High-Level Disinfection: AORN Issues Updated Guidance

The Association of periOperative Registered Nurses (AORN) has published the 2018 Guidelines for Perioperative Practice with five updated guidelines, as well as a completely new guideline that addresses team communication. Guidelines for Perioperative Practice, published each January, is a collection of 32 guidelines that provide evidence-based recommendations to deliver safe perioperative patient care and achieve workplace safety.

Updated -- Guideline for Manual Chemical High-Level Disinfection- the updated and re-titled guideline changes focus to address safe manual chemical high-level disinfection of reusable semi-critical items, while also discussing the evidence-based rationale for using automated HLD as a superior method to protect patients and personnel. A new recommendation for high-level disinfection or sterilization of endocavity ultrasound probes highlights the risk for probe contamination with lower levels of disinfection, even when a sheath or cover is used. The recommendation also notes that some HLDs are not effective against all pathogens that could be on the probes, such as human papilloma virus (HPV).

“Every AORN guideline recommends team involvement and shared communication with all stakeholders on the perioperative team, yet research still identifies ineffective team communication as a common cause of adverse events,” says Ramona Conner, MSN, RN, CNOR, editor-in-chief of AORN’s Guidelines for Perioperative Practice. “Understanding the evidence supporting strategies to strengthen team communication is critical for teams to successfully implement all AORN guidelines for safe perioperative care.”

“Our world is moving rapidly and it is very challenging for the perioperative professional to keep up with all of the new evidence coming out to ensure safe perioperative practice,” Conner adds. “AORN is dedicated to making sense of this wealth of evidence by exploring the literature, rating the evidence, and shaping practice recommendations that perioperative practitioners can easily apply in their unique practice settings.”

According to the guideline, "Failure to correctly perform high-level disinfection can lead to transmission of pathogens via contaminated medical or surgical devices. The vast majority of patient infections and exposures related to processing medical or surgical has involved high-level disinfection of reusable semi-critical items. In a recent safety report, the Joint Commission noted that processes for high-level disinfection of equipment and devices are frequently found to be inadequate, especially in ambulatory care centers and de-centralized locations in hospitals. Breaches in the performance of high-level disinfection can result in outbreaks or viral or bacterial organisms."

In the updated guideline, AORN makes the following recommendations:
- Reusable semi-critical items may be processed using manual methods when manual chemical high-level disinfection is the only processing method recommended by the manufacturer.
- The interdisciplinary team should select HLDs that will be used within the healthcare organization.
- The interdisciplinary team should determine the locations where HLDs will be stored within the healthcare organization.
- Manual chemical high-level disinfection should occur in areas controlled and maintained to support processing activities.
- Personnel should prepare reusable semi-critical items to be processed by high-level disinfection per the device manufacturer's IFU.
- Personnel must prepare and use HLDs in accordance with the disinfectant and device manufacturers' IFU.
- Personnel should protect reusable semi-critical items that have been processed by high-level disinfection from contamination until the item is delivered to the point of use.
- The healthcare organization must provide a safe environment for personnel who handle or use HLDs.
- The healthcare organization should maintain records of manual chemical high-level disinfection processes.
- The healthcare organization should provide initial and ongoing education and competency verification activities related to manual chemical high-level disinfection for personnel who are handling and using chemical HLDs.
- The healthcare organization should develop policies and procedures for manual chemical high-level disinfection that are reviewed periodically, revised as necessary, and readily available in the practice setting in which they are used.
- The healthcare organization's quality management program should evaluate manual chemical high-level disinfection processes.

Conner offers further insights into the updated HLD guideline.

Q: What was the impetus for changing the focus of the guideline to address safe manual chemical high-level disinfection of reusable semi-critical items?

A: The collective evidence shows that using automated methods (i.e., mechanical processing) improves cleaning effectiveness, increases efficiency, and minimizes personnel exposure to hazardous substances (e.g., chemical, biological). Mechanical processors contain the disinfection process, reducing worker exposure to HLDs. Mechanical processing methods can also be more successfully monitored for quality and consistency than manual methods of high-level disinfection. Mechanical HLD is the preferred method, however we recognize that mechanical processors are not available in all facilities and there are some circumstances when mechanical processing may not be possible or practical. Because of this reality, we provide guidance for safely performing manual HLD processing. Guidance for using mechanical processors is provided in the Guideline for Processing Flexible Endoscopes.

