Q&A: Operating Room Airflow Moots COVID Social Distancing

October 28, 2020
Frank Diamond

Franklin Dexter, MD: “I would recommend to those people working in different surgical suites to recognize that within an operating room, you shouldn’t assume that stepping away from the patient would put you in reduce risk. You should think about what the airflow is in the operating room.”

The design of modern operating rooms means that healthcare professionals are more likely to be exposed to dangerous pathogens along the walls or away from the patient than they are standing close to a patient. That’s an important thing to consider during the coronavirus disease 2019 (COVID-19) pandemic, says Franklin Dexter, MD, a professor of anesthesia at the University of Iowa. Dexter and his co-writers looked at just where infection is most likely to occur in an operating room, and their findings were recently published in the American Journal of Infection Control. Dexter recently talked to Infection Control Today® about some of the implications of those findings, including the idea that social distancing from a patient in an operating room might make a healthcare worker more exposed to COVID or any other dangerous pathogen. “The airflow systems in modern operating rooms are so well designed to protect the patient and to protect the surgical team, that this is a natural consequence of it,” says Dexter.

Infection Control Today®: What made you decide to do this study in the first place?

Franklin Dexter, MD: Well, I knew [the co-authors] Dr. [Jennifer] Wagner, and Mr. [Kevin] Schreiber from SLD Technology. So, before the pandemic, I was aware of their work, both trying to improve the airflow in operating rooms to reduce infections. And to measure particles in the operating rooms. I was asked at the University of Iowa, in terms of evaluating the airflow in the operating rooms. I knew of their previous studies that they published in the American Journal of Infection Control. I contacted them and asked them to look into whether or not they could apply the work that they had previously done for this new problem.

ICT®: I wrote about your study and that article is on our Infection Control Today® website. I found it fascinating on many levels. I think one of the things that you are getting at is to tell healthcare professionals that the six feet distancing from patients doesn’t necessarily give you any more protection. In fact, it could lead you to an area where you get less protection.

Dexter: Yes, that exactly. The airflow in modern operating rooms, the design of the airflow systems is it comes from the ceiling above the operator bed. And because surgical smoke rises, therefore, what you want to do is have the airflow from the ceiling push down back towards the patient, and out away from the patient. The airflow goes like this, and then it goes out from there. Every other location in the operating room is functionally downwind of the patient. And the study results really highlight that they’re so effective…. The airflow systems in modern operating rooms are so well designed to protect the patient and to protect the surgical team, that this is a natural consequence of it. It’s not that anything is going wrong. In fact, it’s going exactly as designed. These systems are designed in that way.

ICT®: You looked at three operating rooms. Two built in 2017 and one built in 1992. Is that correct?

Dexter: One was much older. Yes.

ICT®: But even with the older OR you found that at least the larger particles are still more concentrated along the walls and then they are around the patient. Is that true?

Dexter: Yes, that is correct. But it was even more so with the current operating rooms.

ICT®: Now, 1992: Is that an old operating room as far as hospital standards are concerned these days? Or is that too sadly all too common?

Dexter: I don’t know. I don’t know enough to know.

ICT®: What advice would you give to infection preventionists who have to inspect the hospitals looking for problems with infection and also train their fellow healthcare workers about what to do about infection?

Dexter: I think it’s important for people working in operating rooms, to make sure that they understand that when you’re in the operating room, trying to step back away from the patient is not a method in terms of protection. Being not in the operating room would be protective. And things, for example, if you’re doing ionizing radiation, the further away you are from the ionizing radiation source that is protective. But that it won't work in terms of airborne pathogens.

ICT®: How many people can be in an operating room? I guess it depends on what the operation is?

Dexter: There can be 15 for some types of procedures.

ICT®: I think you might have said, in so many words in your study, that surgeons obviously don’t have a choice. They are certainly going to have to be over to the patient no matter what.

Dexter: Well, there are, for example, when people are doing a robotic procedures, one of the surgeons, usually the attending surgeon, would be at the console, and the console would not be near the operating room table. You want to have a clear line of sight. One of the things to consider would be is that the surgeon at the console would not have a lower risk than the assistant surgeon at the table.

ICT®: It seems to me that you you want to send a message to healthcare providers. Were you hearing things, anecdotally, that surgeries weren’t going the way they should go? I don’t mean outcomes, but I mean procedures, because of fear of COVID?

Dexter: No. The question really was that I was asked, is what could be done to reduce the risk for the spread of COVID-19 from a patient to the personnel in the operating room. And hypothetically it could be the opposite. And if you are not going to have people absent from the operating room, which often in many situations is impractical, then what would be an appropriate response? And what had been discussed was the concept; people mentioned the idea of distance. And what we set out to do with I knew that the information that had been collected by Dr. Wagner and her colleagues probably could be applied to test whether or not that was true. From having listened to them over the past year, I kind of thought that quite possibly that that wasn’t so. That’s why I encouraged them. This is work that they had previously done, but the question to analyze the data and in a way to be able to test this wasn’t something which had been thought of before the pandemic.

ICT®: The data collected were from 2018. Pre-COVID, right?

Dexter: Exactly. And so, one of the things from a science point of view, it’s very kind of interesting, and it very often happens this way. That people set out to do work where they have one objective, but realized later on that it can be used to answer an unexpected question. And this was definitely unexpected.

ICT®: Who would be in an operating room? You mentioned there could be as many as 15 people. But what kind of specialties aside from the specialty for which the person is getting operated on?

