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Inhaled Nitrous Oxide

Inhaled Nitrous Oxide is very useful as analgesia for joint injections but can be used with other procedures such as dressings or removal of plaster casts. Nurses who are involved in the administration of inhaled Nitrous Oxide require specific training. 

A checklist for use of inhaled Nitrous Oxide (Entonox®) is provided here.

Assemble Cylinder of Entonox® with attached supply valve, tubing and mouthpiece. Ensure that there is adequate supply and that the supply valve is turned on.

Ensure patient has received written leaflet and that they understand procedure.

Assess patient suitability for Entonox®;

Does the patient feel fit and well today?  Any cough, cold or chest infection? Any recent injury to chest or face? If applicable, date of last menstrual period. Any other medical conditions eg, respiratory, cardiac, or neurological problems.

Ensure patient is positioned comfortably. Check that they know how to use mouthpiece.

Allow patient to practice holding the mouthpiece and taking 2-3 adequate inhalations. Observe that the mouthpiece is being held correctly, the supply valve is hissing (indicating correct flow) and the patient is inhaling and exhaling correctly.

During procedure encourage patient to breathe in and out deeply and regularly.

At end of procedure observe patient until effects of the gas have worn off.

Advice given about possible post injection complications.

Turn off Entonox® supply from cylinder. The guage should read empty. Depress the diaphragm under the valve to express residual gas.  Dispose of mouthpiece and filter in clinical waste.


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