Infections and exposures: reported incidents associated with unsuccessful decontamination of reusable surgical instruments

A proposed cleaning classification system for reusable medical devices to complement the Spaulding classification

A central tenet in infection prevention is application of the Spaulding classification system for the safe use of medical devices. Initially defined in the 1950s, this system defines devices and surfaces as being critical, semi-critical or non-critical depending on how they will be used on a patient. Different levels of antimicrobial treatment, defined as various levels of disinfection or sterilization, are deemed appropriate to reduce patient risk of infection. However, a focus on microbial inactivation is insufficient to address this concern, which has been particularly highlighted in routine healthcare facility practices, emphasizing the underappreciated importance of cleaning and achieving acceptable levels of cleanliness. A deeper understanding of microbiology has evolved since the 1950s, which has led to re-evaluation of the Spaulding classification along with a commensurate emphasis on achieving appropriate cleaning. Albeit underappreciated, cleaning has always been important as the presence of residual materials on surfaces can interfere with the efficacy of the antimicrobial process to inactivate micro-organisms, as well as other risks to patients including device damage, malfunction and biocompatibility concerns. Unfortunately, this continues to be relevant, as attested by reports in the literature on the occurrence of device-related infections and outbreaks due to failures in processing expectations. This reflects, in part, increasing sophistication in device features and reuse, along with commensurate manufacturer's instructions for use. Consequently, this constitutes the first description and recommendation of a new cleaning classification system to complement use of the traditional Spaulding definitions to help address these modern-day technical and patient risk challenges. This quantitative risk-based classification system highlights the challenge of efficient cleaning based on the complexity of device features present, as an isolated variable impacting cleaning. This cleaning classification can be used in combination with the Spaulding classification to improve communication of cleaning risk of a reusable medical device between manufacturers and healthcare facilities, and improve established cleaning practices. This new cleaning classification system will also inform future creation, design thinking and commensurate innovations for the sustainable safe reuse of important medical devices.

Reuse of Orthopaedic Equipment: Barriers and Opportunities

» Reuse of orthopaedic equipment is one of many potential ways to minimize the negative impact of used equipment on the environment, rising healthcare costs and disparities in access to surgical care.» Barriers to widespread adoption of reuse include concerns for patient safety, exposure to unknown liability risks, negative public perceptions, and logistical barriers such as limited availability of infrastructure and quality control metrics.» Some low- and middle-income countries have existing models of equipment reuse that can be adapted through reverse innovation to high-income countries such as the United States.» Further research should be conducted to examine the safety and efficacy of reusing various orthopaedic equipment, so that standardized guidelines for reuse can be established.

Risk of disease transmission to patients from "contaminated" surgical instruments and immediate use steam sterilization

BACKGROUND

There are several sources of pathogens that cause surgical site infections (SSI) to include the patients endogenous microflora and exogenous sources (e.g., air, surfaces, staff, surgical equipment).

METHODS

We searched the published English literature (Google, Google Scholar, PubMed) for articles on reprocessing surgical instruments, effectiveness of sterilization methods, microbial load on surgical instruments, frequency of "contaminated" instruments, and the infection risk associated with "contaminated" surgical instruments and immediate use steam sterilization.

RESULTS

There is substantial redundancy in instrument reprocessing to include: even if a patient was exposed to a "contaminated" instrument, the decontamination and sterilization process would have removed and/or inactivated the contaminating pathogens due to the exceptional effectiveness of the manual and mechanical cleaning (i.e., washer-disinfector) and the remarkable robustness of sterilization technology; and the low-level of microorganisms on surgical instruments after use and before cleaning.

CONCLUSIONS

A critical review of the literature suggests that the risk of acquiring an SSI from instruments used in surgery is essentially zero if the sterilization cycle is validated.

