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

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.

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.

Powered air-purifying respirator (PAPR) disinfection and risk of surface damage from hydrogen peroxide and quaternary ammonium chloride-based disinfectants

Reusable Powered Air Purifying Respirators (PAPRs) have been increasingly used as an alternative to disposable masks or respirators for healthcare workers needing protection from respiratory droplets containing respiratory viruses, but little information is available concerning how well PAPRs resist damage from repeat disinfection over their lifetime. This study tested parts from four PAPRs against four commercially available hydrogen peroxide and quaternary ammonium chloride disinfectants by immersion for 28 days to simulate prolonged exposure. Risk of surface damage was assessed through color change, mass change, and visual observation of damage. Minimal risk of damage was found for three of the disinfectants tested and for the fourth disinfectant, a risk of surface damage to a small number of parts. Exposure to tap water caused similar damage in many cases. The study demonstrated that risk of surface damage varied by part and disinfectant, indicating that some disinfectants are more likely to be compatible against the wide range of materials and parts in a commercial PAPR and other disinfectants may show varying compatibility, with more risk to certain materials or parts.

Mask decontamination methods (model N95) for respiratory protection: a rapid review

BACKGROUND

N95 respiratory protection masks are used by healthcare professionals to prevent contamination from infectious microorganisms transmitted by droplets or aerosols.

METHODS

We conducted a rapid review of the literature analyzing the effectiveness of decontamination methods for mask reuse. The database searches were carried out up to September 2020. The systematic review was conducted in a way which simplified the stages of a complete systematic review, due to the worldwide necessity for reliable fast evidences on this matter.

RESULTS

A total of 563 articles were retrieved of which 48 laboratory-based studies were selected. Fifteen decontamination methods were included in the studies. A total of 19 laboratory studies used hydrogen peroxide, 21 studies used ultraviolet germicidal irradiation, 4 studies used ethylene oxide, 11 studies used dry heat, 9 studies used moist heat, 5 studies used ethanol, two studies used isopropanol solution, 11 studies used microwave oven, 10 studies used sodium hypochlorite, 7 studies used autoclave, 3 studies used an electric rice cooker, 1 study used cleaning wipes, 1 study used bar soap, 1 study used water, 1 study used multi-purpose high-level disinfection cabinet, and another 1 study used chlorine dioxide. Five methods that are promising are as follows: hydrogen peroxide vapor, ultraviolet irradiation, dry heat, wet heat/pasteurization, and microwave ovens.

CONCLUSIONS

We have presented the best available evidence on mask decontamination; nevertheless, its applicability is limited due to few studies on the topic and the lack of studies on real environments.

Microbial contamination of powered air purifying respirators (PAPR) used by healthcare staff during the COVID-19 pandemic: an in situ microbiological study

Background

Powered air purifying respirators (PAPR) are an option for healthcare workers requiring respiratory protection during the current COVID-19 pandemic; they are shared between multiple people. PAPR hoods are intended for multiple uses by a single user and may pose an infection risk between wearers.

Methods

Internal components of PAPR hoods and corrugated air supply hoses were swabbed for evidence of bacterial, fungal, common respiratory viruses and severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) contamination.

Results

Twenty-five PAPR hoods were swabbed; 10 (40%) returned positive results. Bacterial growth was detected on six PAPR; five of the PAPR tested positive for fungal growth; all tested negative for SARS-CoV-2 and common respiratory viruses.

Conclusions

Bacteria and fungi can remain on internal components of PAPR hoods and air supply hoses despite following recommended disinfection procedures. PAPR hoods have the potential to act as fomites, cross-infecting wearers, and patients. Current guidelines for disinfecting PAPR hoods may not be effective for use in high risk healthcare environments.

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.

Stability of SARS-CoV-2 on critical personal protective equipment

The spread of COVID-19 in healthcare settings is concerning, with healthcare workers representing a disproportionately high percentage of confirmed cases. Although SARS-CoV-2 virus has been found to persist on surfaces for a number of days, the extent and duration of fomites as a mode of transmission, particularly in healthcare settings, has not been fully characterized. To shed light on this critical matter, the present study provides the first comprehensive assessment of SARS-CoV-2 stability on experimentally contaminated personal protective equipment (PPE) widely used by healthcare workers and the general public. Persistence of viable virus was monitored over 21 days on eight different materials, including nitrile medical examination gloves, reinforced chemical resistant gloves, N-95 and N-100 particulate respirator masks, Tyvek, plastic, cotton, and stainless steel. Unlike previous reports, viable SARS-CoV-2 in the presence of a soil load persisted for up to 21 days on experimentally inoculated PPE, including materials from filtering facepiece respirators (N-95 and N-100 masks) and a plastic visor. Conversely, when applied to 100% cotton fabric, the virus underwent rapid degradation and became undetectable by TCID₅₀ assay within 24 h. These findings underline the importance of appropriate handling of contaminated PPE during and following use in high-risk settings and provide interesting insight into the potential utility of cotton in limiting COVID-19 transmission.

