Custom solution for personal protective equipment (PPE) in the orthopaedic setting: retrofitting Stryker Flyte T5 PPE system

The coronavirus disease 2019 pandemic has meant that there is growing pressure on hospital resources, not least the availability of appropriate personal protective equipment (PPE), particularly face masks and respirator masks. Within field orthopaedic surgery, it a common sight to see surgeons wearing ‘space suits’ (SSs) which comprise helmet, hood surgical gown.In this study, authors made modifications two different SS systems incorporate high-efficiency particulate air (HEPA) filter into fan inlet assess their potential as re-usable PPE for with regard protection from virus spread via respiratory droplets. testing was carried out using particle counters upstream downstream mannequin without inlet.The results show layer HEPA filter, cut size sealed in will reduce particulates at user's mouth by >99.5%; equivalent mask. material relatively cheap can be used repeatedly, making viable alternative disposable, even resterilized, setting respiratory-droplet-spread viral pandemic. gown. In inlet. emergence (COVID-19) pandemic, affecting most world's population, led concern regarding an international shortage (PPE). World Health Organization (WHO), recent guidance respect rational use PPE, stated ‘The current global stockpile insufficient, medical respirators’ [[1]World OrganizationRational considerations during severe shortages: interim guidance, 6 April 2020. WHO, Geneva2020Google Scholar]. Current advice number bodies recommends FFP2 or N95 eye protection, well gloves gowns, specific procedures, including surgery [2British Orthopaedic AssociationManagement patients urgent conditions trauma BOA, London2020Google Scholar, 3Royal College Surgeons IrelandIntraoperative recommendations when operating suspected COVID infected patients. RCSI, Dublin2020Google 4Thomas J.P. Srinivasan A. Wickramarachchi C.S. Dhesi P.K. Hung Y.M. Kamath A.V. Evaluating national NHS healthcare workers COVID-19 pandemic.Clin Med. 2020; 20: 242-247Crossref Scopus (55) Google More recently, all (HCWs) advised any person working within 2 m patient confirmed should mask [4Thomas 5Health Service ExecutiveGuidance context HSE Ireland, 6Public EnglandWhen FFP3 respirator. PHE, masks, such provide 95% 94% filtration 0.3-?m particles, they are best broadly available terms filtration, offer seal face. However, these custom fit each individual, face-fitting procedures required have limitations [[7]Ba?azy Toivola M. Adhikari Sivasubramani S.K. Reponen T. Grinshpun S.A. Do respirators level against airborne viruses, how adequate masks?.Am J Infect Control. 2006; 34: 51-57Abstract Full Text PDF PubMed (274) mean diameter acute syndrome coronavirus-2 (SARS-CoV-2) been reported 78 nm [[8]Goldsmith Tatti K.M. Ksiazek T.G. Rollin P.E. Comer J.A. Lee W.W. et al.Ultrastructural characterization SARS coronavirus.Emerg Dis. 2004; 10: 320Crossref (292) efficiencies relate ability submicron particles effectively, standardized uncharged sodium chloride measuring 300 Staphylococcus aureus Scholar,[9]Rengasamy Zhuang Z. BerryAnn R. Respiratory bioaerosols: literature review research needs.Am 32: 345-354Abstract (102) Studies questioned validity suggested performance may underestimate penetration nanosized virions High-efficiency filters same-sized certification, 99.97% efficient filtration. A study National Aeronautics Space Administration showed also smaller (c. 10 nm) [[10]Perry J.L. Agui J. Vijayakimar Submicron nanoparticulate matter removal HEPA-rated media packed beds granular materials. NASA, Langley, VA2016Google possibility bidding wars between governments acquire HCWs, Irish Government [[11]Éireann Raidió Teilifís seeks accelerate deliveries but warns supply remains challenging RTE, Dublin2020https://www.rte.ie/news/coronavirus/2020/0419/1132459-covid-19-ppe/Google With high reliance external supplies need design ways more self-reliant particular endure resurface, prepared future pandemics. Protocols being developed regards standardization sterilization acceptable retention efficiency after five cycles [[12]Teesing G. van Straten B. de Man P. Horeman-Franse Is commercially manufactured masks? comparison various materials forms.J Hosp Infect. 