Useful Information

When administering Inhalation Sedation dedicated purpose-designed machines should be used. Such machines should conform to British Standards and be maintained according to O.E.M. (Original Equipment Manufcturer) guidance with regular documented servicing.

"Scavenging of Waste Gases must be active and sufficient to fully conform to current C.O.S.H.H. (Control of Sustances Hazardous to Health) Standards. Breathing Systems should have a separate inspiratory and expiratory limb to allow proper scavenging. Nasal masks should be close fitting providing a good seal without air entrainment valves".*

* Conscious Sedation in the Provision of Dental Care. Report of an Expert Group onSedation for Dentistry. Department of Health 2003.

HTM 02-01 Medical Gas Pipeline Systems - Part A Department of Health 2006

Chapter 10.5 : "Active Scavenging for dental installations is an entirely different concept. An active system is one in which there is a flow generated through the patient's nasal mask and this carries away the waste gases exhaled by the patient. This flow is in the order of 45 L/min and is achieved by connection of the mask (via a suitable flow-limiting adaptor) to either a dental vacuum system or directly to an active scavenging system (BS/EN) wall terminal unit".

Appendix L : Active AGS (dental);

8. Active AGS systems for use with dental nasal scavenging masks operate by maintaining a flow of air through the outer layer of a specially designed concentric nose mask. Waste gases from the patient pass from inner to outer layers of the mask and aire carried away to the exhaust termination by this air stream.

9. The flow rate necessary to achieve effective removal of waste gases by such a method is in the order of 45 L/min, which is less than the flow rate achieved at a medical vacuum system terminal.

10. Active dental scavenging systems using this type of mask must therefore be driven (via a special flow adjuster) from the dental vacuum system, a dedicated separate high-flow vacuum system, or an active medical AGS System, the special flow adjuster would be plugged directly into an AGS system wall terminal. A receiver (air break) system would not be used between the wall terminal and the special flow adjuster.

MDA/2003/007 - Medical Gas Hoses for Oxygen

Risk of Fire from worn or damaged hoses
The MDA has been informed of incidents involving the rupture and ignition of oxygen hoses used beyond the lifetime or use-by date recommended by the manufacturer. Due to heavy wear and tear the risk of rupture is greatest in oxygen hoses used with transport devices. Although the incidents related to this Alert only involved oxygen hoses, there is a need for a system to regularly inspect and replace all medical gas hoses.
Many device users and their managers are not aware of manufacturers' instructions to check the hoses and their connectors regularly and the need for hose replacement, usually between 2 and 5 years. The instructions for use of a medical device incorporating an oxygen hose may not mention the care and replcement of the hose. In these cases, the hose may have been supplied separately and should have its own instructions for use.

Action:

Oxygen hoses should be regularly inspected, cleaned, stored and replaced according to the manufacturers' instructions
Users should be especially aware of the possibility of damage to oxygen hoses when attached to transport devices
If there is any doubt over the age of the hose, or the time recommended by the manufacturer for its replacement, or no care instructions, then the hose must be replaced.
Only oxygen hoses supplied, or recommended by the manufacturer of the medical device should be attached to that device

MDA/2003/016 - Medical gas regulators and flowmeters

Risk of rupture, ignition or inadequate therapy
Pressure regulators and flow meters for use with gas cylinders or the wall outlets of medical gas pipeline systems. This Notice does not apply to pressure regulators or flow meters built in, or permanently attached to other medical devices and serviced with these deivces e.g. anaesthetic machines and gas cylinders with integrated regulators.
The MHRA has been informed of a number of incidents involving the rupture and ignition, or gross inaccuracy, of pressure regulators and lfow meters that have not been appropriately serviced as recommended by the manufcturer. Poor servicing by a thord party agent contributed to a further incident of regulator ignition.
Pressure regulators and flow meters that are built in, or permanently attached, to other medical devices are not always covered by the servicing arrangements for these devices. This Alert is intended to supplement advice given in Medical Device Alert MDA/2003/007 "Medical Gas Hoses for OXygen" and Safety Notice 2000 (07) "Medical Gas Cylinders; Risk of Fire"

Action:

Ensure that devices are inspected regularly and service according to the manfacturers' instructions/service manuals
Ensure that devices have a unique inventory marking to ensure traceability for future servicing
If there is any doubt over the service history then ensure that these deivces are serviced immediately
Ensure that devices on loan or rented are exchanged by the service provider on a regular basis
If servicing is to be undertaken by third party agents ensure that this is in line with recommendations outlined in Device Bulletin 2000 (02) "Medical DEvices and Equipment MAnagement: Repair and Maintenance Provision".
Ensure that older gas regulators without instructions for servicing, or where spare parts are no longer available, are replaced
Ensure that pressure regulators or flow meters that are built in, or permanently attached, to toher medical devices are appropriately service with those devices