Introduction

• The COVID-19 pandemic has led to current or impending shortages of personal protective equipment (PPE), including masks and face shields, among other items

• Different types of PPE have been investigated for their potential to protect wearers from exposure to aerosolized particulates

• PPE shortages have led to investigation of strategies to extend use, reuse, and decontaminate PPE

• This scoping review aims to compile existing evidence on the use and efficacy of various forms of facial protection (surgical masks, face shields, N95 respirators, improvised masks, and others) for healthcare workers amidst the growing global shortage

Methods

This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews reporting standards. Included records needed to focus on the following criteria: transmission or prevention of SARS and other respiratory illnesses; strategies for extended use, reuse and decontamination of medical-grade masks; or the efficacy and safety of alternative and improvised masks with regard to materials, design and decontamination strategies. Record searches limited to those published or most recently updated between January 1, 2000 and March 24, 2020, and records were included if published in English language and discussed COVID-19 transmission prevention or PPE use.

• Peer-reviewed documents were identified using MEDLINE via PubMed database

• Grey literature (such as preprint publications, guidelines, product descriptions, and others) were also included; reviewed by at least one author and records selected if eligibility criteria were met

• Records with relevant English-language titles were selected; records selected if available in English and focused on the criteria described above

• Systematic reviews and meta-analyses excluded, as well as articles not applicable to healthcare settings, dealing with product design at the industrial level, or not including N95 respirators, surgical masks, or face shields

• Each record tagged by focus

• Records grouped by topic and setting, and the study designs, measures used, and broad findings were summarized when possible

Results

A total of 5462 peer-reviewed articles were retrieved, 269 of these accessed in full text, and 48 met the inclusion criteria; 41 grey literature sources identified, and 19 met inclusion criteria; total of 67 records included

Medical-grade facial protection:

• Laboratory/controlled settings:

  • N95 respirators demonstrate efficient filtration of nanoparticles and bioaerosols, with superior protection against aerosols and viruses similar in size to influenza compared to surgical masks, especially when paired with eye protection

  • Isolated surgical mask material protects against >95% of viral aerosols under laboratory conditions, and surgical masks reduce aerosolized influenza exposure by an average of sixfold

  • Ensuring fit of N95 respirators enhances their protection

  • Face shields may be used as adjunct PPE with facial protection and goggles; face shields may limit risk of inhalational exposure immediately following aerosol production but do not offer suitable protection on their own

• Inpatient settings:

  • Studies offer conflicting evidence of the effectiveness of N95 respirators compared to surgical masks in limiting viral exposure and infection, where some studies indicate that N95 respirator use yields lower respiratory infection rates than use of surgical masks, while another study indicates non-inferior rates of influenza when using surgical masks compared to using N95 respirators

  • The safety and effectiveness of N95 respirator extended use are unclear. One study demonstrates the fit factor of N95 respirators decreases after 5 consecutive donnings, and another record states that N95 respirators maintain function for 8 hours of continuous or intermittent use. Manufacturer recommendations indicate that N95 masks should be disposed of following close contact with patient with an infectious disease, after use during an aerosol-generating procedure, or when contaminated with bodily fluids

• Outpatient settings:

  • Minimal evidence is available, but one randomized controlled trial (RCT) conducted in the outpatient setting found no difference in respiratory infection rates between those wearing surgical masks compared to those wearing N95 respirators

• N95 respirator decontamination procedures:

  • Decontamination methods must effectively decontaminate the item of pathogens while not compromising the item’s filtering and protective capabilities

  • Methods using microwave irradiation, microwave-generated steam and moist heat incubation can compromise the item’s physical integrity

  • Treatment with bleach results in residual odor, release of chlorine gas on exposure to moisture and, in one model, partial nose pad dissolution without an associated increase in aerosol penetration

  • Decontamination with hydrogen peroxide gas plasma, autoclave, 160°C dry heat, 70% isopropyl alcohol and soaking in soap and water may cause significant loss of filtration efficiency

  • Application of chlorine and alcohol-based methods led to a significant decrease in the efficiency of N95 filtration media due to loss of microfiber static charge, while use of ultraviolet light, boiling water vapor and dry oven heating maintained filtration efficiency and successfully decontaminated N95 respirators

  • Although ultraviolet germicidal irradiation (UVGI) has previously been shown to inactivate SARS-CoV-1 and preserve N95 performance after three cycles of exposure (totalling 45min at 1.8mW/cm2), one study found that increasing UVGI doses could compromise the strength of N95 respirator material and straps

  • Overall, strategies involving the use of UVGI, ethylene oxide, dry oven heating and hydrogen peroxide vapor may be most promising for preservation of mask function and integrity

  • Additional research is required

Improvised Masks:

• Overall:

  • One RCT found significantly higher incidence of respiratory illness with use of two-layer, cotton cloth masks compared to use of surgical masks (relative risk=13.00, 95%CI 1.69 to 100.07)

  • One laboratory study found that cloth masks offered inferior protection to surgical masks and respirators but were superior to no masks in decreasing exposure and infection risk

  • Cloth masks may increase infection risk in hospital workers for several reasons, trapping of moisture, reuse, and the requirement for cleaning

  • Peripheral air leakage may decrease their protection, but air leakage may be limited by employing additional features to improve facial fit (such as the use of nylon hosiery)

  • Some household items may offer protection against nanosized particles, including 70% cotton/30% polyester sweatshirt material

  • One study found that tea towels and a cotton blend fabric captured 0.02 μm particles with respective effectiveness of 73% and 70%, while the scarves tested were shown to be less than 50% effective; this study concluded that pillowcases and 100% cotton T-shirts (T-shirt preferred for potential for superior fit compared to pillowcase) were the best readily available household options for improvised masks

  • The use of surgical sterilization wrap has been proposed, but data on its use in masks or its protection capability against respiratory viruses was not found during the course of this review

• Addition of layers/filters:

  • Little data is available on the effectiveness of adding a filter to a two-layer mask

  • It is important to consider durability, breathability and the need for replacement in selection of filter material

  • Use of heating, ventilation and air conditioner filter inserts has been proposed but cost is likely prohibitive

  • A news report from South Korea mentions an innovative washable electrostatic cotton which can serve as a more durable, insertable filter

  • Further research in these areas is required

• Reuse and decontamination of improvised masks:

  • No literature identified regarding reuse and decontamination of improvised masks

Discussion

• Evidence supports the superiority of medical-grade masks for protection against respiratory viruses

• Improvised masks of certain materials offer better protection than no mask at all, while little evidence regarding best material and design is available

• Additional research regarding safety and effectiveness of improvised masks is needed, particularly the use of and best material for a filter added to a two-layer improvised mask compared to no added filter

• Research regarding development of effective and safe decontamination methods that do not compromise the physical integrity or filtration capabilities of facial protection is needed

• Limitations:

  • Included literature limited in scope, design, sample size, and population diversity

  • Review limited to records published in English language

  • Studies on SARS-CoV-2 have been performed in settings experiencing the early phases of the pandemic, which does not lend easily to standardized RCTs or uniform study planning and execution

Conclusions

• Alternative forms of facial protection are less effective, but may serve as an intermediary in emergent situations

• Based on the literature, the safest approach to address this shortage is to ensure provision of a sufficient quantity of medical-grade facial protection for healthcare workers

• Reused and improvised masks should be used as a last resort, but may be beneficial when medical-grade facial protection is unavailable. Face shields should not be used as primary protection, but rather as an adjunct to improvised masks

• Continued research in these areas is necessary

Introduction

• Face shields in combination with additional PPE including mouth/nose mask and/or goggles) has been shown to reduce risk of inhalational exposure to COVID-19, especially when performing activities with aerosol formation

• Face shields are used as an adjunctive PPE in combination with other types of PPE

• The World Health Organization has appealed for an increase in face shield production, and use of face shields is recommended for high-risk HCWs

• Face shields made from safe materials are exempt from FDA Pre-Market Notification and may be 3-D printed by individuals, organizations, or manufacturers

• This study evaluates the utilization of 3-D printers normally used for dental purposes in producing face shields from open source data and investigates their clinical suitability

Materials and Methods

• Four selected face shield frame models:

  • RC1 (Prusa Research, Holešovice, Czech Republic, https://www.prusa3d.com/covid19)

  • RC2 (Prusa Research, Holešovice, Czech Republic)

  • Budmen V3 (3D Face Shield V3, Budmen Industries, Philadelphia, PA, USA, https://budmen.com/)

  • Easy 3D (Easy 3D printed Face Shield, Hanoch Hemmerich, La Laguna, Tenerife, Spain, https://www.thingiverse.com/thing:4233193)

