1. Lynn Morrison Regional QA Pharmacist NHS Greater Glasgow and Clyde
Medical Gases
Lynn Morrison
Regional QA Pharmacist
NHS Greater Glasgow and Clyde

2. Medical Gases Introduction and session objectives
To describe the different medical gases found within a hospital
To understand the design and construction of a medical gas pipeline system (MGPS)
To be aware of the system of controls applied to facilitate the safe and secure operation of a medical gas pipeline system
To understand the roles and responsibilities of key personnel involved in medical gases
To understand the role of the Quality Controller (MGPS)
To have an awareness of medical gas testing
To appreciate the role of the EDC pharmacist in an emergency situation

3. Medical Gases – what gases are found in hospitals?
Oxygen
Nitrous oxide
Medical Air
Surgical Air
Oxygen / Nitrous oxide mixture 50:50 “Equanox” or “Entonox”
Vacuum

4. What are the medical gases used for?
Oxygen – used to sustain life
Medical air – used to drive ventilators
Surgical air – used to operate surgical tools
Nitrous oxide – used in theatres for anaesthetic purposes
Equanox / Entonox – used as an analgesic, home delivery
Vacuum - suction

5. What other gases could you find?
Carbon dioxide
Helium / oxygen mixtures
Nitric oxide
What are these gases used for?
Carbon dioxide – clinical and physiological investigations
Helium/oxygen mixtures – respiratory assessment and treatment e.g. COAD
Nitric oxide – aids oxygen exchange in respiratory distress conditions

6. How are the gases supplied to the hospital?
Oxygen – delivered as a liquid via a tanker to a liquid oxygen tank compound with vacuum insulated evaporators - VIE
Nitrous oxide – cylinders
Medical air – cylinders or compressors
Equanox / Entonox – cylinders
Other gases – cylinders
NHS Scotland - national contracts for supply of medical gases

7. Where are the gases stored?
Liquid Storage Tank with VIE – oxygen
Cylinder store – various gases
Manifold rooms – e.g. medical air, nitrous oxide, Equanox/ Entonox
Medical and surgical air compressor systems and receiver tanks
Other locations – e.g. ready use stores
ambulances
patient transport

8. Oxygen tank – VIE tank “Duty” tank and a “stand by” tank
Vacuum insulated evaporator
Valve box (with test point)
Alarm panel
Copper pipework – medical gas pipeline system - connecting tanks to the hospital pipeline system

9. Oxygen tank and VIE

10. Oxygen tank – control panel

11. Cylinder store separate from other buildings
Visit the cylinder store on site
Cylinder stores should be :-
separate from other buildings
no “naked flames”
clean, tidy, locked
full cylinders should be stored separately from empty
each gas type to be stored separately
etc
Can you think of any other storage requirements?
separate cylinders by size
temperature control
log of issue and return

12. Cylinders Currently :- Oxygen – black body / white shoulders
Nitrous oxide – blue
Medical air – grey body / black and white shoulders
Equanox / Entonox – blue body / blue and white shoulders
Heliox – black body / brown and white shoulders
Carbon dioxide - grey
Future :-
EU Directive – all cylinders will have white body and colour coded shoulders as above
Implementation to be completed by 2025

13. Manifold rooms
A manifold is defined as a set of pipework to which a series of cylinders is attached.
“Duty” and “stand by” bulk supply to the hospital
Must be in date
Must be checked regularly

14. Oxygen manifold

15. Medical air manifold

16. Medical / Surgical air compressors

17. How do the gases get to the patient ?
Medical Gas Pipeline System (MGPS)
Copper pipelines
Pressure reducing valves
AVSU – area valve service unit
Terminal outlets
Flow meter and tubing
Mask / nasal canulae
Cylinders – valve and flowmeter

18. Area Valve Service Units

19. Terminal Units

20. Safety issues Medical gases
Oxygen – supports combustion – patient’s clothing and bedding can become saturated
Nitrous oxide – causes headaches, drowsiness, cumulative effects, teratogenic effects, can cause asphyxia in confined spaces
also supports combustion
Equanox / Entonox – combination of the above

21. Safety issues Cylinder handling Never carry a cylinder by its neck
Use correct trolleys
Protective equipment
Never roll cylinders!!
Never eat/smoke while handling cylinders
Etc!!
Training vital!!!