106: 246-253Abstract (32) Scholar,[13]de den Dobbelsteen der Eijk Horeman Koeleman H. Sterilization disposable means dry steam processes; fight shortages due COVID-19.J 105: 356-357Abstract (62) There resterilization, namely suffer mechanical damage process, often face-fit damaged process. Face sterilized if grossly contaminated; cannot re-used gross contamination blood spatters splash-back lavage. generates aerosolized human tissue, bone blood, through power tools procedures. These aerosol-generating inability resterilize prompted look question paper whether retrofitting Stryker helmet inlet, draped usual gown, would improve point comparable This proof-of-concept isolate effectiveness retrofitted its coming SS. experimental set-up involved (head torso mounted stand measure 180 cm height) cardiopulmonary resuscitation training subject tests. cleaned chlorohexidine scrub prior experiment, orifices other than nose were Steri-Drape™ (3M, Saint Paul, MN, USA). detector placed leucoplast sleek tape around mouth, isolating internal tubing mannequin, taping over nostrils (see Figure 1). fed bottom Steri-Drape. Testing performed theatre initially, background count found too low discern reliable difference detector. subsequently adjoining anaesthetic room, doors exhaust vents closed sealed. An ambient recording ensure distribution equal both points relation donned confirmed. Flyte T4 T5 [[14]Stryker CorpFlyte system. Kalamazoo, MI: Corp., 2020https://www.stryker.com/content/dam/stryker/orthopaedic-instruments/resources/Flyte%20Personal%20Protection%20System%20-%20COVID-19.pdfGoogle Both grill prevents sucked overlying amenable replacement damaging plastic housing off containing rubber gasket 2a). similar removed replaced housing. 2b illustrates modified allowed periphery prevent 3). taken SoniQ II™ system (Vokes Air, Ludwigsburg, Germany) [[15]VokesAir. IILudwigsburg: Vokes Air.2020http://www.vokes.co.za/SoniQ%20II.pdfGoogle Particulate certified engineer who commissions ventilation infrastructure jurisdiction. detection used, Aerotrak® Handheld Particle Counter Model 9306 (TSI, Shoreview, USA), industry standard; 2.83 L/min intake set read six channels enable reading range 0.3–10 ?m. protocol measurement recorded four challenge samples 60 s either same space relative head hood. Four consistent, readings 15% mean, three outlined below. Ten configurations hoods. counts collected tabulated Excel (Microsoft Redmond, WA, statistical analysis test Student's t-test. follows:•Ambient – no mannequin. confirmed.•Configuration 1. standard gown neck running.•Configuration 2. running medium speed.•Configuration 3. mount 2), 4. 5. 6. sealant bypass 3), then speed. order investigate gas levels non-modified use, second author (JH) wore serial collection data machine (GE Datix Ohmeda Asyis & GE Carescape B650, Madison, Wisconsin, experiment functional laminar airflow narrow (1.2-mm diameter) PVC CO2 sample tube, connected multi-gas analyser E-CAiO Module, Helsinki, Finland), inside participant's end-tidal carbon dioxide (ETCO2) oxygen (ETO2) continuously. side-stream draws 150 mL/min airway gas, where concentration calculated absorption infra-red light, according Beer–Lambert law, paramagnetic analysis. No additional worn. Measures ETCO2, ETO2 fraction inspired (FiO2) 5-min intervals helmet. Table I shows percentage detector, associated deviation, All triplicate. For generations modifications, total taken. II presents t-test significance differences observed. 4 overall (range ?m), 5 provides breakdown channel spectrum sizes detected set-up.Table IMean configurationsConfiguration 1: hood, fanConfiguration 2: hoodConfiguration 3: 4: 5: 6: hoodMean penetration8.8924.244.7910.9020.540.46Standard deviation penetration4.501.411.060.303.780.24 Open table new tab IIComparison configurationsComparative t-tests penetrationTest configuration lower penetrationDifference penetrationP-valueTest configurations1 vs 2115.35%0.00492 3319.45%<0.00012 553.7%0.135 6620.08%<0.00013 664.33%<0.0001 5Results individual Aerotrak (error bars represent +/? one deviation).View Large Image ViewerDownload Hi-res image Download (PPT) system, alone certain degree outside particulates, only 8.89% (? = 4.96%) penetration. Once turned SS, increased 24.24% 1.41%). modification reduced significantly 4.79% 1.06%). 10.9% 0.3%); different. Similar above, once on, 20.54% 3.78%); again, operating. 