Latest / The SHEA Podcast / COVID-19 Role Of Ventilation And Filtration With ASHRAE (Part Two)

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COVID-19 Role Of Ventilation And Filtration With ASHRAE (Part Two) · The SHEA Podcast

• 0:10
  SPEAKER_01: Welcome to We're All In This Together: COVID-19 Allies and Infection Prevention Podcast Series as part of the Society for Healthcare Epidemiology of America, SHA Rapid Response Program.
• 0:20
  SPEAKER_01: My name is Erica Chinoy.
• 0:22
  SPEAKER_01: I'm an infectious diseases physician at Massachusetts General Hospital, where I'm associate chief of the infection control unit, and I will serve as your SHA moderator.
• 0:30
  SPEAKER_01: I'm very happy to welcome back Jonathan Flannery, who's the Senior Associate Director of Advocacy at the American Society for Healthcare Engineering of the American Hospital Association, who's here to represent Ashray, the American Society of Heating, Refrigerating, and Air Conditioning Engineers.
• 0:46
  SPEAKER_01: I'm also pleased to welcome back Dr.
• 0:48
  SPEAKER_01: David Weber, an infectious diseases epidemiologist at the University of Carolina Chapel Hill, where he is a professor of medicine and pediatrics and will be representing today.
• 0:57
  SPEAKER_01: The discussion on the podcast area does not reflect shades or Ashtray's perspectives, but is meant to facilitate communication of multiple perspectives and experiences as we go through this challenging time together.
• 1:08
  SPEAKER_01: Given the intense focus on facility design and specifically the role of ventilation and filtration in reducing the risk of transmission of pathogens, including SARS COVID and healthcare facilities, this is part of a two-part podcast.
• 1:20
  SPEAKER_01: In part one, if you joined us, we learned about ventilation, use of pressurization and filtration in healthcare facilities and in other locations, and focused on the regulatory requirements that set those standards.
• 1:32
  SPEAKER_01: We also covered some of the different ways in which engineers and hospital epidemiologists describe transmission of pathogens such as SARS-CoV-2.
• 1:40
  SPEAKER_01: In today's podcast, this is part two, we will cover some of the most commonly posed questions to both facilities, engineers, and epidemiologists that relate to modifying ventilation, pressurization, and filtration, and learn about the role of ultraviolet germicidal irradiation or UVGI, about plexiglass, which I'm sure that many listening to the podcast have been asked about, and whether or not it is the panacea that many believe it to be, and some of the top research questions that our guests have for the future.
• 2:07
  SPEAKER_01: So we'll get started.
• 2:08
  SPEAKER_01: I'm going to start with you, David.
• 2:10
  SPEAKER_01: As a hospital epidemiologist, one of the most common questions I get is whether or not the ventilation in a particular location, and it can be clinical or non-clinical, is adequate in the context now, really, of a concern of the transmission risk from droplets or droplet nuclei or aerosols when they read about possible airborne transmission in non-healthcare settings.
• 2:31
  SPEAKER_01: These are settings where there maybe have been poor ventilation, and that's been cited as a contributing factor.
• 2:36
  SPEAKER_01: So my question for you is how do you think about approaching this and specifically the differences between clinical and non-clinical environments and the press for more air changes per hour?
• 2:45
  SPEAKER_01: And is more air changes per hour and more filtration always better?
• 2:50
  SPEAKER_00: Thank you very much for that question.
• 2:52
  SPEAKER_00: Let me first say, and most importantly, is that healthcare providers, and when they're in the room with the patient with COVID, the patient has any droplet or airborne spread disease, they must wear an appropriate face mask, an N95 mask for highly contagious diseases or aerosol generating procedures, otherwise, a medical mask.
• 3:13
  SPEAKER_00: No amount of air exchanges or levels of filtration is a substitute for proper use of personal protective equipment.
• 3:20
  SPEAKER_00: And I think the best example of that is there have been a number of air outbreaks on airliners, generally when people are sitting next to the infectious person or within a few rows, and that includes not only SARS-CoV-2, but tuberculosis, flu, and others.
• 3:34
  SPEAKER_00: And airliners have up to 30 air exchanges in hours.
• 3:38
  SPEAKER_00: Again, if you're close to somebody who's infectious and they're giving out a good cough or sneeze, excellent of ventilation and/or excellent filtration or both at more distal sites won't prevent transmission.
• 3:50
  SPEAKER_00: Masks are what prevent transmission.
• 3:52
  SPEAKER_00: That said and done, ventilation and filtration are both important, as are whether the room is positive or negative pressure.
• 4:01
  SPEAKER_00: Certainly, if we have a disease that's airborne transmitted and go longer distances, then we certainly want that person in a negative pressure room so that people in the corridor are not at risk.
• 4:13
  SPEAKER_00: If we have a patient who has is highly immunocompromised, such as a bone marrow patient, we want that person in a positive pressure room so people in the corridor who might have an airborne or droplet spread or disease wouldn't be sucked into the room.
