Feasibility study: Proposed alternative to N95 respirator during the personal protective equipment shortage from COVID-19 pandemic.

INTRODUCTION: Having an adequate supply of personal protective equipment during the COVID-19 pandemic has been a constant challenge for hospitals across the United States. In the event of shortages, our assembled mask might offer noninferior protection compared to an N95 respirator. OBJECTIVE: To study the ability of an assembled mask to pass a quantitative fit testing. METHODS: We conducted a feasibility study at the Oklahoma City Veteran Affairs Health Care System. Volunteers were fitted with an assembled mask made of either a Hans Rudolph half-face mask or a Respironics Performax full-face mask, attached to an Iso-Gard HEPA light Filter 28022 through a Performax SE elbow hinge. Quantitative fit testing was conducted using the Occupation Safety and Health Administration fit testing protocol. The primary outcome was the percentage of participants who pass the quantitative fit test. Secondary outcomes included the overall fit factor (FF), average FF for different exercises, changes in pulse oximetry and end-tidal CO2 at 0 and 15 minutes, willingness to use the mask, and visibility assessment. RESULTS: Twenty participants completed the study, and all (100 percent) passed the quantitative fit testing. The overall FF had a geometric mean of 2,317 (range: 208-16,613) and a geometric standard deviation of 3.8. The lowest FF was recorded while the subjects were talking. Between time 0 and 15 minutes, there was no clinically significant change in pulse oximetry and end-tidal CO2 levels. Most participants reported "very good" visibility and were "highly likely" to use the Hans Rudolph half-face mask in the case of shortage. CONCLUSION: Our assembled respirator offers noninferior protection to N95 respirators in the setting of hypothetical protective equipment shortage.

Size-resolved spatial distribution analysis of aerosols with or without the utilization of a novel aerosol containment device in dental settings.

The coronavirus disease 2019 pandemic has imposed unprecedented occupational challenges for healthcare professionals. In dentistry, handheld instruments such as air and electric handpieces, ultrasonic scalers, and air/water syringes are capable of generating aerosols, droplets, and splatter, thereby exposing dental professionals to airborne contaminants such as viruses, bacteria, and fungi. The objective of the present study was to determine the spatial distribution of aerosols by size (0.30 to 20.00 µm) and the efficacy of a novel aerosol containment device (ACD) in a large operatory room with 12 dental chairs. Real-time portable laser aerosol spectrometers were used to measure the size-resolved number concentration of aerosols generated by a collision nebulizer. Results reported demonstrate that aerosol number concentrations significantly decreased as a function of distance with or without the utilization of the ACD. The ACD was able to efficiently decrease (up to 8.56-fold) the number and size distribution of particles in a large dental clinic. The novel device demonstrated higher efficiency for particles shown to contain the highest levels of severe acute respiratory syndrome coronavirus 2 in Chinese hospitals, thereby showing great promise to potentially decrease the spreading of nosocomial pathogens in dental settings.

Quantitative fit testing of filtering face-piece respirators during the COVID-19 pandemic reveals anthropometric deficits in most respirators available in Iran.

PURPOSE: Frontline health care workers (HCWs) must wear a standard N95 or FFP2 respirator during worldwide pandemics of respiratory diseases including COVID-19 to protect against airborne infectious pathogens when performing care activities. This study aimed to quantitatively investigate the fit of most of the common FFRs used during the COVID-19 pandemic in Iran. METHODS: A total of 37 volunteers were fit tested in 20 selected FFRs in a randomized order. The selected FFRs were underwent quantitative fit testing by PortaCount® model 8038. To determine the effects of face sizes on respirator fit, the participants' facial dimensions were measured using a digital caliper. RESULTS: The rate of passing fit tests for the studied FFRs were surprisingly low with 11 out of 20 FFRs having less than 10% passing fit tests and the best performers having only 43% and 27% passing fit tests (brands 2 and 20, respectively). Cup-shaped respirators provided significantly greater fit than the vertical flat-fold ones (p < 0.001). A significantly different FFs were found among the respirator brands (F = 13.60, p < 0.001). CONCLUSION: Overall, unacceptably low fit factors were obtained from the studied FFRs. The main reasons for this are suspected to single size and style for each studied FFR. It confirms the importance and requirement of the proper respirator selection in that way fitted optimally into facial dimensions, appropriate usage, and properly performing the fit testing procedure. A unique fit test panel should be developed to guide respirator wearers in selecting the appropriate FFR for their specific face sizes.