Disinfection of reusable elastomeric respirators by health care workers: a feasibility study and development of standard operating procedures

Provider experiences with daily use of elastomeric half-mask respirators in health care

BACKGROUND

During public health emergencies, demand for N95 filtering facepiece respirators (N95 FFRs) can outpace supply. Elastomeric half-mask respirators (EHMRs) are a potential alternative that are reusable and provide the same or higher levels of protection. This study sought to examine the practical aspects of EHMR use among health care personnel (HCP).

METHODS

Between September and December 2021, 183 HCPs at 2 tertiary referral centers participated in this 3-month EHMR deployment, wearing the EHMR whenever respiratory protection was required according to hospital protocols (ie, when an N95 FFR would typically be worn) and responding to surveys about their experience.

RESULTS

Participants wore EHMRs typically 1 to 3 hours per shift, reported disinfecting the respirator after 85% of the removals, and reported high confidence in using the EHMR following the study. EHMRs caused minimal interference with patient care tasks, though they did inhibit communication.

DISCUSSION

HCP who had not previously worn an EHMR were able to wear it as an alternative to an N95 FFR without much-reported interference with their job tasks and with high disinfection compliance.

CONCLUSIONS

This study highlights the feasibility of the deployment of EHMRs during a public health emergency when an alternative respirator option is necessary.

Evaluation of the effects of wiping decontamination for filter cartridges of elastomeric half-mask respirators (EHMRs)

BACKGROUND

A major concern among health care experts is a shortage of N95 filtering facepiece respirators during a pandemic. If the supply of N95 filtering facepiece respirators becomes limited, reusable elastomeric half-mask respirators (EHMRs) may be used to protect health care workers. The focus of this study was to evaluate the effects on the filter performance of wiping decontamination for EHMR P100 filter cartridges.

METHODS

The filter cartridge exterior of EHMR Honeywell, Moldex, and Mine Safety Appliance (MSA) models was wiped using quaternary ammonium and sodium hypochlorite wipes. These filter cartridge properties were assessed including observational analysis and filter performance tests. These wiping and assessing procedures were repeated after each set of wiping cycles (50, 100, 150, 200, and 400 cycles) to determine the effects of wiping decontamination.

RESULTS

For sodium hypochlorite wipes, Honeywell, Moldex, and MSA models passed the National Institute for Occupational Safety and Health (NIOSH) liquid particulate penetration criteria for all wiping cycles from 50 to 400 (penetrations<0.014%). For quaternary ammonium wipes, filter penetrations of Moldex failed (penetrations>0.03%) after 150 cycles, while the filter penetrations of Honeywell and MSA passed for all wiping cycles (penetrations ≤0.013%).

CONCLUSIONS

Wiping decontamination methods using sodium hypochlorite and quaternary ammonium wipes could be considered promising decontamination candidates for Honeywell, Moldex, and MSA reuse, except for the wiping number selection for Moldex (<150 cycles) when using the quaternary ammonium wipe.

Elastomeric half-mask respirator disinfection practices among healthcare personnel

BACKGROUND

Disposable N95 respirator shortages during the COVID-19 and 2009 H1N1 influenza pandemics highlighted the need for reusable alternatives, such as elastomeric half-mask respirators (EHMRs). Two US medical organizations deployed reusable EHMRs during the COVID-19 response. In addition to wipe-based disinfection following patient care episodes expected per local policies at both organizations, postshift centralized cleaning and disinfection (C&D) was expected at one site (A), permitting shared-pool EHMR use, and optional at the other (Site B), where EHMRs were issued to individuals. Using a survey, we evaluated disinfection practices reported by EHMR users and predictors of disinfection behaviors and perceptions.

METHODS

Surveys assessed EHMR disinfection practices, occupational characteristics, EHMR use frequency, training, and individual-issue versus shared-pool EHMR use.

RESULTS

Of 1080 EHMR users completing the survey, 76% reported that they disinfect the EHMR after each patient encounter, which was the expected practice at both sites. Increasing EHMR use, recall of disinfection training, and work in intensive care or emergency settings significantly influenced higher reporting of this practice. 36% of respondents reported using centralized C&D, although reporting was higher at the site (A) where this was expected (53%). Confidence in cleanliness of the EHMR following centralized C&D was not influenced by individual versus shared-pool EHMR issue.

