Effect of an N95 respirator and a surgical mask-covered N95 on the cardiovascular responses of dentists treating paediatric patients: A crossover clinical trial.

BACKGROUND: The studies on cardiovascular alterations when using an N95 respirator or surgical mask-covered N95 during dental treatments are limited. AIM: To investigate and compare the cardiovascular responses of dentists treating paediatric patients while wearing an N95 respirator or a surgical mask-covered N95. DESIGN: This was a crossover clinical trial in 18 healthy dentists wearing an N95 respirator or surgical mask-covered N95 during the dental treatment of paediatric patients. Oxygen saturation (SpO2 ), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were monitored at baseline, intraoperation, and postoperation. The data were analyzed using the generalized estimating equation. RESULTS: The mean SpO2 , HR, SBP, DBP, and MAP significantly changed from baseline up to the end of the procedures after wearing an N95 by 3.1%, 19.3%, 11.5%, 17.7%, and 13.8% and after wearing a surgical mask-covered N95 by 3.0%, 20.2%, 5.3%, 13.9%, and 8.8%, respectively (p < .05). No significant differences in these values were found between groups (p > .05). CONCLUSIONS: N95 respirators and surgical mask-covered N95s significantly impact the cardiovascular responses of dentists treating paediatric patients with no differences between the two types of masks.

Aerosol-Generating Medical Procedures: Controversies in Definition, Risks, and Mitigation Strategies

An aerosol-generating medical procedure (AGMP) is any procedure performed on a patient that can induce the production of aerosols of various sizes, including droplet nuclei. AGMPs have become a subject of increasing interest during the COVID-19 pandemic for two critical reasons. First, AGMP likely increases the risk of transmission from patients infected with respiratory infections to healthcare personnel and other patients in their environment. Second, special risk mitigation strategies, including selection of specific types of personal protective equipment and environmental controls, are necessary to protect staff during the performance of AGMPs. Heightened awareness for AGMPs began during the 2003 severe acute respiratory syndrome (SARS) pandemic, where it was noted that, in outbreaks, many frontline HCWs had increased risk of contracting the virus related to certain procedures performed on the respiratory tract (Tran et al. PLoS One 7:e35797, 2012). Numerous clinical guidelines were published attempting to categorize and classify the risk associated with various AGMP. However, while numerous procedures have been identified as "aerosol generating, " the scientific evidence for the creation of aerosols associated with these procedures, the burden of potential viable microbes within the created aerosols, and the mechanism of transmission to the host have not been well studied (Davies et al. J Infect Prev 10:122-6, 2009). Almost 20 years later, there are still large gaps in knowledge around AGMPs - what defines them, what is the added risk associated with them, and which strategies are most effective at mitigating the risks associated with them. Here, we summarize the current knowledge around AGMPs including the types, risk, and mitigation strategies. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Review of the Effect of Continuous Use and Limited Reuse of N95 Respirators on Respirator Fit.

Background: Coronavirus disease 2019 (COVID-19) has led to severe shortages of filtering facepiece respirators (FFRs). As a result, extended use, limited reuse, and FFR decontamination have been utilized to extend the life of single-use FFRs. Although some studies have raised concerns that reuse could affect the FFR's ability to form a seal, no comprehensive literature review of the effect of extended use or limited reuse on FFR seal exists. Objective: The goal of this review was to assess the effect of extended use and reuse on respirator fit, with and without decontamination. Methods: Searches of PubMed and Medrxiv yielded 24 papers that included assessment of fit after extended use or limited reuse on a human. One additional handpicked paper was added. Results: Studies report a wide variation in the number of donnings and doffings before fit failure between different models of respirators. Additionally, while seal checks lack sufficient sensitivity to reliably detect fit failures, individuals who failed fit testing were often able to pass subsequent tests by re-positioning the respirator. Even with failure, respirators often maintained a substantially higher level of fit than a surgical mask, so they may still provide a level of protection in crisis settings. Conclusion: Based on currently available data, this literature review was unable to establish a consensus regarding the amount of time a respirator can be worn or the number of uses before fit failure will occur. Furthermore, variations in reuses before fit failure between different models of N95 respirators limit the ability to offer a comprehensive recommendation of greater than one reuse or a specific amount of wear time.

