Fit and filter integrity of a respirator mask after multiple cycles of autoclave

2021 ◽  
pp. bmjinnov-2020-000521
Author(s):  
Nidhi Desai ◽  
Hasan Naveed ◽  
Michael Koenig ◽  
Jörg Huber ◽  
Nikil Kapur ◽  
...  

BackgroundThe COVID-19 pandemic has led to profound shortages in personal protective equipment worldwide. The availability of filtering facepiece class 3 (FFP3) respirators could be greatly increased if they could be reused after sterilisation.AimsTo determine the effects of repeated autoclave cycles on the fit and filter function of the 3M 1863 FFP3 disposable respirator.MethodsParticipants underwent fit tests with 3M 1863 FFP3 respirators. Respirators were subjected to autoclave cycles and a repeat fit test was conducted after each cycle until failure. The filter function of both unused and autoclaved respirators was determined by quantitatively assessing the differential pressures and filter penetration of aerosolised sodium chloride particles. Mask structural inspection was also carried out by light microscopy.ResultsA total of 38 participants were recruited. Repeat fit testing with a new respirator was passed by 30 of 38 (79%) participants in comparison with 31 of 38 (82%) of participants after the respirator had undergone one autoclave cycle. There was fit test failure with further rounds of autoclave. There was no evidence of structural changes after one autoclave cycle, but the nose foam began to separate from the mask following further cycles. Filter efficiency of all 15 autoclaved respirators that underwent filter testing was 97.40% or more. Differential pressure (breathability) of respirators was unaffected by autoclaving.Conclusions3M 1863 FFP3 respirator retains good fit and filter function after a single autoclave cycle. Addressing nose foam separation and further testing to EN149 standards would be required before respirators could be considered for reuse.

Author(s):  
Stephanie Toigo ◽  
Michel Jacques ◽  
Tarek Razek ◽  
Ewa Rajda ◽  
Sidney Omelon ◽  
...  

ABSTRACT Objective: Bottlenecks in the personal protective equipment (PPE) supply chain have contributed to shortages of PPE during the COVID-19 pandemic, resulting in fractures in the functionality of healthcare systems. This study was conducted with the aim of determining the effectiveness of retrofitted commercial snorkel masks as an alternative respirator for healthcare workers during infectious disease outbreaks. Methods: A retrospective analysis was performed, analyzing qualitative and quantitative fit test results of the retrofitted Aria Ocean Reef® full-face snorkeling mask on healthcare workers at the McGill University Health Centre between April-June 2020. Historical fit test results, using medical-grade respirators, for healthcare workers were also analyzed. Results: During the study period, 71 participants volunteered for fit testing, 60.6% of which were nurses. The overall fit test passing rate using the snorkel mask was 83.1%. Of the participants who did not previously pass fit testing with medical-grade respirators, 80% achieved a passing fit test with the snorkel respirator. Conclusions: The results suggest that this novel respirator may be an effective and feasible alternative solution to address PPE shortages, while still providing healthcare workers with ample protection. Additional robust testing will be required to ensure that respirator fit is maintained, after numerous rounds of disinfection.


2021 ◽  
Vol 19 (7) ◽  
pp. 192-202
Author(s):  
Ahel El Haj Chehade, MD ◽  
Jesintha Stephenson, MD ◽  
Evan Floyd, PhD ◽  
Jean Keddissi, MD, FCCP ◽  
Tony Abdo, MD ◽  
...  

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 endtidal 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.


2020 ◽  
Vol 4 (4) ◽  
pp. 203-209
Author(s):  
Shiv Dalla ◽  
Rohit Shinde ◽  
Jack Ayres ◽  
Stephen Waller ◽  
Jay Nachtigal

Personal protective equipment (PPE) shortages persist amidst increasing COVID-19 caseloads. These shortages encouraged some to pursue 3D printing to produce stopgap N95 alternatives. The design presented is an adapter for a commercially available snorkel mask to serve as a full-face respirator, used in dire PPE shortages or in individuals who failed fit testing. Masks were fit tested at The University of Kansas Health System in Kansas City, KS. The mask was fit tested on 22 individuals who previously failed fit testing, and all passed qualitative fit testing with the snorkel mask, adapter and viral filter apparatus. The authors endorse this design as a stopgap measure, proven to be effective in situations of dire PPE shortage or for individuals who have failed fit testing with conventional PPE.