CONCLUSIONS

Most EHMR users reported adherence with expected post-care individual-based disinfection of EHMRs but did not necessarily use standardized, centralized C&D. Future efforts to limit reliance on behavior related to respirator disinfection may improve EHMR implementation in healthcare to avert dependence on single-use, disposable N95 respirators.

A framework for comparing N95 and elastomeric facepiece respirators on cost and function for healthcare use during a pandemic- A literature review

SARS-CoV-2 has posed implications for personal protective equipment supply. In this literature review we examine if elastomeric facepiece respirators (EFRs) are effective substitutes for N95 respirators through comparing their functionality and cost. We reviewed 30 articles which researched the advantages and disadvantages of each respirator. We compiled the reported results and found, among other things, that users favour N95 respirators for comfort but prefer EFRs for protection. EFRs are more cost effective when N95s are used as designed (single use) but mixed strategies minimize costs when N95s are reused (as practiced during shortages). Future research is needed on multicriteria analyses and to incorporate SARS-CoV-2 specific data to support future pandemic planning.

The need for systematic quality controls in implementing N95 reprocessing and sterilization

BACKGROUND

Due to increased requirement for personal protective equipment during the coronavirus disease 2019 pandemic, many medical centres utilized sterilization systems approved under Food and Drug Administration Emergency Use Authorization for single-use N95 mask re-use. However, few studies have examined the real-world clinical challenges and the role of ongoing quality control measures in successful implementation.

AIMS

To demonstrate successful implementation of quality control measures in mask reprocessing, and the importance of continued quality assurance.

METHODS

A prospective quality improvement study was conducted at a tertiary care medical centre. In total, 982 3M 1860 masks and Kimberly-Clark Tecnol PFR95 masks worn by healthcare workers underwent sterilization using a vaporized hydrogen peroxide gas plasma-based reprocessing system. Post-processing qualitative fit testing (QFT) was performed on 265 masks. Mannequin testing at the National Institute for Occupational Safety and Health (NIOSH) laboratory was used to evaluate the impact of repeated sterilization on mask filtration efficacy and fit. A locally designed platform evaluated the filtration efficiency of clinically used and reprocessed masks.

FINDINGS

In total, 255 N95 masks underwent QFT. Of these, 240 masks underwent post-processing analysis: 205 were 3M 1860 masks and 35 were PFR95 masks. Twenty-five (12.2%) of the 3M masks and 10 (28.5%) of the PFR95 masks failed post-processing QFT. Characteristics of the failed masks included mask deformation (N=3, all 3M masks), soiled masks (N=3), weakened elastic bands (N=5, three PFR95 masks), and concern about mask shrinkage (N=3, two 3M masks). NIOSH testing demonstrated that while filter efficiency remained >98% after two cycles, mask strap elasticity decreased by 5.6% after reprocessing.

CONCLUSIONS

This study demonstrated successful quality control implementation for N95 mask disinfection, and highlights the importance of real-world clinical testing beyond laboratory conditions.

Surface Contamination of Reusable Respirators and Face Shields During Care of Critically Ill COVID-19 Patients

BACKGROUND

With the emergence of SARS-CoV-2, healthcare workers (HCW) have relied on reusable personal protective equipment (PPE), including respirators and face shields (FSs). The effectiveness of decontamination procedures outside experimental settings is unclear. We examined the prevalence of surface contamination on reusable PPE used by HCWs at a hospital incorporating daily centralized decontamination and post-use wiping by sampling for common pathogens.

METHOD

Samples were collected from HCWs' CleanSpace Halo respirator face masks (FMs) and FSs at the start of shift, immediately after use, and after cleaning with disinfecting wipes. Samples were analyzed for pathogens using the Applied Biosystems™ TaqPath™ COVID-19 Combo Kit and ThermoFisher TaqMan Array Card. Patient charts were reviewed for clinical correlation.

FINDINGS

Of the 89 samples, 51 from FMs and 38 from FSs, none tested positive for SARS-CoV-2, despite 58 being obtained from PPE used in the care of patients with COVID-19, many with recent aerosol-generating procedures. Four samples tested positive (4.5%) for Staphylococcus aureus, two each from FMs and FSs. FMs that tested positive were not worn concurrently with FSs that tested positive. The FM and FS samples testing positive were worn in the care of patients without diagnosed S. aureus infection. No FMs tested positive following wipe-based disinfection, but both positive FS samples were found after disinfection wiping.