• Each face shield model may be 3-D printed using biodegradable material (DIN EN ISO 14855) as a filament for printing on a powder-coated printing bed; each face mask was printed individually

• Each face shield was completed by adding a 0.1 mm thick PET transparent laser foil to the 3-D printed frame

• The filament weight, total weight, printing time, and the necessary tools for assembling the framework were determined from the open-source STL model data

• For clinical assessment, 10 dental clinicians and/or intensive care nurses wore each of the four face shields for one hour per face shield type while performing patient care

• Clinical parameters of fit, cocomfort, space (for additional PPE behind shield), protection (sealing and coverage area), and overall evaluation were rated on a visual analogue scale and statistical analysis performed using software IBM SPSS Statistics, ver. 22.0, IBM Corp, Armonk, NY, US

Results

Clinical Assessment:

• Fit (contact of headframe with forehead) rated significantly better for RC1 and RC2 than Budmen V3 and Easy 3D

• Easy 3D and RC2 displayed highest wearing comfort compared to RC1 and Budmen V3

• Additional space for PPE rated highest for RC2, no difference between Budmen V3 and Easy 3D, and lowest for RC1

• Protection rated highest for Easy 3D, followed by RC1 and RC2, all followed by Budmen V3

• For overall evaluation, Easy 3D and RC2 received significantly higher scores than RC1 and Budmen V3

RC1 Type Face Shield

• Advantages:

  • Printing possible without support structures

  • Spacing of foil attachment points match standard foil perforator spacing

  • Additional reinforcement piece available to print

• Drawbacks:

  • Extra step required to make perforations for foil

  • May detach from print bed during printing

  • Clamp fit uncomfortable when work for extended time

  • Limited space for additional PPE such as goggles/mask

  • Open space between headframe and visor attachment leaves gap of protection from aerosol

RC2 Type Face Shield

• Advantages:

  • Printing possible without support structures

  • Spacing of foil attachment points match standard foil perforator spacing

  • Additional reinforcement piece available to print

  • No clamp fit headframe increases comfort compared to RC1

  • Adequate space for additional PPE such as goggles/mask

• Drawbacks:

  • Extra step required to make perforations for foil

  • May detach from print bed during printing

  • Less lateral protection when using DIN A4 foils

  • Heavier weight

  • Open space between headframe and visor attachment leaves gap of protection from aerosol

Budmen V3 Type Face Shield

• Advantages:

  • Simplified geometry minimizes print failure risk and print time

  • Space for additional PPE comparable to RC2

  • Greater protection from above and laterally

• Drawbacks:

  • Extra step required to make perforations for foil

  • Rigid headband prevents completely intimate adaptation to forehead

  • Rigidity reduces comfort compared to RC2

Easy 3D

• Advantages:

  • Detachment during printing is unlikely and print time is minimized

  • No perforations required

  • Foil may be changed easily

  • Comfortable to wear

  • Adequate space for additional PPE

  • Headframe fits snugly and foil extends laterally for better overhead and lateral coverage

• Drawbacks:

  • Visor slot is narrow and may not print well at higher speeds or may be prone to breaking

Discussion

• Fused deposition modeling (FDM) preferred for manufacturing for faster print times, less post-print processing, and greater durability

• Prusa i3 MKS3 printer used to print sample face shield frames is suitable for all face shield models assessed

• Lignin-based filament material (DIN EN ISO 14855) is biodegradable and does not change in volume during sterilization procedures, unlike other filaments that may potentially be used

• Easy 3D face shield does not require additional perforation step, has sufficient space for additional PPE, and has best lateral protection of all masks, though even it does not meet recommendation of foil extending to ear

• Printing of RC2 may be stacked to print a sequence of 4 stacked face shields for overnight orienting, but Easy 3D must be printed one at a time, so stackable RC2 (known as RC3) is recommended for mass production in non-industrial environments

• Other foil types and sizes may be tested in the future to achieve better coverage

• Face shields should not be used as solitary face/eye protection but rather in addition to PPE such as mask and goggles

Conclusions

• Easy 3D face shield shown most effective, but lacks scalability potential

• RC2 recommended when large-scale production is a priority

Introduction

The COVID-19 pandemic has led to shortages of personal protective equipment, including disposable N95 masks, across the globe. To alleviate this shortage, N95 masks could be sterilized and reused, where sterilization methods must not degrade the filtration efficiency of the mask. This study investigates cobalt-60 gamma irradiation as a method of N95 mask sterilization, as gamma radiation of 10 kGy may inactivate SARS-CoV-2 but may also damage the crosslinking of N95 polymer material and reduce its filtering efficiency.

Methods

This study was performed as part of hospital infections control at Massachusetts General Hospital in partnership with the Massachusetts Institute of Technology.

• Sets of 3 masks of each type (3M 8210, 1805, 9105 types) were irradiated using a cobalt-60 irradiator at 0 kGy (control), 1 kGy, 10 kGy, and 50 kGy of approximately 1.3 MeV gamma radiation at a dose rate of 2.2 kGy/hr

• One set of control and irradiated masks were subjected to the Occupational Safety and Health Administration Gerson Qualitative Fit Test 50

• Another set of control and irradiated masks underwent particulate single-pass filtration efficiency testing (using 0.3, 0.5, and 1 μm particulates) to assess for relative changes in filtration efficiency

• Statistical analyses performed using R statistical software version 3.6.3

Results

• Nine of the tested control and irradiated masks passed the qualitative fit test

• However, the single-pass filtration study found statistically significant degradation of filtration efficiency for all treated masks compared to control masks

• No statistically significant difference in filtration efficiency for treated masks comparing different levels of irradiation

• Filtration efficiency of irradiated masks for 1 μm particles was greater than for 0.5 μm particles, which was in turn greater than filtration efficiency for 0.3 μm particles

Discussion

Limitations:

• The test used to assess filtration efficiency is not approved by the National Institute for Occupational Safety and Health

• Filtration of particulate matter smaller than 0.3 μm not studied

• Number and types of masks tested limited by current shortage

Key Points:

• A qualitative fit test alone is unable to fully assess mask integrity

• At the doses required for sterilization, gamma radiation degrades the filtration efficiency of N95 masks

Objective

This Concise Communication seeks to promote the investigation of ultraviolet germicidal irradiation for decontamination of disposable particulate filtering facepiece respirators during the COVID-19 pandemic.

Background

The COVID-19 pandemic has created demand for disposable particulate filtering facepiece respirators (FFRs) such as N95 respirators. CDC guidelines for optimizing supply stocks through limited use, reuse, and alternative PPE may increase the risk of SARS-CoV-2 infection in healthcare workers from FFR contamination.

FFR mask sterilization using ultraviolet germicidal irradiation

• Decontamination must not compromise filtration capacity or structural integrity

• Testing of several N95 mask types demonstrate that they should withstand sterilization by ultraviolet germicidal irradiation (UVGI) and other methods

• UVGI also demonstrates significant reduction of influenza virus contamination of N95 FFRs, even with mucin or sebum soiling

• UVGI demonstrated efficacy in destroying the original SARS-CoV in viral culture media

Recommendations

Use of UVGI for FFR sterilization

• Wide variety of UVGI sterilization technologies and facilities are currently in use for other purposes

• Such devices may be calibrated to deliver proper dose of radiation to decontaminate N95 FFRs

• Smaller UVGI units may be suitable for small facilities or point-of-care use, with appropriate oversight

• Such decontamination could allow for single-user use of an assigned individual FFR mask that is regularly decontaminated to help prevent pathogen transmission between users

Key Points

• Further work needed to determine dose of UVGI required to sterilize SARS-CoV-2 contaminated FFRs

• UVGI has potential to expand limited FFR supply in a simple, cost-effective, and readily deployable manner

• Hospitals and healthcare facilities should implement collection programs for FFRs in anticipation of near-future sterilization and reuse programs

Variation of PPE

• powered air-purifying respirator (PAPR): reusable and protective against aerosol-generating medical procedures

• N95 respirators: single use (currently being reused due to storages)

Global vs local guidelines

• PPE guidelines vary internationally based on disease prevalence, testing and resources

• Impossibility to practice the globally social distancing at the hospital or other healthcare settings such as nursing homes leading to increased HCP exposure

• Rapid emergence of data and information = HCP should be up- to date with current guidelines

• Robust basic IPC guidelines and international collaboration needed to protect HCPs in individualized subspecialties or healthcare settings

Cutaneous Complications of COVID-19

In the setting of COVID-19, healthcare workers have increased personal protective equipment requirements and consequently the largest risk of complications. The filtering face piece respirator (FFP), required for aerosol generating procedures, has been linked to skin problems. Current literature advocates for the use of a skin protectant and regular breaks when wearing a FFP to allow for pressure and humidity relief. The current article hypothesizes that reported cutaneous complications are due to PPE induced hyperhidrosis, friction, epidermal breakdown, pressure urticaria, and contact dermatoses.

