Oxygen Therapy

Oxygen is nature’s own powerful vasodilator for the arteries in the lung. Using oxygen at night is therefore part of the treatment regime for many patients. Supplementary oxygen can be prescribed for PH patients who have inadequate amounts of oxygen available in the blood whilst at rest or during physical activity. Supplementary oxygen is therefore an important addition to treating the symptoms of a PH patient with low levels of oxygen. It can also be used in special conditions for example, such as when hospitalised with a chest infection or at high altitudes (in mountains) or sometimes when travelling by air. If your oxygen levels go lower than the normal levels for sustained periods, you may find that oxygen therapy improves your mental and physical ability.

Some people with PH may have to work much harder to obtain all the oxygen they need. The extra effort involved can cause breathlessness and tiredness, particularly after walking or coughing. It is well understood that for some people, breathing air with a higher concentration of oxygen can reduce these symptoms.

In PH it must be remembered that supplementary oxygen is not helpful or even required for many people with PH and it is important to ask your PH specialist team to assess whether extra oxygen is appropriate for you. Oxygen can be obtained from compressed oxygen cylinders or from an oxygen concentrator machine, which extracts oxygen from the air. Both of these methods are available on NHS prescription. Oxygen can also be obtained from liquid oxygen storage tanks delivered to the home, but these are not available on prescription. If you use oxygen for short periods to relieve attacks of breathlessness you will probably be prescribed oxygen cylinders. For those people who would benefit from oxygen for a significant number of hours a day, often taken whilst asleep, oxygen concentrator machines are more convenient and cost effective.

Oxygen cylinders are supplied by a local pharmacy and delivered regularly to the home, along with tubing and a mask or a nasal cannulae (small tubes for breathing the oxygen in through the nose).

An oxygen concentrator is a machine about the size of a small refrigerator and it plugs into the ordinary household electricity supply. It filters oxygen from the air in the room and this oxygen is then again delivered by plastic tubing to a mask or nasal cannulae. Long tubing can be fixed around the floor or skirting board, with two points where the user can "plug in" to the oxygen supply.

If you are prescribed an oxygen concentrator, your doctor will notify the company which supplies them for the NHS in your area. The machine is very quiet and compact and the engineer will explain to you or to a friend or relative, how to use it and will be able to answer any questions you may have. A back-up cylinder of oxygen is also provided for use in case of a machine breakdown or during an electricity power cut. Regular maintenance visits will be made to make sure that the concentrator is always operating perfectly however.

Tanks containing oxygen compressed into liquid form can contain up to 2 weeks supply. They have the advantage that portable liquid oxygen tanks can be filled from them, which last longer than conventional portable oxygen cylinders. Liquid oxygen is not widely used in the UK - it is not available on NHS prescription and can be expensive. People with PH who are using oxygen in the home (either for short periods to relieve attacks of breathlessness or for a number of hours each day or night as a long-term therapy) may wish to have a small portable cylinder to enable them to take oxygen outside the home. It is important that you discuss this matter with your GP. Portable cylinders contain 230 or 260 litres of oxygen (depending on the manufacturer) and are available with flow outputs set at 2 litres per minute, 4 litres per minute or with an adjustable scale (up to 4 litres per minute). The flow required is assessed by your PH specialist team. When full these cylinders weigh about 2½ kg and hold just under two hours of oxygen at 2 litres per minute.

It is also possible for GP’s to prescribe semi-portable oxygen cylinders. These cylinders are heavier than the 230 litre size, at 300 litres and not really suitable for carrying far but do facilitate getting out of the house. Once turned on, oxygen cylinders usually release a constant flow of oxygen whether the user is inhaling or not. A system is available which regulates the oxygen flow according to each breath, eliminating oxygen wastage so that the cylinder lasts many times longer than with a continuous flow system. This type of flow regulator (conserver) can be fitted to the majority of oxygen bottles used in the UK but at the present time are not available on prescription. Please note that the way in which oxygen is delivered to patients by the NHS is due to change in late 2005 early 2006. Keep checking the PHA-UK website and Newsletter for update information about this or contact your local oxygen supplier.