Presentation on theme: "Unit 7.1. Respiratory protection TB Infection Control Training for Managers at National and Subnational Level Photo courtesy of WHO/Dominic Chavez."— Presentation transcript:
1Unit Respiratory protection TB Infection Control Training for Managers at National and Subnational LevelPhoto courtesy of WHO/Dominic ChavezJohn Donnelly. Airborne: a journey into the challenges and solutions to stopping MDR-TB and XDR-TB WHO/HTM/STB/
2Objectives After this unit, participants will be able: To describe the differences between a surgical mask and a respiratorTo name the types of respirators that protect against TB transmission, and when to use themTo list the elements of a respiratory programme[Review slide]
3Outline WHO recommendations Surgical mask vs. particulate respirator Respirator standardsRespirator programmeProper useFit testingThis unit starts with WHO recommendations for respirators.We’ll then contrast the surgical mask with the particulate respirator.We’ll address respirator standards.We’ll talk about how a respiratory programme is needed whenever respirators are used.In the exercise that follows, participants will get “hands-on” experience putting on and fit testing respirators.
4WHO recommendationsWhen used with administrative and environmental controls, particulate respirators may provide health care workers (HCW) additional protection from TBRespiratorsMust meet or exceed standardsBe properly usedBe part of a training programme[Review slide]WHO also recommends when to use respirators, as we’ll see on the next slide.CitationWHO. WHO policy on TB infection control in health-care facilities, congregate settings, and households WHO/HTM/TB/
5WHO recommends particulate respirators for HCWs: Caring for patients with confirmed or suspected infectious TB (in particular MDR-TB)Performing aerosol-generating procedures on infectious TB patientsBronchoscopy, intubation, sputum inductionUse of high speed devices for lung surgery or autopsy[Review slide]CitationWHO. WHO policy on TB infection control in health-care facilities, congregate settings, and households WHO/HTM/TB/
6Surgical masksReduce the spread of microorganisms from the wearer to others, by capturing large wet particlesDo not protect the wearer from inhaling small infectious aerosols.This person is wearing a surgical mask.Surgical masks are designed to capture large, wet particles.During surgery, they prevent contamination of the sterile field by the surgeon’s germs.They do not protect the wearer from inhaling small infectious aerosols.Surgical masks have large pores and lack a tight seal around the edges.
7Particulate respirators Protect the wearer from inhaling droplet nucleiFilter out infectious aerosolsFit closely to the face to prevent leakage around the edges[Review slide]Photo courtesy of GB Migliori
8Photo from “Control de infecciones de tuberculosis en establecimientos de salud- Módulo de capacitación. Ministerio de Salud, Peru,” courtesy of Paul Jensen
9Surgical masks (yes for patients) The slide shows infectious MDR-TB patients in an MDR-TB department.[Ask participants]: Is respiratory protection being used correctly here?Problems include:One patient is not wearing a mask.One patient’s mask is not tied properly.While working with infectious MDR TB patients, the health care worker is not using a respirator.Photo courtesy of GB Migliori
10Surgical masks do not protect staff from TB Surgical masks do not protect health care workers from TB.The picture on the left shows a physician wearing a mask in a former Soviet Union country, in a room where TB patients receive directly observed therapy.If some of the patients are infectious, this mask is not sufficient protection for the health care worker.The picture in the right side shows an operating room in an African hospital. The masks protect the sterile field, not the health care workers.If this is an infectious TB patient undergoing lung surgery with high speed devices, the staff are not adequately protected from TB transmission.Photos courtesy of Paul Jensen (upper left) and GB Migliori (lower right)
11Particulate respirators used for TB exposure N95 (USA)Filter out > 95% of particlesFFP2, FFP3 (Europe)Filter out > 94-98% of particlesBoth the US and Europe have respirator standards in use throughout the worldOn the left of the slide, N95 respirators from the US effectively filter out > 95% of the particles 0.3 μm in aerodynamic diameterThe equivalent respirators according to the European standard are FFP2 and FFP3 (on the right).The FFP2 filters out > 94% of the particles 0.4 μm in aerodynamic diameter; the FFP3 filters out >98%Adapted from: Control de infecciones de tuberculosis en establecimientos de salud- Módulo de capacitación. Ministerio de Salud, Peru
12USA standards* Filter efficiency N (not resistant to oil) TB protection95%N95✓99%N9999.97%N100For providing routine TB care, the N-95 respirators are sufficient.Their filtration efficiency is 95%.The N stands for “not resistant to oil.” This is only an issue in industrial settings where oil aerosols can block the filter.CitationCenters for Disease Control and Prevention (USA). Guidelines for preventing the transmission of Mycobacterium tuberculosis in health care settings, MMWR 2005:54(No. RR-17). (See also errata published on 25 September 2006)*National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC)
13European standards* Total inward leakage Filtering Face Piece TB protection<25%FFP1Not adequate<11%FFP2✓<5%FFP3The total inward leakage defines the FFP2, FFP2 and FFP3 levels in the European standard.FFP2 and FFP3 are like N95, appropriate for TB protectionFor more information see*Comité Européen de Normalisation (CEN)(European Committee for Standardization)