Q: Which devices tend to be most problematic in terms of difficulty of reprocessing/device design and why?

A: Flexible endoscopes and other devices with long, narrow channels present special challenges in cleaning, disinfection, and sterilization or HLD. The complex design of flexible endoscopes increases the efficiency and effectiveness of endoscopic procedures; however, it creates enormous challenges for effective processing. Some parts of the endoscope may be difficult or impossible to access, and effective cleaning of all areas of flexible duodenoscopes may not be possible.

Q: What evidence prompted the new recommendation for high-level disinfection or sterilization of endocavity ultrasound probes?

A: There is strong evidence to support a minimum of HLD for these probes. Endocavity ultrasound probes are introduced into a variety of body orifices (e.g., vagina, rectum, trachea). These probes contact mucosal tissue and therefore require cleaning and a minimum of high-level disinfection. The collective evidence shows that endocavity ultrasound probes present a high risk of contamination with pathogenic microorganisms after ultrasound procedures and that disinfection by methods other than high-level disinfection or sterilization may not be sufficient to eliminate the organisms even when a sheath or cover is used.

Westerway, et al. conducted a blinded prospective study in the ultrasound unit of a private clinic and public hospital in Australia. They collected and analyzed a total of 129 samples from transvaginal and transabdominal ultrasound probes. The samples from the probes were collected after use (transvaginal: n = 28; transabdominal: n = 32), after low-level disinfection (transvaginal: n = 26; transabdominal: n = 32), and after high-level disinfection (transvaginal: n = 9; transabdominal: n = 2). The researchers found that although a sheath or cover was used with all the probes, 60 percent (n = 19) of the transabdominal and 14 percent (n = 4) of the transvaginal probes showed bacterial contamination after use. Contaminating pathogenic species on the transabdominal probes included Staphylococcus haemolyticus and Staphylococcus warneri. After low-level disinfection, 3 percent (n = 1) of the transabdominal probes and 4 percent (n = 1) of the transvaginal probes remained contaminated. No contaminating bacteria were detected on any of the probes after high-level disinfection. Inadequately disinfected endocavity probes also increase the risk for transmission of HIV, hepatitis B virus, hepatitis C virus, Neisseria gonorrhea, Chlamydia trachomatis, Trichomonas vanginalis, and HPV.28 In a random probability distribution computer simulation performed to produce hypothetical cohorts for a population of 4 million annual ultrasound examinations in France, Leroy, et al. estimated the number of patients infected by HIV, herpes simplex virus, hepatitis B virus, hepatitis C virus, HPV, cytomegalovirus, and C trachomatis. The simulation showed that despite the use of a sheathed probe and low-level disinfection, the probability of infection from a contaminated probe ranged from 1 percent to 6 percent, depending on the pathogen. For cases of HIV, this would result in approximately 60 infected patients per year. The researchers recommended using high-level disinfection for vaginal and rectal endocavity ultrasound probes.

Casalegno, et al. conducted a prospective study in two phases in the gynecology department of a university hospital in France. In the first phase, the researchers collected and analyzed 217 samples from endocavity ultrasound probes after these were used for patient examination. In the second phase, the researchers collected and analyzed 200 samples before the probe was used for patient examination. Despite the use of sheathed probes, human DNA was detected in 36 (18 percent) of the post-examination samples, and 61 (28 percent) of the pre-examination samples. Seven post-examination samples (3.5 percent) were HPV positive, and six pre-examination samples (2.8 percent) were HPV positive, with four samples (2 percent) positive for high-risk HPV. The researchers recommended replacing the current method of processing (i.e., low-level disinfection with quaternary ammonium compound wipes) with a more stringent high-level disinfection process.

In a prospective study conducted in a French radiology center, M’Zali, et al. collected and analyzed a total of 300 samples from endocavity ultrasound probes for HPV (n = 100), C trachomatis (n = 100), and commensal or environmental bacteria (n = 100). The samples were collected after disinfection of the probes with wipes impregnated with a quaternary ammonium compound and chlorhexidine. The researchers found HPV on 13 percent of the samples (n = 13), C trachomatis on 20 percent of the samples (n = 20), and commensal or environmental bacterial flora on 86 percent of the samples (n = 86). The researchers concluded that endocavity ultrasound probes remained contaminated after low-level disinfection.