Case Report

Two female nurses working within the same surgical unit in the United Kingdom reported similar cutaneous eruption following a single uninterrupted 4.5-hour use of FFP. Symptoms upon removal of the mask included mild erythema and pain that progressed overnight. Crops of pustules were evident on the nasal bridge, sidewall, and ala that were clinically consistent with localized miliaria. Two weeks later, there was noted post-inflammatory hyperpigmentation and residual scaling.

Discussion

Miliaria, also known as heat rash, is a disorder of eccrine glands due to obstruction and retention of sweat. The three subtypes include: miliaria crystalline (typically on the face and trunk), miliaria rubra/pustulosa (most common, typically on the back), and miliaria profunda (rare, typically on trunk and extremities). To the authors’ knowledge, this is the first report of localized facial miliaria due to FFP use.

Summary

A study measuring viral detection in respiratory droplets and aerosols of patients infected with rhinovirus, influenza viruses, and coronavirus was performed to determine efficacy of surgical mask use by infected individuals.

Methods

246 participants were randomized into two groups - one group did not wear a surgical mask during the first exhaled breath collection while the other group wore a mask. Participants underwent RT-PCR to assess whether they were infected with a respiratory virus. Subsequently, viral RNA was measured in the exhaled breaths of participants in both groups.

Results

1. • 1. Infection Rate: 50% of participants were confirmed with a respiratory virus infection. 90% of infected patients were diagnosed with either human (seasonal) coronavirus, influenza viruses or rhinovirus, with three cases of coinfection with two of the three viruses. Viral shedding (viral copies per sample) was tested via nasal swabs, throat swabs, respiratory droplet samples, and aerosol samples. This data was compared between both groups.

     2. Clinical Presentation: Coronavirus patients coughed the most, averaging 17 coughs during the 30 minute exhaled breath collection. Influenza patients were twice as likely to exhibit a fever greater than 37.8’C than patients with coronavirus or rhinovirus.

     3. Testing: Viral shedding was higher in nasal swabs than throat swabs for coronavirus and rhinovirus.

     4. “Face mask” group versus “No face mask” group: Viral RNA was identified from respiratory droplets and aerosols for all three viruses in groups not wearing face masks. For coronavirus, OC43 and HKU1 were identified from both respiratory droplets and aerosols, but NL63 was only identified from aerosols.

        1. Coronavirus: For groups not wearing face masks, coronavirus was detected in 30% of samples obtained from respiratory droplets, and in 40% of samples obtained from aerosols. In contrast, the virus was not detected in respiratory droplets or aerosols from the samples obtained from the facemask wearing group.

        2. Influenza: For groups not wearing face masks, influenza was detected in 26% of samples obtained from respiratory droplets and 35% of samples obtained from aerosols. In the facemask wearing group, only 4% (n=1) of samples were positive for the virus in respiratory droplets and none in aerosols.

        3. Rhinovirus: There was no significant difference in detection between the two groups.

Limitations

A large proportion of study participants exhibited undetectable viral shedding in their exhaled breaths for all three viruses.

Significance

The trials demonstrated that surgical face masks can effectively reduce the emission of influenza virus in respiratory droplets, but not in aerosols. In contrast, the use of facemasks reduced the emission of coronavirus in both respiratory droplets and aerosols. This suggests that surgical masks should be utilized by infected individuals to curb the transmission of coronaviruses.

This perspective reviews scientific evidence behind universal public masking based on 4 considerations

1. SARS-CoV-2 is highly contagious

   • At the time of writing, there was an excess of 1.8 million COVID-19 cases

2. Increasing evidence that SARS-CoV-2 has viral shedding from asymptomatic or presymptomatic people

   • Research papers have shown that SARS-CoV-2 displays high rates of viral shedding in the upper respiratory tract even in paucisymptomatic individuals

   • Data from the Diamond Princess cruise ship suggest that up to 18% of cases were asymptomatic despite having detectable SARS-CoV-2 RNA in the nasopharynx or oropharynx

   • Analysis of presymptomatic and symptomatic patients demonstrated high viral loads and viable virus was isolated in culture before and after the onset of symptoms.

   • The degree of transmissibility from asymptomatic individuals is the most compelling argument for universal pubic masking

3. Evidence from Asian countries that incorporated universal masking and are having receding epidemics

   • Universal public masking was adopted in Singapore, South Korea, Hong Kong, Thailand and Taiwan.

4. The potential contribution of masking to facilitate selective return-to-work policies

   • Taiwan has maintained control of the epidemic with universal public masking without having to close schools or work.

   • The United States economy has been devastated by the closure of work and requiring universal masks would allow people to return to work and provide relief for the economy.

Process

A process for N95 respirator decontamination was outlined by the Barnes Jewish Hospital, Washington University School of Medicine, and the BJC Healthcare system for N95 respirator collection and decontamination. Healthcare providers submit their N95 respirator by placing it into a labelled Tyvek pouch, which is placed in a soiled collection bin. Tyvek pouches were selected over paper bags because paper bags absorbed more H₂O₂ and required longer time for off-gassing. Bins are collected every twelve hours and transported to the vaporized hydrogen peroxide (VHP) room, which has been appropriately modified to prevent VHP absorption and leakage. The room contains wire racks, upon which the Tyvek pouches are placed as well as the Bioquell Z-2, two Bioquell aeration units, and a fan. The Bioquell Z-2 disinfection cycle consisting of condition, gassing, dwelling, and aeration of H₂O₂ lasts 4.5 hours, reaching 700 ppm of VHP. After the cycle is completed, the shelving racks containing the Tyvek pouches are moved to an aeration room once the decontamination room reaches H₂O₂ levels under 1ppm. A sensor inserted into a randomly selected Tyvek pouch determines when the Tyvek pouches can be removed from the aeration room (once H₂O₂ reading is at 0 ppm). Tyvek pouches are replaced into clean bins and redistributed throughout the hospital for pick up by healthcare providers. The entire process from pick up to drop-off has a turnaround time of under 24 hours.

Other Considerations

Tyvek pouches were tested with placement on the racks in both tight and loose configurations. Both configurations demonstrated successful disinfection as well as passed N95 respirator fit testing. Additionally, it was determined that placing the Tyvek pouches in a flat position increased surface area exposure to the VHP relative to standing the pouches, albeit less N95 respirators could be decontaminated in the flat position during a cycle. In this orientation, each cycle can disinfect about 1500 Tyvek pouches.

Summary

The Stryker Flyte helmet was modified by attaching a 3D printed manifold to the site previously occupied by the fan cover. Two PALL BB50T breathing circuit filters were attached to the manifold. Anesthesia tubing was attached with a standard Hudson multiadapter. It was noted that special care is necessary in properly donning the helmet to ensure an adequate seal. Safety testing was conducted to determine CO₂ accumulation and particle flow testing determined that the system met HEPA standards. Production of manifolds is ongoing as implementation within other hospitals within Duke’s health system continues. Please refer to the article for photos and illustrations.

Summary

A study was conducted to determine the efficacy of UV-C light on N95 respirator decontamination when applied through a low-pressure room decontamination device versus a UV-C box. Additionally, the efficacy of a high-level disinfection cabinet for N95 respirator decontamination was also assessed.

Methods

Several bacterial and fungal organisms as well as bacteriophages Phi6 and MS2 were subjected to 90-second or 180-second cycles of UV-C through a modified version of the American Society for Testing and Materials standard quantitative carrier disk test method. Additionally, three N95 respirator types (3M 1860S, Moldex 1517, and Kimberly-Clark 46727) were contaminated with a MRSA test strain and bacteriophages MS2 and Phi6. The respirators were placed inside a UV-C box, containing a lamp above and below the respirator, for a 60-second cycle. Finally, the Moldex 1517 was subjected to further testing, by positioning the respirator three feet from a low pressure mercury UV room decontamination device for two 15 minute cycles, facing the respirator interior and then the respirator exterior, respectively. All N95 respirators were subsequently subjected to viable organism quantification procedures, and then compared to untreated control respirators.

Results

• • Efficacy of High-Level Disinfection Cabinet:

    • On steel disk carriers: The cabinet eliminated >5log₁₀ PFU of c. auris, c. difficile spores, MRSA, bacteriophage MS2.

    • For N95 Respirators: The cabinet demonstrated reductions of >2.1log₁₀ or greater with a single cycle. With three cycles, the cabinet demonstrated reductions of >6og_10.

