• Oxygen (O2)
• Carbon dioxide (CO2)
• Nitrous oxide (N2O)
• Air
• Oxygen/carbon dioxide mixture
• Oxygen/helium mixture
• Oxygen/nitrous oxide mixture

Compressed air 

• Most often, the drive of lung ventilators or just their supply (basic breathing mixture). Also the drive of other devices/tools (sternal saws, atheroplate cutters, etc.) – separated from the use of ventilation.
• The air supply is in a pressure reservoir supplemented by a compressor.
• The need to dehumidify the compressed air by freezing so that water vapour does not condense in the pipes and in the devices.

Oxygen – properties 

• Boiling point    –182.98 °C
• 1.1 x more massive than air
• Highly reactive
• In air 21 %
• An increase in concentration by only a few % = self-ignition, burning of normally non-flammable substances
• Colourless, tasteless and odourless

Oxygen – safety 

• In contact with substances strong oxidation, heat, light, burning, even steel burns in pure oxygen.
• Do not smear anything with anything, risk of fire, explosion
• Beware of clothing – saturated with gaseous or liquid oxygen will ignite immediately, even from a discharge of static electricity
• Beware of frostbite when in contact with liquid oxygen – as destructive to tissues as a burn
• In the liquid state, free evaporation into the atmosphere must be ensured – proper ventilation is important, containers in the exterior

Nitrogen – properties

• Boiling point  -195.8 °C
• 0.967 mass of air
• Low reactive, inert (N2)
• In air 78%
• Colourless, tasteless, odourless 

Nitrogen – safety 

• It is not poisonous but causes suffocation by displacing air; after a few breaths unconsciousness and then death. Frequent cases of tragedies of rescuers who enter the space without breathing apparatus independent of the surrounding atmosphere
• Beware of frostbite in the liquid state
• In the liquid state, free evaporation into the atmosphere must be ensured (Dewar container) –  important proper ventilation, containers in the exterior 

Dewar container 

• Dewar container is open to the atmosphere. A gas – N2 – escapes from the container.
• Caution during handling – if the container is overturned, liquid gas may spill out and cause frostbite.

Nitrous oxide – properties (laughing gas)

• Boiling point  –88.5 °C
• approx. 1.5 x times more massive than air
• Non-flammable, but supports combustion at temperatures above 600 °C 
• Narcotic (mixed with oxygen)
• Colourless, sweet smell and taste

Nitrous oxide – safety 

• Non-toxic, but suffocation hazard due to displacement of air
• The gas is stored in a liquid state in pressure cylinders, therefore increased caution when handling them

Carbon dioxide

• Boiling point – 78.5 °C
• approx. 1.5 times more massive than air
• Non-toxic, colourless, non-flammable, tasteless and odourless
• Suffocation hazard due to air displacement
• Use: filling gas in laparoscopic operations
• It is supplied in pressure cylinders (liquid state) –  beware of solidification during rapid exhaust 

Helium 

• Boiling point – 269 °C – closest to absolute zero
• Only 0.14 of the mass of air
• Completely inert, non-toxic, no compounds under no circumstances, colourless, tasteless and odourless
• Suffocation hazard (displacement of air)
• Use: the first cryogenic coating of superconducting windings of MR magnets. Due to its insolubility in blood, it is used for periodic inflation of aortic balloons or in a breathing mixture for divers

Subatmospheric pressure


So-called VACUUM

IT IS NOT A MEDICAL GAS!!!

• Purpose: suction from surgical wounds, from the airways through water lock.
• A vacuum is sometimes „produced“ by rapid pressurized airflow through a nozzle.
  
  
  

Storage and handling (Czech technical standard ČSN 07 8304) 

• NO temperature higher than 50 °C
• NOT without fall protection (tapes, chains)
• NOT without ventilation
• NO different gases together (but in zones)
• NOT without manufacturing date resolution
• NOT without distinguishing full from empty
• NO more than 8 cylinders in one utility room of a multi-story building
• NO more than 24 cylinders in one fire sector 

Storage and handling (continuation) 

• NOT in communication areas
• NOT in areas not used directly for taking gas from cylinders
• NOT less than 3 m from sources of open fire and 1 m from heating elements
• NOT without cap
• NO to mechanical stress and impacts
• NO carrying by the valve, by the cap