Stability of SARS-CoV-2 on critical personal protective equipment

The spread of COVID-19 in healthcare settings is concerning, with healthcare workers representing a disproportionately high percentage of confirmed cases. Although SARS-CoV-2 virus has been found to persist on surfaces for a number of days, the extent and duration of fomites as a mode of transmission, particularly in healthcare settings, has not been fully characterized. To shed light on this critical matter, the present study provides the first comprehensive assessment of SARS-CoV-2 stability on experimentally contaminated personal protective equipment (PPE) widely used by healthcare workers and the general public. Persistence of viable virus was monitored over 21 days on eight different materials, including nitrile medical examination gloves, reinforced chemical resistant gloves, N-95 and N-100 particulate respirator masks, Tyvek, plastic, cotton, and stainless steel. Unlike previous reports, viable SARS-CoV-2 in the presence of a soil load persisted for up to 21 days on experimentally inoculated PPE, including materials from filtering facepiece respirators (N-95 and N-100 masks) and a plastic visor. Conversely, when applied to 100% cotton fabric, the virus underwent rapid degradation and became undetectable by TCID₅₀ assay within 24 h. These findings underline the importance of appropriate handling of contaminated PPE during and following use in high-risk settings and provide interesting insight into the potential utility of cotton in limiting COVID-19 transmission.

Stability of SARS-CoV-2 on critical personal protective equipment

The spread of COVID-19 in healthcare settings is concerning, with healthcare workers representing a disproportionately high percentage of confirmed cases. Although SARS-CoV-2 virus has been found to persist on surfaces for a number of days, the extent and duration of fomites as a mode of transmission, particularly in healthcare settings, has not been fully characterized. To shed light on this critical matter, the present study provides the first comprehensive assessment of SARS-CoV-2 stability on experimentally contaminated personal protective equipment (PPE) widely used by healthcare workers and the general public. Persistence of viable virus was monitored over 21 days on eight different materials, including nitrile medical examination gloves, reinforced chemical resistant gloves, N-95 and N-100 particulate respirator masks, Tyvek, plastic, cotton, and stainless steel. Unlike previous reports, viable SARS-CoV-2 in the presence of a soil load persisted for up to 21 days on experimentally inoculated PPE, including materials from filtering facepiece respirators (N-95 and N-100 masks) and a plastic visor. Conversely, when applied to 100% cotton fabric, the virus underwent rapid degradation and became undetectable by TCID₅₀ assay within 24 h. These findings underline the importance of appropriate handling of contaminated PPE during and following use in high-risk settings and provide interesting insight into the potential utility of cotton in limiting COVID-19 transmission.

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.

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.

Exploring options for reprocessing of N95 Filtering Facepiece Respirators (N95-FFRs) amidst COVID-19 pandemic: A systematic review

BACKGROUND

There is global shortage of Personal Protective Equipment due to COVID-19 pandemic. N95 Filtering Facepiece Respirators (N95-FFRs) provide respiratory protection against respiratory pathogens including SARS-CoV-2. There is scant literature on reprocessing methods which can enable reuse of N95-FFRs.

AIM

We conducted this study to evaluate research done, prior to COVID-19 pandemic, on various decontamination methods for reprocessing of N95-FFRs.

METHODS

We searched 5 electronic databases (Pubmed, Google Scholar, Crossref, Ovid, ScienceDirect) and 1 Grey literature database (OpenGrey). We included original studies, published prior to year 2020, which had evaluated any decontamination method on FFRs. Studies had evaluated a reprocessing method against parameters namely physical changes, user acceptability, respirator fit, filter efficiency, microbicidal efficacy and presence of chemical residues post-reprocessing.

FINDINGS AND CONCLUSIONS

Overall, we found 7887 records amongst which 17 original research articles were finally included for qualitative analysis. Overall, 21 different types of decontamination or reprocessing methods for N95-FFRs were evaluated. Most commonly evaluated method for reprocessing of FFRs was Ultraviolet (Type-C) irradiation (UVGI) which was evaluated in 13/17 (76%) studies. We found published literature was scant on this topic despite warning signs of pandemic of a respiratory illness over the years. Promising technologies requiring expeditious evaluation are UVGI, Microwave generated steam (MGS) and based on Hydrogen peroxide vapor. Global presence of technologies, which have been given Emergency use authorisation for N95-FFR reprocessing, is extremely limited. Reprocessing of N95-FFRs by MGS should be considered for emergency implementation in resource limited settings to tackle shortage of N95-FFRs.