Efficacy of Surgical Masks Versus N95 Respirators for the Prevention of COVID-19 in Dental Settings: A Systematic Review.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. (SARS-CoV-2). It spreads mainly through saliva droplets or nasal discharge. Dentists are among the professionals with the greatest risk of contracting and transmitting COVID-19. We compared the efficacy of surgical masks versus N95 respirators in preventing COVID-19 infection in dental settings. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched. Search terms corresponded to a predefined PICOS (patient/population, intervention, comparison, and outcomes) question. The risk of bias was evaluated using AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews-2), ROBIS (Risk of Bias in Systematic Reviews), and Health Evidence tools. A total of 191 articles were screened, and nine of them were further evaluated for eligibility, of which five articles (fulfilled the selection criteria) and were included in this study. Two studies concluded that surgical masks could provide equivalent protection to N95 respirators. Another study found that N95 respirators were superior to surgical masks. The fourth study found that better protection can be achieved when using surgical masks by the aerosol source than when the recipient uses an N95 respirator, while the last study concluded that surgical masks or N95 respirators alone do not provide full protection. Thus, according to this systematic review, N95 respirators provide better protection against COVID-19 infection compared to surgical masks.

Assessment of best-selling respirators and masks: Do we have acceptable respiratory protection for the next pandemic?

BACKGROUND: COVID-19 pandemic caused a high demand for respiratory protection, caused a scarcity of approved respirators and the production of alternative respiratory protection. To raise public awareness through the scientific community, bestselling respirators and masks in the United States' leading online retailer, Amazon.com, were evaluated. METHODS: Ten respirators and masks, 5 Face Protective Equipment (FPE) and 5 Cloth Face Masks (CFMs), were evaluated compared to the N95 standard. Two groups were established with the intention of comparing all masks together. The fractional efficiency and pressure drop were measured and compared to the National Institute for Occupational Safety and Health (NIOSH) standards. In addition, grading factors for protection, comfort, and affordability were developed that can be used by the scientific community to readily disseminate to consumers for the selection of the appropriate respiratory protection. RESULTS: Two FPE provided acceptable efficiency (>95%) similar to the N95, while the remaining products were below or extremely below NIOSH standards. All products provided pressure drops within NIOSH standards (≤35 mmH2O) ranging from 2.3-10.3 mmH2O. The grading factors show that the CFMs have minimal protection, and the N95 has average comfort and affordability compared to all the products. CONCLUSION: The N95 remains the best respiratory protection, and in the event of the next airborne pandemic, FPEs could serve as adequate alternative protection against the viral spread.

Elastomeric Half Mask Respirators: An Alternative to Disposable Respirators and a Solution to Shortages during Public Health Emergencies.

During public health emergencies such as an influenza pandemic, disposable filtering facepiece respirator (FFR) shortages have a significant impact on the national response, affecting many types of workplaces that rely on respiratory protection. During the COVID-19 pandemic, severe FFR shortages led the CDC to publish strategies for optimizing the supply of N95 FFRs. These strategies included the extended use and limited reuse of FFRs, wearing decontaminated FFRs, wearing respirators that meet an international respirator standard, or wearing FFRs that were past their manufacturer-designated shelf life. An additional strategy to mitigate supply shortages that was highlighted during the COVID-19 pandemic was to wear reusable respirators, such as elastomeric half mask respirators (EHMRs), or powered air-purifying respirators, which can be cleaned, disinfected, and reused. A decade of nationwide initiatives to increase the utility of EHMRs in healthcare settings were realized during the COVID-19 pandemic as EHMRs became more well-known and were used in healthcare settings for respiratory protection. This expanded use of EHMRs led to an increase in federal procurement, research, guidance, and private sector research and development of innovative EHMR designs by manufacturers to respond to workers' needs for both respiratory protection and source control. This paper describes the role of reusable EHMRs before and during the COVID-19 pandemic, and reviews past and current research, to inform successful EHMR implementation in healthcare and first responder settings.

Assessing the Fit of N95 Filtering Facepiece Respirators Fitted with an Ear Loop Strap System: A Pilot Study.

