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Special Coverage on COVID-19

2020; Lippincott Williams & Wilkins; Volume: 42; Issue: 4B Linguagem: Inglês

10.1097/01.eem.0000662064.45093.d5

1552-3624

Mark Mosley,

Disaster Response and Management

FigureFigureEvery great hero movie has a moment when the enemy is closing in. Everyone in the audience wants the hero to save the day, but he has only one shot. Too early or too late, and we all die. He has to make it count. You hear the hero whisper to himself, "Wait for it, wait for it, wait...now!" Timing is critical for survival. And the timing must depend on the conditions—the location, the site, and the particular circumstances at that moment. Each emergency department is a separate battalion with its own stockpile of human and material resources. We will not meet this virus at the same time or in the same way. We will blow a quarter or half of all our materials before we need them if a small rural ED in the South or a freestanding emergency department in a medium-sized midwestern town follows the protocols of a large metropolitan city like New York. Every unnecessary COVID-19 test and every unnecessary gown and mask we use today is one we won't have two weeks from now when they may be lifesaving. This is all about timing and using our resources at the right moment. Perhaps as you are on shift tonight you will see boxes of surgical masks and N95s. You should know that federal officials have said the strategic national stockpile contains just one percent of the masks that experts predict could be needed for this pandemic. There are plans to add 500 million N95 respirators to the stockpile, but that could take up to 18 months. (Los Angeles Times. March 21, 2020; https://lat.ms/33OjYUV.) How do we control our fear not to pull the trigger when someone comes to work and says his cousin is an ICU nurse in Seattle and that everyone working in the ED there is wearing a mask? Or the highly respected doctor who walks down the hospital hall with a N95 on? How do you calm yourself when you aren't the lucky soldier issued a helmet? Knowledge is power. And that power will allow us to calm that fear. We must start with the knowledge that diagnosis is not usually helpful for the vast majority of emergency patients unless we also have a treatment. Indiscriminate testing will use up our precious materials. For every false-positive, two or more tests prove a patient is negative. Our primary objective is the timing of human and material resource utilization. Respiratory Protection The Centers for Disease Control and Prevention has stated that we are to "minimize the number of individuals who need to use respiratory protection." They recommend using alternatives to N95 respirators, and they allow for extended use or limited use under shortages without knowing their effectiveness in this situation. (CDC. March 28, 2018; https://bit.ly/2QLwfnM.) The types of respiratory protection in the ED are surgical masks (molded cup and pleated paper), N95 respirators, and Elastrometric respirators (they look like grasshoppers). Everything is not a mask. Most EDs will have surgical masks or N95s. Pillars of Knowledge I propose several pillars of basic knowledge from which we should build our recommendations and protocols. Granted, there will always be important exceptions (e.g., an ED staff member on immunosuppressive drugs), but the exceptions do not change the foundation. COVID-19 is spread predominantly by large droplets. Airborne particles and fomites appear likely, and they may not routinely come into play with noncritical respiratory patients, especially with a no-touch or one-touch physical exam. Surgical masks are not necessary for ED staff unless they are seeing a potential COVID-19 patient for respiratory symptoms. If you are sick, you should be home rather than work with a surgical mask on. The surgical mask is intended primarily for sick people, not healthy ones. Its purpose is to block water droplets from being coughed or sneezed out by the wearer. It does not prevent airborne virus from coming into the health professional's nose or mouth (respiratory therapists doing nebulizations and suctioning are exceptions). Healthy people should not be wearing surgical masks around the community unless they are sick. And why are they out if they are sick? N95s have proven more effective than surgical masks in vitro to block airborne viral particles, but have not proven better than surgical masks in vivo for real-life situations (whether this is because of improper usage is unknown). (JAMA. 2019:322[9]:824, https://bit.ly/2JkeFTY; CMAJ. 2016;188[8]:567, https://bit.ly/2Jh6Q15.) You don't need an N95 for noncritical respiratory patients, and you certainly don't need one in any routine medical situation or community activity. The CDC agrees that a