• 4:28
  SPEAKER_00: There's no question in my mind that improved ventilation and improved filtration will lower the risk both for a droplet and airborne spread diseases.
• 4:37
  SPEAKER_00: What we don't know really is what that relationship is.
• 4:40
  SPEAKER_00: So we can't say going from an 85% filter to a 95% filter or 40 to 60% filter, or going from eight air exchanges to 10 air exchanges lowers your risk, that I'm aware of for any airborne or droplet disease by X amount.
• 4:57
  SPEAKER_00: On the other hand, if you look at swimming beaches, there's a very nice algorithm that would tell you how many coliforms you find in swimming water, when you need to close the beaches and what the risk is.
• 5:07
  SPEAKER_00: But those types of nomograms have not been created for these airborne and droplet diseases.
• 5:14
  SPEAKER_00: Obviously, we're focusing on SARS-CoV-2.
• 5:17
  SPEAKER_00: Let me say, of course, since 40% of patients who get the disease are asymptomatic, and we know pre-symptomatic patients are highly infectious.
• 5:26
  SPEAKER_00: We need to worry about every patient as being potentially infectious, and wear our masks universally throughout the healthcare facility as well as eye protection.
• 5:35
  SPEAKER_00: We need to treat every aerosol generating procedure as though it might be done on a patient with SARS-CoV-2, whether known infectious or not, and need to use an N95 respirator, and ideally, those should be in a minimum in private rooms.
• 5:50
  SPEAKER_00: And I think clearly we need to be very careful about proper donning and doffing.
• 5:55
  SPEAKER_00: That said and done for a SARS-CoV-2.
• 5:58
  SPEAKER_00: I'm not aware, unlike measles, varicella, smallpox, and tuberculosis, that there's any evidence that people out in the corridors, on other floors, in adjacent rooms have acquired SARS-CoV-2, even if the individual is undergoing an aerosol-generating procedure in that private room with the door closed.
• 6:19
  SPEAKER_00: So I think we need to keep in mind, and this is again how infectious disease epidemiologists separate the droplet that spread diseases, such as SARS-CoV-2 from the true airborne long-distance diseases there.
• 6:33
  SPEAKER_01: That was terrific.
• 6:34
  SPEAKER_01: I think that we still get questions about the volume of this pandemic in terms of number of patients that we're seeing in our facilities, would in seconds outstrip our capacity for negative pressure wounds or airborne infection isolation rooms, even perhaps in patients who require aerosol generating procedures.
• 6:52
  SPEAKER_01: So we end up, as the CDC describes, placing patients in a standard room with a door closed and then reserving our airborne infection isolation rooms for aerosol generated procedures.
• 7:04
  SPEAKER_01: Now, there's often been requests to, for example, make a room or a space negative to adjacent environments.
• 7:10
  SPEAKER_01: Can you talk about when it might make sense or what you say when you get asked by someone in your facility, can I make this a negative pressure room or a space?
• 7:22
  SPEAKER_00: So, first of all, yes, I think minimally such patients should be in a private room with the door closed.
• 7:28
  SPEAKER_00: Obviously, ideally with the patient masked, obviously, if they're undergoing an aerosol generating procedure, that may be impossible.
• 7:34
  SPEAKER_00: And all the healthcare providers in that room need to have on minimally a medical mask and eye protection.
• 7:41
  SPEAKER_00: And if their patient is undergoing an aerosol generating procedure, an N95 respirator.
• 7:47
  SPEAKER_00: With regard to making rooms negative pressure, that is really a complex question.
• 7:52
  SPEAKER_00: If you change the pressure relationships in any one room, you can make a room negative pressure by closing off the intake air and just letting the exhaust air, and that'll create negative pressure.
• 8:03
  SPEAKER_00: But you're going to change the pressure relationships in all the rooms, corridors that are connected to that particular air distribution system.
• 8:11
  SPEAKER_00: And if you're going to do that, you really need to get your aerosol and air engineers involved and your building people at your facility because it is not a simple process and it changes all the relationships up and down that corridor.
• 8:25
  SPEAKER_00: Now, you could, of course, use a HEPA filter, and there may be some advantage there.
• 8:29
  SPEAKER_00: You do have to be careful about all the issues that Jonathan brought out in the previous podcast about noise and trips and expelling the air, but that potentially could be used.
• 8:40
  SPEAKER_00: If you did use it, ideally it would be placed between the patient and the door because that's what you're trying to protect.
• 8:46
  SPEAKER_00: But in general, it's really not necessary.
• 8:48
  SPEAKER_00: A private room, closed door, and appropriate personal protective equipment are the key.
• 8:54
  SPEAKER_01: So on that point where you said involve the engineers, maybe Jonathan, you could take us through what would go through your mind if someone came and said, I'd like to change this standard patient room into a negative pressure room.
• 9:09
  SPEAKER_02: Eric, I'd be glad to.
• 9:10
  SPEAKER_02: Thank you.
• 9:11
  SPEAKER_02: I'd like to kind of use an example on this.
• 9:14
  SPEAKER_02: So basically, what we're asking to do is to take the air conditioner at home and make it blow more air.
