RE: Autoclaves

Alison Clare Hickman — Thu, 30 Apr 2015 16:10:24 GMT

Cheers James,

Great info! Useful for SVN training/learning too!!

Ali h

RE: Autoclaves

James Johnson — Thu, 30 Apr 2015 14:12:12 GMT

J.A.K Marketing offer all 3 types of Autoclaves in a B,N and S Class. Proven in the dentistry industry to be one of the leading British manufactured autoclaves

I do have to agree that it is very important to receive the after-care. J.A.K Marketing are providing Autoclaves which are manufactured and maintained within the UK so I feel very confident that service/maintenance after-care would be hassle free.

Below is an explanation between the types of Autoclaves;

Autoclaves commonly sterilise by exposing its charge (items to be sterilised) to elevated temperatures of 121 to 134ºC under pressure of 15 to 30 psi, for a holding time of anywhere between three to 30 minutes. Please note that the three to thirty minutes time is the holding time at the set elevated temperature and not the total process or cycle time. Total cycle time would be far greater. The combination of the three lethal parameters of time, temperature and steam, deliver a powerful kill rate which even the hardest of bacteria find hard to survive. This effective and yet clean method of lethality is unmatched by any of the other methods of sterilisation.

Saturated steam at this temperature is an excellent carrier of heat. The operative word is saturated steam. The steam condenses onto its charge and as it does so, it not only expands its huge latent heat but also draws in additional steam to replace the condensed steam. Thus, the heat transfer is very efficient and the penetration levels extremely high.

However, if there is residual air in the chamber and load, it will interfere with steam-instrument contact and may compromise sterilisation. This residual air can prevent penetration of steam to the depths of the load, leaving your sterilisation incomplete. When you load the autoclave with instruments and close the lid, there is already a lot of stale air trapped inside. For sterilisation to take place, this air needs to be effectively purged and replaced with saturated steam. To resolve this problem of purging entrapped air, normal autoclaves will have a manual, mechanical or electrically operated valve open till about 100ºC. Once it is closed, the pressure and temperature begins to rise. It is presumed that by this time, the entire entrapped inner air has been purged. However, tests have shown that this is not an effective method for vials, wrapped items, implants, garments and certain types of hollow ware. You can never be assured of efficient penetration of steam right inside, if you are using a regular autoclave. Even a small volume of entrapped air can compromise your sterility assurance level simply because ordinary entrapped air is a very bad conductor of heat and moisture. These pockets of air cannot conduct heat to the load with the same vigour as steam and therefore cold spots remain within the load.

The type N-cycle is suitable for sterilising only unwrapped and solid instruments. N-cycle sterilisers are the most popular bench top autoclaves (top or front loading) and are classified as passive systems (also known as gravity or non-vacuum). Typically, as steam is generated or admitted into the sterilisation chamber, it forces unsaturated and saturated air out through a vent. The major concern with the N-cycle sterilisers is the non-removal of trapped air (especially air pockets in lumens and difficult-to-access areas of the load) during displacement. Errors in packaging or overloading the steriliser chamber can result in cool air pockets where items are not sterilised.

The type B sterilisation cycle is used to process loads that can retain air. It can sterilise solid, hollow, and porous instruments, be they wrapped or unwrapped. Pressurised steam is an effective sterilising agent provided that the internal air has first been removed from the chamber as well as the air retentive load. Residual air prevents direct contact between steam and the load to be sterilised. Hence this B-cycle involves the use of active (forced) air removal, usually by using an inbuilt vacuum pump. These pre vacuum or Class-B sterilisers create a vacuum, thus removing air from the load prior to the chamber being pressurised with steam. This can be done from one to three times, depending on the cycle selected. This technique allows faster and more effective steam penetration throughout the entire instrument load than the gravity displacement technique typically employed in sterilisers with N-cycles.

RE: Autoclaves

Leah Morley — Thu, 30 Apr 2015 12:13:44 GMT

We are also looking at purchasing a new autoclave and had been looking at the Vacuvet from Eickemeyer. Is anyone using this machine?

Also, I'm having trouble getting a firm answer on S-Type v B-Type. Can anyone help me clear up this debate? We are 100% small animal, we autoclave bagged instruments, drapes and gowns.

RE: Autoclaves

Nicola Smith — Wed, 18 Mar 2015 21:52:36 GMT

We have a kronos vacuum.one.

Very happy with it. Supplied and serviced by a dental supplier - dentalex. Not cheap but worth it and excellent service from them.

RE: Autoclaves

S B — Wed, 18 Mar 2015 21:41:17 GMT

Thanks...but a lot of the posts are old. Looking at eikmeyre....what do people think of them???

RE: Autoclaves

Sal the 1st — Wed, 18 Mar 2015 20:59:36 GMT

theres a few threads on this if you go through the search. Just make sure that whatever you do buy that somebody will service it as this is a big problem with some of the manufacturers