Notably, not all HLDs may be effective against all pathogens that could potentially be found on endocavity ultrasound probes. Ryndock et al35 conducted a nonexperimental study to compare the efficacy of immersion in a liquid chemical HLD (i.e., ortho-phalaldehyde) and exposure to nebulized hydrogen peroxide mist against HPV type 16 and HPV type 18 on endocavity ultrasound probes. The researchers found the liquid chemical HLD had only minimal efficacy against HPV. The HPV type 16 was highly resistant to the ortho-phalaldehyde, demonstrating only a 0.52 log10 reduction in viral infectivity. The HPV type 18 was also highly resistant to the ortho-phalaldehyde, demonstrating only a 0.39 log10 reduction in viral activity. The nebulized hydrogen peroxide mist method showed greater than 5 log10 reductions for both HPV type 16 and HPV type 18.
The Centers for Disease Control and Prevention (CDC) and the American Institute of Ultrasound Medicine recommend that endocavity probes, used with or without a sheath or cover, be processed with high-level disinfection at a minimum.

Q: What does AORN say about the recent studies that indicate all steps in the cleaning/disinfection/sterilization process are not being followed by sterile processing personnel?

A: The research results are not surprising. The research validates what many of us have long suspected to be true. Sterile processing personnel are faced with the difficult and increasingly challenging tasks necessary to complete all the steps in the cleaning process for a myriad of different instruments. Complex, multi-step instructions are often confusing and difficult to interpret. SPD is faced with the challenge of following a multitude of differing IFUs while under severe time and resource constraints. Our hope is that this new research leads to a greater awareness and understanding the of risks and costs of processing failures and will lead to greater investment in the resources necessary to safely process reusable medical devices. A focus on improved instrument designs, simplification of IFUs, increased staff education and training, and concentrated efforts directed toward evidence-based process improvement will lead to improved patient safety.

Q: Is there a consensus that sterilization is the new minimum to safeguard patients?

A: There is growing consensus among experts that sterilization should be the minimum requirement and there is growing evidence to support that position. Sterilization provides the highest level of assurance that surgical items are free of viable microbes. Sterilization is preferable whenever possible.

Q: What does AORN think about the new emphasis on visual inspection and validation?

A: AORN has long recommended visual inspection. That is not new. Efficacy of cleaning has traditionally been evaluated visually. Several studies comparing visual analysis with microscopic analysis have demonstrated that visual inspection alone is not sufficient to determine levels of cleanliness. Visual inspection is subjective. In addition, infectious microorganisms and residues are not visible to the naked eye. It is also not possible to visually inspect most lumens. Even under ideal cleaning conditions, instruments may retain debris. However, there is a growing emphasis on cleaning verification. Currently, there is no single standard of clean, nor is there a standard test soil. Agreement as to what level of residual soil is acceptable after cleaning and what level of residual soil is clinically significant is also lacking. There are a number of tests that can be used to assess cleaning efficiency. Qualitative tests usually involve swabbing a device, immersing it in a reagent, and observing for a color change that indicates the presence of organic markers, such as protein or blood. Quantitative tests provide a measure or action limit against which test results are measured. Adenosine tri-phosphate (ATP) bioluminescence is an example of a quantitative test. The item to be tested is swabbed to collect ATP, the swab is inserted into a reaction tube, and the ATP on the swab is released using chemicals in the reaction tube. The reaction tube is then inserted into a hand-held luminometer that converts the ATP released from microorganisms or human cells into a light signal, which is measured in relative light units (i.e., RLUs). Manufacturers may establish “benchmark cutoffs” for manual cleaning of instruments (e.g., flexible endoscopes) that users can employ so that any instrument failing this quantitative cutoff after cleaning is re-cleaned before disinfection/ sterilization.

Q: What can infection preventionists do to help the sterile processing department/OR comply with this guideline?
A:The infection preventionist can work with the operating room to standardize processes, especially pre-cleaning at the point of use. They can help develop competencies if high-level disinfection is being performed in the OR suite itself, but also encourage the OR to send instruments requiring high-level disinfection to the sterile processing department. It is best practice for personnel to perform high level disinfection in areas where staff are trained and competent and appropriate spaces and equipment are in place, and most importantly have no other conflicting responsibilities. An infection prevention risk assessment is a primary responsibility of infection preventionists and includes where and how HLD is being done, what processes are being used and should be used and surveillance to track infections as a result of processing failures. Infection preventionists should also be part of the process in selection of high-level disinfectants and equipment used in high-level disinfection. Automated processes can take the human factor out of instrument processing and if possible should be used.