Throughout the COVID-19 pandemic, hundreds of millions of people worldwide have become new users of respiratory protective devices. Facemasks and KN95 respirators utilizing an ear loop straps system (ELSS) have recently become popular among occupational and non-occupational populations. Part of this popularity is due to the ease of wearability as compared with traditional devices utilizing two headbands, one worn over the head and the other behind the neck-a universal strap system used in NIOSH-certified N95 filtering facepiece respirators (FFRs). Some users convert the two-strap configuration to an adjustable ELSS. The first objective of this pilot study was to quantitatively characterize how such a conversion impacts the respirator fit. Additionally, a novel faceseal (NFS) technology, which has been previously demonstrated to enhance the fit of N95 FFRs, was deployed to modify the ELSS-converted N95 FFRs. The second objective of this study was to quantify the fit improvement that results from adding the NFS to the ELSS. The study was conducted by performing the Occupational Safety and Health Administration (OSHA)-approved quantitative fit testing (QNFT) on 16 human subjects featuring different facial shapes and dimensions. Three models of cup-shaped N95 FFRs were tested in three versions: the standard version with manufacturer's strap system, the ELSS-converted, and the ELSS-converted version modified by adding the NFS. QNFT demonstrated that the fit of an N95 FFR featuring the traditional/standard headbands strap system is negatively impacted when this system is converted to an ELSS. The fit of an ELSS-converted respirator can be significantly improved by the addition of the NFS. We found that the FFR model and the strap system version are significant factors affecting the QNFT-determined respirator fit factor (FF), as well as the OSHA QNFT pass rate (FF ≥100). The findings suggest that the current NFS, if further improved, has a potential for developing a 'universally fitting' ELSS-equipped N95 FFR that can be used by the general public, the vast majority of whom do not have access to OSHA fit requirements.

Design, Implementation, and Evaluation of an N95 Respirator Decontamination and Reuse Program for Healthcare Workers During the COVID-19 Pandemic.

Early in the COVID-19 pandemic, substantial disruptions in personal protective equipment (PPE) supply chains forced healthcare systems to become resourceful to ensure PPE availability for healthcare workers. Most worrisome was the global shortage of N95 respirators. In response, a collaboration between the Department of Infection Control and Healthcare Epidemiology and the Department of Biosafety at the University of Texas Medical Branch developed a PPE recycling program guaranteeing an adequate supply of respirators for frontline staff. The team successfully developed and implemented a novel workflow that included validated decontamination procedures, education, and training programs as well as transportation, labeling, and storage logistics. In total, 15,995 respirators of various types and sizes were received for recycling. Of these, 12,752 (80%) were recycled. Following the program's implementation, we surveyed 134 frontline healthcare workers who overwhelmingly graded our institution's culture of safety positively. Overall impressions of the N95 respirator recycling program were mixed, although interpretation of those results was limited by a lower survey response rate. In an era of increasing health security threats, innovative recycling programs like this one may serve as a model for other health systems to respond to future PPE supply chain disruptions.

Fit-failure rate associated with simulated reuse and extended use of N95 respirators assessed by a quantitative fit test.

OBJECTIVE: We quantitatively assessed the fit failure rate of N95 respirators according to the number of donning/doffing and hours worn. DESIGN: Experimental study. SETTING: A tertiary-care referral center in South Korea. PARTICIPANTS: In total, 10 infection control practitioners participated in the fit test. METHODS: The first experiment comprised 4 consecutive 1-hour donnings and fit tests between each donning. The second experiment comprised 2 consecutive 3-hour donnings and fit tests between each donning. The final experiment comprised fit tests after an 1-hour donning or a 2-hour donning. RESULTS: For 1-hour donnings, 60%, 70%, and 90% of the participants had fit failures after 2, 3, and 4 consecutive donnings, respectively. For 3-hour donnings, 50% had fit failure after the first donning and 70% had failures after 2 consecutive donnings. All participants passed the fit test after refitting whenever fit failure occurred. The final experiment showed that 50% had fit failure after a single use of 1 hour, and 30% had fit failure after a single use of 2 hours. CONCLUSIONS: High fit-failure rates were recorded after repeated donning and extended use of N95 respirators. Caution is needed for reuse (≥1 time) and extended use (≥1 hour) of N95 respirators in high-risk settings such as those involving aerosol-generating procedures. Although adequate refitting may recover the fit factor, the use of clean gloves and strict hand hygiene afterward should be ensured when touching the outer surfaces of N95 respirators for refitting.