CONCLUSION/APPLICATION TO PRACTICE

Contamination of reusable PPE appears uncommon, especially with SARS-CoV-2, when regular decontamination programs are in place. The rare presence of S. aureus highlights the importance of doffing procedures and hand hygiene by HCW to prevent surface contamination.

Conservation Practices for Personal Protective Equipment: A Systematic Review with Focus on Lower-Income Countries

During the start of the COVID-19 pandemic, shortages of personal protective equipment (PPE) necessitated unprecedented and non-validated approaches to conserve PPE at healthcare facilities, especially in high income countries where single-use disposable PPE was ubiquitous. Our team conducted a systematic literature review to evaluate historic approaches for conserving single-use PPE, expecting that lower-income countries or developing contexts may already be uniquely conserving PPE. However, of the 50 included studies, only 3 originated from middle-income countries and none originated from low-income countries. Data from the included studies suggest PPE remained effective with extended use and with multiple or repeated use in clinical settings, as long as donning and doffing were performed in a standard manner. Multiple decontamination techniques were effective in disinfecting single use PPE for repeated use. These findings can inform healthcare facilities and providers in establishing protocols for safe conservation of PPE supplies and updating existing protocols to improve sustainability and overall resilience. Future studies should evaluate conservation practices in low-resource settings during non-pandemic times to develop strategies for more sustainable and resilient healthcare worldwide.

Evaluation of the Microbiological Effectiveness of Three Accessible Mask Decontamination Methods and Their Impact on Filtration, Air Permeability and Physicochemical Properties

The need to secure public health and mitigate the environmental impact associated with the massified use of respiratory protective devices (RPD) has been raising awareness for the safe reuse of decontaminated masks by individuals and organizations. Among the decontamination treatments proposed, in this work, three methods with the potential to be adopted by households and organizations of different sizes were analysed: contact with nebulized hydrogen peroxide (H2O2); immersion in commercial bleach (NaClO) (sodium hypochlorite, 0.1% p/v); and contact with steam in microwave steam-sanitizing bags (steam bag). Their decontamination effectiveness was assessed using reference microorganisms following international standards (issued by ISO and FDA). Furthermore, the impact on filtration efficiency, air permeability and several physicochemical and structural characteristics of the masks, were evaluated for untreated masks and after 1, 5 and 10 cycles of treatment. Three types of RPD were analysed: surgical, KN95, and cloth masks. Results demonstrated that the H2O2 protocol sterilized KN95 and surgical masks (reduction of >6 log10 CFUs) and disinfected cloth masks (reduction of >3 log10 CFUs). The NaClO protocol sterilized surgical masks, and disinfected KN95 and cloth masks. Steam bags sterilized KN95 and disinfected surgical and cloth masks. No relevant impact was observed on filtration efficiency.

The impact of surge adaptations on hospitalist care teams during the COVID-19 pandemic utilizing a rapid qualitative analysis approach

Background

Hospital systems have rapidly adapted to manage the influx of patients with COVID-19 and hospitalists, specialists in inpatient care, have been at the forefront of this response, rapidly adapting to serve the ever-changing needs of the community and hospital system. Institutional leaders, including clinical care team members and administrators, deployed many different strategies (i.e. adaptations) to manage the influx of patients. While many different strategies were utilized in hospitals across the United States, it is unclear how frontline care teams experienced these strategies and multifaceted changes. As these surge adaptations likely directly impact clinical care teams, we aimed to understand the perceptions and impact of these clinical care and staffing adaptations on hospitalists and care team members in order to optimize future surge plans.

Methods

Qualitative, semi-structured interviews and focus groups with hospitalist physicians, advanced practice providers (APPs), and hospital nursing and care management staff at a quaternary academic medical center. Interviews focused on the impact of COVID-19 surge practices on the following areas: (1) the experience of clinical care teams with the adaptations used to manage the surge (2) the perception and experience with the communication strategies utilized (3) the personal experience with the adaptations (i.e. how they impacted the individual) and (4) if participants had recommendations on strategies for future surges. We utilized rapid qualitative analysis methods to explore themes and subthemes.

Results

We conducted five focus groups and 21 interviews. Three themes emerged from the work including (1) dynamic clinical experience with a lot of uncertainty, (2) the importance of visible leadership with a focus on sense-making, and (3) the significant emotional toll on care team members. Subthemes included sufficient workforce, role delineation and training, information sharing, the unique dichotomy between the need for flexibility and the need for structure, the importance of communication, and the emotional toll not only on the provider but their families. Several recommendations came from this work.