2020 ◽  
Author(s):  
Mahesh Ramanan ◽  
Alexis Tabah ◽  
Kevin Laupland

The COVID-19 pandemic has led to global shortages of personal protective equipment (PPE). Healthcare workers (HCW) have comprised a significant proportion of COVID-19 cases in many countries. The PPE-SAFE survey was conducted to study current practices, availability, shortages, training and confidence in PPE amongst intensive care HCWs around the world. Herein, we describe the results of the Australian respondents to the PPE-SAFE survey. 29% of respondents reported that at least one item of usually available PPE was missing, and 12% reported reuse of single-use items. Only 40% felt that the PPE available to them offered adequate protection. Fit-testing of respirators had never been performed for 47% of respondents, and 49% reported at least one adverse effect from the use of PPE.


2020 ◽  
Author(s):  
Sven Duda ◽  
Sascha Hartig ◽  
Karola Hagner ◽  
Lisa Meyer ◽  
Paula Wessling Intriago ◽  
...  

Background In 2020 the SARS-CoV-2 pandemic caused serious concerns about the availability of face masks. This paper studies the technical feasibility of user specific face mask production by 3D printing and the effectiveness of these masks. Material and Methods Six different face mask designs were produced by 3D printing and tested by subjective experimenter evaluation and using a respirator fit testing kit. Results were compared to the requirements as given for standard protective face masks. Results None of the printed masks came anywhere near the required standards for personal protective gear.ConclusionIn spite of their euphoric presentation in the press, none of the currently advertised 3D printed mask designs are suitable as reliable personal protective equipment.


2020 ◽  
Vol 59 (04) ◽  
pp. 294-299 ◽  
Author(s):  
Lutz S. Freudenberg ◽  
Ulf Dittmer ◽  
Ken Herrmann

Abstract Introduction Preparations of health systems to accommodate large number of severely ill COVID-19 patients in March/April 2020 has a significant impact on nuclear medicine departments. Materials and Methods A web-based questionnaire was designed to differentiate the impact of the pandemic on inpatient and outpatient nuclear medicine operations and on public versus private health systems, respectively. Questions were addressing the following issues: impact on nuclear medicine diagnostics and therapy, use of recommendations, personal protective equipment, and organizational adaptations. The survey was available for 6 days and closed on April 20, 2020. Results 113 complete responses were recorded. Nearly all participants (97 %) report a decline of nuclear medicine diagnostic procedures. The mean reduction in the last three weeks for PET/CT, scintigraphies of bone, myocardium, lung thyroid, sentinel lymph-node are –14.4 %, –47.2 %, –47.5 %, –40.7 %, –58.4 %, and –25.2 % respectively. Furthermore, 76 % of the participants report a reduction in therapies especially for benign thyroid disease (-41.8 %) and radiosynoviorthesis (–53.8 %) while tumor therapies remained mainly stable. 48 % of the participants report a shortage of personal protective equipment. Conclusions Nuclear medicine services are notably reduced 3 weeks after the SARS-CoV-2 pandemic reached Germany, Austria and Switzerland on a large scale. We must be aware that the current crisis will also have a significant economic impact on the healthcare system. As the survey cannot adapt to daily dynamic changes in priorities, it serves as a first snapshot requiring follow-up studies and comparisons with other countries and regions.


1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.


2020 ◽  
pp. 30-33
Author(s):  
E. V. Panina ◽  
M. V. Pugachev ◽  
A. G. Shchesiu

The article shows that in the daily activities of nursing staff of functional diagnostics departments (offices), it is necessary to strictly observe the requirements and rules for the prevention of infections associated with medical care, especially during the COVID-19 pandemic. The types of personal protective equipment (PPE) of medical personnel (MP), as well as current effective methods of disinfection, rules for collecting medical waste in a complex epidemiological situation are presented.


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