Disposable and reusable instruments in dental health practice: A comparison of cost factors in a public provider organization in Queensland, Australia

OBJECTIVES

Choosing between reusable instruments (RIs) and disposable instruments (DIs) for dental care provision requires a careful consideration of costs and their contributing factors, alongside other choice criteria. This study aimed to assess the current use of instruments in the West Moreton Oral Health Service (WMOHS) in Queensland, Australia, with a broader goal of informing future practice in this and comparable organizations.

METHODS

A cost model was developed reflecting costs arising from procurement, reprocessing and disposal, depending on the RI and DI composition of instrumentation. The current practice in WMOHS was compared to modular (RI-only and DI-only) strategies by considering four standard instrument sets (examination, simple extraction, surgical extraction, restoration) and the annual use of instruments in the organization at large. The use of resources (water, electricity) and emissions (waste) were quantified for each strategy. The robustness of findings was explored across a range of scenarios that involved varying instrument prices, lifespans, factors impacting on the cost of reprocessing (labour, water, energy), the cost of waste disposal and couriering.

RESULTS

At the organization level, the current mix of instruments (A$1.28 m per year) was 4% more costly than the lower cost, RI-only alternative (A$1.23 m). However, with lower DI prices or higher labour costs current practice would become the lowest cost option. Results for specific instrument sets varied by service type. DI-only offered the lowest cost option for oral examinations (A$6.29), and the current practice of mixed instrumentation for simple extractions (A$16.56). RI-only sets were less costly in more resource intensive procedures such as surgical extractions (A$40.19) and restorations (A$43.83). In terms of environmental impacts, the use of instruments based on current practice required 37% of water and energy use of an RI-only alternative and generated 36% waste of the DI-only alternative.

CONCLUSIONS

Reusable instruments are generally less costly than DIs, but for specific instrument sets the outcome depends on the type of procedure. In some circumstances, mixed instrumentation can provide the lowest cost alternative. While the WMOHS instrument mix used in current practice does not minimize cost for the provider, it may be justified in light of operational risks, logistics and uncertainty regarding cost factors.

Adenosine triphosphate (ATP) sampling algorithm for monitoring the cleanliness of surgical instruments

BACKGROUND

Timely detection of cleaning failure is critical for quality assurance within Sterilising Service Units (SSUs). Rapid Adenosine Triphosphate (ATP) testing provides a real time and quantitative indication of cellular contaminants, when used to measure surface or device cleanliness. The aim of this study was to investigate the use of an ATP algorithm and to whether it could be used as a routine quality assurance step, to monitor surgical instruments cleanliness in SSUs prior to sterilisation.

METHODS

Cleanliness monitoring using rapid ATP testing was undertaken in the SSUs of four hospitals located in the western (Amazonia) region of Brazil. ATP testing was conducted (Clean Trace, 3M) on 163 surgical instruments, following manual cleaning. A sampling algorithm using a duplicate swab approach was applied to indicate surgical instruments as (i) very clean, (ii) clean, (iii) equivocal or (iv) fail, based around a 'clean' cut-off of 250 Relative Light Units (RLU) and a 'very clean' <100 RLU.

RESULTS

The four cleanliness categories were significantly differentiated (P≤0.001). The worst performing locations (hospitals A & C) had failure rates of 39.2% and 32.4%, respectively, and were distinctly different from hospitals B & D (P≤0.001). The best performing hospitals (B & D) had failure rates of 7.7% and 2.8%, respectively.

CONCLUSION

The ATP testing algorithm provides a simple to use method within SSUs. The measurements are in real time, quantitative and useful for risk-based quality assurance monitoring, and the tool can be used for staff training. The four-tiered approach to the grading of surgical instrument cleanliness provides a nuanced approach for continuous quality improvement within SSU than does a simple pass/fail methodology.

