Handling N95s, Ventilated Face Masks, and Social Distancing
March 24, 2020
Hail to the Americans who are at the front lines fighting SARS-CoV-2! The healthcare providers and public servants continue to do their work despite the threats that come their way.
Following the guidelines for infection control is a little more challenging though, in light of this pandemic. Because the infection is world-wide, it has affected the supply chain of necessary personal protective equipment (PPE). The demand has exceeded the supply.
What may have been habit, simply donning and doffing PPE for both standard and transmission-based precautions, now requires more thought and some commonsense application. Healthcare workers must be conservative while protecting themselves and preventing transmission. Fortunately, the Centers for Disease Control and Prevention (CDC), provides some commonsense guidance. This is especially important regarding the use of respirators.
N95 respirators are the PPE most often used to control exposures to infections transmitted via the airborne route. N99, N100, P95, P99, P100, R95, R99, and R100 are at least as protective as the N95. Viral loads in the upper respiratory tract of patients infected with the SARS COV-2 are high, so patients are likely to secrete aerosolized particles, those less than 5 micrometers and droplets, particles larger than 5 micrometers.
Respirator effectiveness is highly dependent upon proper fit and use. Testing for air leaks should be done at each application of an N95 respirator.
During the short supply of respirators, infection control specialists and leaders at individual facilities should consider a combination of measures to protect their employees and prevent infection transmission. For instance, engineering controls function without a healthcare provider having to take action. Airborne infection isolation rooms (AIIR) should be constructed and maintained so that air from these rooms is exhausted to the outside or is first filtered with a HEPA filter and before recirculation. Aerosol-generating procedures should be performed in an AIIR.
Other measures include the use of physical barriers in intake, triage, triage and at information booths.
Administrative controls include limiting face-to-face encounters with patients and qualitative fit-testing of N95 respirators.
N95s that Exceed the Recommended Shelf-Life
Under guidance from the CDC, one of the first strategies is to use respirators that are beyond the manufacturer-designated shelf-life for patients with COVID-19, measles, tuberculosis, and varicella. Be mindful that straps and nose bridges may degrade, affecting the quality of the fit and seal, so an inspection and seal-check is always necessary. If the integrity is compromised, users should discard it and try another.
The National Institute for Occupational Safety and Health (NIOSH), is in the process of studying stockpiled N95s and have determined that many brands and models will provide their expected level of protection even though they exceed the beyond use date. If these products have been stored according to the manufacturers’ recommendations, the following models may be protective:
- 3M 1860
- 3M 1870
- 3M 8210
- 3M 9010
- 3M 8000
- Gerson 1730
- Medline/Alpha Protech NON27501
- Moldex 1512
- Moldex 2201
These respirators should only be used as outlined in the Strategies for Optimizing the Supply of N95 Respirators. In other words, they should not be used if NIOSH approved, in date respirators are available.
Respirators Approved Under NIOSH Similar Standards
A second strategy is to use respirators which are approved under standards used in other countries. They are expected to be suitable alternatives to NIOSH approved respirators when supplies are short. A list of these are located on the CDC website: Respirators approved under NIOSH similar standards. “They should not be used during aerosol-generating medical procedures unless the alternative is a loose-fitting surgical mask or improvised device. On April 3, 2020, FDA issued an update to the Non-NIOSH Approved Respirator Emergency Use Authorization (EUA) concerning non-NIOSH-approved respirators that have been approved in other countries.” (CDC, 2020) This memo informs staff and manufacturers of requirements if this strategy is necessary.
Thirdly, respirators may have to be re-used. This practice carries the risk of contact transmission when touching or removing the respirator between uses and should be limited. NIOSH recommends using a cleanable face shield or disposable face mask over the respirator to prevent its contamination. They can be stored in a paper bag between uses. Ensure protection against damage and disfigurement during storage. Wear a pair of clean non-sterile gloves when re-applying the respirator. If the manufacturer provides information on the maximum number of donnings and doffings, then follow those instruction. Otherwise, don’t use an N95 more than five times.
Extended use is another option, but the wearer must make sure that the respirator maintains a good fit and seal during use. When practicing extended use of N95 respirators, they should not be used beyond 8-12 hours or for multiple shifts. They should not be re-used after extended use. Always remove and discard them before activities such as meals and restroom breaks.
The CDC informs us that N95 respirators beyond their manufacture-designated shelf life, when available, are preferable to use of facemasks.
The use of N95s, elastomerics, or PAPRs should be prioritized for healthcare providers with the highest potential exposures including being present in the room during aerosol generating procedures performed on symptomatic persons.