Conclusions

COVID-19 surge practices have had direct impact on hospitalists and care team members. Several tactics were identified to help mitigate the many negative effects of COVID-19 on frontline hospitalist providers and care teams.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00804-7.

Spanish nurses' experiences with personal protective equipment and perceptions of risk of contagion from COVID-19: A qualitative rapid appraisal

AIMS AND OBJETIVES

Explore nurses' experiences and perception of risk regarding the use of personal protective equipment during the first wave of the pandemic in Spain.

BACKGROUND

The contribution of our study is to use qualitative methods to understand nurses' experiences and perceptions of the risk of the contagion linked to the shortage of PPE during the first wave of the pandemic, whose explosive start strained health systems around the globe.

DESIGN

Qualitative descriptive design according to the Rapid Research Evaluation and Appraisal model.

METHODS

Semi-structured videoconference interviews were conducted to explore the experiences of 29 nurses including staff nurses, nursing supervisors and nursing directors from hospital and community services of the Spanish health system. Interviews lasted 30-45 min and were conducted in May 2020. We carried out a thematic analysis using Dedoose. The COREQ checklist was used to report findings.

RESULTS

We identified the following themes and subthemes: 1. Experiences with personal protective equipment: scarcity, inequality, reutilization, self-protection, delegation of responsibility, and gap between protocols and reality; 2. Perception of the risk of contagion: lack of credibility, lack of trust, lack of support, and meeting subjective needs.

CONCLUSIONS

The scarcity of personal protective equipment and inequality in its distribution led nurses to take initiatives to feel more protected. Mid-ranking supervisors were caught between the responsibility of monitoring and rationing personal protective equipment and providing the necessary protection to nurses. The disjuncture between protocols and the available supply of personal protective equipment caused confusion. Lack of credibility, lack of trust and lack of support from management influenced participants' perception of the risk of contagion. Mid-ranking supervisors were often responsible for trying to alleviate fear among nursing staff.

RELEVANCE TO CLINICAL PRACTICE

Understanding the factors involved in risk perception can be helpful to decision-makers who help protect nurses in clinical practice. These results can help administrators and policymakers because they point to the need for nurses to feel that their departments and centers look after their safety at work. Transparent communication and emotional support may contribute to their well-being in the face of risk.

The pragmatic use of industrial elastomeric facemasks in health care practice during the COVID-19 pandemic

Introduction

The COVID-19 pandemic has forced health care workers to explore alternative personal protective equipment (PPE) strategies due to traditional product shortages in the setting of increased global demand. Some physicians have chosen to use elastomeric face masks (EFMs), traditionally used in non-healthcare industries.

Methods

We performed a prospective cohort study of Emergency Medicine (EM) physicians working at a Level 1 Trauma Center who chose to use self-supplied EFMs for PPE. All subjects used commercial EFMs with disposable filters (N95, P95, or P100). All subjects chose their mask size independently with no input from employee health regarding appropriate fit. Per study protocol, subjects were fit tested periodically during clinical shifts over the course of the 6-week study period. All investigators performing fit testing underwent OSHA qualitative fit testing training. Data collected included mask/filters age, subjective assessment of mask seal quality, and fit test results. The data were analyzed using descriptive statistics.

Results

105 fit tests were performed on physicians wearing EFMs over the course of 49 shifts. Physicians felt their fit was adequate for all tests performed. There were no fit test failures in any subjects.

Conclusions

EFMs have an extremely low failure rate. Physicians are able to assess the adequacy of fit and accurately choose EFM size.

Staff perceptions of military chemical-biological-radiological-nuclear (CBRN) air-purifying masks during a simulated clinical task in the context of SARS-CoV-2

