High-Level Disinfection

Purpose

High-level disinfection is a process that deactivates all types of microorganisms with the exception of bacterial spores and prions.¹  The purpose of this document is to provide guidance to health care personnel for

• performing safe and effective manual chemical high-level disinfection of reusable semicritical items and

• preventing patient and health care worker injury associated with the handling and use of liquid chemical high-level disinfectants (HLDs).

The Spaulding classification system defines reusable medical items as critical, semicritical, or noncritical.²  The level of processing required (ie, sterilization; high-, intermediate-, or low-level disinfection) is based on the manner in which the item is to be used.²  Items that contact mucous membranes (eg, endocavity ultrasound probes) or nonintact skin are considered to be semicritical.²  Spaulding²  recommended that semicritical items be processed by sterilization or, at a minimum, by high-level disinfection.

Failure to correctly perform high-level disinfection can lead to transmission of pathogens via contaminated medical or surgical devices.^3,4  The vast majority of patient infections and exposures related to processing medical or surgical devices have involved high-level disinfection of reusable semicritical items.³  In a recent safety report, The Joint Commission⁵  noted that processes for high-level disinfection of equipment and devices are frequently found to be inadequate, especially in ambulatory care centers and decentralized locations in hospitals. Breaches in the performance of high-level disinfection can result in outbreaks of viral or bacterial organisms.⁵ 

High-level disinfectants are harmful to human tissue and the environment.⁶  Health hazards associated with the use of HLDs vary from minor irritation of mucous membranes to more serious injury (eg, chemical burns).¹  Health care organizations are responsible for informing health care workers about chemical hazards in the workplace and for implementing measures to reduce personnel exposure and mitigate identified hazards.⁷  Implementing safe processes for handling and using chemical HLDs is essential for preventing injury to both patients and personnel.⁶ 

Guidance for the following topics is outside of the scope of this document:

• processing critical items for sterilization;

• processing semicritical items using thermal high-level disinfection (ie, pasteurization);

• processing flexible endoscopes and accessories and other semicritical items using mechanical (ie, automated) processes for high-level disinfection or liquid chemical sterilization (See the AORN Guideline for Processing Flexible Endoscopes⁸ );

• processing endocavity ultrasound probes and other semicritical items using nebulized hydrogen peroxide mist;

• processing semicritical items potentially contaminated with prions;

• processing noncritical items for intermediate- or low-level disinfection;

• assessing risk and notifying patients regarding high-level disinfection failures; and

• using specific HLDs.

Evidence Review

A medical librarian conducted a systematic literature search of the Ovid MEDLINE®, CINAHL®, and Scopus® databases and the Cochrane Database of Systematic Reviews for meta-analyses, randomized and nonrandomized trials and studies, and systematic and nonsystematic reviews. The initial search was conducted in August 2014, and an additional search was performed in December 2016. In each search, the results were limited to literature published in English in the 5 years prior to the search date. The medical librarian established continuing alerts on the topics covered in this guideline and provided relevant results to the lead author. During the development of this guideline, the author requested supplementary searches for topics not included in the original search as well as articles and other sources that were discovered during the evidence-appraisal process. The lead author and the medical librarian also identified and obtained relevant guidelines from government agencies, standards-setting bodies, and other professional organizations.

Search terms included high-level disinfection, semi-critical item or device, automated endoscope reprocessor, Spaulding schema or criteria, peracetic acid, hydrogen peroxide, glutaraldehyde, ortho-phthalaldehyde, thermal or heat disinfection, pasteurization, medical device washer, equipment contamination or reuse, anesthesia equipment, disease transmission, cross-infection, biofilm, bacteria, microbial, spores, fungus, prion, Creutzfeldt-Jacob syndrome, Klebsiella, Pseudomonas aeruginosa, carbapenemase-producing Enterobacteriaceae, Staphylococcus aureus, Pseudomonas putida, Mycobacterium massiliense, storage, shelf life, cabinet, transport, protective clothing, eye protective devices, occupational disease or exposure, hypersensitivity, health personnel, medical waste disposal, waste management, and documentation. Subject headings and key words for specific types of endoscopes also were included.

Included were research and non-research literature in English, complete publications, and publication dates within the time restriction when available. Excluded were non-peer-reviewed publications, older evidence within the time restriction when more recent evidence was available, and research and non-research evidence related to thermal high-level disinfection, specific disinfectants, workplace safety and occupational illness not related to high-level disinfection, sterile processing activities not associated with high-level disinfection, environmental and surface disinfection, and high-level disinfection of single-use devices. Editorials, news items, and other brief items were excluded. Low-quality evidence was excluded when higher-quality evidence was available, and literature outside the time restriction was excluded when literature within the time restriction was available. In total, 321 research and non-research sources of evidence were identified for possible inclusion, and of these, 148 are cited in the guideline (Figure 1).

Figure 1

Flow Diagram of Literature Search Results

Adapted from Moher D, Liberati A, Tetzlaff J, Atman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(6):e1000097.

Articles identified in the search were provided to the project team for evaluation. The team consisted of the lead author and one evidence appraiser. The lead author and the evidence appraiser critically appraised each reference using the AORN Research or Non-Research Evidence Appraisal Tools as appropriate. The literature was independently evaluated and appraised according to the strength and quality of the evidence. Each reference was then assigned an appraisal score. The appraisal score is noted in brackets after each reference, as applicable.

Each recommendation rating is based on a synthesis of the collective evidence, a benefit-harm assessment, and consideration of resource use. The strength of the recommendation was determined using the AORN Evidence Rating Model and the quality and consistency of the evidence supporting a recommendation. The recommendation strength rating is noted in brackets after each recommendation.

Note: The evidence summary table is available at http://www.aorn.org/evidencetables/.

Editor’s note: MEDLINE is a registered trademark of the US National Library of Medicine’s Medical Literature Analysis and Retrieval System, Bethesda, MD. CINAHL, Cumulative Index to Nursing and Allied Health Literature, is a registered trademark of EBSCO Industries, Birmingham, AL. Scopus is a registered trademark of Elsevier B.V., Amsterdam, The Netherlands.