- How do I store and handle gas cylinders?
- Cylinders should ideally be stored undercover in a secure, dry and well ventilated area and they should not be stored near to combustible materials.
- E or D sized cylinders can be stored in the horizontal position but F and larger must be stored upright, secured in racks or with chain across the cylinder bank to prevent toppling.
- The floor should be level and constructed of concrete or other non-combustible material.
- The store should have adequate means of access – preferable level – to facilitate delivery and collection of cylinders.
- So far as practicable, lighting and electrical equipment should be sited in a safe position, remote from cylinder storage.
- Lubricants should be avoided. Only lubricants that are made for oxygen service and specified by the equipment supplier should be used.
- Always use clean hands or gloves when assembling oxygen equipment i.e. when changing cylinders. Check that hands are free from oil or grease before handling equipment.
- Separate empty, full and faulty cylinders.
- Never repaint, obscure or alter the marking on cylinders.
- The storage area should be clearly identified i.e. by use of appropriate signage. This can take several forms:
- Internal surgery doors and cylinder storage areas to be identified with a green compressed gas diamond and yellow oxidising warning triangle.
- External cylinder storage areas should carry more robust signage i.e. Compressed Gases / No Smoking / Oxidising Substance / Contact Information - all according to requirements under HTM 02-01
The Emergency Services should be informed of cylinder store location and No Smoking Signs should be clearly displayed within the premises.
Flowmeters/Mobile 4 Cylinder Stands
These are frequently 'stored' in the actual surgery setting between procedures, complete with oxygen/nitrous oxide cylinders. The same rules apply as above (where practicable) and the surgery door should be signed with a green compressed gases diamond and yellow oxidising triangle.
When moving the flowmeter and stand, care should be taken over surfaces that are not completely level (for example door sills) as excessive movement of the cylinders can put strain on the yoke assembly pins, causing expensive damage. Later mobile stand design incorporates a cylinder restraint facility to help prevent damage on movement. This restraint can be retro-fitted to older stands if required.
- How do I determine what type of r a system and equipment would work for me?
The best method is to initially speak to one of our Customer Service Team. They can advise on equipment available, supply product information and book a survey if this is required. Following that, we would issue a quotation based on the information gathered.
- How do I measure the levels of exposure in my surgery environment?
Measurement of exposure levels can be achieved in two ways;
- Use of diffusion pens worn in the breathing zone for a typical r a session, then returned to the Laboratory for evaluation.
- Using an Analyser such as the latest G200. This unit is designed to accurately verify the level of exposure and can be used to check both background and breathing zone levels of nitrous oxide. This model was released in March 2010 and replaces the earlier PM 3010 which was discontinued around 2006.
- I cannot adjust the vacuum flow - the ball is not lifting on the Vaccum Control Block
Check that your vacuum control block is in the correct orientation i.e. see Vac/Mask instruction on reverse of block body. Ensure that the on/off switch is in 'on' position. Mask must be on patient's face prior to adjusting scavenging flow. If this does not resolve the problem, contact your supplier.
- The reservoir bag is emptying during a sedation procedure
The reservoir bag is emptying (going flat) during a sedation procedure with the patient breathing normally and the r a machine set at a flowrate of 6 L/min total. We are using the Porter brown breathing system.
As the the Porter brown double mask has a superior fit against the patient's face, it effectively means that most of the fresh gas flow is inhaled. With the old style single mask there is often an improper fit which allows room air to be entrained during breaths.
Ensure that the inner liner flutter valve membrane is in place and not damaged. Set the correct scavenging flow with nasal mask in place on patient. Commence the r a session with the bag inflated (but not overinflated) and ensure patient is not breathing too rapidly or taking abnormal breaths.
Inspect all rubber goods e.g. reservoir bag, tubings to ensure they are not holed or damaged. Note: The outlet non-return valve on the r a flowmeter is set to produce a bias to direct some of the titrated fresh gas flow into the reservoir bag. If the problem continues, ask your service provider for advice.
- We seem to be using a lot of medical gas
Prior to commencing the r a session, use a check list to ensure all equipment is in good working order, with no holes or tearson the reservoir bag and tubings.
On 4 cylinder stands, ensure a bodok seals is in place at all cylinder yoke points (these should ideally be replaced at the first sign of wear or damage) and ensure cylinders are firmly clamped in position.
- What equipment is required for administration of Inhalation Sedation?
The basic requirement is a purpose-designed flowmeter, medical gas supply - either an installed pipeline system or mobile 4 cylinder stand, with a scavenging system for removal of waste nitrous oxide.
- Why do I need to use an Active Scavenger Breathing System?
C.O.S.S.H. and H & S require that staff are protected from exposure to waste nitrous oxide in the surgery environment.
Chronic exposure to nitrous oxide has been linked to occurences such as spontaneous abortion and reduced fertility. The currrent recommended occupational limit of exposure is 100 ppm (parts per million) over an 8-hour TWA (Time Weighted Average). This can only be achieved by use of the following; Active Scavenging (defined as a flow rate of 45 L/min at the nasal hood), staff rotation and good surgery ventilation or room air changes (recommended 12-15 p/hour). A number of active scavenger breathing systems are available. A paper published in 2002 stated "This study compared the effectiveness of three nitrous oxide scavenging systems; the Porter rtbwonm the Accutron and the Matrx, in actual time during use in a standardized mock treatment protocol that reflected clinical practice while minimizing the influence of confounding variables. At every occasion during the procedure, the Porter brown scavenger system left the operatory with significantly less nitrous oxide than any of the other scavengers tested. The Porter brown removed between 71% and 91% of the nitrous oxide compared to the control (no device)"
Ref: Clinical evaluation of the efficacy of three Nitrous Oxide Scavenging Units during Dental Treatment. Certismo, Walton,
Hartzell, Farris. Published in General Dentistry September/October 2002.
Please note: A copy of the complete article is available upon request to Customer Services.
- Why won't the nitrous oxide cylinder pressure gauge fall to zero with both cylinders turned off?
In order to vent nitrous oxide from the system leave the oxygen cylinder on until the nitrous oxide pressure gauge falls to zero.
- Will the nitrous oxide cylinder pressure gauge on my four cylinder stand tell me how much nitrous oxide gas I have left?
The pressure gauge is not an indication of the cylinder contents. Because nitrous oxide is in liquid form, the pressure gauge is only a reference that some nitrous oxide is in the cylinder. Weighing the cylinder is the only accurate means of determining the contents but this is not very feasible in practice. This is why, on a four cylinder stand, you should always have an 'In-Use' and 'Full' cylinder in place prior to the commencement of the sedation procedure.