key: cord-0735848-pm03zbrw
authors: Trehan, Rajiv S.; McDonnell, Erin P.; McCoy, Jonathan V.; Ohman-Strickland, Pamela A.; Donovan, Colleen; Quinoa, Travis R.; Morrison, Daniel S.
title: Pilot Study: Comparing the Quantitative Fit Testing Results of Half-Mask Respirators with Various Skin Barriers in a Crossover Study Design
date: 2021-02-15
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2021.02.010
sha: 6ec4a7d8ebcc859dd61349437da20fd5c81f6708
doc_id: 735848
cord_uid: pm03zbrw

Clinicians around the world are experiencing skin breakdown due to the prolonged usage of masks while working long hours to treat patients with COVID-19. The skin damage is a result of the increased friction and pressure at the mask-skin barrier. Throughout the COVID-19 pandemic, clinicians have been applying various skin barriers to prevent and ameliorate skin breakdown. However, there are no studies to our knowledge that assess the safety and efficacy of using these skin barriers without compromising a sufficient mask-face seal. We report the largest study to date of various skin barriers and seal integrity with quantitative fit testing (QNFT). Our pilot study explores whether the placement of a silicone scar sheet (ScarAway®), Cavilon™, or Tegaderm™ affects 3M™ half-face mask respirator barrier integrity when compared to no barrier using QNFT. We collected data from nine clinicians at an academic Level 1 trauma center in New Jersey. We found that the silicone scar sheet resulted in the lowest adequate fit while Cavilon™ provided the highest fit factor when compared to other interventions (p<0.05). Our findings help inform clinicians considering barriers for comfort when wearing facemasks during the COVID-19 pandemic and for future pandemics.

Throughout the COVID-19 pandemic, many healthcare providers are required to use facemasks for protection. Due to mask shortages, many providers choose to wear their own personal protective equipment (PPE), including 3M™ half-face mask respirators. Both the Joint Commission as well as the American College of Emergency Physicians have endorsed the use of self-obtained PPE by providers [1, 2] . N95 respirators, currently cleared in phase 4 by the Food and Drug Administration (FDA), are both labeled and recommended by the Center for Disease Control as single-use masks [3, 4] . Unfortunately, providers are wearing masks for extended periods and are reusing the N95 and 3M™ half-face mask respirators across multiple shifts due to PPE shortages [5] . As a result, providers are experiencing skin irritation, breakdown, and ulcerations due to protracted use of N95s [6] .

Before the COVID-19 pandemic, researchers viewed clinician mask discomfort from various angles, including facemask ventilation side effects. Previous 3-dimensional scanning of respirator facemasks predicted that prolonged use of these masks would cause skin damage at the nasal bridge due to increased point of force contacts [7] . Additionally, this work found that many attempts to reduce the discomfort at the nasal bridge of these masks can cause significant impediment to the seal of the respirator [8] .

More recently, during the initial wave of the COVID-19 pandemic, researchers used social media, provider anecdotes, and cross-sectional studies to garner information about healthcare workers' skin breakdown [9] [10] [11] . A cross-sectional study with 51 providers found that 38.2% of the participants failed the qualitative fit test with their dome-shaped or duckbill N95 respirators [5] . Additionally, after surveying 542 healthcare workers in China, Lan et al. (2020) found that 97% of providers reported skin damage from PPE and highlighted the nasal bridge as the most J o u r n a l P r e -p r o o f common area of skin breakdown. Additionally, recent reports from the New York Times and CNN highlights the general public's issue with skin breakdown which proclaimed, "maskne is the new acne" [10, 13] .

Various researchers have proposed, without conducting studies, different mask barrier solutions to prevent skin breakdown, including the use of various dressings, which indicate an acute need and an interest in this field [14] [15] [16] . In an informal effort to gather preliminary data, an email questionnaire, receiving 45 responses, found that providers were experimenting with the hospital recommended option of Cavilon™ as well as silicone scar sheet and Tegaderm™ to reduce friction between their face and their N95 respirator. Thus, providers are experiencing discomfort due to prolonged respirator use, and could be following recommendations for dressings without rigorous studies on their compromise of the face-mask seal.

The efficacy of the mask's barrier function can be measured by both qualitative and quantitative testing. Evidence suggests that QNFT is a more accurate and objective measurement of fit compared to QLFT [17] [18] [19] . Once clinicians pass either QNFT or QLFT to ensure their barrier is suitable and safe, they perform a fit check each time they subsequently don their respirator. Prior research indicates that this "fit check method" inaccurately indicates a mask's fit 18-31% of the time [17] [18] [19] . Thus, quantitative measures are of great value and were chosen for our pilot study. More specifically, the overall fit factor from QNFT was chosen a priori as our primary outcome in this study.