Air-purifying full-face masks, such as military chemical-biological-radiological-nuclear masks, might offer superior protection against severe acute respiratory syndrome coronavirus 2 compared to disposable polypropylene P2 or N95 masks. In addition, disposable masks are in short supply, while military chemical-biological-radiological-nuclear masks can be disinfected then reused. It is unknown whether such masks might be appropriate for civilians with minimal training in their use. Accordingly, we compared the Australian Defence Force in-service chemical-biological-radiological-nuclear Low Burden Mask (AirBoss Defense, Newmarket, Canada) with polypropylene N95 masks and non-occlusive glasses worn during simulated tasks performed by civilian clinicians in an Australian tertiary referral hospital intensive care unit. After brief training in the use of the Low Burden Mask, participants undertook a simulated cardiac arrest scenario. Previous training with polypropylene N95 masks had been provided. Evaluation of 10 characteristics of each mask type were recorded, and time to mask application was assessed. Thirty-three participants tested the Low Burden Mask, and 28 evaluated polypropylene N95 masks and glasses. The Low Burden Mask was donned more quickly: mean time 7.0 (standard deviation 2.1) versus 18.3 (standard deviation 6.7) seconds; P = 0.0076. The Low Burden Mask was rated significantly higher in eight of the 10 assessed criteria, including ease of donning, comfort (initially and over a prolonged period), fogging, seal, safety while removing, confidence in protection, and overall. Visibility and communication ability were rated equally highly for both systems. We conclude that this air-purifying full-face mask is acceptable to clinicians in a civilian intensive care unit. It enhances staff confidence, reduces waste, and is likely to be a lower logistical burden during a prolonged pandemic. Formal testing of effectiveness is warranted.

Fomite Transmission, Physicochemical Origin of Virus-Surface Interactions, and Disinfection Strategies for Enveloped Viruses with Applications to SARS-CoV-2

Inanimate objects or surfaces contaminated with infectious agents, referred to as fomites, play an important role in the spread of viruses, including SARS-CoV-2, the virus responsible for the COVID-19 pandemic. The long persistence of viruses (hours to days) on surfaces calls for an urgent need for effective surface disinfection strategies to intercept virus transmission and the spread of diseases. Elucidating the physicochemical processes and surface science underlying the adsorption and transfer of virus between surfaces, as well as their inactivation, is important for understanding how diseases are transmitted and for developing effective intervention strategies. This review summarizes the current knowledge and underlying physicochemical processes of virus transmission, in particular via fomites, and common disinfection approaches. Gaps in knowledge and the areas in need of further research are also identified. The review focuses on SARS-CoV-2, but discussion of related viruses is included to provide a more comprehensive review given that much remains unknown about SARS-CoV-2. Our aim is that this review will provide a broad survey of the issues involved in fomite transmission and intervention to a wide range of readers to better enable them to take on the open research challenges.

Mask shortage during epidemics and pandemics: a scoping review of interventions to overcome limited supply

OBJECTIVE

To characterise published evidence regarding preclinical and clinical interventions to overcome mask shortages during epidemics and pandemics.

DESIGN

Systematic scoping review.

SETTINGS

All healthcare settings relevant to epidemics and pandemics.

SEARCH STRATEGY

English peer-reviewed studies published from January 1995 to June 2020 were included. Literature was identified using four databases (Medline-OVID, EMBASE, CINAHL, Cochrane Library), forwards-and-backwards searching through Scopus and an extensive grey literature search. Assessment of study eligibility, data extraction and evidence appraisal were performed in duplicate by two independent reviewers.

RESULTS

Of the 11 220 database citations, a total of 47 articles were included. These studies encompassed six broad categories of conservation strategies: decontamination, reusability of disposable masks and/or extended wear, layering, reusable respirators, non-traditional replacements or modifications and stockpiled masks. Promising strategies for mask conservation in the context of pandemics and epidemics include use of stockpiled masks, extended wear of disposable masks and decontamination.

CONCLUSION

There are promising strategies for overcoming face mask shortages during epidemics and pandemics. Further research specific to practical considerations is required before implementation during the COVID-19 pandemic.

Disposable masks: Disinfection and sterilization for reuse, and non-certified manufacturing, in the face of shortages during the COVID-19 pandemic

The COVID-19 pandemic is posing a huge global health threat. To deal with this problem, in addition to research and work in the medical field, the main health measures being taken in the workplace and at home involve the establishment of safety protocols, which include distance measures, hygiene and the use of personal protective equipment, such as masks, etc. The WHO still does not recommend the use of masks for the general population. However, their successful use in China, South Korea and the Czech Republic has encouraged their widespread use, and the shortage that already existed. This has caused that companies and individuals are looking at the best way to reuse them, and to manufacture, homemade or not, of non-certified masks. This paper is based on two objectives: to consult the scientific literature to identify the main strategies for disinfecting them, and to determine the effectiveness of non-certified disposable masks. A rapid review has been conducted in which the main publications and other information available online have been analyzed. Results showed that the most promising methods are those that use hydrogen peroxide vapor, ultraviolet radiation, moist heat, dry heat and ozone gas. Soapy water, alcohol, bleach immersion, ethylene oxide, ionizing radiation, microwave, high temperature, autoclave or steam are not fully recommended. Regarding the effectiveness of surgical masks compared to PPE, the former have been seen to be slightly less effective than PPE. As for other types of masks the effectiveness of homemade or non-certified masks is very low.