22. Control systems - Documentation
HTM 02-01
Part A ;
Design, installation, validation and verification
Part B ;
Operational Management
In Scotland (s)HTM

23. Control systems - Documentation
Permit to work system
controls any engineering work to be carried out on the MGPS
safeguards the integrity of the MGPS and patient safety
4 part documentation signed by all those involved in the work activity
Operational policies
Controlled document
Scope
Responsibilities and training for staff
Record drawings and accompanying documentation
Description of MGPS, valves, alarms etc
Medical gas committee
Emergency procedures

24. Control systems - Documentation
Health and Safety at Work legislation
Manufacturer / supplier product material safety data sheets
C11
CHIP
SPQAG testing protocols

25. Control systems – defined roles and responsibilities
Designated Medical Officer or Nursing Officer
Authorised Person
Competent Person
QUALITY CONTROLLER (MGPS)

26. Control systems – defined roles and responsibilities
QUALITY CONTROLLER (MGPS)
responsible for the quality control of medical gases as terminal units and plant
accepts professional responsibility for the last independent check of a MGPS
must be able to provide evidence of training, competence
registered - QC (MGPS) register

27. Your involvement with medical gases
Clinical function
Clinical need
Equipment
Understand operation of MGPS
Understand safety considerations for cylinders
Regulators, flowmeters and associated tubing etc

28. Emergency situations
Must be aware of day to day operational aspects of MGPS / cylinder management to ensure have fundamental knowledge to cope with emergency situation
Examples
Procedure to be followed
Operational policy documents and
emergency information cards

29. Emergency situations YOUR ROLE
to ensure back up supply is made available and additional cylinders sourced as required
to contact suppliers and arrange delivery
Must ensure you know :-
where back up supply (cylinders / tank) stored on site
how to contact suppliers (cylinders or liquid supply)
how many cylinders to ask for
the size of cylinder to ask for
the delivery location
BEFORE AN EMERGENCY OCCURS !!

30. Medical gases
Testing

31. Medical gas testing RQAS Med Gas test team
Tests carried out – commissioning new installations
modifications to existing systems
de-commissioning of systems
routine compressor testing

32. Medical gas testing Tests completed Identity / purity
Particulate contamination
Non specific contamination
Water vapour
Carbon Dioxide
Carbon Monoxide
Oil
Sulphur dioxide
Nitrous fumes
Line pressure
Vacuum pressure

33. Acceptance criteria (Ph. Eur.)
Identity and purity – acceptance criteria
oxygen - > or equal to 99.5%
(absence of nitrous oxide)
oxygen in medical / surgical air –
20.4% to 21.4%
nitrous oxide - >98%
(absence of oxygen)
oxygen / nitrous oxide mixture
48% to 52% of each component
Particles – absence of particles e.g. copper oxide, copper, “verdigris”
Non- specific contamination – polytest tube – absence of colour change in crystals
Water vapour – not more than 0.05mg/L / 67vpm

34. Acceptance criteria (Ph. Eur.)
CO2 – not more than 500ppm / 300ppm
CO – not more than 5ppm
Oil – not more than 0.1mg/L – medical / surgical air to ensure no carry over from compressor motors
Sulphur dioxide – not more than 1ppm
Nitrous fumes – not more than 2ppm
Vacuum – not less than 400mmHg

35. Visit to Medical Gas storage facilities and wards/ departments
Visit the following :-
Oxygen tank and VIE plant
Medical air compressor plant
Nitrous oxide manifold
Visit a ward :-
What gases are supplied via a piped system?
- look out for terminal units, area valve service units (AVSU)
What gases are supplied in cylinder form?

36. Quiz
Please complete multiple choice questions