Applying a combination of controls can provide an additional degree of protection, even if one intervention fails or is not available.
Face Masks and Distancing
For instance, controlling the source by masking a symptomatic patient and keeping a distance of six feet is recommended when N95s are in short supply. Keeping a distance of six feet or more is just good sense. Viral loads in the upper respiratory tract of patients infected with the SARS COV-2 virus are high so patients are likely to secrete aerosolized particles, those less than 5 micrometers and droplets, particles larger than 5 micrometers.
If care requires that a healthcare worker be closer to the patient, that is, between three and six feet, then both the patient and the healthcare worker should wear a facemask. This is the case for distances closer than three feet too. However, if a healthcare worker needs to be very close, within three feet of the patient, and a symptomatic patient cannot wear a face mask, then the health care worker must don an N95, elastomeric or powered air purifying respirators (PAPRs), based on what is available.
During aerosol generating procedures, performed on symptomatic patients, the available respirator must be worn, whether or not the patient is masked. It should always be discarded after use.
The guide below outlines the guidance from the CDC.
Source: (CDC, 2020)
When No Respirators are Left
Since certain individuals are at higher risk of severe illness from COVID-19, these workers should be excluded from working with COVID-19 patients. This includes those HCP who are:
- Have chronic medical conditions
Those who are recovered from COVID-19 may have developed some immunity to the virus. These healthcare providers are preferred to provide care to COVID-19 patients.
Create an expedient patient isolation room by using portable fan devices with high-efficiency particulate air (HEPA) filtration. In this environment, face masks can be used.
Use a ventilated headboard that draws exhaled air from a patient into a HEPA filter. Using this along with HCP and patient masking may decrease exposure.
As a last resort, masks that have not ever been approved by NIOSH or homemade masks may afford some protection. Use caution when considering this option.
Social distancing and diligent hand hygiene along with not touching your eyes, nose or mouth, play a large role in preventing transmission of SARS-CoV-2.
New Information on the Persistence of SARS-CoV-2 on Surfaces
It is still uncertain how individuals who do not have symptoms can spread the virus throughout the course of their day. So, researchers have been curious about just how long SARS-CoV-2 remains on surfaces.
According to a new study by Neeltje van Doremalen, PhD, of the Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, in Hamilton, Montana, and colleagues, SARS-CoV-2 remains viable in aerosols for hours and on surfaces for days.
They looked at plastic, air, stainless steel, paper and copper and this is what they discovered:
Knowing how long the SARS-CoV-2 remains on surfaces helps us understand that contact transmission is possible and probable.
CDC. (2020, March 6). Release of Stockpiled N95 Filtering Facepiece Respirators Beyond the Manufacturer-Designated Shelf Life: Considerations for the COVID-19 Response. Retrieved March 23, 2020, from Centers for Disease Control and Prevention: ttps://www.cdc.gov/coronavirus/2019-ncov/release-stockpiled-N95.html
CDC. (2020, April 3). Strategies for Optimizing the Supply of N95 Respirators: Crisis/Alternate Strategies. Retrieved April 6, 2020, from Centers for Disease Control and Prevention: https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-strategy/crisis-alternate-strategies.html
NIOSH. (2018, March 28). Recommended Guidance for Extended Use and Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings. Retrieved March 23, 2020, from Centers for Disease Control and Prevention/The National Institute for Occupational Safety and Health (NIOSH): https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html
Ricki Lewis, P. (2020, March 17). Coronavirus Stays in Aerosols for Hours, on Surfaces for Days. Medscape Medical News. Retrieved March 23, 2020, from Medscape Medical News: https://www.medscape.com/viewarticle/926929?nlid=134587_4622&src=WNL_mdplsnews_200320_mscpedit_nurs&uac=364950EN&spon=24&impID=2318484&faf=1#vp_1
U.S. Food & Drug Administraton. (2020, April 3). Guidance Memo Regarding Imported, Non-NIOSH-Approved Disposable Filtering Facepiece Respirators. Retrieved April 6, 2020, from FDA.gov: https://www.fda.gov/media/136664/download
Learn more by reading similar blogs:
What Healthcare Officials Need to Know About the Coronavirus COVID-19 (Part 1)
What Healthcare Professionals Need to Know About the Coronavirus COVID-19 (Part 2)
What Healthcare Professionals Need to Know About the Coronavirus COVID-19 (Part 3)
Preventing Viruses: Strategies of Containment, Protection, & Prevention
Benefits & Challenges of Working Remotely in Times of Crisis