Electron beam technology for Re-processing of personal protective equipment.

Beginning with the outbreak of COVID-19 at the dawn of 2020, the continuing spread of the pandemic has challenged the healthcare market and the supply chain of Personal Protective Equipment (PPE) around the world. Moreover, the emergence of the variants of COVID-19 occurring in waves threatens the sufficient supply of PPE. Among the various types of PPE, N95 Respirators, surgical masks, and medical gowns are the most consumed and thus have a high potential for a serious shortage during such emergencies. Considering the unanticipated demand for PPE during a pandemic, re-processing of used PPE is one approach to continue to protect the health of first responders and healthcare personnel. This paper evaluates the viability and efficacy of using FDA-approved electron beam (eBeam) sterilization technology (ISO 11137) to re-process used PPE. PPEs including 3M N95 Respirators, Proxima Sirus gowns, and face shields were eBeam irradiated in different media (air, argon) over a dose range of 0-200 kGy. Several tests were then performed to examine surface properties, mechanical properties, functionality performance, discoloration phenomenon, and liquid barrier performance. The results show a reduction of filtration efficiency to about 63.6% in the N95 Respirator; however, charge regeneration may improve the re-processed efficiency. Additionally, mechanical degradation was observed in Proxima Sirus gown with increasing dose up to 100 kGy. However, no mechanical degradation was observed in the face shields after 10 times donning and doffing. Apart from the face shield, N95 Respirators and Proxima Sirus gown both show significant mechanical degradation with ebeam dose over sterilization doses (>25 kGy), indicating that eBeam technology is not appropriate for the re-processing these PPEs.

Exploring inactivation of SARS-CoV-2, MERS-CoV, Ebola, Lassa, and Nipah viruses on N95 and KN95 respirator material using photoactivated methylene blue to enable reuse.

BACKGROUND: The COVID-19 pandemic resulted in a worldwide shortage of N95 respirators, prompting the development of decontamination methods to enable limited reuse. Countries lacking reliable supply chains would also benefit from the ability to safely reuse PPE. Methylene blue (MB) is a light-activated dye with demonstrated antimicrobial activity used to sterilize blood plasma. Decontamination of respirators using photoactivated MB requires no specialized equipment, making it attractive for use in the field during outbreaks. METHODS: We examined decontamination of N95 and KN95 respirators using photoactivated MB and 3 variants of SARS-CoV-2, the virus that causes COVID-19; and 4 World Health Organization priority pathogens: Ebola virus, Middle East respiratory syndrome coronavirus, Nipah virus, and Lassa virus. Virus inactivation by pretreating respirator material was also tested. RESULTS: Photoactivated MB inactivated all tested viruses on respirator material, albeit with varying efficiency. Virus applied to respirator material pre-treated with MB was also inactivated, thus MB pretreatment may potentially protect respirator wearers from virus exposure in real-time. CONCLUSIONS: These results demonstrate that photoactivated MB represents a cost-effective, rapid, and widely deployable method to decontaminate N95 respirators for reuse during supply shortages.

Developing home-disinfection and filtration efficiency improvement methods for N95 respirators and surgical facial masks: stretching supplies and better protection during the ongoing COVID-19 Pandemic.