  • Efficacy of UV-C light

    • On steel disk carriers: Bacteriophage MS2 and Phi6 were less susceptible to UV-C than NDM1 escherichia coli, MRSA, klebsiella pneumoniae, vancomycin resistant enterococcus faecium, and acinetobacter baumanii, but less susceptible than candida auris, candida albicans, clostridioides difficile spores, and baccillus subtillus spores.

    • For N95 respirators: Reductions in MRSA were greater than reductions of bacteriophage MS2 or Phi6. Differences in reduction across masks were statistically significant, with the 3M 1860s N95 respirator demonstrating lower reduction than the other respirators. Reductions were also lower on the interior surface of the respirators than the exterior surface for all respirators.

  • Comparison of the low-pressure room decontamination device versus UV-C box: Greater reductions were observed using the longer UV-C cycles of the low-pressure room decontamination device than the shorter cycles of the UV-C box. No visible changes were observed on the respirators after being subjected to three or more treatment cycles via the decontamination device or the UV-C box.

Limitations

• • Respirator integrity was not quantitatively measured after being subjected to decontamination methods.

  • Test organisms were directly placed on the surface of the respirators rather than applied through a method that mimics aerosol deposition. The test organisms were spread over a very small surface area. The study cited prior studies reporting that organism inoculation over a larger surface area increases UV-C efficacy.

Background

Due to the 2019 coronavirus outbreak (COVID-19), there is currently a high demand for disposable surgical masks and no established method for self-sterilization. While steam sterilization is often used, masks often have a low melting point and thus present a challenge. Resulting high economic and environmental costs of single use masks are damaging societies across the world. The present study reports a novel method for functionalizing commercially available surgical masks with self-cleaning and photothermal properties.

Introduction to Superhydrophobic States

Surfaces in a superhydrophobic state possess self-cleaning capabilities. Masks made with polymer fibers are smooth at the nanoscale and thus do not have superhydrophobic properties. While superhydrophobic coatings have been developed utilizing fluorinated polymers, metal nanowires, and graphene, there are no reports regarding the use of these coatings on surgical masks.

Method for Producing Superhydrophobic Surgical Masks

Functional graphene can be produced via laser-induced graphene at low cost using commercially available precursors. The near-infrared laser beam can be precisely controlled to generate superhydrophobic and superhydrophilic surfaces on opposite sides of the polyimide. The resulting membrane shows excellent superhydrophobic and photothermal properties with 99.9% higher bactericidal performance toward drug-resistant E. coli compared to the glass substrate control sample. While application to modern surgical masks is possible, nonwoven masks prove challenging due to the low melting point of the polymer fibers. Therefore, a dual-mode laser-induced forward transfer process has been developed to add the laser-induced graphene to commercial surgical masks as a superhydrophobic and photothermal porous coating. The mask then contains self-cleaning properties and has the ability to withstand both solar illumination and solar desalination for sterilization.

Applications and Future Directions

At sufficiently low temperatures, laser-induced graphene can be coated onto a surgical mask without damaging its surfaces. This method can be easily integrated within existing automatic mask manufacturing production lines and may even serve a purpose once the virus is eradicated. Due to the outstanding photothermal and porous properties of the graphene-coating, masks may be directly used as solar steam generators. However, the evaporation performance of these masks can be improved upon by incorporating other functional materials and requires further study.

Summary

The study demonstrates the potential use of rice cooker-steamers as tools for accessible, efficient, and effective decontamination of masks.

Method

Cotton, quilting fabric cloth masks, surgical masks, and N95 respirators were inoculated with MRSA and a nonenveloped, single-stranded RNA virus bacteriophage MS2. These masks were subsequently subjected to a cycle of treatment in a steamer for 13-15 minutes; this process entails 8-10 minutes of heating and 5 minutes of steaming. Viable organisms were then quantified and the data was compared to masks that had not undergone decontamination efforts as well as masks which had undergone dry heat contamination in an oven at 100°C for 15 minutes.

Results

• • No visible changes were observed in the masks after 5 cycles of decontamination.

  • Steamed masks demonstrated a 5log₁₀ reduction in viable organisms. Dry heat treated masks only showed a 3log₁₀ reduction in viable organisms.

Limitations

Effect of treatment on mask integrity was not studied.

Significance

This data is consistent with previous data that moist heat or microwave-generated steam is more effective than dry heat for virus inactivation. This process also offers an easily accessible method for decontamination in a short period of time.

Background

Due to the 2019-2020 SARS-CoV-2 outbreak, the use of cloth masks has become increasingly prevalent. However, there is limited data available regarding the filtration efficacy of common cloth materials that are used to make homemade face masks. The current paper reports the filtration efficiencies of a number of common fabrics, including cotton and silk, as a function of aerosol sizes ranging from approximately 10nm to 6µm to simulate potential respiratory particle sizes. While physical barriers are sufficient to limit spread of larger droplets, they are ineffective for aerosol particles that remain suspended in the air. As a result, understanding the filtration capabilities of different fabric fibers is paramount.

Previous Research

Existing literature reports upon the use of cloth masks during the Influenza Pandemic of 2009, but does not address the performance of different fabrics as a function of particle size or address the potential benefits of a hybrid multilayer mask.

Methods

15 different fabrics were tested and compared to N95 respirator and surgical masks. In addition, the efficacy of multiple layers of a single fabric or a combination of multiple fabrics for hybrid cloth masks was tested. The experimental apparatus used was composed of an aerosol generation and mixing chamber with a downstream collection chamber. The aerosol particles were produced utilizing commercial sodium chloride and their size was measured with two different particle analyzers. Air was generated by a fan upstream of the fabric sample and the differential pressure and velocities between the upstream and downstream chambers were measured. Airflow was adjusted to represent either a resting or moderately exerted respiratory rate. Filtration efficiency was then determined by the difference in concentration of particles upstream versus downstream.

Results

Four layers of silk were found to have the highest filtration efficiency across the entire range of particle sizes, followed by one layer of chiffon then one layer of flannel. Cotton, the most common homemade mask fabric, was found to have increased filtration capability at higher weave density or thread count. However, filtration efficiency dropped by more than 60% with improper fit of the mask.

Guidance for Selecting Fabric for Homemade Masks

This study finds that fabric with tight weaves and low porosity, like that found in cotton sheets with high thread count, are preferable. Natural silk, chiffon weave, and flannel provide electrostatic filtering of particles with additional protection provided with additional layers of fabric. In particular, combining high thread count cotton with two layers of natural silk or chiffon may be most effective. However, the current suggested filtration efficiency assumes a perfect fit. Therefore, it is critically important that cloth mask designs also maximize fit to minimize air leakage, which significantly reduces mask effectiveness.

Summary

The public perceives that “simple” medical masks or improvised face coverings are ineffective against COVID-19, as well as burdensome and unattractive. But there is scientific rationale for asking the public to wear these.

• These masks (improvised and simple medical masks) directly capture exhaled aerosols and particles by surface adhesion.

  • Two recent studies showed that cytokines were detected on the inside of all the masks studied, confirming that the residues were of human origin and not from contamination.

  • The analyses were conducted long after the aerosols had dried. Thus, it's reasonable to conclude that aerosol content remains on surfaces even after the wet layer has evaporated.

  • These studies indicate that the proximity of the surface of the masks to the humid exhaled breath and the kinetic properties of the aerosols, lead the particles to “crash” into these surfaces.

  • These masks may not protect the wearer from inhaling external contaminants, but it may reduce the viral load exhaled from an asymptomatic person. Without daily testing, nobody can be certain that they are not an asymptomatic disease vector.

Caveats

• Wearing masks or improvised facial covers should not replace social distancing. The masks serve to protect others from the wearers aerosols, not to protect the wearer.

• The use of these masks has a valid scientific rationale for reducing the transmission of exhaled aerosols but how much is removed will require specific testing.

Summary

The use of N95 respirators for more than 4-6 hours can lead to pressure sore on the nose bridge.

This brings intense discomfort to the user and continuous use of masks could make sore more serious.

• Hydrocolloid dressing: often used to prevent and cure pressure sore by applying it to skin before the mask.

  • But strong adhesiveness aggravates pressure sore when removing the dressing.

• Improved method: using Benzalkonium Chloride patch on the pressure sore first and then hydrocolloid dressing second.

  • The adhesive is only on the lateral portions of the Benzalkonium Chloride patch, allowing the central non-adhesive part to provide protection to pressure sore due to decompressing effect.

The above improved method is only an expedient measure, and improvement on protective masks would be meaningful for future epidemics.