• 9:21
  SPEAKER_02: And of course, I thought the only way to do that is to replace that air conditioner.
• 9:25
  SPEAKER_02: Because the one that you've got isn't designed to blow more air.
• 9:29
  SPEAKER_02: Well, it's very similar.
• 9:31
  SPEAKER_02: Air handlers that are the units, the machines that provide all the air flow and the volume of air to the various rooms are designed with a very specific amount of air that it's going to move involved to increase the airflow within that machine is really pretty difficult because it is a static machine that has a very set amount of airflow going through it.
• 9:56
  SPEAKER_02: The only way to do that really is to increase the amount of air that the fans can move that are involved in that machine.
• 10:03
  SPEAKER_02: We have some technical ways of doing that, but it's never easy and it does require shutting them down, which is one of the things as a healthcare facility manager or a healthcare engineer, the last thing we ever want to do is shut down an air handler because it impacts dozens and dozens of rooms and everybody in them.
• 10:23
  SPEAKER_02: As David mentioned earlier, you could just lock off the supply, and that would make the room more negative because you're drawing air out of it, so it'd make it more negative.
• 10:31
  SPEAKER_02: The problem with doing that, one thing I'd like to mention on that is remember in our part one, we talked about the air changes per hour.
• 10:40
  SPEAKER_02: In a typical room, you're supplying air into the room, and that's how you're getting the outside air changes, is through the supply of the air.
• 10:49
  SPEAKER_02: So if you just block that off, you're really, I mean, you're eliminating the amount of outside air, which we know is our dilution process for that.
• 10:58
  SPEAKER_01: That's a good point because ACH is not just about changes, it's what you're changing in.
• 11:03
  SPEAKER_01: You need a portion of that that's your outside air.
• 11:05
  SPEAKER_01: It's the dilution, is the solution to pollution framework that I've learned.
• 11:11
  SPEAKER_01: So if you were to stop the supply, you don't have any outside air as part of your ACH.
• 11:16
  SPEAKER_02: Exactly.
• 11:17
  SPEAKER_02: And as David mentioned, what that's going to do is the room's going to be starved for air now because you're pulling air out of it.
• 11:23
  SPEAKER_02: So it's going to seek for air somewhere else.
• 11:26
  SPEAKER_02: If it's a patient room through the bathroom, that's never a good corridor, which that's not a good thing because you don't know what's running up and down the corridor either.
• 11:35
  SPEAKER_02: So we really want to be careful with that.
• 11:37
  SPEAKER_02: And again, as we mentioned in uh part one, the only way to do this is to get a multidisciplinary team together of clinicians, epidemiologists, infection prevention folks, your facility engineers, and sit down and discuss how we want to go about doing this.
• 11:52
  SPEAKER_02: And one other thing I'd like to mention there, Erica, is the fact that different types of air handling units lend themselves to uh ease your adjustments.
• 12:03
  SPEAKER_02: So there might be an area of the hospital that could be easily adjusted to increase the amount of air coming in, whereas another floor may not be, depending on what type of unit you have there.
• 12:16
  SPEAKER_02: So that's where it becomes so important to get your facility people very involved.
• 12:20
  SPEAKER_01: Yeah, I was about to say that that's really complex, and you gotta weigh what are we trying to achieve and what are the potential kind of pros and cons here, and you can't really have that discussion without hearing everything that the engineer has to say.
• 12:33
  SPEAKER_02: Absolutely.
• 12:33
  SPEAKER_02: And as you mentioned, we're gonna assess this.
• 12:36
  SPEAKER_02: So a risk assessment really needs to be done and documented, as we know, for surveys and later on discussions.
• 12:44
  SPEAKER_00: I'd like to make two comments there, Erica.
• 12:46
  SPEAKER_00: First, let me just mention our engineers have very sophisticated ways of measuring air exchanges.
• 12:53
  SPEAKER_00: But a simple way that people, all our colleagues, can use is the so-called tissue test, first described by my colleague Bill Rutella many years ago, which is you just close the door of the room, you take a tissue, if it's a two-ply, you rip it so it's only one ply, hang the tissue, hold the tissue so with the door closed, it's just below the door where there's a little gap between the door and the floor.
• 13:18
  SPEAKER_00: And if you're standing outside the room, if it's positive pressure, the bottom edge of the tissue will bend towards you.
• 13:24
  SPEAKER_00: If it's even pressure, the tissue will just hang straight down limply.
• 13:28
  SPEAKER_00: And if it's negative pressure, the tissue will be pushed down into the door.
• 13:32
  SPEAKER_00: It's not super accurate, but in general, it's not a bad way of getting a quick gestalt of whether the room is negative even or positive pressure, not near as exact as the more sophisticated measurements that can be done, but can be useful if you're in a clinic room or in a hospital room and you're wondering.
• 13:49
  SPEAKER_00: The other thing I'd like to ask, Jonathan, we've carefully talked about the issues of how you changing air intake or output and effect on air exchanges.