SYSTEMATIC REVIEW IDENTIFIER

PROSPERO, PROSPERO ID: CRD42020189684, (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020189684).

Cleaning and Disinfection Perceptions and Use Practices Among Elastomeric Respirator Users in Health care

BACKGROUND

Reusable elastomeric respirator use in health care may represent one solution to address N95 respirator shortages experienced during infectious disease outbreaks, but cleaning and disinfection requirements may limit their utility. Evidence of respirator cleaning and disinfection behaviors and practices by health care workers may inform guidance on reusable respirator use.

METHODS

Medical system elastomeric respirator users were surveyed about respirator cleaning and disinfection practices and perceptions via an electronic survey. Respondents were subsequently classified based on reported compliance with their assigned respirator use. To explore whether respirator cleaning and disinfection issues affected compliance with assigned device use, responses were compared between user groups and adjusted for covariates.

RESULTS

A total of 432 of 2,024 (21%) eligible elastomeric respirator users completed the survey. Most (>90%) reported that their respirator was clean, but only 52% reported that they always disinfect their respirators after use according to the hospital's expected practice. Only 40 respondents (9%) reported regularly cleaning the respirator with soap and water, in accordance with manufacturer recommendations. Reporting of suboptimal decontamination practice was not associated with assigned device compliance, however, except among providers and respiratory therapists.

CONCLUSION/APPLICATION TO PRACTICE

Although perceptions of cleanliness and adherence to expected decontamination practices during routine use did not appear to influence compliance with assigned respirator use overall, this did predict compliance among providers and respiratory therapists, both of whom have nonfixed workstations. Practical and effective strategies to assure easy access to and availability of clean reusable respiratory protective devices are needed to facilitate their use in health care respiratory protection programs.

Endoscopic Skull Base Surgery Protocol From the Frontlines: Transnasal Surgery During the COVID-19 Pandemic

Objective

The coronavirus disease 2019 (COVID-19) pandemic disrupted the standard management paradigms for care of patients with sinus and skull base presentations due to concern for patient and health care provider safety, given the high aerosol-generating potential of endonasal procedures.

Data Sources

We reviewed the relevant literature complied from available sources, including PubMed, Google Scholar, and otolaryngology journals providing electronic manuscripts ahead of indexing or publication.

Review Methods

Incorporating available evidence and the projected infection control and resource limitations at our institution, we collectively authored a dynamic set of protocols guiding (1) case stratification, (2) preoperative assessment, (3) operative setup, and (4) postoperative care of patients with sinus or skull base presentations. Due to the rapidly evolving nature of COVID-19 publications, lack of rigorous data, and urgent necessity of standardized protocols, strict inclusion and exclusion criteria were not employed.

Conclusions

As scarce hospital resources are diverted to COVID-19 care and staff are redeployed to forward-facing roles, endonasal procedures have largely ceased, leaving patients with ongoing sinonasal and skull base complaints untreated. Skull base teams now weigh the urgency of surgery in this population with the regional availability of resources.

Implications for Practice

The COVID-19 pandemic will have an enduring and unpredictable impact on hospital operations and surgical skull base practices and will require a dynamic set of management protocols responsive to new evidence and changing resources. In the current resource-limited environment, clinicians may utilize these protocols to assist with stratifying patients by acuity, performing preoperative assessment, and guiding peri- and postoperative care.

Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators

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Ultraviolet light can significantly reduce viable influenza on N95 respirators.

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Ultraviolet decontamination of N95 respirators can vary between models.

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Straps of N95 respirators are challenging to decontaminate using ultraviolet light.

Background

Safe and effective decontamination and reuse of N95 filtering facepiece respirators (FFRs) has the potential to significantly extend FFR holdings, mitigating a potential shortage due to an influenza pandemic or other pandemic events. Ultraviolet germicidal irradiation (UVGI) has been shown to be effective for decontaminating influenza-contaminated FFRs. This study aims to build on past research by evaluating the UVGI decontamination efficiency of influenza-contaminated FFRs in the presence of soiling agents using an optimized UVGI dose.

Methods

Twelve samples each of 15 N95 FFR models were contaminated with H1N1 influenza (facepiece and strap), then covered with a soiling agent—artificial saliva or artificial skin oil. For each soiling agent, 3 contaminated FFRs were treated with 1 J/cm² UVGI for approximately 1 minute, whereas 3 other contaminated FFRs remained untreated. All contaminated surfaces were cut out and virus extracted. Viable influenza was quantified using a median tissue culture infectious dose assay.

Results

Significant reductions (≥3 log) in influenza viability for both soiling conditions were observed on facepieces from 12 of 15 FFR models and straps from 7 of 15 FFR models.

Conclusions

These data suggest that FFR decontamination and reuse using UVGI can be effective. Implementation of a UVGI method will require careful consideration of FFR model, material type, and design.