Implementation of an Elastomeric Mask Program as a Strategy to Eliminate Disposable N95 Mask Use and Resterilization: Results from a Large Academic Medical Center

Background

The COVD-19 global pandemic has placed a large demand on personal protective equipment for healthcare workers. N-95 respirators, required to perform aerosolizing procedures, are in short supply and have increased significantly in cost. The lack of a clear end to the pandemic requires hospitals to create a long-term, cost effective solution to the N95 shortage. We initially used previously described methods to reuse and resterilize N95 masks; however, we found they did not solve the issues related to just-in-time fit-testing and cost.

Study design

We initiated a program with the aim to reduce our dependence on N95 masks by initiating a phased program to acquire industrial style elastomeric P100 masks as a substitute for reuse and resterilization of disposable N95s. We created an allocation strategy based on availability of the masks, as well as an operational plan to fit test, educate, and disinfect the masks.

Results

Within 1 month, we were able to reduce the number of N95s needed by our network by 95%. We also found that the cost was, conservatively, 10 times less per month than purchasing disposable N95s, and the cost benefit increases the longer they are needed.

Conclusions

Establishment of an elastomeric mask program is feasible and less expensive than programs focused on reusing and disinfecting disposable N95 masks. A well thought out elastomeric distribution and disinfection program does not pose greater operational challenges than an N95 reuse and resterilization program. In addition, elastomeric masks can be stored for future surges and should be considered an essential part of all healthcare facilities’ supply of personal protective equipment. Implementation of the program has eliminated our dependence on disposable N95s to maintain normal operations during the global pandemic.

Extended use of face masks during the COVID-19 pandemic - Thermal conditioning and spray-on surface disinfection

The current COVID-19 pandemic has resulted in globally constrained supplies for face masks and personal protective equipment (PPE). Production capacity is limited in many countries and the future course of the pandemic will likely continue with shortages for high quality masks and PPE in the foreseeable future. Hence, expectations are that mask reuse, extended wear and similar approaches will enhance the availability of personal protective measures. Repeated thermal disinfection could be an important option and likely easier implemented in some situations, at least on the small scale, than UV illumination, irradiation or hydrogen peroxide vapor exposure. An overview on thermal responses and ongoing filtration performance of multiple face mask types is provided. Most masks have adequate material properties to survive a few cycles (i.e. 30 min disinfection steps) of thermal exposure in the 75°C regime. Some are more easily affected, as seen by the fusing of plastic liner or warping, given that preferred conditioning temperatures are near the softening point for some of the plastics and fibers used in these masks. Hence adequate temperature control is equally important. As guidance, disinfectants sprayed via dilute solutions maintain a surface presence over extended time at 25 and 37°C. Some spray-on alcohol-based solutions containing disinfectants were gently applied to the top surface of masks. Neither moderate thermal aging (less than 24 h at 80 and 95°C) nor gentle application of surface disinfectant sprays resulted in measurable loss of mask filter performance. Subject to bio-medical concurrence (additional checks for virus kill efficiency) and the use of low risk non-toxic disinfectants, such strategies, either individually or combined, by offering additional anti-viral properties or short term refreshing, may complement reuse options of professional masks or the now ubiquitous custom-made face masks with their often unknown filtration effectiveness.

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Thermal conditioning and gentle surface disinfection to aid extended use of masks.

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Adequate material properties for most masks to survive a few cycles at 75°C.

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Temperature control important, as conditioning is near the softening point for some of the plastics and fibers used.

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No measurable loss of mask filter performance after moderate thermal exposure or gentle application of surface disinfectant.