• 13:59
  SPEAKER_00: Can you comment, Jonathan, on uh the fact that simply the other part of it is filtering capacity?
• 14:05
  SPEAKER_00: It's not straightforward just to go from a 40% to an 80% filter because that's going to cut down your air exchanges by giving you more resistance, I believe.
• 14:14
  SPEAKER_00: So maybe you can comment also about the similar impact of just trying to upgrade and putting in much more strict filters.
• 14:23
  SPEAKER_02: Thanks, David.
• 14:24
  SPEAKER_02: Appreciate that.
• 14:24
  SPEAKER_02: Yeah, that's probably one of the biggest questions we get on our side of the fence is you know, why can't you just put HEPA filters in there?
• 14:31
  SPEAKER_02: Or, or better yet, clean room filters is what they really wanted, which are even higher efficiency than a HEPA filter.
• 14:38
  SPEAKER_02: In technical terms, what we call that is the static pressure drop caused by the filter.
• 14:44
  SPEAKER_02: Just like your coffee filter, the tighter that filter is, the more pressure it takes to get the liquid through that filter.
• 14:53
  SPEAKER_02: Well, an a filter within the air handler, the air handler is designed when originally designed for a certain type of filter.
• 15:01
  SPEAKER_02: And if you take out the current MERV 14 filter, as we talked about on our part one, and you put in a HEPA filter, a high efficiency particulate filter, you're gonna create more drag with that HEPA filter.
• 15:16
  SPEAKER_02: Therefore, you're gonna get less air downstream.
• 15:20
  SPEAKER_02: And that's gonna impact every single room that air handler serves.
• 15:25
  SPEAKER_02: And typically, an air handler will serve an entire wing of a hospital floor, maybe even the same wing on multiple floors.
• 15:31
  SPEAKER_02: So you can see how just by replacing the filter, you could significantly impact the pressure relationships throughout several floors of a hospital.
• 15:42
  SPEAKER_02: So you definitely need to consult with your facility staff before doing that and understand the fact that even though it sounds like it'd be the best thing to do, it may not be possible, just literally may not be possible to do.
• 15:56
  SPEAKER_01: I feel like I need to put the facilities engineer on speed dial, and hopefully they'll put the hospital epic people on speed dial so that when we get these requests, we can all meet and sort out the best way forward.
• 16:07
  SPEAKER_01: Very complicated.
• 16:08
  SPEAKER_01: I'm gonna switch gears a little bit and talk about adjunctive technologies that are out there and we're hearing a lot about to mitigate the risk of transmission is a obviously huge focus on anything that can possibly be done.
• 16:21
  SPEAKER_01: So ultraviolet light is an effective method to activate microorganisms.
• 16:26
  SPEAKER_01: We know that that has been shown.
• 16:27
  SPEAKER_01: And I guess, Jonathan, I'll start with you.
• 16:30
  SPEAKER_01: What is your assessment of the evidence to date to support upper room UVGI and then the fixed-mounted UVGI and air handling equipment?
• 16:39
  SPEAKER_01: Because I get that last question quite a bit, and I'm wondering what your perspective is on that.
• 16:43
  SPEAKER_01: And then I'll turn to David and see what you think about the evidence to support preventing transmission of SARS-CoV-2 or other pathogens.
• 16:52
  SPEAKER_02: So, Erica, great topic, one that's being researched significantly now, far more than it was before.
• 16:58
  SPEAKER_02: We do have good research already about upper room uh UVGI, UVC, especially.
• 17:05
  SPEAKER_02: And it's an effective way to definitely treat for tuberculosis.
• 17:09
  SPEAKER_02: We know that there's been multiple research projects that have done that.
• 17:12
  SPEAKER_02: One of the major challenges within the United States that we have is the need, the way that is effective for upper room UVGI is to make sure that there is proper air mixing above uh the normal vision height, so eight feet and above.
• 17:30
  SPEAKER_02: Most of our facilities don't have 10 or 12 foot patient room at ceiling height.
• 17:36
  SPEAKER_02: So having that proper air mixture above the eight-foot height, and that's to protect the people in the room, is pretty difficult.
• 17:44
  SPEAKER_02: There are systems out there that can do that, and I would encourage people to look at those because we do know it is effective that way.
• 17:50
  SPEAKER_02: When it comes to fixed UVGI devices within the air handling unit, that type of equipment has been around for many years.
• 17:58
  SPEAKER_02: What we have found though is that it's not really a system to kill pathogens within the airstream.
• 18:07
  SPEAKER_02: The issue becomes that the air flow through an air handler is such a large volume that it goes by the UV system so quickly that it doesn't have enough kill time, as we call it, with the particles in the air.
• 18:23
  SPEAKER_02: What we have found is that it is very successful in helping to clean the air because it destroys the particles as they go flying through the larger particles.
• 18:33
  SPEAKER_02: And what that does is, as we mentioned in part one, you have a coil within the air handler.
• 18:40
  SPEAKER_02: And that coil is where you either heat or cool the air.
• 18:44
  SPEAKER_02: And it's just like the radiator in your car, it's got just literally thousands of thin tubes in it.
