There is an excellent Forbes of India article on how oxygen is made for use by patients in hospital.

There are three different ways:

1. Vacuum Insulated Evaporator: Storage system of liquid oxygen

2. Oxygen Cylinders: hold oxygen under pressure

3. Oxygen Concentrators: Concentrates from a gas supply (typically ambient air*) to supply an oxygen-enriched gas stream. NB. Ambient air is typically 78% nitrogen and 21% oxygen. The extra 1% is made up of a combination of carbon, helium, methane, argon and hydrogen. The closer the air is to sea level, the higher the percentage of oxygen.

Hospital oxygen supplies have run out when the medical facility has been overwhelmed with patients and the storage system has become exhausted. This has happened in many countries.

First, the oxygen has to be manufactured. An example of the industry is INMATEC.

Those administering oxygen to people with lung problems have to be careful of side effects. It has to be monitored to avoid harm.

Medical oxygen is used to: 

• provide a basis for virtually all modern anaesthetic techniques
• restore tissue oxygen tension by improving oxygen availability in a wide range of conditions such as COPD, cyanosis, shock, severe haemorrhage, carbon monoxide poisoning, major trauma, cardiac/respiratory arrest
• aid resuscitation
• provide life support for artificially ventilated patients
• aid cardiovascular stability 

Contraindications/side effects

There are no absolute contraindications to the use of oxygen but the inspired concentration should be limited in the case of premature infants and those patients with chronic bronchitis and emphysema.  However guidelines have been published by the British Thoracic Society (BTS) on the safe therapeutic use of medical oxygen, which encourages proper assessment of the patient before use.

Compressed medical oxygen toxicity may manifest itself in the following ways:

• retrolenticular fibroplasia in premature infants exposed to oxygen concentrations greater than 40%
• convulsions appear after a few hours exposure to medical oxygen at pressures above 3bar(g)
• retrosternal soreness associated with coughing and breathing difficulties, made worse by smoking and exposure to cold air after breathing pure medical oxygen at atmospheric pressure for several hours.

If all health provisions is free at the point of need in a civilised country, then planning has to be extensive to secure sufficient oxygen infrastructure for the population of that nation.

Where only private care is offered to a small percentage of the population, then if, in the event of running out of supplies due to excessive demand (never planned for) it will lead to huge criminal networks selling oxygen to the highest bidder.

This pandemic has laid bare the weaknesses in health care infrastructure in many countries. There have been thousands of preventable deaths as a result. Covid kills in a dispassionate fashion. Loved ones are torn apart by the sight of family members dying in such an ugly way.

I have experienced, first hand, what it is like to lose the ability to breathe and know I am near death. We have an NHS which supplied me with oxygen before I faded. I did not have a huge bill to pay. I trusted the medical professionals and was so, so grateful to them.

Poor health planning and elitist health support have led to the disadvantaged having no chance to survive as Covid caused their lungs to fill, and be blocked.

This situation, the Haves and Have Nots, is now stark to see and the Pandemic hits hard, allowing variants to mutate at will where the poorly served people are left to die in such dire misery. Covid will never be overcome, even with vaccines, if we continue to ignore our obligations to our fellow human beings.