Summary

Reactions causes by non-glove PPE

• N95 Respirators

  • Acne - most prevalent

  • Irritant/contact facial dermatitis - often present with pruritic skin lesions

  • Pigmentation of nasal bridge, cheeks and chin

• Goggles

  • Skin reaction on nasal bridge

  • Irritant/contact dermatitis

  • Frictional erosions

  • Pressure injury

  • Heat stress

  • Dehydration

• Gowns:

  • Heat stress

  • Dehydration

  • Skin dermatose - especially in areas where gown adhere tightly to the skin

Conclusion

Avoiding tight gowns and sufficient ingestion of liquids are very important for health care workers to balance self-protection and the ability to care for patients efficiently. Application of topical moisturizers or lubricants can also help reduce irritation and friction from PPE

Purpose

1. Share the innovations of nurses that have helped during the COVID-19 pandemic

2. Encourage other nurses to share on social media the innovations that have worked in their hospital

Reduce unnecessary use of PPE

• Designating an RN to be a “runner”

  • This “runner” is not in an isolation room. It allows a nurse to stay in a COVID-19 room without the need to doff PPE to retrieve supplies/medications

• Videoconferencing and digital stethoscopes

  • Allows staff to assess patient without being in the room

• Relocating equipment (IV pumps,ventilator control panel) to outside the room

  • Reduces number of times RN needs to go inside the room with PPE

  • Urinary catheter stabilization device was repurposed to secure IV tubing to prevent a trip hazard and prevent tubing from occluding

Reduce foot traffic

• Makeshift breakroom

  • Decreased the need for staff to leave the ward

  • Helped promote staff wellness by creating a safe place to relax

• One floor of the hospital with zero patients and wider hallways was designated as the route to transport COVID-19 patients.

Staff safety

• Had a dedicated person to observe doffing

  • Helped monitor for accidental exposure risk

• Tape was placed inside the patient's room at 6 feet from bed to designate where initial doffing took place

• With help from engineering, the nurses station ventilation was adjusted to increase positive pressure, and patients rooms became negative pressure.

Summary

There is no convincing evidence that hand hygiene is effective in the SARS-CoV-2 epidemic. There is evidence that hand hygiene can reduce respiratory diseases, however it has not been proven that it can reduce SARS-CoV-2 transmission.

• In a 2009 study to determine the value of hand hygiene for influenza or influenza-like illnesses, it found “hand washing habits were the same in both face mask-only and control groups”. Suggesting mask use alone may provide protection regardless of hand washing.

• Efficacy of handwashing in the reduction of transmission is determined by whether SARS-CoV-2 virus spreads primarily by large droplets or by small-particle aerosols.

  • If it's transmitted by large droplets, the more likely that hand hygiene will reduce transmission.

  • If it's transmitted by small particle aerosol, then hand hygiene may not be as beneficial

Additional studies are needed to determine whether hand hygiene is effective in SARS-Cov-2 control.

Significance

An increased use of PPE amongst the medical staff during this pandemic has led to half (42.8%) of staff members experiencing skin injuries. These vary from pressure injuries, moisture-associated skin damage, as well as skin damage. The highest risk factors were sweating, daily wear time, and grade 3 PPE. Only a fifth (17.7%) of medical staff took preventative measures and only half (45.0%) of these injuries were treated. More awareness, prevention, and treatment needs to be implemented while using PPE this extensively in pandemics.

Background

With the increased use of PPE in the medical field, it is important to recognize the impact of prolonged PPE use on skin. This article attempts to measure the prevalence, characteristics, and preventive status of skin injuries caused by PPE in medical staff

Methods

A cross-sectional survey was conducted online for understanding skin injuries among medical staff fighting against COVID-19 in February 8-22, 2020. The questionnaire included grade of PPE, daily wearing time, skin injuries types, anatomical sites, and preventive measures.

Results

4,308 surveys completed across 161 hospitals.

42.8% of respondents experienced device-related pressure injuries, moisture-associated skin damage, and skin tears.

Sweating, daily wearing time, and grade 3 PPE were associated with more skin injuries.

Only 17.7% of respondents took preventative measures.

Only 45.0% of skin injuries were treated.

Conclusions

With the increased use of PPE, there needs to be more awareness and preventive measures for PPE-related skin injuries. These injuries are serious and currently have insufficient prevention and treatment. A more comprehensive implementation of PPE should be taken in similar circumstances.

Summary

Several brands of masks underwent decontamination with steam to evaluate whether mask integrity would be compromised via this decontamination method. Additionally, viral samples were subjected to steam to assess its efficacy in viral inactivation.

Methods

Four brands of MMs and two brands of N95Ms were subjected to the vaccine strain of avian infectious bronchitis virus H120 (to mimic COVID-19). A nebulizer aerosolized the viral particles, while a piston mediated syringe inhaled the aerosols 100 times through the respective masks. RNA was extracted for viral detection using TaqMan RT-PCR. Decontamination efficacy was measured by steaming tubes containing allantoic fluid with the avian coronavirus over boiling water for five minutes. Control tubes were kept at room temperature. Fluid from the test and control tubes was used to inoculate embryonated eggs, followed by detection via TaqMan RT-PCR.

Results

• 1. MMa, MMc, MMd, N95Ma, and N95Mb blocked 99% of virus before steaming while MMb blocked 98% of the virus.

  2. Hot steaming the masks did not alter their blocking efficacy.

  3. Avian coronaviruses were completely inactivated after undergoing 5 minutes of steam over boiling water. In contrast, room embryonated eggs inoculated by fluid from the room temperature control tubes were all positive for avian coronavirus.

Conclusion

The boiling technique appeared to inactivate viral particles while maintaining integrity of the masks. This presents a simple, quick, and inexpensive method for mask decontamination.

Summary

• Routine wearing of disposable masks by everyone, would probably intercept the transmission link of SARS-CoV-2

• Problems arising from masks deficits:

  • People are wearing cloth masks

    • Cloth masks do not protect as well against pathogens as medical masks.

    • Tests showed that cloth masks allowed 97% of particles to penetrate. In contrast to 44% in medical masks.

  • People are reusing masks

    • This can potentially increase infection risk because cloth masks allow moisture to be retained.

    • The virus may survive on the surface of masks.

    • Self contamination through repeated use and improper doffing is possible.

Summary

• The authors review the policies and efficacy of mask use for viral transmission prevention, mask use in public settings as well as effective cloth mask designs.

Policy

• The World Health Organization’s (WHO) discouragement of facemask use may have stemmed from concern over PPE shortages for healthcare workers, since several clinical trials have determined that facemask use along with appropriate hand hygiene may reduce transmission.

Efficacy of Masks versus Hand Hygiene

• RCTs have demonstrated that masks alone may reduce infection risk in households with a sick child, while other trials have demonstrated that hand hygiene alone was not effective in transmission prevention. Hand hygiene and mask use simultaneously was effective in transmission prevention, begging the question whether transmission prevention is attributed to both processes or primarily to mask wearing.

Mask use in Public

• • No RCT for measuring face mask use in public spaces exists at this time, but smaller scale studies suggest some transmission prevention when sick individuals wear masks.

  • The two main arguments for utilizing masks in public spaces is to prevent healthy individuals from getting infected as well as to prevent infected individuals from transmitting the virus, especially prior to symptom onset.

Cloth Mask Use and Design

• • Current studies deduce that cloth masks are not as effective as surgical masks in prevention of viral transmission, and therefore are not adequate for healthcare workers who carry a higher risk of exposure, but that they may be of some use to the general public, in which the risk of exposure is lower.

  • Cotton blend T-shirt material has higher filtration than scarves and silk. Hydrophobic materials filter best. Design should entail 2-3 layers of this fabric as well as a good fit to prevent air leakage.

  • A mathematical model of face mask use by a population during an influenza pandemic demonstrated that if masks are only 20% effective, then 25% use by the population would reduce infectivity by 30%.

N95 masks are made of microfiber polypropylene - the mask is permanently electrostatically charged creating a superior filter.