• 18:50
  SPEAKER_02: Well, those tubes are compressed real tightly together, and any kind of particle can get caught in between those.
• 18:57
  SPEAKER_02: And cleaning them can be very difficult.
• 18:59
  SPEAKER_02: And as we mentioned when we talked about the air filters, putting a HEPA filter in causes more pressure, static pressure.
• 19:06
  SPEAKER_02: Same thing if your coil gets dirty, it causes static pressure and the air can't get through it as well.
• 19:11
  SPEAKER_02: And that could starve your system down the line.
• 19:13
  SPEAKER_02: So what we have found, and the way we actually use UV in our air handling systems is to help keep them cleaner.
• 19:21
  SPEAKER_02: That provides two major benefits.
• 19:23
  SPEAKER_02: One, you get better airflow, but two, uh even more importantly, when it comes time to have to clean the system, there's a lot less cleaning that needs to be done, which reduces the shutdown time that you might have to have.
• 19:36
  SPEAKER_02: And that shutdown time is a critical factor when it comes to treating patients and making sure that we're getting proper air conditioning to the patients.
• 19:45
  SPEAKER_01: So it's about bioburden, not pathogen kill.
• 19:48
  SPEAKER_01: That's very helpful to know.
• 19:49
  SPEAKER_01: What about you, David?
• 19:51
  SPEAKER_00: So there's certainly been both reports in the lay press and, in fact, editorials in medical journals suggesting that these UVGI units should be placed in every hospital room and in some cases in restaurants, K through 12, classrooms, and others.
• 20:07
  SPEAKER_00: There's at least one study that looked at looking for viable virus in rooms, which they found greater than 10 feet or greater than 4 meters, but as the room also had a UVGI unit with 90% recycled air through it, and still there was viable virus.
• 20:22
  SPEAKER_00: Again, masks are the prevention.
• 20:24
  SPEAKER_00: A unit in the ceiling is not going to prevent someone giving a good sneeze or cough from potentially infecting somebody if they're not wearing a mask who's five, six, eight, or ten feet away.
• 20:35
  SPEAKER_00: Now, will they reduce the risks of transmission in places like K through 12 schools or others where the children may not be able to wear masks as effectively?
• 20:45
  SPEAKER_00: I have an open mind.
• 20:46
  SPEAKER_00: But before we spend enormous amounts, meaning into the hundreds of millions of dollars, to emplace that, redesign all our air handling systems, as with any other device that we use in medicine, I would like to see evidence that it actually reduces the risk.
• 21:02
  SPEAKER_00: I think we need research.
• 21:03
  SPEAKER_00: I have an open mind.
• 21:05
  SPEAKER_00: But at the present time, I don't think the data supports the widespread use of UVIG GI units to mitigate the effects of COVID.
• 21:13
  SPEAKER_00: Again, they are not a substitute for wearing masks and eye protection and the other ventilation mechanisms, such as closed door private room that we've already talked about.
• 21:24
  SPEAKER_01: So we did UVGI now plexi class, or maybe I should say transparent barriers.
• 21:29
  SPEAKER_01: From the start, we started getting lots of requests for installation of these transparent barriers, not just at registration or triage desk, where it may make sense to form a barrier when distance is not an option, when patients or visitors may arrive without being masked and they may have some sustained interactions there, but everywhere.
• 21:47
  SPEAKER_01: People want these in work rooms and break rooms.
• 21:49
  SPEAKER_01: I'll start with David.
• 21:51
  SPEAKER_01: Tell me what you think transparent barriers make sense as an infection prevention strategy and where they don't.
• 21:57
  SPEAKER_01: And then Jonathan, maybe a facilities perspective.
• 22:00
  SPEAKER_01: Perspective on transparent barriers.
• 22:03
  SPEAKER_00: So I think my major concern is if the barriers have gaps like you would find at a bank tellers to pass things forward or at a medical desk where people need to sign forms or they're fenestrated with holes.
• 22:16
  SPEAKER_00: And particularly we often see them directly in front of the person, but they're obviously not going to the walls, the ceiling, and the floor.
• 22:23
  SPEAKER_00: And the airflow will go around them depending upon the turbulence and where the air conditioner or air ducts are and the intake and output.
• 22:30
  SPEAKER_00: They are not a substitute for wearing a mask if you are within six feet of another person.
• 22:35
  SPEAKER_00: I'll say that again.
• 22:36
  SPEAKER_00: They're not a substitute for both people actually wearing masks.
• 22:40
  SPEAKER_00: Whether they do provide some protection against sort of direct stream and lower potentially the infectious dose by impacting on the barrier, that may be true.
• 22:50
  SPEAKER_00: I'm certainly not opposed to them, but I think at times they give people a false sense that this glass or plexiglass, whatever the barrier is that goes up a little over your head and a couple of inches wider than your body, is providing you mysterious protection from somebody who's six or eight inches away on the other side, and therefore you can sit on the other side and eat and drink safely.
• 23:11
  SPEAKER_00: And that really is a mistake.