14CEN standards Total inward leakage Initial filter penetration NaCL Paraffin oil<20%=P NA=P1< 6%=P2 <2%=P2< 3%=P3 <1%=P3Maximum breathing resistanceLoading testIn addition to total inward leakage, CEN standards include initial filter penetration of NaCl and paraffin oil.Two additional CEN parameters are maximum breathing resistance and loading.Which is the difference between CDC-NIOSH and CEN standards?CDC-NIOSH criteria deal with filtration efficiency only, while CEN (European) standards cover, in addition, how many people the respirators fit.For more information see
15Air-purifying respirators Remove specific air contaminants by passing ambient air through the air-purifying filter, cartridge or canisterHere are pictures of air-purifying respirators.The picture on the left shows a disposable air purifying respirator. The N95s and FFPs we just discussed are disposable air purifying respirators. The face piece itself is the filter.In the other 2 pictures, cartridges or canisters filter the air. These respirators are not disposable; they are made of a rubber-like material that is washable.The picture in the middle is a half-facepiece respirator, while the picture on the right covers the full face. Both have exhaust valves.The wearer may feel ‘cooler’ when wearing a respirator with an exhaust valve. But respirators with exhaust valves should not be used when a sterile field is needed, as in surgery.Photos courtsey of Paul Jensen
16Negative pressure respirators air pressure inside the facepiece is negative during inhalationcontaminated air can avoid the higher-resistance filter and leak in through gaps in the face sealFace seal leakage is an inherent problem in negative pressure respirators.Leakage around the face seal limits a respirator’s protective abilityEach time the wearer inhales, negative pressure (relative to the workplace air) is created inside the facepieceBecause of this negative pressure, contaminated air can avoid the higher-resistance filter and leak through any gaps in the face sealPhotos courtesy of Paul Jensen
17Types of air purifying respirators Non–powered (negative pressure)Powered air-purifying respirators (PAPR)A blower draws air through the filter and blows it into the face piecePressure inside face piece reduces face-seal leakage (offers more protection)Loose fitting PAPRs can be used for people that cannot achieve an adequate sealWe have been talking about non powered air purifying respirators, and that face seal leakage is an inherent problem with negative pressure respirators.There is another type of air purifying respirator that is powered.A blower draws air through the filter and blows it into the face piece.This creates pressure inside face piece which reduces face-seal leakage during inhalationThis means the respirator offers more protection.In the US, powered air purifying respirators (PAPRs) may be used during high risk procedures, such as bronchoscopy on potentially infectious patientsLoose fitting PAPRs can be used for people that cannot achieve an adequate seal (such as health care workers with facial hair)CitationCenters for Disease Control and Prevention (USA). Guidelines for preventing the transmission of Mycobacterium tuberculosis in health care settings, MMWR 2005:54(No. RR-17). (Errata published on 25 September 2006)
18Respirator programme elements Person assigned responsibilityWritten proceduresMedical evaluationTrainingSelection of respiratorsFit testingMaintenanceProgramme evaluationWhenever respirators are used, a respirator programme is necessary.The main elements of the respirator programme are summarized in the slide.One person should be given the authority and responsibility to manage the programme.Written procedures should describe when and how respirators are to be used.Health screening is done to be sure that health care workers are physically capable of performing job duties when wearing a respirator.Training should include information on the risk of TB transmission and how to prevent it, and the appropriate use of respirators.Respirators should be selected that meet standards for protection (N95, FFP2 or FFP3).Several sizes are necessary to fit a range of faces.We’ll talk about fit-testing next and maintenance later in this unit.Finally, the respirator programme should be evaluated periodically.
19Why is fit testing necessary? Ensure a proper seal between respirator and wearerDetermine appropriate make/modelDetermine appropriate sizeWe conduct fit testing in order to be sure that each person’s respirator fits adequately.This means checking that there is a proper seal, as face seal leakage compromises the respirator’s ability to protect the wearer.We do not want people to have a false sense of security when wearing the respirator.The fit test is required to select the appropriate model and size.
20When should fit testing be done? Employees should pass a fit test:Prior to initial useWhenever a different respirator facepiece (size, type, model or make) is usedPeriodically thereafterWhenever changes in the worker’s physical condition or job description that could affect respirator fit are noticed or reported[Review slide][Ask participants]:What is done in the participants’ own hospitals/settings?
21Sources of facepiece leakage Around facepiece/skin interfaceThrough air-purifying elementThrough exhalation valve[Review slide]Arrows show leakage points if the fit is not correct.from: Control de infecciones de tuberculosis en establecimientos de salud- Módulo de capacitación. Ministerio de Salud, Peru, courtesy of Paul Jensen
22Factors contributing to poor fit Weight loss or gainFacial scarringChanges in dental configuration (dentures)Facial hairCosmetic surgeryExcessive makeupMood of workers (smiling/ frowning)Body movementsWhich are the factors responsible for poor fitting respirators?[Review slide]There is no one size that fits all.You will always have people who will require a different model.
