1. 1 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

2. How Oxygen is produced Fractional Distillation Physical Separation -Nitrogen Molecular sieve Semi-Permeable membrane

3. 3 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

4. Medical Gases Oxygen, Carbon Dioxide, Helium, Nitrous Oxide, Nitric Oxide, Nitrogen, Carbon Monoxide

5. RsCr 220 5 Properties of Common Gases Chemical symbol Molecular weight Color, odor, taste Physical state  Critical temperature, boiling point Combustion characteristics

6. RsCr 220 6 Oxygen 0 2 Molecular Weight 32 Colorless, odorless, tasteless Slightly heavier than air  Density of 1.29 g/L Nonflammable but supports combustion

7. RsCr 220 7 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 Some situations (patients are C02 retainers) when oxygen is contraindicated

8. Carbon Dioxide C0 2 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)

9. 9 Helium He Odorless, tasteless, non-flammable Second lightest of gases Combined with oxygen (heliox) to reduce work of breathing with swollen upper airways

10. Nitrous Oxide N 2 0 Nonflammable but supports combustion Used as an anesthesia in OR (laughing gas) Always mixed with oxygen (Entonox) and other anesthesia agents

11. RsCr 220 11 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

12. Nitrogen N 2- inert gas, most abandoned in the atmosphere Used as lab gas (liquid) for freezing tissue

13. 13 Carbon Monoxide CO Used in Pulmonary Function Lab Very diffusible – used to test how easily gas will pass through the lung membranes

14. 14 Cyclopropane Strictly an anesthesia gas

15. RsCr 220 15 Ethylene Oxide Used to gas sterilize medical equipment Useful for equipment that can’t handle high temperatures or immersion in water

16. Oxygen Storage Tanks – Liquid Tanks - Gas

17. Tank Sizes and Capacities Large Cylinders Small Cylinders made of aluminium

18. RsCr 220 18 Oxygen Tank Sizes

19. 19 Types and colors of cylinders Air-Yellow Oxygen-Green – Int’l (White) Helium-Brown CO 2 -Grey Nitrogen-Black Nitrous Oxide-Blue Do NOT trust the color of the tank as sole Indicator of it’s contents

20. RsCr 220 20 Labels – The only sure way

21. RsCr 220 21 Other Oxygen Tank Markings

22. RsCr 220 22 Large Oxygen Supply System

23. RsCr 220 23 Small Bank of Cylinders

24. RsCr 220 24 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

25. RsCr 220 25 Go figure

26. RsCr 220 26 Liquid Oxygen Constantly losing oxygen despite insulation Needs pressure and insulation for cold temperature (-118 o C) 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

27. RsCr 220 27 Bulk Liquid Oxygen supply

28. RsCr 220 28 Home Liquid Oxygen

29. RsCr 220 29 Flowmeters Thorpe Tube is most common Can use Bourdon Gauge

30. RsCr 220 30

31. RsCr 220 31 Thanks for listening