Other researchers in this field have also shown a specific interest in using qualitative and quantitative measures of fit to study the effects of various skin dressings on the face-mask seal.

A Canadian study by Lansang et al. (2020) measured the fit test results both quantitatively and qualitatively of healthcare workers after applying various skin barriers. However, their study was J o u r n a l P r e -p r o o f limited to three participants and lacked statistical analysis on the quantitative results. Of note, similar studies in the literature used non-validated tests or unrelated outcomes to assess masks' fit factors', such as oxygen saturation, or focused on solutions to prevent patient, rather than clinician, skin breakdown [16, [21] [22] [23] .

Considering the COVID-19 pandemic, and future airborne pandemics, we chose to quantitatively investigate potential solutions that maintain provider comfort and mask compliance without compromising safety.

This pilot study was conducted in September 2020 at a medical school affiliated with an academic Level 1 trauma center in central New Jersey. We enrolled nine clinicians, including physicians, physician assistants, nurses, and technicians. The exclusion criteria for the pilot study consisted of individuals that were < 18 years old, had an inability to wear masks due to preexisting conditions or anxiety, had known allergies to mask or skin dressing materials, and were included in populations requiring special consent. Participants who were experiencing flulike or COVID-like symptoms were also ineligible for this study.

We recruited clinicians of varying ages who had their own 3M™ 6000 series or 3M™ 7000 series half-face mask respirator ( Table 1) . 3M™ half-mask respirators were of interest because these respirators were already being used by providers clinically, are reusable, and readily available. Of note, the clinicians under investigation had already passed QLFT with their personal 3M™ half-face mask respirator that was used in the study. Furthermore, destruction of N95 respirators for use with QNFT seemed irresponsible when there was a critical supply shortage during the pandemic.

J o u r n a l P r e -p r o o f

In order to accurately assess the participant's fit factor, the TSI Incorporated PortaCount® Plus Model 8038 was used to quantitatively calculate each participant's results with their personal 3M™ respirator. The 3M™ half-face mask respirators were attached to the PortaCount® Plus Model 8038 via a 3M Model 601 Quantitative Fit Test Sampling Adapter and 3M™ 2091(P-100) filters were used for all participants. Additionally, Cavilon™, Tegaderm™, and silicone scar sheet (ScarAway®) were used as the skin barrier interventions in this pilot study.

Using a cross-over study design, all participants were randomized to the order of testing between wearing their 3M™ half-face mask respirator with no barrier, Cavilon™, Tegaderm™, and silicone scar sheet (Figure 1 ).

The participants were instructed to apply the supplied dressing on their nasal bridge. No further instruction was given to the participant regarding the placement of the dressing.

Moreover, the study aimed to see the effects of the dressing as they would be commonly placed and used with masks in clinical use. Each volunteer served as their own control as they were tested without a barrier, as well as with all the skin barriers, and were using their own 3M™ halfface mask respirator (Figure 1 ). Prior to testing, the PortaCount® machine's daily check programmes were run daily including a classifier check for half mask respirators and particle check for 1000 ambient particles per mL to ensure enough ambient particles were in the air for testing [24, 25] .

We guided the participants through the Occupational Safety and Health Administration (OSHA) protocol to quantify their fit factors during specific movements [24, 26] . These movements included normal breathing, deep breathing, moving head side to side, moving head up and down, reading half of the rainbow passage aloud, grimacing (to break the mask seal), bending at the waist, and then normal breathing again. We repeated normal breathing to quantify the impact of the grimace movement on the face-mask seal.

We also measured the participant's Realtime Fit Factor using the PortaCount® machine.

The Realtime Fit Factor allowed the research team to observe real-time graph data as the subject continued to adjust the mask to maximize the output fit factor [25] . In addition, the participant changed their strap tension to alter their comfort and fit as they would in a clinical setting [27] .

Thus, the Realtime function provided the highest quantitative fit test measurement that one could achieve with each skin dressing. Additionally, as the numbers tended to fluctuate, the median, lowest and highest value of the range were recorded and analyzed for trends across all three values.

The results of the Realtime and OSHA protocol fit test scores were stored on a USB attached to the PortaCount®, with each participant's information coded as a randomized number.