Chemical Changes Over Time Associated with Protein Drying

Upon drying, physical changes of the characteristics of proteins are observed by coagulation, but the nature and chronology of these changes have not been well studied. Coagulation changes the structure of protein from liquid to a solid or a thicker liquid by heat, mechanical action, or acids. Changes may have implications regarding the cleanability of reusable medical devices; therefore, an understanding of the chemical phenomena associated with drying of proteins is essential to ensuring adequate cleaning and mitigation of retained surgical soils. Using a high-performance gel permeation chromatography analysis with right-angle light-scattering detector at 90°, it was demonstrated that as soils dry, the molecular weight distribution changes. From the experimental evidence, the molecular weight distribution trends over time with drying to higher values. This is interpreted as a combination of oligomerization, degradation, and entanglement. As water is removed through evaporation, the distance between proteins decreases and their interactions increase. Albumin will polymerize into higher-molecular-weight oligomers, decreasing its solubility. Mucin, commonly found in the gastrointestinal tract to prevent infection, will degrade in the presence of enzymes releasing low-molecular-weight polysaccharides and leaving behind a peptide chain. The research described in this article investigated this chemical change.

Evaluation of cleaning and sterilization of liposuction cannulas after intentional contamination with human fat, Mycobacterium abscessus subspecies bolletii and Geobacillus stearothermophilus

BACKGROUND

The complex design of cannulas is a major challenge for reprocessing due to the retention and accumulation of fat residues.

AIM

To evaluate the cleaning of liposuction cannulas and the protective effects of the remaining fat residues on Mycobacterium abscessus subspecies bolletii (MASB) and Geobacillus stearothermophilus inactivation during steam sterilization.

METHODS

In Phase 1, six standard operating procedures (SOP) were evaluated for cleaning of liposuction cannulas. In Phase 2, the sectioned lumens of the liposuction cannulas were contaminated with the largest and smallest volume of human fat found in Phase 1, with the addition of MASB. In Phase 3, the same volumes of human fat from Phase 2 were used to contaminate paper strips containing G. stearothermophilus.

FINDINGS

In phase 1 the residual amount of fat ranged from 6 to 52mg. In phases 2 and 3, the minimum and maximum amounts of fat (6 to 50mg) protected microorganisms during steam sterilization at 134ºC for 1.5 and 3min.

CONCLUSION

Effective cleaning and sterilization of liposuction cannulas intentionally contaminated with human fat, MASB and G. stearothermophilus could not be performed.

Failure of sterilization in a dental outpatient facility: Investigation, risk assessment, and management

In 2017, an incident of failed sterilization of dental instruments occurred at a large dental outpatient facility in Singapore. We aim to describe findings of the investigation of the sterilization breach incident, factors related to risk of viral transmission to the potentially affected patients, and the contact tracing process, patient management, and blood test results at a 6-month follow-up. A full assessment of the incident was immediately carried out. The factors related to risk of viral transmission due to affected instruments were analyzed using 3 keys points: breached step(s) and scale of the incident, prevalence of underlying bloodborne diseases and immunity in the Singapore population, health status of potential source patients, and type of dental procedure performed, and health status of affected patients and type of dental procedure received. Up to 72 affected instrument sets were used in 714 potentially affected patients who underwent noninvasive dental procedures. The investigation revealed that there was a lapse in the final step of steam sterilization, resulting in the use of incompletely sterilized items. The assessment determined that there was an extremely low risk of bloodborne virus transmission of diseases to the patients. At the 6-month follow-up, there were no infected/colonized cases found related to the incident. Lapses in the sterilization process for medical and dental instruments can happen, but a risk assessment approach is useful to manage similar incidents. Quick response and proper documentation of the sterilization process can prevent similar incidents.

Influence of Fine Management Combined With PDCA Cycle Method on Disinfection Qualified Rate and Performance Grade of Ophthalmic Precision Instruments

Objective

The aim of this study is to explore the influence of fine management combined with the plan-do-check-action (PDCA) cycle method on the management of ophthalmic precision instruments.

