Ch. 41 Storage and Delivery of Medical Gases

Flammable

The gas itself burns readily.

Nonflammable

Does not burn

Oxidizing

Supports combustion

Bourbon gauge

Gauge for transports

Thrope tube

Compensated flowmeter with ball

Reducing valve

Reduces and controls gas pressure from tank

Regulator

Controls both pressure and flow

Flowmeter

Controls and indicates flow

Zone valves

Shut off for fire

Nonflammable gases

Nitrogen
Carbon dioxide
Helium

Describe the second methods used to separate oxygen from air. What concentration is produced by each method? (order doesn’t matter)

Semipermeable membrane—Air is forced through a plastic membrane which allows oxygen and water vapor to pass at a faster rate than other gases; 40% oxygen

What is Heliox? What is it used for in the clinical setting?

is a mixture of helium and oxygen. It is used to treat severe large airway obstruction such as life-threatening asthma.

What is the primary medical use for nitrous oxide? What are some of the hazards of nitrous oxide administration?

is an anesthetic gas used for sedation and pain relief.

causes severe central nervous system depression. Long-term exposure may result in neuropathy. It can be linked with fetal disorders.

Describe two possible hazards of using nitric oxide

can cause methemoglobinemia
can form the toxic gas NO2, which can cause a chemical pneumonitis

In the U.S., identify the proper color for these gas cylinders: Oxygen

Green

In the U.S., identify the proper color for these gas cylinders: Carbon dioxide

Gray

In the U.S., identify the proper color for these gas cylinders: Nitrous oxide

Blue

In the U.S., identify the proper color for these gas cylinders: Helium

Brown

In the U.S., identify the proper color for these gas cylinders: Nitrogen

Black

In the U.S., identify the proper color for these gas cylinders: Air

Yellow

What are the cylinder factors for the “E” gas-filled oxygen cylinders?

0.28

What are the cylinder factors for the “G” gas-filled oxygen cylinders?

2.41

What are the cylinder factors for the “H gas-filled oxygen cylinders?

3.14

Write the formula for calculating duration of flow in minutes of gas-filled cylinders.

Duration of flow (min) = (pressure x cylinder factor) / flow (L/min)

What is the normal working pressure for a hospital oxygen piping system?

50 psi

What are zone valves? Give two reasons you might need to use these values

are used to shut off the flow of gas to specific areas of the hospital for system maintenance or in case of fire. The RT is responsible for patients and to operate the zone valves.

List first basic indexed safety systems (order doesn’t matter)

ASSS: American Standard Safety System

List second basic indexed safety systems (order doesn’t matter)

DISS: Diameter-Index Safety System

List third basic indexed safety systems (order doesn’t matter)

PISS: Pin-Index Safety System

What type of cylinder typically uses pins and holes for the safety connection system?

Small cylinders up to size E

Describe the action of Reducing valve

Reduces gas pressure to a safe working value

Describe the action of flowmeter

Controls gas flowrate

Describe the action of regulator

Controls pressure and flow

What happens to the float in a compensated Thorpe tube when you connect it to a 50 psi gas source?

If the valve is closed, the float will jump, the return to zero as the flow tube is pressurized.

A patient is to be transported from the ICU to the imaging department for a CT scan. The patient requires continuous supplemental oxygen at 10 L/min by mask. You will need to provide portable oxygen for the transport. An E cylinder is available.

What type of regulator is most appropriate for the transport?

A Bourdon gauge is the best choice.

A patient is to be transported from the ICU to the imaging department for a CT scan. The patient requires continuous supplemental oxygen at 10 L/min by mask. You will need to provide portable oxygen for the transport. An E cylinder is available.

How long will the cylinder last at the given flow rate if the pressure is 1000 psi?
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28 minutes

A patient is to be transported from the ICU to the imaging department for a CT scan. The patient requires continuous supplemental oxygen at 10 L/min by mask. You will need to provide portable oxygen for the transport. An E cylinder is available.

When you turn on the cylinder valve, a hissing noise is heard from the regulator. The flowmeter is off, so there must be a leak. What should you check to try to correct the leak?

Tighten the hand screw (and check the pins and holes)
Check the washer (bushing)

What is the formula for oxygen cylinder duration?

Duration (min) = PSI x Cylinder factor / Flow (L/min)

Calculate duration of an E cylinder with 1500 psi running at 2 L/min
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210 minutes (3.5 hours)

Calculate the duration of an H cylinder with 1500 psi running at 2 L/min

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2355 minutes (39.25 hours)

An H cylinder of oxygen is being used to deliver oxygen to a patient in a subacute care facility where no piped in oxygen is available. The cylinder gauge shows a pressure of 1000 psi. The patient is receiving oxygen at 5 L/min by cannula. Approximately how long will the cylinder gas last at this flow rate?
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10 hours

An RT notices that a flowmeter plugged into the wall outlet continues to read 1 L/min even though it is not turned on. What is the most appropriate action at this time?

Replace the flowmeter

An RT has to transport a patient via air from the island of Maui to Honolulu. The patient is being manually ventilated with an oxygen flow set at 10 L/min using an E cylinder of gas. The cylinder gauge reads 2000 psi. How long will the cylinder last?

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56 minutes

A fire breaks out in the pediatrics unit because of a faulty electrical cord. One RT has ensured that patients with oxygen are safe. Your responsibility in this situation would be to

Prepare to shut off the zone valves to the unit