Oxygen Cylinder


  • cylinder filled with oxygen for use as a medical gas


  • Provision of supplemental oxygen to maintain aerobic metabolism during patient transport


  • See chart for BOC gas cylinder characteristics
  • pressure varies from cylinder to cylinder
  • typically stored at 13,700 kPa (137 bar) — may vary between 12,000 – 17,000kPa depending on the cylinder
  • Oxygen cylinders have white body with a white top (in the UK they have a black body and white top)
  • Contains gaseous oxygen (pressure drops linearly as oxygen is depleted)


  • cylinder connected to a flow and pressure regulator
  • pin index system ensures appropriate connections


  • explosion
  • oxygen toxicity
  • barotrauma (must use a regulator)
  • trauma from dropping the cylinder on someone!


Safety features

  • safety outlet is fitted between the block and the cylinder neck which melts at low temperatures, allowing the escape of gas in case of a fire
  • Pin index safety system (6 pin positions, each one is unique to a different medical gas)
  • Cylinder colour
  • Nozzle colour
  • Diameter index safety system
  • Labelled yolk
  • Knob texture
  • matching wall connectors

INHALO* integrated valve cylinder

  • these are now widely used (universally?) in Australia
  • can be started right away, without any complex set-up, unnecessary manual handling or connection of a flow regulator
  • consists of:
    • lightweight cylinder
    • a built-in pressure regulator and valve
    • easy on/off handwheel and  integral flow selector
  • advantages
    • simple to use
    • lighter cylinder
    • quick to connect and start
    • provide low constant outlet pressure and flow settings
    • has a “live” contents gauge, giving a clear indication of contents at all times even when the cylinder is turned off
  • * N.B. INHALO is a registered trademark with BOC, there are equivalent integrated cylinders with valves through other medical gas suppliers.


  • Oxygen: white body with white shoulders
  • Nitrous oxide: white body with ultramarine shoulders
  • Entonox: white body with ultramarine and white quadrant shoulders (alternating blue and white)
  • Medical Air: white body with black and white quadrant shoulders
  • Carbon dioxide: white body with a black stripe down the length of the cylinder and with green grey shoulders
  • Heliox: white body with brown and white quadrant shoulders

Of note, cylinder sizes may vary ever-so-slightly between medical gas supplier

  • B: 170 litres
  • C: 490 litres
  • CD (comes with integrated valve, your typical bedside O2): 630 litres
  • D: 1600 litres
  • E: 4000 litres
  • G: 8075 litres

FOAM and web resources


CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

ICU Advanced Trainee BMedSci [UoN], BMed [UoN], MMed(CritCare) [USyd] from a broadacre farm who found himself in a quaternary metropolitan ICU. Always trying to make medical education more interesting and appropriately targeted; pre-hospital and retrieval curious; passionate about equitable access to healthcare; looking forward to a future life in regional Australia. Student of LITFL.

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