Comparative evaluation of the microbicidal activity of low-temperature sterilization technologies to steam sterilization

Patient Safety Incidents in Operating Rooms Reported in the Past Five Years (2017-2021) in Korea

Purpose

Patient safety incidents in the operating room require special attention because they can cause catastrophic and irreversible conditions in patients. Although patient safety incidents have different characteristics, there may be similarities and patterns of risk factors that may be common. Therefore, this study analyzed factors associated with the PSIs by analyzing data from the Korean Patient Safety Reports from 2017 to 2019.

Methods

The "Patient Safety Incidents Data from 2017 to 2021" systematically collected by the Korea Institute for Healthcare Accreditation, include patient safety incident reports from medical institutions. Data on 1140 patient safety incidents in the operating room were analyzed. They included patients' gender and age, Hospital size, Incident seasons, incident time, Incident reporter, incident type, Medical department, and Incident severity. The Incident severity was analyzed by dividing it into three stages: near miss, adverse event, sentinel event, which are applied by domestic medical institutions.

Results

The highest number of OR patient safety incidents were related to surgery and anesthesia. On analyzing the probability of adverse events based on near misses, the significant variables were patient gender, incident reporter, incident type, and Medical department. Additionally, the factors that were likely to precipitate sentinel events based on near misses were patient gender, incident time, reporter, and incident type.

Conclusion

To prevent sentinel events in Patient safety incidents, female and during night shifts are required to pay close attention. Moreover, it is necessary to establish a patient safety reporting system in which not only all medical personnel, but also patients, generally, can actively participate in patient safety activities.

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.

Reprocessing semicritical items: An overview and an update on the shift from HLD to sterilization for endoscopes

BACKGROUND

Semicritical medical devices are defined as items that come into contact with mucous membranes or nonintact skin (e.g., gastrointestinal endoscopes, endocavitary probes). Such medical devices require minimally high-level disinfection.

METHODS

Analyze the methods used to reprocess semicritical medical devices and identify methods and new technologies to reduce the risk of infection.

RESULTS

The reprocessing methods for semicritical medical devices is described as well as a shift from high-level disinfection to sterilization for lumened endoscopes.

CONCLUSIONS

Strict adherence to current guidelines and transition to sterilization for endoscopes is required as more outbreaks have been linked to inadequately disinfected endoscopes and other semicritical items than any other reusable medical devices.

Sterilization of 20 billion medical devices by ethylene oxide (ETO): Consequences of ETO closures and alternative sterilization technologies/solutions

BACKGROUND

To prevent healthcare-associated infections, it is essential that critical medical devices be sterilized before use. Although there are several sterilization technologies for medical devices, only ethylene oxide (ETO) sterilization has virtually universal material compatibility.

METHODS

We searched the published English literature (Google, Google scholar and PubMed) for articles on the sterilization of medical devices by ethylene oxide, the consequences of ETO closures, and alternative sterilization technologies/solutions.

RESULTS

ETO's compatibility and effectiveness with medical products allows for sterilization of many medical devices that would otherwise be rendered ineffective or unsafe if sterilized with an alternative method.

CONCLUSIONS

At present, there are no alternatives to ETO that provide the same sterility assurance and result in the same device performance as ETO; therefore, it is likely irreplaceable for years.

Advances in the application of functional nanomaterial and cold plasma for the fresh-keeping active packaging of meat

The most recent advancements in food science and technology include cold sterilization of food and fresh-keeping packaging. Active packaging technology has received much interest due to the photocatalytic activity (PCA) of functional nanoparticles, including titanium dioxide (TiO2) and ferric oxide (Fe2O3). However, there are still significant concerns about the toxicity and safety of these functional nanoparticles. This review emphasizes the bacteriostatic and fresh-keeping properties of functional nanoparticles as well as their packaging strategies using the ultraviolet photo-catalysis effect. High-voltage electric field cold plasma (HVEF-CP) is the most innovative method of cold-sterilizing food. HVEF-CP sterilizes by producing photoelectrons, ions, and active free radicals on food media, which come into contact with the bacteria's surface and destroy their cells. Next, this review also assesses the photocatalytic activity and bacteriostasis kinetics of nanosized TiO2 and Fe2O3 in poultry, beef, and lamb. In addition, this review also emphasizes the importance of exploiting the complex interaction processes between TiO2 and Fe2O3, along with dietary components and their utilization in the fresh meat industry.

