COMPRESSED MEDICAL OXYGEN

Medical Oxygen is administered by inhalation through the lungs. The major exception is when a metered supply is fed into the oxygenator of an extracorporeal circulation of a cardio-pulmonary by-pass system. The need for medicinal oxygen should be determined by obtaining arterial blood gas values and/or by monitoring SpO2.

The inspired oxygen should be titrated when used for long term oxygen therapy in patients with chronic hypoxic respiratory failure. A SaO2/SpO2 between 88 and 92% is commonly assessed as adequate in patients with chronic obstructive pulmonary disease (COPD).

A too liberal administration can increase the oxygen SaO2/SpO2 clearly above the patient's normal range, which may cause respiratory depression because of chemoreceptor insensitivity for CO2. Blood gases should be monitored to avoid excessive retention of CO2 in patients with hypercapnia or reduced CO2- sensitivity, in order to adjust the oxygen therapy For cluster headache, oxygen should be administered as soon as possible after the onset of the attack, via a non-rebreathing facemask at a flow of 6 to 12 l/min for approximately 15 minutes.

Compressed Medical Oxygen toxicity can occur as manifested by: • 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 3 bar(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.

The most serious side effects that may occur are severe difficulty in breathing, so called respiratory distress syndrome. g. some patients with chronic obstructive pulmonary disease (COPD) causing hypercapnia (frequency not known). Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important.

It allows continued monitoring of the benefit/risk balance of the medicinal product. uk/yellowcard.

Special care is needed when Medical Oxygen is administered: • to neonates where the inspired concentration should not exceed 40% because of the risk of retrolenticular fibroplasia • to elderly chronic bronchitic patients in whom the inspired concentration should only be raised in stages of 1% and probably should not exceed 30% • in hyperbaric chambers in the management of conditions such as carbon monoxide poisoning, anaerobic infections and acute ischaemic disease.

Convulsions may occur at 3 bar (g) after a few hours. Careful monitoring of oxygen levels on the breath, blood and tissue is required to ensure that appropriate concentrations are not exceeded. In patients with reduced sensitivity for carbon dioxide pressure in arterial blood, high concentrations of oxygen may cause, respiratory depression subsequently causing carbon dioxide retention (hypercapnia), which in extreme cases can lead to carbon dioxide narcosis.

Where the patient has been exposed to agents which are toxic to the lungs, such as Paraquat, the use of gases containing more than 21% oxygen should be avoided. Compressed Medical Oxygen is non flammable but strongly supports combustion and should not be used near sources of ignition.

Compressed Medical Oxygen Cylinders should be set up and tested before placing near the patient. Do not place the cylinder on the patient’s bed unless there is no suitable alternative for retaining the cylinder. Smoking should be prohibited when using Compressed Medical Oxygen.

Under no circumstances should oils or grease be used to lubricate any part of the Compressed Medical Oxygen cylinder or the associated equipment used to deliver the gas to the patient. Where moisturising creams are required for use with a facemask or in nasal passages, oil based creams should not be used.

Check that hands are clean and free from any oils or grease. Where alcohol gels are used to control microbiological cross-contamination ensure that all alcohol has evaporated before handling Compressed Medical Oxygen cylinders or equipment.

There are no absolute contraindications to the use of Compressed Medical Oxygen, but the inspired concentration should be limited in the case of premature infants and those patients with chronic bronchitis and emphysema.