The U.S. CDC announced on 04/03/2020 that all citizens should wear face coverings when in public, potentially increasing demand for medical face masks from the public and exacerbating mask shortages for Covid-19 response staff. One solution is reuse after disinfection for the general public. Prior studies have shown that heating for 30 mins at 70°C or above effectively kills SARS, including SARS-CoV-2, and Influenza viruses on masks. Black carbon (BC) particles generated from a kerosene-lamp were used as a proxy for Coronavirus aerosols to test mask performance after disinfection given overlapping size distributions. We determined filtration efficiency (FE) measurements by comparing BC values on both sides of the respirators or masks (Moldex N95 and 3M N95 respirators, HSI surgical masks) placed under vacuum on mannequins. To obtain the maximum FE, each mask type was first measured while taped or modified to tightly fit a mannequin's face when new and after each heating cycle. No reduction in average FE was observed even after 10 disinfection cycles, with FE statistically greater than 95% for N95 respirators and 70% for surgical masks. In sharp contrast, the FE of all medical masks with no additional sealing decreased to ~ 40%, confirming the effectiveness of facial masks relies upon a tight fit. For solving this issue, we designed a method for making individualized custom nose clips to hold a mask tightly to face; FE of 3M N95 respirators and surgical masks remained above 95% and 80%, respectively. Surprisingly, the FE of three homemade thick cloth coverings (in normal use) were 55%. Though more work is still needed, this result supports the public announcements that the public could wear cloth coverings instead of N95 respirators or surgical masks in low-risk environments. When worn with a customized nose clip, N95 respirators and surgical masks have higher FE than the CDC design for cloth coverings.

The effect of plastic tape seal to reduce face seal leak in respirator N-95 type 1860.

The risk of face seal leak while using N-95 respirators is experienced by health workers and thus failing fit test are quite common. Finding solutions to overcome face seal leaks is crucial; one of which is by sealing the N-95 respirator. The seal used in this research was Tegaderm® a transparent film dressing or a plastic tape which is known to have the advantages of strong adhesion, high level of pore density and standardized medical grade. This study tries to determine the effectiveness of plastic tape adhesive on the N-95 type 1860 respirator in overcoming face seal leak qualitative fit test using Bitrex immediately after being worn and after 4 h of using it. The study used a quantitative approach with an incidence study design conducted pre and post experimental without comparison to see the effectiveness of plastic tape sealing. The subjects for the research were 81 health workers in the CMH environment who were at risk of being exposed to COVID-19. The study found a significant difference in the Bitrex fit test immediately after sealing the N-95 type 1860 respirator with plastic tape; 100% passed the fit test immediately after sealing, and 64.2% passed the fit test after 4 h of working. The effectiveness of sealing using plastic tape is considered to be quite good to overcome face seal leak on the N-95 type 1860 respirator. Health care workers need to be more vigilance to ensure better face seal.

Development of Economical and Effective Ultraviolet (UVC) Irradiation Solutions and Equipment for Rapid Decontamination of SARS-CoV-2 on N95 Respirators

N95 disposable respirator masks are of particular importance to the Covid-19 pandemic. The high cost and limited supply of N95 disposable respirators promote research and safe and effective methods of reusing medical masks. The CDC of USA has announced that ultraviolet (UVC) irradiation inactivates SARS-CoV-2, virus, and other microorganisms known to culture on N95, as well as the results affecting mask fit and filterability. In this study, we analyze and evaluate the pathogen inactivation mechanism and the performance of respirators after treatment and perfect the method of ultraviolet irradiation (UVC) to help inactivate of SARS-CoV-2. At the same time, the research team successfully designed, fabricated and tested a semi-automatic system with UVC capacity 0.15 mW/cm2 at 220 nm that inactivated SARS-CoV-2 (3 log reduction) substances analogues of viruses, and other microorganisms grown on N95. The research results aim to commercialize the system technology (1) to inactivate the SARS-CoV-2 virus through the our application of UVC irradiation at the appropriate wavelength and effective dose, and (2) maintain the suitability and N95 filter rate. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Real work experiences, practices, and adverse events associated with long term usage of N95 respirators during the COVID-19 pandemic - A cross-sectional survey amongst Indian physicians