0.46% 0.24%), better offers N99 Counter, showing <0.5% run addition impenetrable cover except area did efficiency, leading conclusion positive experienced enough negate possible infiltration directly III illustrated 6, 7, 8. ETCO2 remained steady throughout recording. higher compared unmodified 6). FiO2 appeared slightly FiCO2, dioxide, normally 0. It observed resulted increase FiCO2 7). normal 21%, demonstrated reduction SSs 8). user report mild discomfort hoods; however, rated regular mask.Table IIIResults (fan switched on)Time (min)Modified systemNon-modified systemETCO2 (%)FiCO2 (%)FiO2 (%)ETCO2 (%)051.5194.40.22054.91.11940.320104.71.6194.10.520154.91.1194.40.520204.91.1194.40.220ETCO2, dioxide; FiO2, oxygen. 7Comparison (blue line) (orange variation (FiCO2) (%) time.View (PPT)Figure 8Comparison offered close 90% particles; 20–25% systems. Implementation significant penetration; <0.5%, longer life-span resterilization pilot filters, further confirm recommended establish timing quality assurance checks efficacy protect [[16]Abraham Smith P.M.L.B. McCabe experience biological laboratory.J Am Biol Saf Assoc. 1998; 134-142Google Scholar,[17]Mittal Parks S.R. Pottage Walker J.T. Bennett A.M. Survival microorganisms filters.Appl Biosaf. 2011; 16: 163-166Crossref Derrick al. previously investigated feasibility [[18]Derrick Gomersall C.D. Surgical helmets infection.Emerg 277Crossref (39) They concluded suit insufficient HCWs Scholar], present SSs. Their comparative volunteers combination N100 filtering facepiece full-face shield. methodology, breathing zone 1 below edge transparent piece, whilst respirator, probe passed covering right valve. confounders observed, potentially in-vivo testing, follows:•The necessarily replicate true entering allowing entrainment surrounding slightest breach Scholar].•Similarly, area, account subject's hair skin counting towards readings, given environment top downwards. Currently, jurisdictions, recommendation dealing cases SARS-CoV-2 [[4]Thomas reliant adequacy face-fit; studies shown face-fit, controlled environments, variable depend rate position Previous work undertaken effect exerted exert way down breach, glove–sleeve interface [[19]Hooper Rothwell Frampton C. Wyatt Does flow suits early deep infection hip knee replacement? ten-year New Zealand Joint Registry.J Bone Surg Br. 93: 85-90Crossref (186) Scholar,[20]Nakajima D. Tateiwa Masaoka Takahashi Y. Shishido Yamamoto K. modern intraoperative joint study.Eur Orthopaed Traumatol. 2017; 27: 1139-1143Crossref (5) Although tests static provided highly filtered source face-fit. Rather, protected static. reason why methods because shedding millions forced pushed head/hair/face, breathed living person, hence changing micro-environment accounted therefore lead systematic bias could influence findings pull considered valid method acting form user, confounding factor having inherently change responsible protecting user. Another benefit bloodborne viruses reassurance surgeon cutting creating tissue material. transmission yet known, RNA donation theoretical risk [[21]Chang L. Yan Wang Coronavirus 2019: coronaviruses safety.Transfus Med Rev. 75-80Crossref (433) Scholar,[22]Le Chang L.Z. Gong Severe donations.Emerg 26: 1631Crossref (131) Erickson three-dimensional printed manifold [[23]Erickson M.M. Richardson E.S. Hernandez N.M. Bobbert II, D.W. Gall Fearis Helmet 3D printing Duke University Medical Center: novel technique.J Arthroplast. 35: S23-S27Abstract (70) details filtered, independently verified meet standards added volume weight had hoses exited toga posteriorly jeopardize sterility field. contrast, described add encumberment outward appearance appears hoods safe appreciable interval time. approximation arterial concentration, system; continue fresh result filter. appear impact respiration prolonged period, deterioration gaseous exchange noted duration study. Similarly, although systems, reductions state time, suggesting ventilation, sufficient keep up consumption conclusion, aim evaluate reasonable PPE. well-established routine solution shortage. By fitting months time before needing assessed changed, require burden. rigorous validation mass roll-out. validated evidence safely operation some c. 10% concerns raised previous valid, whereby suction allows 25%. must operated <5% Downstream (<0.5%) shape edges (>99% 0.3 um particles) equivalent, greater purposes reducing areas health care COVID-19, palatable surgeons. None declared.