[QUOTE=justapax;11940324]
Originally Posted by
G SXTY
That's depressing. It means my remaining lung isn't giving me sufficient oxygen for me to feel comfortable at 6000', not 8000' as I had previously thought.
At SFC I can walk for about 20 minutes on the flat before I get really breathless and need to sit down and gasp for air. Aloft, as I'm just sitting and being served food and drinks (lots of drinks, especially on EK!) the lower oxygen pressure doesn't seem to matter on an A350, but does on a 787. Can 1000' really make that much difference?
I actually have slightly over 50% lung function, I had half a lung out, but in the process the left lingula became strangulated, so I only have a bit of lung function left from the bottom of what's left of my left lung.
If you have knowledge about lung function vs. effective altitude, I'd be grateful to know about it. The last thing I want to do is board an unpressurised aircraft and find that the little cylinder of oxygen I carry runs out before the flight does. I get enough grief at LHR and EMA taking *any* oxygen on board.
I work in the gas industry and would strongly recommend that you first discuss with your doctor or your oxygen supplier whether or not to bring oxygen on board. They will be best able to advise you on how much oxygen your condition may require and what type of cylinder, if any, will be appropriate. It certainly won't be a scuba-sized cylinder.
Hospitals use large oxygen cylinders, but these are usually reserved for critical patients who may have a continuous oxygen consumption of around 10-15 L/min. This is quite a lot, to compare - a healthy person in a calm condition consumes about 1.5–2 liters of oxygen per minute. In most cases, heavy patients are connected to a central oxygen supply; when cylinders are used, they are not always large. Smaller cylinders and lightweight composite cylinders are also widespread. Larger cylinders are more common, mainly because they are cheaper, so they are common in hospitals (and elsewhere).
I would suggest that you use a cylinder of around 0.5 L at a pressure of around 150 bar. This will give you around 15-30 minutes or more of continuous breathing, depending on the condition. However, if you only need oxygen for occasional inhalation rather than continuous breathing, a small cylinder may be sufficient. But again - you need to speak with your doctor at first.
From my ongoing research into oxygen supply on commercial aircraft, I know that there are usually several medical oxygen cylinders (usually 1–2L size) on board. They are designed to provide sufficient breathing support in case of breathing difficulties during the flight.
Bringing your own oxygen cylinder on board can be tricky, as compressed gas cylinders are considered dangerous. If something happens, such as a valve failure, the cylinder will fly around the cabin like a rocket. All oxygen cylinders carried on board an aircraft are regularly checked according to strict protocols, and larger cylinders are always securely fastened. This does not guarantee 100% safety, but it significantly reduces the risks. At the same time, the staff does not know where you bought your cylinder and what condition it is in - so it is difficult for them to agree to allow you on the plane with a bottle of gas under high pressure.