Steam penetration in thin-walled channels and helix shaped Process Challenge Devices

J.P.C.M. van Doornmalen Gomez Hoyos, K. Kopinga

Zentralsterilisation – Central Service 12/2015; 6:429-433.

Medical instruments with narrow channels are often sterilized in steam sterilization processes. Helix shaped Process Challenge Devices (PCDs) are used to mimic steam penetration in such medical devices. Little to no literature has been found indicating to which extent these devices correctly predict the steam penetration in medical instruments. The aim of the present study is to improve the understanding of steam penetration in narrow channels and helix shaped PCDs.

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Case study on the orientation of phaco hand pieces during steam sterilization processes.

van Doornmalen Gomez Hoyos JP, van Wezel RA, van Doornmalen HW.

J Hosp Infect. 2015 May;90(1):52-8. doi: 10.1016/j.jhin.2015.01.013.


Steam sterilization is an essential part of infection prevention. The literature shows that sterilization of medical instruments containing channels is not trivial. Phaco hand pieces have a simple configuration: a device contains a channel with a constant radius. No literature was found indicating whether the sterilization conditions on the inner surface of a phaco hand piece are influenced by the orientation of the hand piece.

To determine whether the orientation of a phaco hand piece influences the results of a sterilization process of this device.

A qualitative case study, including experiments, is performed with a protocolled combination of steam sterilizer, process, phaco hand piece, orientation of the phaco hand piece, and wrapping.

In this specific case, the orientation of the hand piece influenced the result of the steam sterilization process; in vertically (upright) oriented phaco hand pieces with free water drainage, sterilization conditions are reproducibly established. In the same process, in horizontally oriented or vertically oriented hand pieces without free drainage, these conditions are not established in a reproducible way.

In the investigated combination of sterilizer, process, load, loading pattern and wrapping, phaco hand pieces have to be oriented vertically (upright) with free water drainage to obtain steam sterilization conditions on the inner surface. It is likely that instruments with comparable configuration and dimensions will yield comparable results. It is therefore recommended that this issue is considered during the development of medical instruments and during performance qualifications of such instruments.

Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Hand pieces; Loading; Orientation; Phaco; Steam sterilization; Sterilization

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Variability of ATP amount in last rinse water of automated washer-disinfectors demands monitoring of every load

J.P.C.M. van Doornmalen Gomez Hoyos, R.A.C. van Wezel, F. Tessarolo

Journal of Hospital Infection Volume 91, Issue 1, Pages 87–89
Letters to the Editor


Decontamination processes for medical devices, such as washing, disinfection, and sterilization are essential steps in infection control. The end result of a washing–disinfection process is critical for the next step in decontamination, or for the safe use of a device on a patient in cases where no further decontamination is applied. It would be helpful for daily practice and the development of evidence-based standards if a data set were available to demonstrate the reproducibility of automated washer-disinfectors (AWDs).

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