Methods

The ophthalmic precision instruments centralized in the disinfection supply room of our hospital were selected as the research objects and divided into groups A and B. Traditional instrument management method was adopted in group A, and fine management combined with the PDCA cycle method based on the group A was adopted in group B. The instrument management risk scores, the qualified rate of disinfection, instrument performance grade, and incidence of toxic anterior segment syndrome (TASS) of the two groups were compared.

Results

The risk scores of instrument management and incidence of TASS in group B were lower than those in group A (p < 0.05). The qualified rate of disinfection and instrument performance grades in group B were higher than those in group A (p < 0.05).

Conclusion

Fine management combined with the PDCA cycle method can improve the qualified rate of disinfection of ophthalmic precision instruments, optimize the performance of instruments, reduce the risk of instrument management, and reduce the incidence of TASS.

Clinical features of endophthalmitis clusters after cataract surgery and practical recommendations to mitigate risk: systematic review

Intraocular transmission of exogenous pathogens in cataract surgery can lead to endophthalmitis. This review evaluates the features of endophthalmitis clusters secondary to pathogen transmission in cataract surgery. Articles reporting on pathogen transmission in cataract surgery were identified via searches of Ovid MEDLINE, EMBASE, and Cochrane CENTRAL, and a total of 268 eyes from 24 studies were included. The most common source of infectious transmission was attributed to a contaminated intraocular solution (ie, irrigation solution, viscoelastic, or diluted antibiotic; n = 10). Visual acuity at presentation with infectious features was 1.89 logMAR (range: 1.35 to 2.58; ∼counting fingers) and 1.33 logMAR (range: 0.04 to 3.00; Snellen: ∼20/430) at last follow-up. Patients with diabetes had worse outcomes compared with patients without diabetes. The most frequently isolated pathogen from the infectious sources was Pseudomonas sp. (50.0%). This review highlights the various routes of pathogen transmission during cataract surgery and summarizes recommendations for the detection, prevention, and management of endophthalmitis clusters.

Efficacy of Cleaning Methods for Ophthalmic Microscopic Instruments: A Comparison Study

The combination of silicone oil and blood is difficult to remove from ophthalmic surgical instruments during cleaning and decontamination processes. We sought to establish the most efficient cleaning procedure for this type of contaminated instrument. We uniformly contaminated microscopic instruments made of titanium alloy and stainless steel with either blood alone or blood and silicone oil. We randomly assigned each instrument to one of four types of cleaning procedures that involved combinations of water, a multi-enzyme detergent, or an alkaline detergent. After completing the designated cleaning procedure, a sterile processing technician used an adenosine triphosphate cleaning verification test to evaluate the cleaning efficacy. When cleaning blood- and silicone oil-contaminated titanium-alloy and stainless-steel instruments, the alkaline detergent immersion followed by a multi-enzyme detergent ultrasonic cleaning yielded the highest cleaning effectiveness score (92.5%), which indicates this was the most effective of the four cleaning procedures that we tested.

Clinical Issues-July 2021

Debris in sterilized instrument sets Key words: organic debris, inorganic debris, instrument sets, sterile processing, sterilizing agent. Preventing debris in sterilized instrument sets Key words: debris, instrument sets, sterile processing equipment, instructions for use (IFU), quality assurance. Bone cement precautions during pregnancy Key words: bone cement, exposure, methyl methacrylate (MMA), pregnant. Using a bed sheet or blanket for positioning Key words: patient positioning devices, improvised positioning device, pressure distribution, skin shear, pressure injury. Laundering of cloth head coverings Key words: laundering, head covering, reusable cloth hat, surgical attire, disposable bouffant.