Recent advances in sterilization and disinfection technology: A review

Sterilization and disinfection of pollutants and microorganisms have been extensively studied in order to address the problem of environmental contamination, which is a crucial issue for public health and economics. Various form of hazardous materials/pollutants including microorganisms and harmful gases are released into the environment that enter into the human body either through inhalation, adsorption or ingestion. The human death rate rises due to various respiratory ailments, strokes, lung cancer, and heart disorders related with these pollutants. Hence, it is essential to control the environmental pollution by applying economical and effective sterilization and disinfections techniques to save life. In general, numerous forms of traditional physical and chemical sterilization and disinfection treatments, such as dry and moist heat, radiation, filtration, ethylene oxide, ozone, hydrogen peroxide, etc. are known along with advanced techniques. In this review we summarized both advanced and conventional techniques of sterilization and disinfection along with their uses and mode of action. This review gives the knowledge about the advantages, disadvantages of both the methods comparatively. Despite, the effective solution given by the advanced sterilization and disinfection technology, joint technologies of sterilization and disinfection has proven to be more effective innovation to protect the indoor and outdoor environments.

What's new and notable in bacterial spore killing!

Spores of many species of the orders Bacillales and Clostridiales can be vectors for food spoilage, human diseases and intoxications, and biological warfare. Many agents are used for spore killing, including moist heat in an autoclave, dry heat at elevated temperatures, UV radiation at 254 and more recently 222 and 400 nm, ionizing radiation of various types, high hydrostatic pressures and a host of chemical decontaminants. An alternative strategy is to trigger spore germination, as germinated spores are much easier to kill than the highly resistant dormant spores—the so called “germinate to eradicate” strategy. Factors important to consider in choosing methods for spore killing include the: (1) cost; (2) killing efficacy and kinetics; (3) ability to decontaminate large areas in buildings or outside; and (4) compatibility of killing regimens with the: (i) presence of people; (ii) food quality; (iii) presence of significant amounts of organic matter; and (iv) minimal damage to equipment in the decontamination zone. This review will summarize research on spore killing and point out some common flaws which can make results from spore killing research questionable.

Forced convective heating for low-temperature sterilization

A novel impermeable sterile pouch is developed to allow the forced convective heating mechanism for improving the sterilization cycle. The heating process is parametrically investigated to obtain an optimized condition in which a sterilization load is heated from 20 to 45 °C within 2 min, and the forced convection is experimentally and numerically analyzed to find that the convection coefficient is dramatically increased to 450 W/m² K when compared with the conventional natural convection coefficient of 80 W/m² K. The optimized heating process is applied to a sterilization cycle using the impermeable pouch, and the overall sterilization cycle is found to be completed within 7.5 min whose performance is validated by using a process challenge device.

Does blood on "dirty" instruments interfere with the effectiveness of sterilization technologies?

We evaluated the robustness of sterilization technologies when spores and bacteria were placed on "dirty" instruments and overlaid with blood. The results illustrate that steam sterilization is the most effective sterilization technology with the largest margin of safety, followed by ethylene oxide and hydrogen peroxide gas plasma.

Personal respiratory protection and resiliency in a pandemic, the evolving disposable versus reusable debate and its effect on waste generation

The COVID-19 pandemic sweeping much of the globe is not anticipated to be short in duration, with contingency plans suggesting that it may last at least eighteen months. In the United States, one of the critical issues in coping with the pandemic has been a lack of essential personal protective equipment (PPE), at the local, state, and national level. As COVID-19 is primarily transferred through respiratory routes, adequate respiratory protection is a dire necessity. The shift from durable and reusable medical supplies in recent years to their single use counterparts has reduced the resiliency of the medical system with respect to PPE and other critical supplies in the current pandemic. This work explores the role of reusable compared to single use respiratory protection in the current pandemic, including reprocessing of single use options, from the perspective of number of equivalent protection devices needed. The current state of literature is also reviewed to provide context to this work, with respect to resource procurement. The economic cost of PPE throughout a pandemic is explored, and it is found that utilizing reusable PPE options depending on filter cycling may be less costly. Increased waste production is another issue with the current pandemic, and this is explored utilizing a mass basis, finding that reusable respiratory PPE would generate less waste than using single use PPE in a business as usual scenario. As future outbreaks of COVID-19 are likely along with other future pandemics, this work provides insights at how to prepare from the standpoint of PPE, and in particular respiratory protection.