• 23:12
  SPEAKER_00: So I'm not opposed to doing it, but people have to understand the message that it is not protecting them adequately and they need to wear their mask.
• 23:20
  SPEAKER_01: So they still need the distance of six feet or the masking less than six feet.
• 23:25
  SPEAKER_01: You can't really get around that if you put a transparent barrier that's getting you less than six feet apart from individuals.
• 23:32
  SPEAKER_01: That's not a license to not wear a mask, is what you're saying.
• 23:35
  SPEAKER_00: That's what I'm saying.
• 23:36
  SPEAKER_00: Now there are some true totally sealed booths that we've seen on television, and people have designed so that you could go see somebody in a nursing home and it's literally completely 100% sealed with a EPA-filtered air duct.
• 23:49
  SPEAKER_00: In that case, the barrier may be effective that you could see that person who doesn't have a mask.
• 23:54
  SPEAKER_00: But the 99.9% of barriers we see now at uh restaurants and banks and supermarkets and at registration desks and hospital and other places is not that type of a barrier.
• 24:06
  SPEAKER_00: And people need to understand they still need to wear their mask.
• 24:09
  SPEAKER_01: That's true.
• 24:10
  SPEAKER_01: You always need to wear the mask.
• 24:11
  SPEAKER_01: We keep coming back to some of the basics here.
• 24:13
  SPEAKER_01: What about Jonathan?
• 24:14
  SPEAKER_01: Your thoughts on these transparent barriers that are everywhere now?
• 24:18
  SPEAKER_02: Eric, I really appreciate you bringing this topic up because this is one that we are coming up against more and more.
• 24:24
  SPEAKER_02: We have some real concerns and real issues with these.
• 24:27
  SPEAKER_02: Totally agree with David and everything David said, but we also have to keep in mind that within healthcare facilities, we have patients and individuals who are incapable of self-preservation.
• 24:40
  SPEAKER_02: So if there were a fire of some sort, they can't get up and leave.
• 24:45
  SPEAKER_02: We don't evacuate hospitals.
• 24:47
  SPEAKER_02: We move horizontally by compartment within hospitals.
• 24:51
  SPEAKER_02: These type of barriers do not meet the requirements of the life safety code for healthcare facilities when it comes to finishes.
• 25:00
  SPEAKER_02: And that's what they're seen as.
• 25:01
  SPEAKER_02: They're seen as a finish.
• 25:02
  SPEAKER_02: They're not a class A or class B.
• 25:04
  SPEAKER_02: They're not even a class C.
• 25:06
  SPEAKER_02: They don't meet any class as far as it comes to flame spread, and the smoke they generate is significantly toxic.
• 25:13
  SPEAKER_02: That's our biggest concern.
• 25:15
  SPEAKER_02: More and more of this product coming into the facilities creates just a nightmare when it comes to a fire concern.
• 25:22
  SPEAKER_02: The other issue we worry about is their placement.
• 25:26
  SPEAKER_02: When we design healthcare facilities, we place sprinklers in these facilities based on where cubicle curtains are going to be hung.
• 25:34
  SPEAKER_02: Because we want to make sure there's a sprinkler on each side of a cubicle curtain.
• 25:38
  SPEAKER_02: So we look at that much of a detail when it comes to design.
• 25:41
  SPEAKER_02: When you start throwing up these plastic barriers, you interrupt the spread of the sprinkler spray.
• 25:47
  SPEAKER_02: So again, if there were an emergency of a fire, you've interrupted that and could cause some significant concerns and damage.
• 25:55
  SPEAKER_02: And it could cost people their lives.
• 25:58
  SPEAKER_01: That's a very sobering thought there.
• 26:00
  SPEAKER_01: And something that when I initially had gotten the request for these sort of transparent barriers, I it hadn't actually occurred to me.
• 26:06
  SPEAKER_01: So I appreciate you bringing that point up.
• 26:09
  SPEAKER_01: We talked a little bit about the importance of bringing outside air into your facility, but in healthcare facilities, David, we think about not having natural ventilation.
• 26:17
  SPEAKER_01: Maybe you could talk about why we're opposed to natural ventilation.
• 26:21
  SPEAKER_00: Absolutely.
• 26:22
  SPEAKER_00: So our hospital, like most hospitals in the United States, is essentially airtight.
• 26:26
  SPEAKER_00: And thanks to our excellent filtration and air change systems, we've measured our air, and in general, it's about has a hundredfold less fungi than you would see outside the hospital.
• 26:37
  SPEAKER_00: There are many outbreaks, well over 50, related to construction and renovation inside hospitals, but also outside hospitals where the windows were open, or intake vents were near heliports, refuse dumps, or near construction, bringing in outside spores, particularly aspergillus, but also mucor rhizopus, and leading to infections among immunocompromised patients, most commonly cancer patients, but as well other people, high dose steroids, other immune suppressives with severe fungal lung disease and a high fatality rate because of the difficulty treating those people and their underlying comorbidities.