• COVID-19 can survive for: 24 hours on cardboard, 48 hours on metal, & 72 hours on plastic

N95 can be reused by

• Being kept in a dry environment for 3-4 days - ensures virus won’t survive

• Heat mask to 158 degrees F or 70 degrees C for 30 minutes - Hang mask by a clip inside the oven, don’t let it touch the metal

N95 can be damaged by

• UV light - although further evaluation is in progress

• Liquid disinfectant (alcohol or bleach)

Summary

When hospitals respond to infectious disease threats, they rely heavily on Infection Prevention and Control (IPC) programs. These IPC programs are in charge of:

1. Education

2. Reinforcement of infection prevention standards (isolation and PPE usage)

3. Establish processes to ensure i3 strategy (identify, isolate, & inform) is used

4. Guarantee the hospital meets CDC and WHO guidelines

However, IPC programs have many roadblocks that prevent them from being fully prepared for infectious disease threats:

1. Understaffed

2. Majority of their time is spent on reporting requirements and Medicare reimbursement

   1. Hospital administrators prioritize these tasks over efforts to prepare for infectious disease threats (which are often perceived as unlikely)

3. Competing priorities for funding and resources

   1. Eg, active shooter threats or desire to not focus on singular threats

4. Many hospital administrators do not know which tire their hospital falls into in the 2015-established special pathogen tiered hospital framework

Conclusion

It is critical to invest in IPC programs and biopreparedness to enhance U.S health security

Summary

Ultraviolet C (UVC) is being utilized to decontaminate N95 respirators, but significant variability in the UVC dosages used for decontamination has been identified. While no studies pertaining to dosing specific to COVID-19 are available, prior studies conducted for Influenza A (H1N1), Avian influenza A virus (H5N1), Influenza A (H7N9) A/Anhui/1/2013, Influenza A (H7N9)A/Shanghai/1/2013, MERS-CoV, and SARS-CoV all concluded that appropriate dosing was 1J/cm². Therefore, this dosage should be applied to UVC decontamination of N95 respirators until further research specific to COVID-19 dosing becomes available.

Summary

By reviewing the evolution of daily confirmed cases in South Korea, Italy, France, and Germany, the authors suggest that countries employing general population mask use reduced daily confirmed cases significantly, relative to those that did not employ this measure.

Comparison

After the initial surge in cases observed in South Korea, the government recommended mask use for outdoor and public activities. The daily confirmed cases decreased to approximately 100. In contrast, after the initial surge observed in Italy, and the government’s focus on “stay at home” orders and city quarantines, the daily confirmed cases remained at about 4000. Germany and France demonstrated similar trends to those observed in Italy, after implementation of control measures (that did not recommend widespread mask use).

Limitations

Confounding variables were not considered nor was a statistical analysis conducted.

Background of Prototype

In the setting of pandemic crises, shortages of protective face masks for healthcare professionals may occur. This article addresses this scarcity by presenting a proof of concept and prototype for a reusable custom-made three-dimensionally (3D) printed face mask. The mask is composed of a reusable face mask and filter membrane support, which are produced via computer-aided design (CAD) based on individual face scans. In addition, the mask utilizes a disposable head fixation band and filter membrane. Once used, the mask can be disassembled for disinfection utilizing official CORONA guidelines of the AZ Sint-Jan Hospital for cleaning and disinfecting of eye-protective materials in COVID-19 units.

Widespread Availability

This prototype was designed to be adopted and used worldwide if needed. The 3D modeling by CAD designers can be easily performed via a free software download and the disposable filter membrane is globally available from industrial manufacturers who produce protective masks for painting, construction, agriculture, and textile production. In addition, a simple Velcro strap can be used for the disposable head fixation component.

Future Study

Leakage and virological testing of the reusable components after disinfection has not been tested. This data is imperative to understand the number of times the face mask can be safely reused. Furthermore, additional study is necessary to address dermatological complications that may occur after prolonged application of the 3D mask while in humid and warm units.

This study compared particle permeability of used masks which underwent a sterilization process relative to unused masks.

Methods

• Single use FFP2 masks were sterilized with a 15-minute procedure at 121⁰C, using a dry sterilization process as well as with a regular steam process. Unused sterilized masks were compared to sterilized used masks, based on visual inspection, consistency, face fit and breathing resistance. Additionally, a custom test was designed to measure the pressure drop over the masks and outflow to determine mask permeability.

Results

• • Investigators could not distinguish between used and unused sterilized masks based on the comparison.

  • No difference between the amount of passed bacteria (staphylococcus epidermidis) was observed between the used and unused masks.

  • No difference in mask permeability between the used and unused masks was observed.

  • Mask permeability of small particles did not change after multiple heat sterilization procedures.

Significance

• This study demonstrates that sterilization of masks does not compromise its efficacy and is a cheap, simple, and quick procedure to utilize in the setting of a mask shortage.

Background

COVID-19 has undoubtedly posed a significant risk to the safety of healthcare workers given the limited supply of PPE. This has prompted researchers to investigate ways to safely reuse the limited supplies available, while making sure not to increase the risk of infection or contamination.

Given that the CDC has already adopted recommendations for the extended use of the N95 mask, researches in China have examined disinfection using hydrogen peroxide. Researchers utilized a 7.8% H₂O₂ solution that becomes ionized after passing through a cold plasma arc, throughout the surface of the N95 mask respirator.

Experimental Methods

In the experiment, four N95 masks were inoculated with 3 different concentrations of influenza A, H1N1. The ionized solution of hydrogen peroxide was sprayed at a distance of 24 inches, 3 times, for a total of 6 seconds of treatment time. The inoculated N95 receptors without virus inoculation were used as positive control. Influenza A was used in this experiment given its similar enveloped RNA structure to COVID-19.

Results

The pieces of N95 that were inoculated were cut out, neutralized and eluted for viral cultures. Cytopathic changes were observed for 7 days using light microscopy. All ionized hydrogen peroxide did not demonstrate any changes suggesting the presence of live, influenza A virus. These samples were further sub-cultured for another 7 days, confirming negative influenza A detection.

Future Directions

Disinfection may provide a faster alternative to conventional methods which utilize UV irradiation or higher concentrations of H₂O₂ vapor which require longer cycle times and a unique air ventilation system. Further research is needed to determine if there is a maximum number of disinfection cycles to maintain filtration efficiency, if there are risks to potential exposures of these chemicals, and if these results hold promise with COVID-19 viral particles.

Summary

• • Implementing the use of electronic Personal Protective Equipment (ePPE) can help protect health care providers and conserve PPE

Details

• • ePPE is defined as telemedicine tools used by on-site emergency providers to evaluate patients physically in the ED to avoid physical proximity

    • It is NOT telemedicine in that providers are still on-site if needed for direct physical examination/resuscitation

  • There is some evidence for the efficacy of ePPE use in minor, low-acuity situations and consultations

Legal

• • The Emergency Medical Treatment & Labor Act (EMTALA) defines the medical screening obligations of EDs

  • The Centers for Medicare & Medicaid Services (CMS) released an update to EMTALA enforcement on March 30th allowing medical screening exams (MSEs) to be performed via telehealth in response to the COVID-19 pandemic

  • A Notification of Enforcement Discretion made by Health and Human Services and the Office for Human Rights lifted historical restrictions from the Health Insurance Portability and Accountability Act (HIPAA) requiring certified telemedicine software

    • This allows the use of more readily available software such as FaceTime or Skype, as long as used in good faith with every practical effort made to protect patient privacy

Recommendations

• • Implementing MSEs via ePPE for low-risk patients, as determined by the initial triage nurse

    • If the patient is deemed appropriate for discharge based on evaluation, vital signs, and protocol, they may be discharged

    • If the provider determines that a more in-depth physical exam is needed or the patient requires additional testing or treatment, the ePPE-based visit can progress to a traditional ED visit

  • Use a streamlined electronic health record-based note to facilitate documentation, guided by local information technology standards, expedited review by compliance committees for adherence to local policy, and documenting within the medical record that an MSE was performed using ePPE

A subjective overview of various studies was conducted to determine the efficacy of N95 use and reuse relative to surgical masks and cloth masks, while simultaneously considering CDC recommendations in light of the N95 respirator shortage.

Filtration efficacy of Masks

• • N95 respirators: These require a 95% filtration efficacy for particles 100-300 nm per NIOSH requirement to be sold. For context, the SARS-CoV-2 virion diameter is reported to be 125 nm. Extended use of respirators can lead to viral transmission via self-inoculation and touching of the respirator (a study demonstrated that nurses touched their respirator about 25 times per shift), but due to the shortage, extended use can be mitigated through face shields, hand hygiene as well as proper donning and doffing of PPE.

  • Surgical masks: Unlike N95 respirators, these are not required to meet filtration efficacy standards to be sold. Nonetheless, several studies have demonstrated that utilizing this mask alongside handwashing will reduce overall risk of contracting respiratory viral illness.

  • Cloth masks: While studies have demonstrated that these masks are not comparable to N95 respirators, they may be comparable to surgical masks in some cases, taking into account that mask design can vary immensely. At this time the CDC reports that cloth masks may be necessary as a last resort option.

A cross-sectional questionnaire was administered in Wuhan to phenotype adverse skin reactions and their associations, as experienced by healthcare workers during the CoVID-19 pandemic.

Methods

• A cross-sectional questionnaire was administered at several hospitals around Wuhan, collecting information entailing self-perceived adverse skin reactions, types, and sites of eruptions. A univariate and multivariate analysis of the 376 returned questionnaires was conducted.

