DISCUSSION

Because coronaviruses lose their viability significantly after 72 h, a rotation and re-use can be done assuming there is no soiling and minimal to no viral contamination of the mask. ^{Reference van Doremalen, Bushmaker and Morris11} Studies suggest that the protection margin of limited reuse N95 masks begins to decrease after multiple donning, which varies with the ambient conditions and individual use. The type of N95 mask, ie, duck-billed or dome shape and its fit on the individual’s face also affected the duration of extended and limited use. ^{Reference Degesys, Wang and Kwan12} Hence, it is preferable to limit the number of reuses to 5 to warrant an adequate safety margin. ^{Reference Fisher and Shaffer7} The CDC suggests that 5 masks to be acquired for 20 d and rotated daily, allowing them to dry for at least 72 h. In these interim periods, the masks are to be air dried by hanging or placement in individual, clean, breathable container like a paper bag. ^13,14

In conclusion, the effectiveness of N95 masks depends on fit, level of exposures, and appropriate use. Moreover, the mask would only protect from oro-nasal aerosol contamination and not against contact transmission. ^15,16 Despite the above limitations, these reused masks provided better personal protection in comparison to cotton masks and homemade alternatives, such as handkerchiefs, or no protection at all. ¹³ Still, extended use and re-use of single-use masks/respirators should only be considered in situations of critical shortage. Also, when practicing extended use or re-use, policies have to be fixed and individuals made aware of these guidelines. ^{Reference Toomey, Conway and Burton17} There is paucity in the literature of such clear and consistent guidelines, which warrants further attention. After due consideration of all the factors, the decision to provide N95 masks for extended use for all employees was taken, as was suggested by a 2400-bed hospital in Seoul that emphasized on respiratory protection to all patients and employees. ^{Reference Jeon, Park and Jung18} In a communication by Jeon et al. on the experience of protection of HCWs against COVID-19 at a large teaching hospital in Seoul, there was evidence of marked reduction in risk to HCWs from category 3 (needing self-quarantine) to category 0 (usual management) with the use of 4 personal protective equipment (PPE) items, which included N95 respirators. ^{Reference Jeon, Park and Jung18}

Patel et al. suggested that, during the 2009 H1N1 pandemic, projecting the demand and supply of N95 respirators was a major challenge, because the pandemic as well as the supply chain were unpredictable. ^{Reference Patel, D’Alessandro and Ireland19,20} They also suggested that extended use or reuse of N95 masks was sometimes considered by HCWs to tide over the crisis. ^{Reference Patel, D’Alessandro and Ireland19,Reference Sweeney21} The institution anticipated the same challenges when it decided to implement extended use of N95 masks rather than using them for just 1 time.

Tan et al. studied the effect of extended use of N95 respirators on PPE use in COVID-19 outbreak wards of a Singapore hospital. After implementation of extended use, the average use of N95 respirators dropped down to 1710 from 2490. ^{Reference Tan, Linn and Soon22,Reference Fisher and Shaffer23} They further documented that, after nearly 45 d of implementation, there was no confirmed case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among the HCWs who had acquired the same from the hospital. The N95 masks were also found not to be contaminated after patient contact. ^{Reference Tan, Linn and Soon22,Reference Ong, Tan and Chia24,Reference Ong, Tan and Sutjipto25}

In 2020, Garcia Godoy et al. conducted a review regarding facial protection of HCWs during pandemics. They concluded that among HCWs, the rates of respiratory infections were less with use of N95 masks as compared to surgical masks. ^{Reference Garcia Godoy, Jones and Anderson26-Reference MacIntyre, Wang and Seale29} They also stated that extended use of N95 masks along with other infection control measures, such as hand hygiene poses minimal risk to the HCWs. ^{Reference Fisher and Shaffer23,Reference Garcia Godoy, Jones and Anderson26,30} The literature also suggests that continuous use of N95 masks was better as compared to sporadic use at the time of high-risk procedures, ^{Reference Garcia Godoy, Jones and Anderson26,Reference MacIntyre, Chughtai and Rahman27} further strengthening our decision to provide N95 masks to all the employees.