Comparative evaluation of four hydrogen peroxide-based systems to decontaminate N95 respirators

Objective:

Protocols designed to facilitate N95 filtering facepiece respirator (FFR) decontamination by commercial sterilization devices do not recommend that operators verify the device’s performance against pathogens deposited on FFRs. Here, we compared the treatment efficacy of 4 hydrogen peroxide-based systems that were authorized for N95 decontamination during the COVID-19 pandemic.

Methods:

Suspensions prepared from S. aureus ATCC 29213 and 44300, B. subtilis ATCC 6633, a vancomycin-resistant E. faecium isolate (VRE), E. coli ATCC 25922, and P. aeruginosa ATCC 27853 colonies were inoculated onto nine 1-cm² areas on a 3M 1805, 1860, 1860S, 1870+, 8210, 8110S, or 9105S FFR. Contaminated respirators were treated according to protocols recommended by the STERRAD 100NX, Bioquell Z-2, Sterizone VP4, or Clēan Works Mini systems. Decontamination efficacy was determined by comparing colony counts cultured from excised segments of treated and untreated FFR.

Results:

All devices achieved a 6-log reduction in bacterial burden and met FDA sterilization criteria. The Bioquell Z-2 device demonstrated 100% efficacy against both gram-positive and gram-negative organisms with all FFRs tested. Colonies of S. aureus ATCC 29213 and 44300 and VRE were cultivable from up to 9 (100%) of 9 STERRAD 100NX– and Sterizone VP4–treated segments. Viable B. subtilis ATCC 6633 organisms were recovered from 76.0% of STERRAD 100NX–treated FFR segments.

Conclusions:

Variability in decontamination efficacy was noted across devices and FFR types. gram-positive organisms were more difficult to completely eliminate than were gram-negative organisms. Prior to initiating FFR decontamination practices, institutions should verify the effectiveness of their devices and the safety of treated FFR.

Evaluation of Regeneration Processes for Filtering Facepiece Respirators in Terms of the Bacteria Inactivation Efficiency and Influences on Filtration Performance

The regeneration of filtering facepiece respirators (FFRs) is of critical importance because of the severe shortage of FFRs during large-scale outbreaks of respiratory epidemics, such as COVID-19. Comprehensive experiments regarding FFR regeneration were performed in this study with model bacteria to illustrate the decontamination performance of the regeneration processes. The results showed that it is dangerous to use a contaminated FFR without any microbe inactivation treatment because the bacteria can live for more than 8 h. The filtration efficiency and surface electrostatic potential of 75% ethanol-treated FFRs were significantly reduced, and a most penetrating particle size of 200 nm was observed. Steam and microwave irradiation (MWI) showed promising decontamination performances, achieving 100% inactivation in 90 and 30 min, respectively. The filtration efficiencies of steam-treated FFRs for 50 and 100 nm particles decreased from 98.86% and 99.51% to 97.58% and 98.79%, respectively. Ultraviolet irradiation (UVI) effectively inactivated the surface bacteria with a short treatment of 5 min and did not affect the filtration performance. However, the UV dose reaching different layers of the FFP2 mask sample gradually decreased from the outermost layer to the innermost layer, while the model bacteria on the second and third layers could not be killed completely. UVI+MWI and steam were recommended to effectively decontaminate the used respirators and still maintain the respirators' filtration efficiency. The present work provides a comprehensive evaluation for FFR regeneration in terms of the filtration efficiencies for 50-500 nm particles, the electrostatic properties, mechanical properties, and decontamination effects.