Results

• • Data:

    • 74.5% of respondents reported adverse skin reactions. This was greater than the occupational contact dermatitis reported under normal working conditions (31.5%) and during the SARS outbreak (21.4-35.5%).

    • The most commonly reported types of eruptions were dryness/scale, papule or erythema, and maceration, respectively.

    • The three most commonly affected areas were the hands, cheeks, and nasal bridge, respectively.

  • Univariate analysis: Sex, epidemic level, working place, duration with full body PPE, getting soaking wet after work, and frequency of handwashing were significantly associated with adverse reactions.

  • Multivariate analysis: Female sex, working in hospitals with more severe cases, working in inpatient wards, and wearing full body PPE >6 hours/day were significantly associated with adverse reactions.

Limitations

• • Response bias: Individuals with adverse skin reactions were more likely to respond to the questionnaire.

  • Questions regarding existing/predisposing skin conditions were not included in the questionnaire.

Significance

• Adverse skin reactions as a side effect of elevated hand hygiene and PPE practices were reported by healthcare workers, highlighting a need to further characterize the reactions as well as exploring solutions to minimize their occurence.

Electrophysiologists participate in direct and indirect care of patients with COVID-19 in the recent pandemic. With specific regards to the virus, arrhythmia has been reported in 16.7% of hospitalized and 44.4% of ICU patients with COVID-19¹.

Electrophysiology staff may be at risk when they take care of asymptomatic COVID-19 patients

- Follow appropriate PPE recommendations with available supply.

- Reduce interactions with fellow healthcare personnel and with patients to prioritize interactions with patients with urgent or emergent needs.

- Delay non-urgent or non-emergent procedures.

- Engage in telehealth visits when appropriate and available.

Appropriate PPE for electrophysiology procedures in patients with suspected or confirmed COVID-19

- PPAR or N95 mask

- Surgical gown

- Gloves

- Protective eyewear

Determine whether intubation, if required, should be performed in a negative pressure room.

COVID-19 may cause myocardial injury.

- More studies are needed to evaluate the potential cardiac effects of COVID-19 to determine whether patients with COVID-19 will require arrhythmia monitoring or other interventions.

Be aware of the potential cardiac toxicity of hydroxychloroquine. Take precaution if a patient has any of the following:

- Known congenital long QT syndrome

- Severe renal insufficiency

- History of QT prolonging medications

- Electrolyte imbalances

Employ caution when attempting resuscitation in a COVID-19 patient who develops cardiac arrest.

- Only necessary personnel should be present with appropriate PPE.

- Assess for early intubation.

Determination of the urgent or emergent status of a procedure, visit, etc. is necessary. A semi-urgent, urgent, or emergent procedure, if not performed, may result in patient’s death, permanent extremity or organ system damage, or progression to severe symptoms.

A meta-analysis of randomized clinical trials studying influenza-like illnesses was conducted to compare efficacy of medical masks relative to N95 respirators in protecting healthcare workers from viral infection.

Methods

• A meta-analysis of randomized clinical trials pertaining to various influenza-like viral infections was conducted.

Results

• The analysis found no difference between medical masks and N95 respirators in efficacy of protecting healthcare workers from influenza-like infections.

Limitations

• • Only one trial studied was specific to coronavirus infection so results may not be generalizable to SARS-CoV-2.

  • This is a meta-analysis of aggregate data rather than individual data.

  • The definition of influenza-like illness was based on predetermined symptoms, but the threshold used to obtain swabs was likely more lenient in the studies.

Significance

• This goal of this study was to determine whether medical masks could serve as an alternative to N95 respirators in the face of national supply shortages.

A study investigating SARs-CoV-2 transmission by infected patients wearing surgical or cotton masks concluded that neither forms of PPE effectively filtered the virus during patient coughing. Additionally, viral particles were detected on the outer surface of the face masks, but not on most inner surfaces.

Methods

• Confirmed COVID-19 patients coughed five times onto petri dishes containing 1 mL of viral transport media with: no mask on, wearing a surgical mask, wearing a cotton mask, and once again with no mask on, respectively. Outer and inner mask surfaces as well as the petri dishes were analyzed for viral load.

Results (from all 4 patients)

• • Median Viral load of:

    • Nasopharyngeal samples: 5.66 log copies/mL

    • Saliva samples: 4.00 log copies/mL

    • After coughs without a mask: 2.56 log copies/mL

    • After coughs wearing surgical mask: 2.42 log copies/mL

    • After coughs wearing cotton mask: 1.85 log copies/mL

  • All swabs from outer mask surfaces were positive for SARS-CoV-2

  • Most swabs from inner mask surfaces were negative for SARS-CoV-2

Significance

• This study concluded that neither surgical nor cotton masks effectively filtered SARS-CoV-2 during coughs by infected patients. Furthermore, it was suggested that air leakage around the mask edge or high-velocity coughing may account for the presence of SARS-CoV-2 on the outer mask surface in the absence of the virus on the inner mask surface. While its etiology is undetermined, this finding highlights the importance of hand hygiene after handling the outer surface of the face mask.

A study conducted in Singapore reported an increase in de novo PPE-associated headaches amongst healthcare providers, describing the characteristics and phenotype of this condition.

Methods

• 158 participants at the National University Hospital in Singapore completed a self-administered survey involving demographic information, past medical history, PPE usage patterns since COVID-19 started, characteristics of pre-existing headache disorders, as well as characteristics and personal views on de novo PPE-associated headaches. PPE utilized at the institution were two types of 3M N95 face masks with and without goggles. A statistical analysis of survey answers was conducted.

Results

• • 81% of participants reported de novo PPE-associated headaches

  • Participants described the headaches as bilateral, mild, and primarily located in areas of contact from the facemasks/goggles/head straps; most participants (87.5%) described a sensation of pressure or heaviness

  • Majority of participants (81.3%) stated that headache onset was less than 60 minutes from donning the facemask

  • Majority of participants (68.8%) did not need acute analgesic treatment

  • Participants with pre-existing primary headache diagnosis were more likely to develop de novo PPE-associated headaches

  • Participants wearing facemasks and/or protective eyewear for >4 hours/day or >15 days/month had a higher chance of developing PPE-associated headaches

Significance

• This study demonstrates a consequent side effect of continued PPE use on healthcare providers and highlights the need for a future improved facemask/goggle design with an emphasis on tolerability.

Researchers tested the efficacy of 13 different mask designs made by community volunteers for filtering 0.3-1.0 micron particles and compared filtration to surgical masks and N95 respirators.

Results

• The 13 different mask designs varied by type of cloth, number of layers, and quality of material. There were 400 masks tested that were all made from community volunteers.

• The best performing design was made from 2 layers of “quilter’s cotton” with a minimum thread count of 180, achieving 79% filtration compared to the 65% filtration of surgical masks and 97% filtration of N95 masks. A 2 layer mask of outer cotton and inner flannel also did well.

• The best performing materials for masks are materials with tight weaves, thick thread and are high quality. Two layers of fabric perform better than a single layer.

• The worst performing masks were single-layer or were made of lower quality, lightweight cotton. Double-layer lightweight cotton also did not perform well.

Discussion

• Knowledge of efficacious, alternative masks could be essential as availability of personal protective equipment declines. Although non-commercially made masks are not being currently used by Wake Forest Baptist, community members have started making masks based on the highest performing design.

• Community members who would like masks for personal safety can use these fabric guidelines to construct their masks.

The study conducted at the College of Veterinary Medicine at Qingdao Agricultural University, examined the efficacy of hand wiping as well as evaluated the efficacy of three mask types – a one-layer polyester cloth combined with 3 layers of kitchen paper (assumption that kitchen paper refers to paper towels) homemade mask, a medical mask, and an N95 mask.

Methods

• The study utilized avian influenza virus (AIV A/chicken/Qingdao/211/2019) to mock SARS-CoV-2 because both are enveloped and pleomorphic spherical viruses with a diameter of 80-120 nm.

  • Hand Wiping method: Hands were contaminated with the AIV and subsequently wiped three times from the root of the palm to the tips of the fingers using a towel soaked in water and containing 1.00% soap, 0.05% active chlorine or 0.25% active chlorine from sodium hypochlorite. The hand was eluted with PBS and RNA was extracted for detecting using TaqMan RT-PCR.

  • Mask Testing Method: AIV containing fluid was added to a nebulizer to produce aerosols containing the virus, which were subsequently collected into a plastic bag. The air in the bag was inhaled in and out of syringes wrapped within the mask 100 times to mimic human breath. RNA was extracted from sponges within the syringes and underwent TaqMan RT-PCR.