Conservation, extended use, and reuse after decontamination have been described as PPE supply strategies in view of increased demand and failing supply line by Fillingham et al. ^30-34

The most preferred method about disseminating information regarding the use of this mask was pasting instructions on the brown envelopes in which the masks were supplied.

The overall use of N95 masks provided for extended use was 96.5%, and most of the participants used these masks during their entire stay in the hospital. This is imperative for preventing the transmission of infection from asymptomatic or mildly symptomatic HCPs to other providers and patients ^{Reference Klompas, Morris and Sinclair35} as the study by Hu et al. suggests that unprotected exposures are more likely from patients who did not have influenza-like symptoms. ^{Reference Hu, Zhang and Li36,Reference Banach, Bielang and Calfee37} The nonuse of masks provided for extended use was more among the clinical staff as compared to the nonclinical staff. This might be due to the fact that the clinical staff has access to other sources of masks, such as inpatient areas, outpatient departments, and/or procedure rooms, where separate masks were provided for front-line HCWs.

The 5 masks were provided for use during a 20-d cycle, after which they would again be reissued. Although the majority of the participants were satisfied with the quality and fit of the masks, 60% of them did not use it for more than 15 d. Another probable reason for this could be a problem with the N95 masks, which were loss of fit and damage to the slings, as highlighted by 44.6% and 44.4% of the participants, respectively. Also, it was observed that most of the participants used these masks for more than 6 h/d, which was probably because they used them during the duty hours (92.6%) and the shift are usually 8 h long.

In our study, the participants stated that they preferred the cup-shaped mask the most, followed by the duck-billed ones, and lastly the N95 masks and KN95 masks. The literature suggests that the cup-shaped and duck-billed masks are easy to don and doff and are more comfortable as compared to particulate respirators (N95, KN95, FFP2, FFP3, etc.) ^{Reference Honda and Iwata38-40} Also, in our study, surgical masks were considered to provide adequate protection against COVID-19 only by 3.58% of the clinical staff and 0.3% of the nonclinical staff. This finding is consistent with the findings of the study conducted by Hu et al. among HCWs in 21 ICUs in China during the 2009 H1N1 pandemic, where it was revealed that 33.1% of the respondents believed that surgical masks provide adequate protection as opposed to 88.3% who believed N95 masks to be adequate. ^{Reference Hu, Zhang and Li36}

The satisfaction regarding the quality and fit of N95 masks was higher among the nonclinical staff as compared to the clinical staff as the latter has to use the masks continuously for a longer duration as they worked in high-intensity patient care areas. Another reason for dissatisfaction among the clinical staff could be that they had the option to use other types of N95 masks supplied to the clinical area, which were single-use ones. The participants who stated that they used the masks for a longer duration were more satisfied with the quality and fit of the masks, thus reinforcing that good quality and fit is necessary for better compliance.

A study conducted by Scarano et al. regarding the effects of protective face masks on skin temperature and comfort revealed that use of N95 masks was associated with raised skin temperature in the facial region leading to greater discomfort as compared to surgical masks. ^{Reference Scarano, Inchingolo and Lorusso41} Another study by Hua et al. on short-term effects of use of N95 masks, states that skin reaction were more common with N95 masks as compared to surgical masks. ^{Reference Hua, Zuo and Wan42} However, these studies were conducted on subjects in nonclinical setting where the fear of transmission of infection is eliminated. However, in our study, the participants were involved in thecare of suspected and confirmed COVID-19 patients and probably the prevention of transmission was a priority over the discomfort associated with use of N95 masks. The result of our study can be interpreted accordingly.

In a study by Rebmann et al. on effects and compliance of N95 mask use among Nursing staff of ICUs, it was concluded that there was no clinically significant physiological burden for health-care personnel apart from certain subjective symptoms, and the compliance was fairly high, despite the discomfort and repeated readjustments, which increased over time. ^{Reference Rebmann, Carrico and Wang43} In our study, compliance and satisfaction were found to be high as the survey was conducted during early phases of the pandemic when the fear among general population and the health-care personnel was high.

The limitation of the study was that the survey was carried out through a structured questionnaire, which may have tempted the participants to answer the most acceptable response rather than what is their true perception, and it was carried out in a very short period of time, as the future course of action regarding the supply of these masks had to be decided.