An oxygen concentrator is a medical device that provides a continuous flow of high-purity oxygen by filtering out the nitrogen from normal air. Thus a concentrator can provide an unlimited supply of oxygen in the most remote locations in the world. In order to do this, all a concentrator requires is an electricity supply (110v or 240v), and a well-ventilated position.
Concentrators have a distinct advantage over oxygen reservoirs (cylinders) in that they provide a continuous supply of oxygen that may be required by a casualty for an unlimited period, until the casualty can be transferred to a definitive medical facility. In contrast, a typical 2 litre oxygen reservoir containing 400 litres of oxygen, will only last for between 30 minutes and 120 minutes at appropriate flow rates.
All concentrators provide a supply of oxygen that can be varied using a flowmeter, to provide just the right amount of oxygen required by the casualty. There are a variety of concentrators that provide different levels of maximum oxygen, with higher maximum flow rates (up to 10 litres per minute) requiring larger concentrators. The different concentrators available are listed overleaf, with dimensions and weights.
The smallest concentrator supplied provides a maximum flow rate of 5 litres per minute. This is appropriate for a casualty requiring oxygen on a continual basis, but otherwise quite stable. The largest concentrator provides a maximum flow rate of 10 litres per minute, which is appropriate for acute resuscitation, such as during and immediately after a cardiac arrest.
A valuable additional function of a concentrator is that it can provide the oxygen input to a compressor, which can be used to refill oxygen reservoirs (cylinders). This utility can be performed in the most remote locations on the world’s oceans.
The aim of giving oxygen therapy is to supply enough oxygen to a casualty so that the oxygen saturation of their blood is usually greater than 92% (this does depend on the actual patient).
Therefore, the oxygen flow and type of mask being used should be adjusted to achieve at least this minimum blood oxygen saturation level, whilst economising on the amount of oxygen being used.
An essential piece of equipment that enables measurement of blood oxygen saturation levels is a pulse oximeter. It is attached to the end of a finger, and rapidly measures and displays in real time the blood oxygen saturation level. A pulse oximeter is included in all oxygen kits.
Oxygen concentrators can be supplied in Pelicases and also roll-top soft bags, to keep the concentrator relatively protected from the harsh marine environment.