Results

• • Hand Wiping:

    • Soap powder: removed 98.36% of virus

    • 0.05% active chlorine: removed 96.62% of virus

    • 0.25% active chlorine: removed 99.98% of virus

  • Masks:

    • Homemade mask: 95.15% of virus blocked

    • Medical mask: 97.14% of virus blocked

    • N95: 99.98% of virus blocked

Significance

• The study draws emphasis on the significance of mask wearing and hand hygiene in social settings for the prevention of viral transmission.

State of the shortage:

• U.S. hospitals are already reporting shortages of key equipment needed to care for critically ill patients, including ventilators and personal protective equipment (PPE) for medical staff.

• Current estimates of the number of ventilators in the United States range from 60,000 to 160,000, and the estimated need lays in the several hundred thousand to as many as a million

Why is there a shortage?

• Problems with the global supply chain: China produced approximately half the world’s face masks. During the outbreak in China, their exports stopped but now has restarted with China shipping masks to other countries as part of goodwill packages.

  • US has not been a major recipient of these packages

CDC’s recommendation:

• N95 respirator masks be used only during aerosol-generating procedures

• Reusing masks and respirators intended for one-time use and, if stocks are fully depleted, using scarves or bandanas.

What can be done?

• Defense Production Act (DPA) allows the President to direct private companies to produce equipment needed for a national emergency

  • direct these companies to maximize production, and maximize the availability of raw materials

• Reallocated masks and gloves are used in many nonmedical settings (construction, labs, artists, etc)

• Ensure that the areas hardest hit at any given time are receiving needed equipment, rather than have individual state and hospitals competing for resources

• Partnering with technology companies to track the availability of and projected needs for equipment in real time

Conclusions

• A coordinated approach needed to ensure key equipment needed to care for patients and to keep our health care workforce safe is available and properly allocated.

• Summary: A study comparing the performance of PPE donning and doffing between groups receiving PPE training through an in-person training session versus watching training videos, found no difference in evaluation scores between the two groups.

• Methods: 21 medical students and junior doctors either received in-person training or watched training videos. The participants were evaluated using checklists one month later.

• Results:

o Mean donning score for instructor led group was 84.8/100 versus 88/100 for video group (95% CI: -7,5 to 9,5).

o Mean doffing score for instructor led group was 79.1/100 versus 73.9/100 for video group (95% CI: -7,6 to 18).

• Significance: Lack of a significant difference between scores in the instructor led group versus the video trained group suggests that video training can effectively be utilized to minimize contact between individuals as well as conserve PPE.

• Summary: This letter to the editor reflects how shelter hospitals built in China have no recorded infections of healthcare personnel. The article goes through disinfection of contaminated areas, patient decontamination, personnel PPE, and other occupational exposures. These strategies work: with more than 5000 healthcare personnel, not a single member was infected with the novel coronavirus.

• Methods: 1) Three different strategies were dictated to disinfect clean, semi-contaminated and contaminated areas. 2) A protocol is dictated to disinfect patients, including daily face mask changes, personal item disinfection, and disposal of “contaminated” clothes. 3) A specific order to donning PPE, including both N95 and surgical masks, along with isolation gowns with protective suits on top. For exiting the hospital, two sequential decontamination rooms are offered to personnel and multiple mandatory hand-washing stations. 4) Occupational exposure decontamination methods are dictated for skin, mucosa, respiratory exposures, and needle-sticks.

• Results: 3019 infected healthcare personnel (HCP) are recorded as of February 22, 2020 in China. Among them, 1716 HCP had confirmed infection and unfortunately, five of them died of COVID-19. Since the conception of shelter hospitals on February 5th, with more than 12000 beds with approximately 9000 in-hospital patients and 5000 healthcare personnel, there has been no infected staff to date.

• Significance: This article summarizes a successful method of preventing hospital-acquired COVID-19 amongst staff members. This is something to seriously consider as healthcare personnel in the United States are experiencing an alarming rise in the number of COVID-19 cases and deaths.

Summary: Editorial following up JAMA’s initial call for ideas for how to address the impending PPE shortage, based on comments received by the editors.

A wide range of recommendations for PPE conservation and management were compiled by JAMA’s editors.

Recommendations included the following:

• Accumulating Supplies: Importation of supplies from international suppliers. Reclaiming supplies from other industries through charitable movements, individual procurement, buybacks, and bounties.

• Repurposing Supplies: Reusing, repurposing, and creating supply, while also utilizing methods to extend its use. Additionally, stratifying PPE use by patient risk.

• Healthcare Staff: Reducing nonessential services, reducing patient contact, altering staffing, using nonhuman services, and employment of immune workers.

Please view the editorial for details on the proposed recommendations.

• Summary: Researchers associated with the National Centre for Infectious Diseases in Singapore tested N95 and disposable face visors used by providers in contact with known Covid-19 illness for SARS-CoV-2 contamination.

• Method: N95 and face visors were swabbed after provider contact with patient (median = 6 minutes). 90 samples were tested with real-time RT-PCR methods targeting SARS-CoV02 RNA-dependent RNA polymerase and E genes.

• Results: All 90 samples tested negative for viral contamination.

• Limitations:

o Surface swabs for sampling may be insufficient for detection of particles.

o Samples were obtained from patients residing in airborne infection isolation rooms with 12 air exchanges per hour.

o The level of viral contamination of the environment was not conducted so no correlation with level of PPE contamination was provided.

o Gloves and disposable gloves were not sampled with the assumption of single use.

• Significance: This study suggests that extended use of N95 and face visors is a safe option.

Summary

• Physicians at UF Health are re-purposing the sterile surgical-instrument-tray wrappings as simple respirator masks with, potentially, greater efficacy than current N95 masks

Details

• This sterile wrapping is normally used to surround surgical instrument trays before they pass through gas sterilization or an autoclave, which is then discarded

• About 10 masks can be made from one sheet, and an estimated 500 to 1,000 sheets are likely available from UF Health hospitals every day

• The wrapping is made of Haylard H600 two-ply spun polypropylene, which is impenetrable to water/bacteria/particles

• These masks block 99.9% of particulates, 4% more effective than N95 masks, according to Bruce Spiess, M.D., a professor of anesthesiology in UF College of Medicine

As a result of the ongoing pandemic with COVID-19, many hospitals and healthcare facilities worldwide are rapidly facing shortages of personal protective equipment (PPE) including N95 respirator masks. In order to conserve PPE, Nebraska Medicine has developed a decontamination protocol for masks without compromising the fit or integrity of the mask.

Previous UVGI Use

UVGI has shown to inactivate a wide range of microorganisms and pathogens not limited to coronavirus, influenza, and many others.

Previously, researchers have used 2-5 mJ/Cm2 of UVGI. However, researchers at this institution increased the amount of UV radiation to 300 mJ/Cm2 which may increase pathogen inactivation and still fall below the safety margin.

UVGI Setup

A set up of this decontamination process includes 30 N95 placed on a 13 foot line, the UV towers are each placed 4 feet from the center of the room, and the UV light sensor is placed across the masks.

Nebraska Medicine's UVGI Utilization Plan

They plan to mark the masks with the individual’s name, date of use, and the number of decontamination cycles it has been through. The masks are redistributed in clean white bags and are to be returned in the dirty brown bags. Nebraska Medicine plans to utilize this technique until the quality of the masks are compromised.

Conventional Strategies

• Use facemasks according to product labeling and local, state, and federal requirements

Contingency Strategies

• Selectively cancel elective and non-urgent procedures and appointments for which a facemask is typically used by HCP

• Remove facemasks for visitors in public areas

• Implement extended use of facemasks (wearing the same facemask for repeated close contact encounters with several different patients, without removing the facemask between patient encounters)

• Restrict facemasks to use by HCP, rather than patients for source control

Crisis Strategies

• Cancel all elective and non-urgent procedures and appointments for which a facemask is typically used by HCP

• Use facemasks beyond the manufacturer-designated shelf life during patient care activities

• Implement limited re-use of facemasks (using the same facemask by one HCP for multiple encounters with different patients but removing it after each encounter)

• Prioritize facemasks for selected activities (essential surgeries, splash-hazards, prolonged contact with infectious patients, and for performing aerosol generating procedures)

No Facemasks Available

• Exclude HCP at higher risk for severe illness from COVID-19 from contact with known or suspected COVID-19 patients

• Designate convalescent HCP for provision of care to known or suspected COVID-19 patients

• Use a face shield that covers the entire front (that extends to the chin or below) and sides of the face with no facemask

• Consider use of expedient patient isolation rooms for risk reduction

• Consider use of ventilated headboards

• HCP use of homemade masks

For more information, visit the CDC website on optimizing PPE supply lines