• 27:18
  SPEAKER_00: So open windows really are a large risk in healthcare facilities.
• 27:22
  SPEAKER_00: And as I've already discussed in part one, with an outbreak of smallpox, when you have a really highly infectious agent that can be truly long-distance airborne spread, natural ventilation by itself will not be protective.
• 27:35
  SPEAKER_00: So in hospital facilities, all healthcare facilities, really open windows are generally not a good idea.
• 27:43
  SPEAKER_01: So previously we talked about ORs and being positive pressure environments.
• 27:47
  SPEAKER_01: So in part one, we talked all about that.
• 27:49
  SPEAKER_01: Jonathan, they're built to reduce the risk of surgical site infections.
• 27:54
  SPEAKER_01: That's why the way they're constructed, the way they are.
• 27:56
  SPEAKER_01: But one question that comes up frequently, I think less so for now, these many months into the pandemic, but still periodically, is what to do about pressurization when you have a patient with confirmed COVID active infection who needs to go to the OR.
• 28:11
  SPEAKER_01: At our facility, we use the CDC guidance, the analogy to tuberculosis.
• 28:15
  SPEAKER_01: And I'm interested in what your perspective is on a case such as this.
• 28:20
  SPEAKER_02: Erica, you're you're right on point with that.
• 28:23
  SPEAKER_02: We recommend follow the tuberculosis guidance that CDC produces.
• 28:27
  SPEAKER_02: We have an entire document on this, and basically it's to keep that case to the last part of the day so that there's no one else in the OR suite when you're doing that case.
• 28:37
  SPEAKER_02: Leave the room in a positive pressure status to help protect the patient.
• 28:42
  SPEAKER_02: All of the staff have to be properly masked, as David has mentioned multiple times, have to have proper PPE and protection face shields, N95s.
• 28:50
  SPEAKER_02: You do the procedure and then you allow the proper settling of the room.
• 28:56
  SPEAKER_02: This is one of the things that people have the biggest question on.
• 28:59
  SPEAKER_02: Within the CDC document, they have a table.
• 29:02
  SPEAKER_02: It's called the airborne contaminant removal table.
• 29:05
  SPEAKER_02: And it's table B1.
• 29:06
  SPEAKER_02: Within that table, it tells you if you have 20 air changes per hour, you need to wait 15 minutes to be able to have air to exchange itself enough times to be able to clean the contaminants out of the air as much as needed.
• 29:21
  SPEAKER_02: Then you should go in and start your cleaning process.
• 29:24
  SPEAKER_02: And they have that table set up for all different types of rooms.
• 29:27
  SPEAKER_02: Patient rooms are typically four air changes per hour, so that's 69 minutes you gotta wait.
• 29:33
  SPEAKER_02: Within your ER, you have rooms that are 10 and 6.
• 29:36
  SPEAKER_02: 10 air changes per hour, you can wait 28 minutes, six air changes per hour, 46 minutes.
• 29:42
  SPEAKER_02: So this table is available through the CDC.
• 29:45
  SPEAKER_02: And we actually have it within the ASHRAY recommended guidance documentation because it's a very important one to follow.
• 29:52
  SPEAKER_02: Once the room is clear and you no longer have a source that's generating the contaminant in the room, that's when the clock starts and you can start counting the time to be able to get into that room without being concerned about the contaminant.
• 30:07
  SPEAKER_02: One other thing I'd like to mention on that if you do the waiting process, that does allow you to go into the room, for example, in the ORs, because we were talking about ORs, you know, with 20 air changes per hour, if you wait 15 minutes, the staff can now go in there and not be concerned about having to wear an N95 respirator.
• 30:25
  SPEAKER_02: And having done terminal cleaning in an OR, it's a lot of work.
• 30:30
  SPEAKER_02: You don't want to be wearing an N95 when you're doing that.
• 30:32
  SPEAKER_02: So letting the room sit will actually get the room turned over quicker than trying to do it in full PPE.
• 30:40
  SPEAKER_01: I think that's a great point.
• 30:41
  SPEAKER_01: And I have printed out that table from the CDC and just pasted up near my desk so that I can look up to it and reference it.
• 30:47
  SPEAKER_01: So it's a useful table.
• 30:48
  SPEAKER_01: What about an anti-room?
• 30:50
  SPEAKER_01: So an anti-room for an OR, and then thinking about if facilities are planning a new building, is that the kind of thing you might advise?
• 30:59
  SPEAKER_01: Is it somehow superior than following the guidance that you've just led us through from the CDC, which has been out there for quite a while, which a lot of facilities adhere to?
• 31:08
  SPEAKER_02: Yes, an anti-room is a great addition.
• 31:10
  SPEAKER_02: And if you're building a new OR suite, we highly recommend that you have at least one, depending on how many rooms you're going to have, but have at least one that has an anti-room built into the OR.
• 31:21
  SPEAKER_02: What that does is it allows you to have a buffer zone between the rest of the surgical suite and the OR.
• 31:28
  SPEAKER_02: And that anti-room can be made negative so that none of the air coming from the OR is getting out into the surgical suite.