Introduction: Doctors are at increased risk of exposure to the SARS-CoV-2 virus, and the use of N95 respirators has emerged as a critical preventive measure. We studied the real-world experiences, practices, and adverse effects of N95 respirator usage amongst Indian physicians. Methods: We conducted an analytical, cross-sectional online survey between November 2020 and January 2021. Real-world usage characteristics of N-95 respirators were collected via a pre-validated questionnaire and compared amongst different sub-cohorts. Results: A total of 453 responses from physicians were analyzed. The most important adjunct to the N95 respirator perceived by the respondents was the full-face shield (81.9%). Most doctors had to purchase extra masks per month (median = 5 ± 8), which was more among the medical specialties (p = 0.006). The highest mean VAS scores for adverse events reported were for breathing on exertion (6.62 ± 2.25) and ear pain (6.34 ± 2.69). VAS ear pain was higher in ages < 40 and doctors working in the public sector (p = 0.017 and p = 0.019 respectively). Conclusion: Despite many inadequacies regarding proper mask removal, doffing techniques, and multiple reported prolonged mask usage-related adverse effects, there is generally good adherence to protocols and good practices of mask usage amongst physicians in the hospital setting. This journal is licensed under a Creative Commons Attribution-Non Commercial 4.0 International License.

Effects of Various Physical and Chemical Disinfection Methods on the Fine Particle Collection Efficiency of N95 Respirators and Surgical Masks.

Several studies have reported on the effectiveness of various disinfection methods for severe acute respiratory syndrome coronavirus 2 and their applicability to the disinfection of N95 respirators and surgical masks. To date, there have been no reports on the decontamination of deep in the intermediate layers of the multilayered structure. In this study, the conditions required for decontamination of such layers were simulated by considering the thickness and shape of N95 respirators or surgical masks (samples). After applying heat (steam, dry heat, or hot water) at 75°C for 60 min or chemical (benzalkonium chloride or laundry detergent) treatment, the collection efficiency of the samples was evaluated. Following the dry heat treatment, the time between the treatment and heat reaching the intermediate layer of the filter fiber was extended by 10 min. A dry heat disinfection method that combines hot water and a closed container was also evaluated, and satisfactory conditions were extended by 60 min. For each heat treatment, there was almost no effect on the collection efficiency, although there were cases where deformation was caused by mechanical stress. In contrast, chemical treatment resulted in a reduction in the collection efficiency of smaller particles.

Filtration efficiency of N95 filtering facepiece respirators during multi-cycles of '8-hour simulated donning + disinfection'.

BACKGROUND: Aerosol-borne diseases such as COVID-19 may outbreak occasionally in various regions of the world, inevitably resulting in short-term shortage and corresponding reuse of disposable respirators. AIM: To investigate the effective disinfection methods, reusable duration and frequency of N95 respirators. METHODS: Based on the self-built respirator simulation test system, and under combinations of experimental conditions of three N95 respirators × 0-200 nm NaCl aerosols × three simulated breathing flow rates (15, 50 and 85 L/min) × two disinfection methods (dry heating and ultraviolet (UV) radiation), this study continuously measured the changes in filtration efficiency of all respirators during multi-cycles of '8-h simulated donning + disinfection' until the penetration reached ≥5%. FINDINGS: Multi-cycles of dry heating and UV radiation treatments on the reused (i.e., multiple 8-h donning) N95 respirators had a minimal effect (<0.5%) on the respirator filtration efficiency, and even at 85 L/min, all tested N95 respirators were able to maintain filtration efficiencies ≥95% for at least 30 h or four reuse cycles of '8-h donning + disinfection', while a lower breathing flow rate (15 L/min) plus the exhalation valve could further extend the N95 respirator's usability duration up to 140 h or 18 reuse cycles of '8-h donning + disinfection'. As the respirator wearing time extended, aerosol penetration slowly increased in a quadratic function with a negative second-order coefficient, and the penetration increment during each cycle of 8-h donning was less than 0.9%. CONCLUSION: Multi-cycles of N95 respirator reuse in combination with dry heating or UV irradiation disinfection are feasible.