23Qualitative fit tests: Rely on the individual’s response to the test agent to assess the adequacy of respirator fitAre scored as pass/fail[Review slide]Photo from: Control de infecciones de tuberculosis en establecimientos de salud- Módulo de capacitación. Ministerio de Salud, Peru, courtesy of Paul Jensen
24Test solutions for qualitative fit testing Four methods recognized and acceptedIsoamyl acetateIrritant aerosolSaccharinBitrexTM (Denatonium benzoate)• Four methods are presently accepted to perform qualitative fit tests.• Among them, saccharin and BitrexTM tests are the easiest to perform
25Fit tests using saccharin or BitrexTM Can be used for all respirators (i.e. 95-, 99- and 100- series and FFP2 and FFP3)Uses subject’s sense of tasteRequires the use of small test hood[Review slide]
26Saccharin and BitrexTM Subject demonstrates ability to detect weak solution in the test hoodSubject dons respiratorStrong solution (~100 times) sprayed into hoodRespirator passes if subject does not taste aerosolAssumed fit factor = 100If the subject tastes the Bitrex or saccharin while wearing the respirator he/she failed the test.Otherwise, the test was passed.This is assume to be equivalent to a fit factor of 100 if a quantitative fit test had been done.(We’ll talk about quantitative fit tests in a moment.)
27Qualitative fit test equipment The 3M Qualitative Fit Test Apparatus is shown, as an example, in the picture.There are several other options in the market.
28Quantitative fit tests: Measure the amount of leakage into the respirator to assess the adequacy of respirator fitAre scored with a number[Review slide]
29Maintenance and storage Take care of your disposable respiratorDecontamination NO!Cleaning NO!Storage Clean & dry place!Take care when re-using respirator – closely monitor service lifeInspect prior to each useDispose of the respirator if you question its performanceWhat should be done and what should not be done to take care of a disposable respirator?Never try to clean or decontaminate it!The respirator should be kept in a clean, dry place.A disposable respirator may be re-used by the same health worker, as long as it is not wet, damaged, or contaminated with blood or body fluids, and as long as breathing resistance does not increase.Check the manufacturer’s instructions for the specified service life.Filtering facepieces must be inspected prior to each use
30Read the manufacturer’s instructions to don the respirator properly Staff wearing respirators should carefully read the instructions before using them.Photo courtesy of Paul Jensen
31Is this respirator put on properly? [Ask participants]:Is this respiratory put on properly?Problems include:The filter is not centered. In the side view, you can see some of the wearer’s right nostril.The lower elastic band is missing.In many respirators, the elastic is of poor quality, and it stretches or can break after pulling it a couple of times only.Photo courtesy of Paul Jensen
32Post warning signThe slide shows a warning sign posted outside a patient’s room in Brasil.This is a reminder that health care workers who enter need to wear a respirator.If the patient needs to be transported, he or she should wear a surgical mask.From: Control de infecciones de tuberculosis en establecimientos de salud- Módulo de capacitación. Ministerio de Salud, Peru, courtesy of Paul Jensen.
33Time to clear the air between patients Here is another example of a warning posted on a room after an infectious TB patient has left.The time is recorded on the clock, indicating when it is safe to enter without a respirator.Once the time has passed, a new patient can enter the room.The time to clear the air is determined on the basis of the room’s air changes per hour we discussed in the unit on ventilation.Photos courtesy of Paul Jensen
34Bronchoschopy roomNow lets look at respiratory protection in several settings.The picture shows a bronchoscopy room in central Europe.[Ask participants:]What is wrong with this picture?[Responses should include]:Bronchoscopy is a high risk medical procedure, and staff should be wearing respirators.Only one health care worker is wearing a mask, but it provides no protection from droplet nuclei since it is a surgical mask, not a respirator.Also, in terms of administrative controls, too many staff are present. No more staff than necessary should be present.Courtesy of GB Migliori
35DOT room Does this nurse providing DOT need respiratory protection? There is insufficient information from the picture on the risk of TB transmission.Here are factors to consider:Could infectious TB patients be present, such asundetected TB cases (e.g. suspects)newly diagnosed patients during the first days of the intensive phase of treatment being still potentially infectiouspatients not responding to treatment, who may have MDR-TBWhat is the ventilation in the area?Photo courtesy of GB Migliori
36Isolation XDR-TB tent and DOT This young patient with XDR-TB lived in a isolation tent placed in front of a hospital in Africa.The nurse provided DOT (including injections) outside of the tentThe patient is not wearing the surgical maskThe patient died in spite of treatment with second line drugs. Should the nurse have worn a respirator?No, the nurse is interacting with the patient outdoors, where there is ample ventilation.Courtesy of Mario C. Raviglione
37SummarySurgical masks prevent infectious particles from being expelled by the wearerRespirators protect the health care worker from inhaling infectious particlesWhen used with administrative and environmental controls, N95, FFP2 or FFP3 respirators provide additional protection when HCWs care for infectious TB patientsWhenever respirators are used, a respirator programme is necessary[Review slide]