ATP Bioluminescence for Assessing the Efficacy of the Manual Cleaning Procedure during the Reprocessing of Reusable Surgical Instruments

Achieving sterilization by adopting proper practices is essential to ensure that surgical instruments do not transmit microorganisms to patients. As the effectiveness of sterilization mandates effective cleaning, it is necessary to verify the success of cleaning procedures. In this study, we used the adenosine triphosphate (ATP) bioluminescence method for assessing the efficacy of the manual cleaning procedure during the reprocessing of reusable surgical instruments. The ATP bioluminescence assay was performed on 140 surgical instruments of 12 different types, both before being cleaned (baseline) and after each of the cleaning procedures (i.e., decontamination, manual washing, drying, and visual inspection). For each instrument, two swabs were used as follows: one to sample the entire surface (test point 1) and the other to sample the most difficult part of the surface to clean (test point 2). Overall, for each type of instrument, there was a decrease in contamination ranging from 99.6 to >99.9% (log reduction from 2.40 to 3.76). Thus, in order to standardize the assessment of cleanliness, it may be useful to introduce the bioluminescence method into the daily routine or, at least, at regular time intervals as a complementary check combined with visual inspection. This would allow real-time verification of the achievement of an adequate level of cleanliness.

Climate change: challenges and opportunities to scale up surgical, obstetric, and anaesthesia care globally

Climate change affects human health in a myriad of ways, requiring reassessment of the nature of scaling up care delivery and the effect that care delivery has on the environment. 5 billion people do not have access to safe and timely surgical care, and the quantity and severity of conditions that require surgical, obstetric, and anaesthesia care will increase substantially as a result of climate change. However, surgery is resource intensive and contributes substantially to greenhouse-gas emissions. In response to climate change, the surgical, obstetric, and anaesthesia community has a key role to play to ensure that a scale-up of service delivery incorporates mitigation and adaptation strategies. As countries scale up surgical care, understanding the implications of surgery on climate change and the implications of climate change on surgical care will be crucial in the development of health policies.

Current State of Surgical Lighting

Surgical performance in the operating room (OR) is supported by effective illumination, which mitigates the inherent environmental, operational, and visual challenges associated with surgery. Three critical components are essential to optimize operating light as illumination: (1) centering on the surgeon's immediate field, (2) illuminating a wide or narrow field with high-intensity light, and (3) penetrating into a cavity or under a flap. Furthermore, optimal surgical illumination reduces shadow, glare, and artifact in visualization of the surgical site. However, achieving these principles is more complex than at first glance, requiring a detailed examination of the variables that comprise surgical illumination. In brief, efficacious surgical illumination combines sufficient ambient light with the ability to apply focused light at specific operative stages and angles. But, brighter is not always merely better; rather, a nuanced approach, cognizant of the challenges inherent in the OR theater, can provide for a thoughtful exploration of how surgical illumination can be utilized to the best of its ability, ensuring a safe and smooth surgery for all.

Effectiveness of manual versus automated cleaning on Staphylococcus epidermidis biofilm removal from the surface of surgical instruments

BACKGROUND

Biofilm removal is a challenge during surgical instrument processing. We analyzed the time required for Staphylococcus epidermidis to form biofilms on surgical instruments, and how cleaning methods removed them.

METHODS

Different areas (ratchet, shank, and jaw) of straight crile forceps were contaminated by soaking in Tryptic Soy Broth containing 10⁶ colony forming units (CFU)/mL of S epidermidis for 1, 2, 4, 6, 8, and 12 hours. S epidermidis adhesion and removal, after manual or automated ultrasonic cleaning, was evaluated by microbiological culture and scanning electron microscopy.

RESULTS

Microbial load increased with time (10¹-10² CFU/cm² after 1 hour; 10⁴ CFU/cm² after 12 hours). Exopolysaccharide was detected after 2 hours and gradually increased thereafter. Bacterial load was reduced by 1-2 log₁₀ after manual cleaning and 1-3 log₁₀ after automated cleaning, but biofilms were not completely eliminated. In general, bacterial load was lower in shank fragments. This difference was significant at 6 hours.