Storage and Availability of Elastomeric Respirators in Health Care

Use of reusable respirators, such as elastomeric half-face respirators (EHFRs), may serve as one solution to combating the problem of N95 respirator shortages experienced during infectious disease emergencies. To clarify whether logistical issues like respirator storage and availability are barriers to implementation of healthcare respiratory protection strategies that include EHFRs, this study aimed to evaluate the availability, storage, and respirator and filter replacement practices of EHFRs used in healthcare settings under routine use. Healthcare workers using EHFRs were surveyed about their use practices. To explore whether issues related to storage and availability of EHFRs affected compliance with assigned respirator use, responses were compared between concordant users and EHFR users who were assigned to use EHFRs but currently use different respirators ("discordant users"). Most concordant EHFR users reported that their respirator was always available when needed (63.8%). Almost two-thirds of concordant but only half of discordant users reported storing their EHFRs conveniently in the patient care area (p = <0.001). Among mobile workers, discordant users had higher odds (aOR = 3.2, 95% CI [1.4,7.5]) of reporting that their respirator was not stored in the patient care area, suggesting that storage location has a significant impact on compliance with expected practice, particularly in this group. Storage and access are barriers to optimal elastomeric respirator use in healthcare. Strategies to assure ready availability and storage of respirators will permit EHFR inclusion in pandemic and routine respiratory protection programs.

User acceptance of reusable respirators in health care

BACKGROUND

Inclusion of reusable respirators, such as elastomeric half-face respirators (EHFRs) and powered air-purifying respirators (PAPRs), in hospital respiratory protection inventories may represent 1 solution to the problem of N95 respirator shortages experienced during pandemics. User acceptance of these devices is 1 potential barrier to implementing such a strategy in respiratory protection programs.

METHODS

To assess user attitudes toward various respirators, health care workers enrolled in respiratory protection programs in a medical system using EHFRs, N95s, and PAPRs and completed an online questionnaire that addressed attitudes, beliefs, and respirator preferences under different risk scenarios. Responses were compared between user groups.

RESULTS

Of 1,152 participants, 53% currently used N95s, 24% used EHFRs, and 23% used PAPRs. N95 users rated their respirators more favorably compared with EHFR and PAPR users (P < .001) regarding comfort and communication, however, EHFR users rated their respirators much more highly regarding sense of protection (P < .001). For all user groups, reusable respirators were significantly more likely (odds ratios 2.3-7.7) to be preferred over N95 filtering facepiece respirators in higher risk scenarios compared to "usual circumstance" scenarios.

CONCLUSIONS

Despite somewhat less favorable ratings on comfort and communication, experienced EHFR and PAPR users still prefer reusable respirators over N95s in certain higher risk scenarios. This suggests that reusable respirators are an acceptable alternative to N95 respirators in health care and offer 1 viable solution to prevent pandemic-generated respirator shortages.

Disinfection efficiency of positive pressure respiratory protective hood using fumigation sterilization cabinet

Concerns have been raised about both the disinfection and the reusability of respiratory protective equipment following a disinfection process. Currently, there is little data available on the effects of disinfection and decontamination on positive pressure respiratory protective hoods (PPRPH). In this study, we evaluated the effect of vaporized hydrogen peroxide (VHP) on the disinfection of PPRPH to determine applicability of this method for disinfection of protective equipment, especially protective equipment with an electric supply system.

A hydrogen peroxide-based fumigation sterilization cabinet was developed particularly for disinfection of protective equipment, and the disinfection experiments were conducted using four PPRPHs hung in the fumigation chamber. The pathogenic microorganism Geobacillus stearothermophilus ATCC 7953 was used as a biological indicator in this study and the relationship between air flow (the amount of VHP) and disinfection was investigated. Both function and the material physical properties of the PPRPH were assessed following the disinfection procedure. No surviving Geobacillus stearothermophilus ATCC 7953, both inside and outside of these disinfected PPRPHs, could be observed after a 60 min treatment with an air flow of 10.5–12.3 m³/h. Both function and material physical properties of these PPRPHs met the working requirements after disinfection.

This study indicates that air flow in the fumigation chamber directly influences the concentration of VHP. The protective equipment fumigation sterilization cabinet developed in this paper achieves the complete sterilization of the PPRPHs when the air flow is at 10.5–12.3 m³/h, and provides a potential solution for the disinfection of various kind of protective equipment.

A tolerability assessment of new respiratory protective devices developed for health care personnel: A randomized simulated clinical study

BACKGROUND

U.S. health care personnel (HCP) have reported that some respiratory protective devices (RPD) commonly used in health care have suboptimal tolerability. Between 2012 and 2016, the U.S. National Institute for Occupational Safety and Health, and the Veterans Health Administration collaborated with two respirator manufacturers, Company A and B, to bring new RPD with improved tolerability to the U.S. health care marketplace. The purpose of this study was to compare the tolerability of four new prototype RPD to two models commonly used in U.S. health care delivery.

