EFHSS Questions and Answers - Question Q00088

We are using a AMSCO Reliance 444 Washer Disinfector to disinfect Anaesthetic Equipment. The process of this machine uses a thermal rinse of 180 degrees for 10 minutes with a continuous spray rinse. Is this adequate for disinfection of anaesthetic equipment and would this be considered high level disinfection?

Dixie LaRose, Administrative Support
Stettler Health Centre
ph: (403) 742-7405
fax: (403) 742-1244

Dixie

This type of WD is used to process anaesthetic and respiratory accessories; both those which are not required to be sterile (but are required to be disinfected) as well as those which will be subject to further processing, eg sterilization.

Disinfection is achieved by direct contact of the load with water, in your case 180 degrees f or 82 c wayer temp at a pressure near to atmospheric pressure, to raise the temperature of the surface of the load to a specified temperature for not less than a specified time (10 minutes okm if not gross soiling), or a combination of conditions providing equivalent lethality.

The key requirement for WDs of this type is the circulation of water (and/or other aqueous solutions), used for washing, and hot air, used for drying, through the lumen of hollow items.

The facility to process anaesthetic accessories may be provided by a dedicated load carrier using a WD for instruments. A separate drying cabinet is often advantageous when a dedicated load carrier is used in a WD for instruments. Drying times for anaesthetic accessories are much greater than for instruments and the use of a separate drying cabinet improves the overall throughput of the WD.

WDs for anaesthetic accessories may incorporate a drying stage in the automatic process or there may be a separate drying cabinet.

Product compatability
The instructions of the manufacturer of the anaesthetic accessories should be followed regarding the suitability of the various items for processing in a WD for anaesthetic accessories.
A neutral detergent or washing without a detergent may be necessary for some products, eg laryngeal masks made of silicone rubber. The maximum temperature attained during disinfection and drying may need to be controlled to minimise the oxidative degradation of rubber materials.

Load handling
The use of a load carrier specifically intended for anaesthetic accessories is essential. Items with a lumen should be placed over, or connected to, the appropriate nozzle on the load carrier to ensure the free passage of fluids through the lumen during processing.

Summary
The water temperature with your amsco washer is appropriate but this temp must be verified by an independent temperature controller to verify the duration and contact time of the water on the load surface. Validation studies should reinforce GMP and the results should confirm the efficacy and thermal disinfection of the product.