Effect of Skin Protectants on the Total Inward Leakage of N95 Respirators: Testing with an Advanced Static Headform

The COVID-19 pandemic introduced considerable challenges for respiratory protection of different population groups. Disposable medical masks and NIOSH-approved N95 filtering facepiece respirators (FFRs) are typically their only defense against the virus. At the same time, continuous wearing of these devices, especially some N95 FFR models cause damage to the facial skin, such as skin irritation, swelling, and scaling. Skin protectants are becoming increasingly popular and effective in providing a protective barrier for the skin that reduces direct contact between a wearer???s face and respirator. Recent pilot studies involving human subjects have examined the effect of skin protectants on the performance of respirators/masks through fit testing, but their findings are heavily impacted by between-subject variability. This investigation deployed a standardized protocol that utilized the NIOSH advanced static manikin headform connected to a Breathing Recording and Simulation System (BRSS), producing a predetermined breathing pattern. The effect of skin protectants on the total inward leakage (TIL) was evaluated for three N95 FFR models, five different skin protectants, and two breathing flow rates. The aerosol particle concentrations inside and outside the respirator were measured with NaCl serving as the challenge aerosol. The TIL was shown to be significantly affected by the interaction of the skin protectant type, breathing flow rate and FFR models. The data suggest that different skin protectants may influence the performance of disposable N95 FFRs in different ways - by either increasing or decreasing the TIL value relative to one with no skin protectants applied. No negative effects on the TIL was observed for either tape- or gel/cream-type protectants when testing with 3M 8210 or 3M 1870+ FFRs;however, the use of skin protectants of either group with the AOSafety 1050 FFR may compromise its performance as quantified by the TIL.

An Evaluation of the Effect of the Use of N95 Respirators by Surgical Teams on Early Surgical Site Infections in Orthopedic Cases.

Background Surgical site infections (SSIs) are seen in the postoperative period in orthopedic and traumatology clinics. Just as in all surgical clinics, SSIs lead to patient dissatisfaction with the results, prolong the length of stay in the hospital, and increase treatment costs. SSIs are known to occur as a result of wound contamination through inoculation of microorganisms found mainly in the air or in the surgical area. Because of the coronavirus disease 2019 pandemic, N95 masks have been widely used in the operating rooms of our hospital by nurses, residents, and surgeons since March 2020. This study aims to evaluate the effect of N95 respirator use by the surgical team on SSIs determined in patients operated on in our clinic compared to surgical mask use. Methodology In this retrospective study, the use of N95 respirators by the surgical team was compared with the use of surgical masks to evaluate the effect on SSIs in patients operated on in our clinic. Two groups were formed of patients operated on by the surgical team wearing surgical masks between February 2019 and February 2020 and those operated on with the surgical team using N95 respirators between March 2020 and March 2021. Each patient was diagnosed with postoperative SSIs by two different surgeons in the same clinic and by an infection clinic specialist based on clinical and laboratory findings. Results A total of 1,486 patients were examined; 729 patients in February 2019-February 2020 period (Group 1) and 757 in March 2020-March 2021 period (Group 2). In total, 124 and 104 patients were excluded from the first and second groups, respectively, for various reasons, including revision surgery, open fractures, diabetes, smoking, peripheral vascular disease, or other comorbidities that could affect infection rates. SSIs were determined in 35 patients in Group 1 and 13 patients in Group 2. The SSI rates in the second period in both types of procedures (arthroplasty and trauma surgeries) were determined to be significantly lower. Conclusions Because of the use of intraoperative N95 respiratory masks by surgical teams in orthopedics and traumatology procedures, the number of SSIs decreased significantly compared to the use of surgical masks.

A Plasma-Generating N-95 Respirator Decontamination Unit Created from a Microwave Oven

Wearing a mask population-wide is an important preventive measure in address-ing COVID-19 and potential future pandemics. We showed how a household microwave oven, a coat-hanger, and a coffee cup can generate plasma that can be used to decontaminate N95 respirators in less than 1 minute. We proved that microwave-generated plasma can reduce infectivity of the Tulane virus and the transmissible gastroenteritis virus (TGEV) on N95 respirators by > 3-log10. We further studied the Tulane virus by molecular assays to understand inactivation mech-anisms, and we found that the plasma damages both viral proteins and genomes. Spectroscopy of the plasma revealed OH and C-containing radicals as the most prevalent active species expected to cause virus inactivation. The respirators still maintained filtration and fit even after 10 cycles of the plasma treatment. We believe that microwave-generated plasma is an easily accessible respirator decontamination technique that everyone could use for safe respirator reuse. © 2021 by Begell House, Inc.