METHODS

A randomized, simulated workplace study was conducted to compare self-reported tolerability of four new prototype RPD (A1, A2, B1, and B2) worn by HCP and two N95 control respirators commonly used in U.S. health care delivery, the 1870 and 1860, manufactured by 3M Corporation. A new survey tool, the Respirator Comfort, Wearing Experience, and Function Instrument (R-COMFI), developed previously in part for the current study, was used as the primary outcome metric. With a maximum total score of 47, lower R-COMFI scores reflected better self-reported tolerability. Poisson regression analyses were used to estimate prototype relative risks compared to controls.

RESULTS

Conducted between 2014 and 2015 in two inpatient care rooms at the North Florida/South Georgia Veterans Health System, among 383 participants who enrolled, 335 (87.5%) completed the study. Mean total R-COMFI scores for the 3M 1870, 3M 1860, and prototypes A1, A2, B1, and B2 were 8.26, 9.36, 5.79, 7.70, 6.09, and 5.71, respectively. Compared to the 3M 1870, total R-COMFI unadjusted relative risks (RR) and 95 percent confidence intervals (CI) were A1 (RR 0.70, CI 0.60, 0.82), A2 (RR 0.93, CI 0.82, 1.06), B1 (RR 0.74, CI 0.64, 0.85), and B2 (RR 0.69, CI 0.60, 0.80). Compared to the 3M 1860, prototype total R-COMFI unadjusted RR and 95 percent CI were A1 (RR 0.62, CI 0.53, 0.72), A2 (RR 0.82, CI 0.73, 0.93), B1 (RR 0.65, CI 0.57, 0.74), and B2 (RR 0.61, CI 0.53, 0.70). Similarly, models adjusted for demographic characteristics showed that prototypes A1, B1, and B2 significantly improved tolerability scores compared to both controls, while prototype A2 was significantly improved compared to the 3M 1860.

CONCLUSIONS

Compared to the 3M 1870 and 3M 1860, two RPDs commonly used in U.S. health care delivery, tolerability improved for three of four newly developed prototypes in this simulated workplace study. The R-COMFI tool, used in this study to assess tolerability, should be useful for future comparative studies of RPD.

Assessment of half-mask elastomeric respirator and powered air-purifying respirator reprocessing for an influenza pandemic

BACKGROUND

Health care facilities are considering the use of reusable respiratory protective devices (RPDs) to mitigate a potential N95 filtering facepiece respirator shortage caused by an influenza pandemic. US regulators are also considering stockpiling reusable RPDs for pandemic preparedness, but limited data exist on the effectiveness of cleaning and disinfection of these devices. This study defines reprocessing protocols and evaluates their effectiveness against a pandemic influenza strain in a laboratory setting.

METHODS

Five half-mask elastomeric respirator models and 3 powered air-purifying respirator models were contaminated with influenza virus and artificial skin oil on multiple surfaces. RPDs were then manually treated with 1 of 2 methods: cleaned or cleaned and disinfected. Presence of viable influenza was determined via swab sampling and a median tissue culture infectious dose assay.

RESULTS

Across 41 RPD surfaces, a mean log reduction in viable influenza of 4.54 ± 0.97 log₁₀ median tissue culture infectious dose was achieved for all treated surfaces, which included both cleaned and cleaned and disinfected surfaces.

CONCLUSIONS

The methods defined as part of this study are effective for eliminating viable influenza in the presence of artificial skin oil on most of the RPD surfaces tested. Material type and RPD design should be considered when implementing RPD reprocessing protocols.

Prevalence of Respiratory Protective Devices in U.S. Health Care Facilities: Implications for Emergency Preparedness

An online questionnaire was developed to explore respiratory protective device (RPD) prevalence in U.S. health care facilities. The survey was distributed to professional nursing society members in 2014 and again in 2015 receiving 322 and 232 participant responses, respectively. The purpose of this study was to explore if the emergency preparedness climate associated with Ebola virus disease changed the landscape of RPD use and awareness. Comparing response percentages from the two sampling time frames using bivariate analysis, no significant changes were found in types of RPDs used in health care settings. N95 filtering facepiece respirators continue to be the most prevalent RPD used in health care facilities, but powered air-purifying respirators are also popular, with regional use highest in the West and Midwest. Understanding RPD use prevalence could ensure that health care workers receive appropriate device trainings as well as improve supply matching for emergency RPD stockpiling.