surgical mask is an acceptable alternative to an N95. (CDC. March 28, 2018; https://bit.ly/2QLwfnM.) N95s in the ED are needed for all known COVID-19, critical respiratory, and intubated patients and for those on noninvasive positive pressure ventilation, undergoing CPR, with peritonsillar abscess, and perhaps for a small handful of other critical situations. Finally, we should be reminded regularly that there are no good scientific data from the 2009 H1N1 epidemic that surgical masks or N95s actually decrease infection rates. (Emerg Infect Dis. 2009:15[2]:233; https://bit.ly/2WN6SGe.) The recommendations to use respiratory protection is based on public health judgment. This makes complete intuitive sense and should be followed. The CDC has been wise to emphasize that the recommendations should be used in the context of local circumstances. If you work in the ED of a respiratory-designated hospital in a large city and patients are coughing and dying around you, your approach to respiratory protection, given your site-specific local circumstances, will be different from a freestanding Kansas ED where you are in the bunker drinking coffee and having the slowest shift in 25 years. Again, our primary objective is the timing of human and material resource utilization. Finally, there are laws of unintended consequences in which the desire to protect our patients, ourselves, and our families lead us to use surgical masks and N95s (and do COVID-19 tests) unnecessarily, which can lead to increased spread. The CDC recommendation is for those wearing a single-use surgical mask to wear and dispose of them properly. How many patients have you met already where the mask is below their nose and not covering their chin and they leave it behind when they leave? How many health professionals wearing a single-use disposable surgical mask all day pull it down to talk, drink, or eat? One study of nurses showed that nurses touch their faces an average of 25 times each shift. (Am J Infect Control. 2013;41[12]:1218.) How many times have you seen a surgical mask on a counter and not known if it is new or used? The surgical mask worn or used incorrectly becomes a viral grenade with the pin half out. Wear a surgical mask if you are sick at home, and wear a mask for another week if you are better after seven days and return to work. You may want to wear a surgical mask if you are working closely with those at high risk (e.g., elderly in a nursing home). And then there are bandanas for which we have absolutely no data and are reserved as a last resort, but we know they are no longer as effective if they become moist (like a surgical mask but worse). A surgical mask or a bandana that is reused, even if in a limited way, is at great risk for self-inoculation and ineffectiveness. (J Occup Environ Hyg. 2014;11[8]:115; https://bit.ly/2xohdO2.) The kind people making these for us is heartwarming, but it is unclear if it is safe to use in our emergency departments (except out of desperation). Using N95s can also have unintended consequences. Does everyone with a beard and mustache shave them off to use an N95 appropriately? What about not being able to see the video screen during intubation because your glasses are all fogged up? The N95, depending on site-specific location and circumstances, should be used sparingly in the majority of EDs for now. Estimated tolerance for a tight-fitting N95 on a nonbearded person is about an hour at most. And they are less effective if they get moist on the inside, like surgical masks. Our legitimate fears about running out of N95s prompted the CDC to make allowances for them to be reused no more than five times with a potentially impractical recommendation to store them in between patients in a brown bag. Contrary to hearsay, you can't use cleansing agents to sterilize them for reuse. Perhaps, this is why the CDC prefers extended use over reuse. How many N95s will a single staff member burn through in a 12-hour shift? As I write this, our emergency medicine colleagues are sending messages from the big cities reporting apocalyptic conditions: no gowns in the COVID-19 ICU, no N95s, few surgical masks. All emergency department patients and many critical care personnel are using loose cloth or toilet tissue to cover their nose and mouth. Meanwhile, some in quieter EDs are gowning up in full PPE with a N95 for an 8-year-old with a runny nose, cough, and diarrhea. We need to post these texts from the big cities and read them like letters from war. The angel of death may be coming. Maybe it will pass over us as we lay quietly, locked down in the bunker of our town. But there is hope. We must hoard every gown and surgical mask. We must lock up the N95s. Only by holding on to science can we let go of our fear. And if we can just wait, we might have the resources when we need them.