This data was also manually inputted into the data sheet on Rutgers OneDrive which is compliant according to Health Insurance Portability and Accountability (HIPAA) guidelines [25] . Additionally, in order to compare the outcomes between interventions, repeated measures analysis of variance, with an exchangeable correlation structure, was used to determine differences in the outcomes between mask seal types. P-values were calculated via F-tests for the effect of seal type. Then, if results were significant at the 0.05 level, we examined pairwise comparisons between treatments.

The study was approved by the Rutgers New Brunswick Health Sciences IRB and all participants completed informed consent.

When looking at significant pair-wise comparison data, Cavilon™ provided a statistically significant (p<0.05) increase in barrier seal compared to both the silicone scar sheet and Tegaderm™ (Table 2-3) . These results can be further broken down where Cavilon™ superiority with respect to the other interventions was found in both the overall fit factor and, in the case of the silicone sheet, in most of the specific movements. When specifically looking at results from the Realtime fit test, Cavilon™ provides a statistically significant (p<0.05) increase in barrier seal with respect to both the silicone scar sheet and Tegaderm™. Additionally, we found no statistically significant difference between Cavilon™ and the control.

One specific data point of interest is one of the participants which failed the fit test with no barrier in place as well as other interventions. More specifically, this participant had failing (<100) fit test scores of 12 for the control, 15 for the silicone scar sheet, and 36 for the Tegaderm™. This participant, however, had an overall fit factor score 220 for Cavilon™ which J o u r n a l P r e -p r o o f was a passing value. This participant was the only individual to have a failing score for the control case and the implications of these values are found in the discussion.

The results of the silicone scar sheet barrier indicate a statistically significant difference between the silicone scar sheet and control for both overall and most of the specific movements in the fit factor data (Table 2-3) . Of greater interest is that this difference indicates that silicone scar sheet causes a significant negative impact on the seal of the mask. These results again held true for the Realtime fit test data (Table 2-3) .

In terms of statistically insignificant differences, there is a lack of statistically significant difference between both the Cavilon™ and Tegaderm™ with respect to control for both the fit factor and Realtime fit test data (Tables 2-3) . However, based on the small sample size and overall trend for Cavilon™ and Tegaderm™ in providing a greater and lesser degree of seal, respectively, this lack of statistically significant differences should be approached with caution.

On a different note, for both control and interventions, the grimace movement did not seem to have any impact on the seal of the mask.

This research aimed to understand if there are any existing skin barriers that clinicians can apply to prevent skin breakdown on the nasal bridge of clinicians without compromising their face-mask seal. This study focused on 3M™ half-mask respirators due to the shortage of N95 respirators at the time. In addition, we chose to investigate our participants fit test quantitatively, because the QNFT is more specific and sensitive for detecting a break in the facemask seal compared to the QLFT or the fit check [19] .

While the fit check is frequently done by clinicians prior to wearing a respirator on a shift, the test does not accurately detect a break in the respirator's seal and sometimes produces J o u r n a l P r e -p r o o f less accurate and inferior results compared to QLFT or QNFT [17, 18, 27] . In order to pass QLFT, a clinician must be unable to taste or smell an irritant through their facemask. For QNFTs, a PortaCount® machine can be used to measure respirator fit by comparing the concentration of microscopic particles outside the respirator to the concentration of particles that have leaked into the respirator. The ratio of these two concentrations is labeled as the fit factor. A quantitative fit factor of 100 means the concentration of particles inside the respirator is 100 times less compared to the air outside [25] . Since studies suggest that the QNFT is a superior outcome compared to QLFT, we used QNFT for our pilot study [19] .

Several studies in the literature have recently investigated fit factor using skin dressings less commonly found in the United States. In addition, many publications lacked statistical analysis on their quantitative results, had small sample sizes, or measured inferior outcomes. Lansang et al. (2020) used both QNFT and QLFT to compare N95 respirator fit factor results without a skin dressing to results with a bland emollient, foam dressing, film dressing, and silicone cream. All participants in that study passed the QLFTs with each barrier. However, one participant did not pass the QNFT with the foam dressing. Notably, this study only included three participants and lacked any statistical analysis. To our knowledge, this study, along with ours, are the only two that use the PortaCount® to conduct QNFT to assess the efficacy of skin barriers in protecting the face-mask seal. Separately, Smart et al investigated the effects of silicone-based dressings on the seal of N95 respirators, but this study used oxygen saturation to try to determine this outcome, which does not give any indication about the seal of mask.

This pilot study was able to conclude that there are statistically significant differences between the various skin barriers which were found in both the overall results and in certain movements.