• 31:37
  SPEAKER_02: And that allows you to do surgeries for tuberculosis for a positive COVID-19 patient in the room and not worry about that air getting into any other part of your OR because the anti-room will be that buffer zone.
• 31:50
  SPEAKER_02: The cleaning of the OR, you still need to follow that airborne contaminant removal table on that because again, that anti-room is not going to make any difference for the patient being in there and cleaning that room through the dilution and movement of the air.
• 32:04
  SPEAKER_01: Terrific.
• 32:04
  SPEAKER_01: Well, let me start with the same question for both of you to kind of end today, which is if you could provide our listeners with maybe the most precious pearl of advice with respect to the topics that we covered today, namely the role of the built environment in infection prevention, what would that be?
• 32:23
  SPEAKER_01: What would be the most important thing that people could take away from part one and part two?
• 32:28
  SPEAKER_01: And I'll start with Jonathan and then I'll head over to David.
• 32:31
  SPEAKER_02: From my perspective, the most important thing that can be done is to make sure when you're looking at anything that you're doing it as a team and that you're getting together as a team and working together as a team to determine the best processes you can do.
• 32:45
  SPEAKER_02: Whether it's creating negative pressure, whether it's increasing your air changes per hour, whether it's moving patient equipment out of the room and into the corridor, whatever you're doing, clinical staff need to be involved.
• 32:57
  SPEAKER_02: Your epidemiologists must be involved.
• 33:00
  SPEAKER_02: Your facility folks need to be involved.
• 33:02
  SPEAKER_02: Your environmental services folks need to be involved because it impacts all the members of the team.
• 33:08
  SPEAKER_02: And making sure everybody has input into that is really important.
• 33:12
  SPEAKER_00: David?
• 33:13
  SPEAKER_00: I want to just second that from the uh perspective as a hospital epidemiologist.
• 33:18
  SPEAKER_00: Yes, we need to have our engineers on rapid dial.
• 33:22
  SPEAKER_00: There are so many things that impact the hospital, losing electrical power, losing ventilation at times, indoor floods, outdoor floods, all of these things have major impacts, and we need to be working with the engineers on all of these very closely.
• 33:38
  SPEAKER_00: In terms of uh SARS and CoV, again, we know what works, wearing appropriate masks, physical distancing, hand hygiene and disinfection.
• 33:47
  SPEAKER_00: I think improved ventilation and filtering is important.
• 33:50
  SPEAKER_00: We don't know yet the relationship.
• 33:52
  SPEAKER_00: I'm highly in favor of more research, developing uh those algorithms and risk stratification so we actually know the relationship between improved ventilation and filtering and decreased risk.
• 34:05
  SPEAKER_00: We also need to use universal pandemic precautions, wearing a mask and eye protection anywhere by healthcare providers in the facility, daily symptom screening for patients, visitors, and staff.
• 34:17
  SPEAKER_00: And of course, I should say the time to get involved because retrofitting is really difficult and expensive.
• 34:24
  SPEAKER_00: Infection preventionists need to be involved at the blueprint stage early when you're just conceiving new buildings.
• 34:30
  SPEAKER_00: They need to be involved at all renovation steps, and they need to be involved whenever panels are removed or ventilation is changed early on as part of that planning process, just not being called when there's a problem.
• 34:43
  SPEAKER_00: And the same is true for the engineers.
• 34:45
  SPEAKER_00: We can't call them when there's an initial problem.
• 34:47
  SPEAKER_00: They need to be involved at the earliest steps of renovation and construction.
• 34:52
  SPEAKER_01: Well, I think that's terrific.
• 34:53
  SPEAKER_01: We have that process, the ICRA, the infection control risk assessment, and that's where we at hospital epidemiologists, infection preventionists, and engineers all meet together to kind of go through some of these plans.
• 35:04
  SPEAKER_01: This was terrific.
• 35:06
  SPEAKER_01: I really want to thank both of you for joining us today, sharing your perspectives and going through some of these thorny issues.
• 35:13
  SPEAKER_01: And hopefully the audience has had those questions and will be better prepared to answer them, having learned from the both of you.
• 35:20
  SPEAKER_01: As a reminder, for those of you who missed part one of the podcast, you can check out that session.
• 35:24
  SPEAKER_01: Again, that covered a lot of the basics and the vocabulary and the way that engineers and epidemiologists think about some of these issues and the regulatory requirements.
• 35:33
  SPEAKER_01: And I would like a sincere thank you to all of you listeners from SHA, all healthcare personnel, for everything that you're doing to respond to COVID-19.
• 35:41
  SPEAKER_01: This podcast can be accessed on SHA's online education center, Learning CE, under the Rapid Response Program.
• 35:47
  SPEAKER_01: You'll also find additional resources there, such as the recorded webinars and the SHAY COVID-19 town halls, and the additional podcast series COVID-19 update, What We Know Now, and that's released every Thursday.
• 35:59
  SPEAKER_01: This concludes the episode of Allies Infection Prevention Podcast Series, and thank you for tuning in today.