Dexter: You would have oftentimes have an anesthesiologist. You might have a nurse anesthetist. You may have a student nurse anesthetist. Or you might have an anesthesiology resident and a medical student. You would have your circulating nurse. You might have a second circulating nurse in addition to a surgical technologist. You might have a radiology technician. Those are some examples.

ICT®: Has COVID complicated the surgical procedures in any way?

Dexter: When you’re doing different types of procedures that can aerosolized particles, you need to change the processes within operating rooms. And there are many good standards to do that.

ICT®: Standards that were created before COVID?

Dexter: Mostly created afterwards. But people wear for example, the N95 masks. People try to enhance infection control. One of the things that happened was that when the pandemic began, I’ve been for several years working [Randy Loftus, MD] in my department. He’s an anesthesiologist. His expertise is in infection control. He has worked with Dr. Wagner for several years, as well. Dr. Loftus designed a randomized clinical trial. It was funded by the Anesthesia Patient Safety Foundation. And it had been completed right around before the pandemic began. And in fact, the paper had been accepted by JAMA Network, which is their open access journal. But it wasn’t yet available when the pandemic began. And what this study did was looked at a bundle of different practices that can be used to reduce environmental contamination in the operating room. So, pathogenic bacteria can come from the nose and the mouth of patients. Again, the concept of COVID-19. And when what happens you can then get contamination of the anesthesia workstation, meaning the anesthesia machine, the hands of the anesthesiologist and the nurse anesthetist. And then the bacteria can track back into patients. So, anesthesiology and anesthesia, including nurse anesthetist, as a field has worked hard over the past decade at trying to reduce the effect of environmental contamination as a cause of infection during surgery. The same concept can apply to COVID-19.

ICT®: Do you teach anesthesiology where you are now?

Dexter: I teach a course multiple times a year, which is in operating room management. My expertise… I’m an anesthesiologist. I have a PhD in biomedical engineering. Nowadays, we call it analytics. But I’m old and back when I got my PhD there wasn’t quote analytics at the time. The course that I teach is in operating room management, and particularly an analytic so that there are different types of analytical methods where you quantify different types of workflow issues in operating rooms. And I’ve worked in this area since 1993. That’s what I teach. People who take the course are…. The last course that I taught included several anesthesiologists from different universities and hospitals. I routinely teach it to analysts at different hospitals, and operating room nurses, surgeons. Those are typically the people who take the course. That’s what my teaching load is.

ICT®: I was just speaking to one of our Editorial Advisory Board members who oversees courses in nursing. She said how difficult it is these days to teach in medicine because of the lack of hands-on instruction because of COVID-19. Do you find that to be a barrier?

Dexter: So, my situation is that the course that I teach, it teaches people how to work in teams of three to four to basically solve math problems that relate to operating rooms. So therefore, what’s been in the past, people would be together, for example, in a room and everybody’s traveled. And different people from around the country. Basically, you’re at tables of working three. And they have two big computer screens. And they basically solve math problems all day, but things that relate to clinical questions about running operating rooms. When the pandemic began, then yes, it was a tremendous concern, but I’m used to using Zoom. What I did was I modified the course that basically people serve as a single team. I need to give the course more often because I’m limited, and I can practically do one team at a time. But it seems to work pretty well, doing the course remotely. I would expect that in the future because the travel expenses are saved. Although I’m very happy to go and teach again, in person, I suspect most of the teaching likely will be remote. But the people I’m teaching tend to be people who are between 30 years of age and 60 years of age.

ICT®: In your experience, what’s the relationship between the infection preventionist and the operating room personnel in general and the anesthesiologist in particular?

Dexter: I don’t think I have experience or an opinion. Or can you ask the question somewhat differently?

ICT®: Do you interact much with infection preventionists?

Dexter: I interact by email mostly, not so much in person. So that the interactions that I have in terms of trying to reduce infection in the operating room. I do a lot of analysis for the University of Iowa. The data that I use is from the infection prevention department at the hospital. We have a large correspondence relationship, but not in the operating room itself. That may be just Frank Dexter. I don’t know the generalizability.

ICT®: Any final words you might want to give to anybody who’s involved anywhere with operations and how to go about it in this era of COVID-19?

Dexter: I think the important thing to consider is that to focus on those operating rooms where there is the greatest risk of infection. And that my experience is oftentimes when people think about infection, they want to focus in on those procedures, or those specialties, or those rooms that have the highest incidence of infection. The number of infections per case. But that isn’t the same thing as the operating rooms that have the most infection. Operating rooms differ wildly in the number of cases…. Bu wildly, I don’t mean that to be an uncontrolled manner. It’s very designed, it’s scheduled. There’s large heterogeneity in operating rooms of the number of cases per day. There’s large heterogeneity among operating rooms in how long surgical cases last. Cases that are longer duration have a greater chance of infection. And so, it’s very important to focus on those operating rooms that have the greatest chance of infection, the greatest numbers of infection. And that isn’t the same thing as those cases that have the individual greatest chance of infection. That is a major important issue in operating room management.

ICT®: Any words of advice for people who might be working in older buildings with older operating rooms? And where’s the line? What do you consider an older operating room? Below a certain year?

Dexter: I know that I’m not the right person to know the answer to that question. But I do think what I would recommend to those people working in different surgical suites to recognize that within an operating room, you shouldn’t assume that stepping away from the patient would put you in reduce risk. You should think about what the airflow is in the operating room while setting policies.

This interview has been edited for clarity and length.