Even with a relatively small sample size, our results suggest that the Cavilon™ film provides a greater degree of seal protection when compared to other interventions. Additionally, these results indicate that Cavilon™ does not decrease the quality of the seal compared to a mask without a barrier. Silicone scar sheet was also found to provide the lowest level of protection and more research should be done to determine whether it (or any other barriers with similar thickness) should be applied as a skin barrier in clinical settings.

It is important to note that participants were not able to improve the results of the interventions with respect to each other when adjusting their masks using real time data in the Realtime fit test. Therefore, these results indicate that Cavilon™ superiority holds true regardless of method/location of application when compared to the other interventions. Additionally, the silicone scar sheet cannot be adjusted to provide equal results to the control regardless of the method/application style by each participant. While each dressing did provide varying degrees of protection, all the participants received the minimum QNFT requirements to receive a passing score (>100) with each dressing while wearing their personal 3M™ half-mask respirator.

One participant in our study failed the quantitative fit test while wearing Tegaderm™, silicone scar sheet and no barrier. This one failure (11%) of our limited sample size, compares to prior research which indicated a failure rate of 13% of those who had passed QLFT but did not pass QNFT [19, 28] . Interestingly, while the participant failed with the control, the participant safely passed QNFT testing with the use of the Cavilon™ film barrier by a significant margin. This suggests that specific barriers not only protect the face-to-mask seal but might increase the fit factor and improve the seal. This hypothesis can also be strengthened by the overall positive scores (though not statistically significant) with respect to the control for Cavilon™. Thus, further research on this specific scenario is strongly recommended.

It is understandable that researchers are trying to give advice to clinicians to help them reduce skin breakdown. Topical dressings, such as hydrocolloid dressing or silicone perforated tape over the bridge of the nose are being recommended to healthcare workers to reduce skin damage and ulceration [14] [15] [16] 29] . However, these studies are mostly based on a recommendation or qualitative analyses, which are known to be not as sensitive or specific as QNFT analyses. Clinicians need to be physically protected and comfortable when treating COVID-19 patients, and ought to follow their institutional guidelines when donning their own PPE, including respirators. Thus, it is crucial that the research community works together to use QNFT to determine which topical dressings healthcare workers can apply that will alleviate discomfort and not compromise their face-mask seal.

Our aim for this pilot study was to gain an introductory understanding on how specific skin barriers affect, if at all, the overall fit factor of the half-face mask seal. One limitation of this study is that our participant cohort was based on a small convenience sample of clinicians. We believe that this limitation was in part due to the time commitment required to do a true crossover study (4 different fit tests). Future research should focus on increasing the sample size to garner stronger evidence with respect to which barriers clinicians can apply to protect their skin. More research is necessary to have clinicians be fit tested with only one barrier, instead of having the participant apply multiple solutions in one sitting as QNFT is time consuming.

Another limitation of these findings is that they cannot be transferred to individuals who have not been fit tested with a skin dressing and tight-fitting respiratory worn together, non-3M brands of half-mask respirators or single-use N95/other disposable respirators without prior fit testing.

Future studies should evaluate the effect of different skin dressing interventions on longterm clinically significant outcomes, including COVID-19 infection rates. Simultaneously, we J o u r n a l P r e -p r o o f propose future studies that appraise which barriers not only protect skin breakdown, but also alleviate existing skin breakdown. We believe it may be beneficial to study whether disposable N95 masks are affected by any barrier methods and whether the re-sterilization of these masks may affect their fit factors with said barriers. Whether providers are wearing N95 or half-mask respirators, it is imperative to discover ways to reduce their occupational skin disease and physical discomfort without compromising the original function of these masks.

This pilot study provides initial results that Cavilon™ and Tegaderm™ may provide equal fit seal with half-face mask respirators compared to wearing the mask without a skin dressing. Additionally, the data indicates that the silicone gel tape is likely hazardous to clinicians for use with masks due to breaking the fit seal. Researchers in the field of dermatology, infectious disease, and occupational safety need to come together to ensure that our healthcare workers feel comfortable and safe treating COVID-19 patients and other airborne diseases in the coming months and in future pandemics. Table 2 presents the geometric means (because data is skewed) and their 95% confidence intervals. Superscripts indicate which pairs are treatments are independent for each seal type. 

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Table 3 is an alternative presentation of the results. Instead of giving means for the various seal types, we give the percent change from the control. The only significant pairwise effects

We would like to thank the Rutgers Robert Wood Johnson University Hospital clinicians who volunteered their valuable time to participate in our study. Thank you, Thomas Block, and the