3. 3
MEDICAL GASES
• 1. Define a medical gas.
• 2. Describe the types of gases used in respiratory care.
• 3. Explain how medical gases are delivered to the patient.
• 4. Describe how liquid oxygen is formed.
• 5. Describe how liquid oxygen is delivered to the patient.
• 6. Differentiate between liquid and compressed gas.
4. 4
MEDICAL GASES
• 7. Describe the piping system used in acute care facilities.
• 8. Discuss the use of station outlets and the types of connectors used.
• 9. Explain the various methods of testing the hospital gas distribution system.
• 10. Identify problems with a hospital piping system.
• 11. Discuss how medical gases are stored and transported.
• 12. Identify the various cylinder sizes and colors and how they relate to the
particular medical gas contents.
• 13. Discuss how oxygen concentrators work.
5. 5
MEDICAL GASES
• We breathe earth’s atmosphere composed of:
• Nitrogen (78%)
• Oxygen (21%)
• Carbon Dioxide (0.03%)
• Argon and trace gases (0.93%)
• Neon, Xenon, Krypton and Deon
9. 9
Fractional Distillation
• Atmospheric air is filtered of pollutants, carbon dioxide and water
• Air is compressed and cooled to a liquid
• Then it is slowly heated and the nitrogen boils off.
• Liquid oxygen remains
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Oxygen :
◼ Oxygen (O2) is an elemental
gas that is colorless, odorless,
and tasteless at normal pressures
and temperatures.
◼ When oxygen is in liquid form, it has a pale bluish tint and is slightly
heavier than water.
◼ A common misconception is that oxygen is flammable. Oxygen is not
flammable, but it will support combustion. Oxygen will accelerate
combustion, causing the materials to burn at a higher temperature.
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Oxygen uses in Respiratory Care:
◼ Diagnostic and therapeutic purposes :
◼ Diagnostically :
◼ It is used as a source gas to calibrate respiratory care monitoring
equipment
◼ Oxygen is used in concentrations greater than ambient air to treat
and/or prevent the manifestations or symptoms of Hypoxia.
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Properties of Common Gases
• Chemical symbol
• Molecular weight
• Color, odor, taste
• Physical state
• Critical temperature, boiling point
• Combustion characteristics
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Oxygen
• 02
• Molecular Weight 32
• Colorless, odorless, tasteless
• Slightly heavier than air
• Density of 1.29 g/L
• Nonflammable
but supports
combustion
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Compressed Air
• Is the same mixture of nitrogen, oxygen, carbon dioxide and
argon.
• Is piped in to all modern hospitals
• Used to power pneumatically powered equipment
16. Carbon Dioxide
• C02
• Colorless and Odorless
• Does not support combustion
• Used in fire extinguishers
• More soluble in liquids than oxygen
• Easier transporting in blood then oxygen
• Used to treat hiccups (singulation)
17. Carbon Dioxide
• Carbon dioxide is used as an insufflation gas and as a
cryotherapy agent. Carbon dioxide is commonly used as an
insufflation gas for minimal invasive surgery (laparoscopy,
endoscopy, and arthroscopy) to enlarge and stabilize body
cavities to provide better visibility of the surgical area.
18. 18
Helium
• He
• Odorless, tasteless, non-flammable
• Second lightest of gases
• Combined with oxygen (heliox) to reduce work of breathing with swollen
upper airways
19. Nitrous Oxide
• N20
• Nonflammable but supports combustion
• Used as an anesthesia in OR (laughing gas)
• Always mixed with oxygen (Entonox) and other anesthesia agents
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Nitric Oxide
• NO
• Is nonflammable but supports combustion
• Used experimentally in low concentrations (ppm) for pulmonary vasodilation
• Recently has had excellent results with premature babies
22. Nitrogen
• N2- inert gas, most abandoned in the atmosphere
• Used as lab gas (liquid) for freezing tissue
24. 24
Carbon Monoxide
• CO
• Used in Pulmonary Function Lab
• Very diffusible – used to test how easily gas will pass through the lung membranes
25. 25
Cyclopropane
• Strictly an anesthesia gas
Cyclopropane is explosive , colorless gas used in medicine since 1934 as a general anesthetic. Cyclopropane is
nonirritating to mucous membranes and does not depress respiration. Induction of and emergence from
cyclopropane anesthesia are usually rapid and smooth.
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Ethylene Oxide
• Used to gas sterilize medical equipment
• Useful for equipment that can’t handle high temperatures or
immersion in water
30. 30
Types and colors of cylinders
• Air - Yellow
• Oxygen - Green –
Int’l (White)
• Helium - Brown
• CO2 - Grey
• Nitrogen - Black
• Nitrous Oxide-Blue
Do NOT trust the color
of the tank as sole
Indicator of it’s contents
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Liquid vs Gas
• Insulated – Liquid
• Solid metal - Gas
• Large continuous demand – Liquid
• Small portable – Liquid or tank
• Tanks act differently if they contain gas or liquid
• No accurate gauge on liquid tank content
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Liquid Oxygen
• Constantly losing oxygen despite insulation
• Needs pressure and insulation for cold temperature (-118oC)
• Low pressure (200 psi)
• Large system has vaporizers fins to help with heat transfer when
liquid turns to gas (frozen year round)
• Small system is great for mall shopping
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⚫ A central supply
⚫ Piping extending to location where gas supply is
required
⚫ Terminal point
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PIPED DISTRIBUTION SYSTEM
⚫ Main lines pipe connecting the source to riser or branches
lines or both
⚫ Risers vertical pipe line connecting the main lines with
branch lines at various levels
⚫ Branch line that service a room or rooms
⚫ Pipes are made of copper
⚫ Oxygen pipe lines have ½ inch outer diameter.
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⚫Ceiling mounted
Types of terminal unit
64. ⚫ QUICK CONNECTOR
⚫ Allows apparatuses to be connected or disconnected
by a single action
⚫ Each quick connector consist of a pair of gas specific male
and female part
⚫ A releasable spring mechanism locks the components
together
74. PROBLEMS WITH THE PIPING SYSTEM
⚫ Inadequate pressure
⚫ Causes: damage of any part, compressor failure, leaks,
closure off shut off valve , obstruction, kinking of hose
etc
⚫ Leaks
⚫ May hazardous if oxidizing gases are allowed
accumulate in a closed room
75. High pressure
⚫ Causes, most commonly failure of regulator, ice formation
Alarm problems
⚫ Failure, absence or disconnection
⚫ False alarm.
76. ⚫ Contamination of gases
⚫ can be serious problem when a new pipeline is opened
