Autoclaving

Sterilisation of instruments, drapes and gowns in veterinary practice is typically achieved using heat, an effective means of killing micro-organisms. Although most micro-organisms are killed at temperatures above 80°C, some spores can survive temperatures in excess of 120°C. Two methods can be used to achieve the high temperature required, dry heat or steam sterilisation. Dry heat is much less effective than steam and high temperatures for prolonged periods are required, potentially damaging for the items. An autoclave allows steam at above atmospheric pressure to sterilise the items quickly. At 134°C a holding time of three minutes may be sufficient. Ensuring that steam penetrates the entire load without any air pockets remaining is an autoclave design challenge. This is a particular problem with porous loads such as gowns and drapes, together with long hollow instruments such as dental drills. A basic autoclave cannot reliably sterilise these loads. To ensure all air is removed, vacuum cycles are required prior to steam sterilisation. Autoclaves are now classified according to their capabilities:

• Class N - A basic autoclave providing no vacuum cycle. Older and low-cost autoclaves often encountered in veterinary practice fall into this category. They are not suitable for packed, porous or hollow loads.

• Class S - An intermediate category which can sterilise certain specified porous or hollow loads.

• Class B - An autoclave rated for all porous loads and hollow instruments.

To sterilise drapes, gowns and packed instruments for storage, a class B autoclave is required. These are relatively costly, technically complex and regular routine maintenance is essential. Loads must be perfectly clean prior to sterilisation and washing and drying reusable drapes or gowns is a labour-intensive process. In veterinary practice elimination of hair contamination when washing drapes can be a challenge. There should be an audit of the sterilisation process in place with maintained records documenting effective sterilisation cycles.

Sterile disposables supplied by Vygon Vet provide a cost-effective alternative to in-house sterilisation, drastically reducing labour and equipment overheads. They also guarantee clean and sterile supplies for every patient and are manufactured to human healthcare standards.

Disposable theatre products from Vygon Vet:
Surgical masks and gowns
Sterile drape towels
Universal drape packs
Incise drapes
Fenestrated drapes
Limb surgery drapes
Table and trolley covers

© Vygon (UK) Ltd 2009