Dr. Raman Palabindala
The gravest risk behind the universal masking policy is the likely depletion of medical resources.22 A possible solution to this issue could be to modify the policy to stagger the requirement based on the severity of community transmission in that area of residence. In the article appropriately titled “Rational use of face masks in the COVID-19 pandemic” published in The Lancet Respiratory Medicine, researchers described how the Chinese population was classified into moderate, low, and very-low risk of infection categories and advised to wear a surgical or disposable mask, disposable mask, and no mask respectively.23 This curbs widespread panic and eagerness by the general public to stock up on essential medical equipment when it may not even be necessary.
Reuse, extended use, and sterilization
Several studies have been conducted to identify the viability of the COVID-19 on various surfaces.24-25 The CDC and National Institute for Occupational Safety and Health (NIOSH) guidelines state that an N95 respirator can be used up to 8 hours with intermittent or continuous use, though this number is not fixed and heavily depends upon the extent of exposure, risk of contamination, and frequency of donning and doffing26,27. Though traditionally meant for single-time usage, after 8 hours, the mask can be decontaminated and reused. The CDC defines extended use as the “practice of wearing the same N95 respirator for repeated close-contact encounters with several patients, without removing the respirator between patient encounters.” Reuse is defined as “using the same N95 respirator for multiple encounters with patients but removing it (‘doffing’) after each encounter. The respirator is stored in between encounters to be put on again (‘donned’) prior to the next encounter with a patient.”
It has been established that extended use is more advisable than reuse given the lower risk of self-inoculation. Furthermore, health care professionals are urged to wear a cleanable face shield or disposable mask over the respirator to minimize contamination and practice diligent hand hygiene before and after handling the respirator. N95 respirators are to be discarded following aerosol-generating procedures or if they come in contact with blood, respiratory secretions, or bodily fluids. They should also be discarded in case of close contact with an infected patient or if they cause breathing difficulties to the wearer.27 This may not always be possible given the unprecedented shortage of PPE, hence decontamination techniques and repurposing are the need of the hour.
In Anesthesia & Analgesia, Naveen Nathan, MD, of Northwestern University, Chicago, recommends recycling four masks in a series, using one per day, keeping the mask in a dry, clean environment, and then repeating use of the first mask on the 5th day, the second on the 6th day, and so forth. This ensures clearance of the virus particles by the next use. Alternatively, respirators can be sterilized between uses by heating to 70º C (158º F) for 30 minutes. Liquid disinfectants such as alcohol and bleach as well as ultraviolet rays in sunlight tend to damage masks.28 Steam sterilization is the most commonly utilized technique in hospitals. Other methods, described by the N95/PPE Working Group, report include gamma irradiation at 20kGy (2MRad) for large-scale sterilization (though the facilities may not be widely available), vaporized hydrogen peroxide, ozone decontamination, ultraviolet germicidal irradiation, and ethylene oxide.29 Though a discussion on various considerations of decontamination techniques is out of the scope of this article, detailed guidelines have been published by the CDC30 and the COVID-19 Healthcare Coalition.30