CONCLUSIONS

Rapid adhesion of S epidermidis and exopolysaccharide formation was observed on surgical instruments. Automated cleaning was more effective than manual cleaning, but neither method removed biofilms completely. The precleaning conditions and the forceps design are critical factors in processing quality.

The work of sterile processing departments: An exploratory study using qualitative interviews and a quantitative process database

BACKGROUND

The sterile processing of surgical instruments and equipment is an essential part of surgical operations. Although clean instruments prevent infections, little is known about the departments that conduct this work. We sought to describe sterile processing departments (SPDs) and to identify factors impacting them.

METHODS

We analyzed data from 22 qualitative interviews of staff and managers and a quantitative benchmarking database.

RESULTS

Qualitative results indicated 4 primary factors impacting sterile processing work: (1) role and visibility, (2) relationships and communication with other departments and vendors, (3) staffing and management, and (4) technical problems and solutions. Quantitative analysis revealed significant differences in SPD responsibilities and scope.

DISCUSSION

Relationships with operating room staff were of paramount importance in the ability of the SPD to accomplish its job and in staff motivations and feelings. Differences in management practices, communication strategies, and problem-solving resources were also emphasized. Both quantitative and qualitative data showed concern for the role of the SPD in patient safety, particularly concerning practices such as the use of immediate-use steam sterilization.

CONCLUSIONS

To more completely address adverse patient events and surgical patient safety, we must move toward examining the entire surgical process, including the vital role of SPDs.

Medical instrument reprocessing: current issues with cleaning and cleaning monitoring

The complexity of medical devices has increased over the past 10 years, and outbreaks of infections due to contaminated devices have focused attention on the need to adequately clean medical devices in order to ensure the adequacy of disinfection and sterilization. There has been a paradigm shift in reprocessing of medical devices, with increased emphasis on a quality management systems approach that requires validated cleaning instructions from manufacturers and ongoing monitoring by reprocessing personnel to ensure adequacy of cleaning. This article reviews the current issues related to medical device reprocessing and summarizes the approaches used for monitoring cleaning efficacy for surgical instruments and flexible endoscopes.

Biofilms on instruments and environmental surfaces: Do they interfere with instrument reprocessing and surface disinfection? Review of the literature

There is a growing appreciation for the role of biofilm-embedded microbes in many different aspects of infection transmission. The format of biofilm includes traditional hydrated biofilm, build-up biofilm, and dry surface biofilm. The objectives of this article are to discuss how traditional biofilm differs from build-up biofilm and dry surface biofilm, and to review the evidence supporting infection transmission from biofilm that accumulates in reprocessed instruments and from dry biofilm that forms environmental reservoirs.

Challenging the six-hour recommendation for reprocessing sterilizable medical equipment

BACKGROUND

At present, reprocessing of sterilizable medical equipment is recommended to be initiated within 6 h after completion of surgery, to ensure that the quality of the instruments does not deteriorate. A literature search showed a lack of evidence for consequences that may occur if medical personnel deviate from the standard 6 h sterilization protocol.

AIM

To evaluate the 6 h recommendation for reprocessing sterilizable medical equipment by determining whether residual protein increased proportional to holding time before reprocessing was initiated, and likewise whether an increase in corrosion was present on surgical scissors proportional to holding time.

METHODS

Residual protein was identified on surgical instruments contaminated with human blood after different holding times and before washes using the o-phthaldialdehyde (OPA) method. Corrosion was identified on surgical scissors contaminated with human blood after different holding times and after reprocessing using light stereomicroscopy and scanning electron microscopy.

FINDINGS

Protein residues ranged between 14.0 and 51.9 μg and thus below the accepted threshold of 100 μg per instrument surface. Corrosion corresponding to 0.05% of the surface was identified on 22 of 30 scissors. Pitting corrosion was seen on four of 30 scissors.

CONCLUSION

No association was identified between residual protein and holding time, nor between incidence of corrosion and holding time. The study thereby challenges the relevance of upholding the recommendation of a maximum wait of 6 h prior to reprocessing. The findings will potentially have an impact on the organization of reprocessing of surgical instruments in Denmark and internationally.

