deliver/transport gases to anesthetizing locations and patient care areas. Gas 1. O2 2. N2O 3. Medical Air #17

B/c E-cylinder use is not enough, we have a ________ to deliver/transport gases to anesthetizing locations and patient care areas. 3 types of gases utilizing pipelines.

1. Body made of steel or steel carbon fiber (3AA) or aluminum (3AL/3ALM) 2. Flat or concave base (to prevent tip-over) 3. Neck with screw threads #8

Body of gas cylinder: 1. Made of? 2. Base? 3. Neck with ______

N2O and air supply sources have a series of valves, regulators, and alarms (just like our anesthesia machines) to regulate pressure and signify when problems occur. #20

N2O and air supply sources have a series of ____, ____, and ____ (just like our anesthesia machines) to regulate pressure and signify when problems occur.

1. Valves 2. Regulators 3. Gauges #13

Oil, grease or lubricants should not come in contact with what 3 things on the gas cylinder?

1. Visible inspection for defects/tampering of PISS, label, regulator. 2. Presence of tamper-proof seal around valve. **Remember to remove prior to attaching to an anesthesia machine (otherwise, gas will not flow). 3. Presence of sealing washer (absence could lead to gas leakage). **Should only have 1 washer. >1 can ruin the seal and cause leaking, #15

Prior to cylinder use, what you should you look for on the new cylinder? (3)

Shut off valves allow for certain sections/zones in the piping system to be isolated (turned on/off) for maintenance or if problems occur. #22

Purpose of shut off valves?

Regulation requires the gas name, pressure, and flow direction to be marked every 20 feet and in each room. #21

Regulation of pipeline system structure and composition requires what 3 things to be marked every 20 feet and in every room?

Rupture or Frangible Disk: - Good for high temp or overfilling - Downfall: disk can break at really high temps - Non-re-closing **NOT ideal for use in the OR! #11

Rupture or Frangible Disk pressure relief device. - good for what scenario? - downfall? - re-closing or non-re-closing?

Saturated vapor concentration must be diluted by bypass gas flow. #29

Saturated vapor concentration must be diluted by _____.

Some anesthesia machines have as many as 3 vaporizers attached. #27

Some anesthesia machines have as many as ___ vaporizers attached.

Some cylinders may use a combination of fusible plug with one of the other safety relief valves. **However, the ones we use will have a safety relief valve. #11

Some cylinders may use a combination of ____ with one of the other pressure relief valves.

Copper #21

Supply pipelines are made of what kind of metal?

True #2

T/F Compressed gases are read in PSIG. Most of these gauges are calibrated as 0 at Patm.

There are 7 different pin positions depending on the type of gas in the cylinder. ** Always visually inspect pins for damage to avoid attaching the wrong cylinder!! #16

There are ___ different pin positions depending on the type of gas in the cylinder.

O2: 1900 PSI. 660 L. Green Medical Air: 1900 PSI. 625 L. Yellow N2O: 745 PSI. 1590 L. Blue #12

Volume and Pressure of compressed gases will vary in any given cylinder. Volume, pressure, and color of: 1. O2 2. N2O 3. Medical Air

PSI : pounds per square inch PSIG: pounds per square inch gauge #2

What 2 ways are compressed gases measured?

Non-liquefied compressed gases are gases that do not liquify at room temperature, regardless of the pressure applied. Examples: •O2 •Nitrogen •Medical Air •Helium #3

What are non-liquefied compressed gases? 4 examples include?

Quick connectors are adaptors that go into the wall or ceiling. They have pair of male and female parts that only connect when the proper alignment is achieved. Each gas has a specific shape and spacing for the male parts that go into the wall or ceiling. #25

What are quick connectors? Explain how they look and work.

1. Central supply 2. Reserve supply #18

What are the 2 types of pipeline supply sources?

Alarm will sound if the pressure ↑or↓ 20% from normal line pressure. (More likely to have low pressure alarm!) This area alarm can trigger the master alarm. #23

What causes the area pipeline alarm systems to go off? If it does go off, what can it trigger?

PISS = Pin Index Safety System DISS = Diameter Index Safety System. # (somewhere in the slides)

What do PISS & DISS stand for?

Humidity of medical air is unsuitable just means that there's too much humidity in the lines and that can affect the pressure. This will sound like a low-pressure alarm. #24

What does it mean if the humidity of medical air is unsuitable? What does the alarm sound like?

The master pipeline alarm system monitors the entire pipeline system. It is found in 2 places: one in that particular department and one in the main/whole system for facilities management to see. #23

What does the master pipeline alarm system do? Where is it located?

The main line connects gas source to the risers. The risers are vertical pipes that connect the main line to the branch lines on each level of facility. Branches are sections supplying a room or group of rooms on one level of the facility. This is where gas terminates. #21

What does the pipeline system structure's main line, risers, and branches do?

It'll cause damage to the cylinder, which will cause leakage of gas from your cylinder. #9

What happens if we were to screw the retaining screw into the port of the cylinder?

Main supply: turns off EVERYTHING in the building. Anesthetizing area/ICU: turns off gas to ALL those ORs and ICU rooms. **This would interfere with all surgeries and patient care--we would need to switch over to e-cylinders (temporary fix). So, it's very important that we have separate shutoffs for each room or zone! #22

What happens if you turn on the manual shut off valve to the main supply of the building? To branch of anesthetizing areas/ICU?