EQUANOX

Use in adults, including the elderly and children For respiratory use Equanox is administered through a facemask or mouthpiece. The mask is connected to an Equanox supply through a demand valve system. The valve is operated by the act of inhalation of the patient and closes down when the patent ceases to inhale.

In nearly all cases, Equanox is self-administered, but it may be administered by attendant medical personnel trained in its use. Since pain is usually relieved by a concentration of 25% nitrous oxide, continued inhalation does not occur.

However, should inhalation continue, light anaesthesia results and inhalation ceases as the mask falls away. 8) Instructions for Use and Handling of Equanox cylinders If the cylinders of Equanox have not been stored horizontally for at least 24 hours at a temperature above 10°C, (but not exceeding 38°C), then, before use, the cylinders should be maintained at a temperature of above 10°C for at least 2 hours and then completely inverted 3 times.

Alternatively, cylinders may be placed in warm water at body temperature for 5 minutes and then completely inverted 3 times. Thorough ventilation or scavenging of waste gases should take place to reduce operating theatre and equivalent treatment room levels of ambient nitrous oxide to a level below 100ppm.

Preparation for use 1. Cylinder valves should be opened momentarily prior to use to blow any foreign matter out of the outlet. 2. Ensure that the connecting face on the yoke, manifold or regulator is clean and the sealing washer or ‘O’ ring where fitted is in good condition.

3. Cylinder valves must be opened slowly. 4. Only the appropriate regulator should be used for the particular gas concerned. 5. Pipelines for medical gases should be installed in accordance with the conditions set out in HTM 02. 6. Cylinder valves and any associated equipment must never be lubricated and must be kept free from oil and grease.

Leaks 1. Should leaks occur this will usually be evident by a hissing noise. 2. Leaks can be found by brushing the suspected area with an approved leak test solution. 3. There are no user serviceable parts associated with these valves, do not attempt to correct any problems with leakage from any part of the valve itself.

Label any faulty containers, and return them to Air Liquide for repair. 4. Sealing or jointing compounds must never be used to cure a leak. 5. Never use excessive force when connecting equipment to cylinders. Use of Cylinders 1. Cylinders should be handled with care and not knocked violently or allowed to fall.

2. Cylinders should only be moved with the appropriate size and type of trolley. 3. When in use cylinders should be firmly secured to a suitable cylinder support. 4. Cylinders containing liquefiable gas must always be used vertically with the valve uppermost.

Events such as euphoria, disorientation, sedation, nausea, vomiting, dizziness and generalised tingling are commonly described. These events are generally minor and rapidly reversible. Prolonged or frequent use of nitrous oxide, including heavy occupational exposure and addiction, may result in megalobastic anaemia.

4). Myeloneuropathy and sub acute combined degeneration, have also been reported following prolonged or frequent use. 4). Theoretically similar adverse results could result from heavy and prolonged exposure to Equanox. The nitrous oxide constituent of Equanox passes into all gas containing spaces in the body faster than nitrogen passes out.

Prolonged exposure to Equanox may result in bowel distension, middle ear damage and rupture of ear drums. Addiction to a 50% nitrous oxide/50% oxygen gas mixture has been reported.

● Self-administration should be preferred to allow the assessment of the level of consciousness. 5). The nitrous oxide constituent of Equanox causes inactivation of vitamin B12 (a co- factor of methionine synthase) which interferes with folate metabolism.

Assessment of vitamin B 12 levels should be considered in people with risk factors for vitamin B12 deficiency prior to using nitrous oxide. 8). Thus DNA synthesis is impaired following prolonged nitrous oxide administration. 8). Vitamin B12 supplements should be given in the case of repeated and prolonged administration.

Equanox should not be used for more than a total of 24 hours, or more frequently than every 4 days, without close clinical supervision and haematological monitoring. Specialist advice should be sought from a haematologist in such cases.

Haematological assessment should include an assessment for megaloblastic change in red blood cells and hypersegmentation of neutrophils. Neurological toxicity can occur without anaemia or macrocytosis and with B12 levels in the normal range.

In patients with undiagnosed subclinical deficiency of vitamin B12 neurological toxicity has occurred after single exposures to nitrous oxide Thorough ventilation or scavenging of waste gases should take place to reduce operating theatre and equivalent treatment room levels of ambient nitrous oxide to a level below 100ppm.

8). 8), nitrous oxide may be sought and abused for recreational use. 8). The neonate should be checked for possible respiratory depression when nitrous oxide is used around childbirth.

Nitrous oxide should not be used with any condition where air is entrapped within the body and where its expansion might be dangerous.