Implementation and Impact of a Hospital-Wide Instrument Set Review: Early Experiences at a Multisite Tertiary Care Academic Institution

A multidisciplinary team of nurses, sterile processing technicians, and surgeons reviewed 609 otolaryngology-head and neck surgery (OHNS) surgical instrument sets at the study institution's 3 hospitals. Implementation of the 4-phase instrument review resulted in decreased OHNS surgical instrument set types from 261 to 234 sets, and a decreased number of instruments in these sets from 18 952 to 17 084. The instrument set review resulted in an estimated savings of $35 665 in sterile processing costs for the OHNS department. Instrument review applied to all 10 surgical specialties at the institution would result in an estimated annual savings of $425 378. Through effective leadership, multidisciplinary participation of all key stakeholders, and a systematic approach, this study demonstrates that a hospital-wide quality improvement intervention for instrument set optimization can be successfully performed in a large, multisite tertiary care academic hospital.

Slit lamps and lenses: a potential source of nosocomial infections?

PURPOSE

The aim of the study was to evaluate the bacterial contamination level of contact surfaces on slit lamps and the grip areas of lenses.

METHODS

Within unannounced audits, two regions of the slit lamps (headrest and joystick), indirect ophthalmoscopy devices, and ultrasound probes were obtained with rayon-tipped swab. Non-contact lenses used for indirect fundoscopy were pressed on RODAC (Replicate Organism Detection and Counting) plates. One hundred and eighty-one surfaces were sampled. The total number of colony-forming units was assessed and bacterial species were identified. Spa-typing and antimicrobial susceptibility testing were performed from Staphylococcus aureus isolates.

RESULTS

Among the total bacterial isolates from ophthalmological equipment (lenses: 51 of 78, slit lamps: 43 of 88, ophthalmoscopy helmets: 3 of 8, ultrasound probes: 2 of 7), coagulase-negative staphylococci (CNS) was most frequently found, followed by Micrococcus spp. (lenses vs. slit lamps: P < 0.001 and P = 0.01, respectively). The bacterial contamination of lenses (76%) was significantly higher than that of slit lamps (54%) (P < 0.003). A significantly higher contamination with CNS was observed on lenses from residents vs. from consultants (78% vs. 35%, P = 0.01). A total of seven different spa-types of S. aureus were isolated. No correlation was found between S. aureus contamination of different ophthalmological equipments (Spearman's rank correlation coefficient, ρ = 0.04, P = 0.75). Methicillin-resistant S. aureus was not detected.

CONCLUSION

Bacterial species of the normal skin flora were isolated from the ophthalmological equipment. The bacterial contamination of the portable devices was significantly higher than that of slit lamps. Therefore, proper hygiene of the mobile instruments should be monitored in order to prevent transmission of bacteria in residents and consultants.

Challenging Residual Contamination of Instruments for Robotic Surgery in Japan

BACKGROUND

Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery.

OBJECTIVE

To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices.

METHODS

Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan.

RESULTS

The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001).

CONCLUSIONS

Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery.

Infect Control Hosp Epidemiol 2017;38:143–146

A study of the effect of clinical washing decontamination process on corrosion resistance of Martensitic Stainless Steel 420

Corrosion of surgical instruments provides a seat for contamination and prevents proper sterilisation, placing both patients and medical staff at risk of infection. Corrosion can also compromise the structural integrity of instruments and lead to mechanical failure in use. It is essential to understand the various factors affecting corrosion resistance of surgical instruments and how it can be minimised.This paper investigates the effect on corrosion resistance from the clinical washing decontamination (WD) process, specifically by studying the changes in surface roughness and Cr/Fe ratio. Results indicate that the WD process provides a positive effect on smooth polished samples, while a lesser positive effect was observed on rough reflection reduced samples.