COVID-19 technical brief: Masking and face shields for full duration of shifts in acute healthcare settings
This document was created on April 15, 2020. Please refer back for future updates.
This technical brief represents an update to previously issued guidance and is applicable to acute healthcare settings. It applies to acute care settings such as hospitals; please see other guidance for primary care, community care settings, and long-term care.
Community transmission of COVID-19 infection continues to increase across Canada. It is recommended that all healthcare workers (HCWs) follow Routine Practices, including performing hand hygiene and a point-of-care risk assessment to determine the need for additional precautions and choice of personal protective equipment (PPE) during all patient encounters. Additional precautions for encounters with patients who have signs, symptoms, or known exposures to COVID-19, include wearing a mask, gown, gloves, and face or eye protection.
There is emerging evidence of unrecognized asymptomatic, pre-symptomatic, or pauci-symptomatic transmission of this virus. Both HCWs and patients admitted to hospital for other indications may be asymptomatic or have undetected pauci-symptomatic COVID-19 infection. Patients may also be incubating COVID-19 when admitted, but not become symptomatic until more than a week later.
In the context of increasing community transmission and the potential for asymptomatic, pre-symptomatic or pauci-symptomatic transmission, neither symptom-based or travel-based definitions are sufficiently reliable to identify infected patients and HCWs, increasing the risk of transmission to other patients and HCWs.
Physical distancing, environmental cleaning, and adherence to hand hygiene guidelines are essential. However, there is evidence of the introduction of COVID-19 into acute care facilities by both patients and HCWs despite efforts to improve these measures. There are also ongoing concerns about diminishing supplies of PPE in Canadian hospitals, and increasing focus on strategies to conserve existing PPE. This has led to consideration of additional measures to prevent transmission from HCWs to patients and other HCWs, and from patients to HCWs, including extended wearing of masks and eye protection for the full duration of HCW shifts.
The potential benefit of HCWs wearing a mask for the full duration of their shift is prevention of transmission of unrecognized COVID-19 infection to their patients or other HCWs (i.e., for use primarily as source control). Potential risks of wearing a mask continuously include risk of self-contamination through non-adherence to hand hygiene, inappropriate wear, or touching the mask, discomfort, skin irritation or breakdown, and a false sense of security that the wearer is fully protected by the mask.
The potential benefit of HCWs wearing eye protection (e.g., a face shield) in addition to a mask for the full duration of their shift is reduced exposure of HCWs to splash, spray, or droplets from patients who may be infected but not yet identified and placed under additional precautions (i.e., used as PPE). Potential disadvantages of wearing eye protection continuously also include the potential for self-contamination, altered clarity of vision, or discomfort.
There is variability in how these additional measures are being implemented across the country. Representatives of 78 acute care hospitals in the Canadian Nosocomial Infection Surveillance Program (CNISP) network were surveyed on April 8, 2020, asking if they are recommending masking of all HCWs with direct patient contact for the duration of their shifts. Forty-one (75%) of the 55 CNISP hospitals in 7/8 (88%) provinces represented in responses, are recommending masking of HCWs for the full duration of their shifts, and 7 (13%) others supported extended use not otherwise specified.
In the context of the COVID-19 pandemic, masking for the full duration of HCW shifts is recommended for those working in direct patient care areas, to reduce the risk of transmitting COVID-19 infection to patients or other HCWs. Use of eye protection (e.g., a face shield) for the full duration of HCW shifts should be strongly considered due to the increasing prevalence of COVID-19 infection. This guidance applies to all staff working within 2 metres of HCWs and patients. It is important to note that the masking strategy is intended to prevent transmission from asymptomatic or pre-symptomatic HCWs. HCWs with symptoms of illness that may be attributable to COVID-19 must be excluded from duty.
HCWs should refer to provincial and territorial guidance and facility policies on specific recommendations for use of masks, eye protection, and other PPE, and PPE conservation strategies. Provincial and territorial guidance will be informed by their specific epidemic curves. When masks and full-face shields are recommended for the full duration of shifts, HCWs must:
- Perform hand hygiene before they put on their mask and face shield when they enter the acute healthcare facility or patient care area, and before and after removal
- Wear a mask securely over their mouth and nose and adjust the nose piece to fit snugly
- Not touch the front of mask or face shield while wearing it (and immediately perform hand hygiene if this occurs)
- Not dangle the mask under their chin, around their neck, off the ear, under the nose or place on top of head
- Ensure that gloves and a long-sleeved cuffed gown (covering front of body from neck to mid-thigh), are donned prior to entering the room or within 2 metres of any patient on Droplet and Contact precautions
- After seeing a patient on Droplet and Contact precautions:
- Gloves should be discarded in the nearest no-touch waste receptacle, and should never be re-worn
- Disposable gowns should be discarded in the nearest no-touch waste receptacle, and reusable gowns processed as per facility protocols
- Full face shields should be removed (to be reprocessed or disposed of as per facility infection prevention and control guidance) *If masks with attached visors are used these should be removed and discarded in the nearest no-touch waste receptable, and a new mask and eye protection donned
- If multiple patients are seen on units dedicated to confirmed COVID-19-positive patients, face shields or masks with attached visors do not need to be removed between patients unless soiled, or if the mask is damaged, wet, damp, or has touched a patient
- Hand Hygiene must be performed during and after PPE removal and between patient encounters
- Remove their mask and face shield just prior to breaks or when leaving the facility, while in an area where no patients, HCWs, or other staff are present, and discard them in the nearest no-touch waste receptacle, or otherwise store in accordance with facility policy (see statement below on re-use of masks). Reusable shields should be processed as per facility protocols
- When seeing a patient undergoing an aerosol-generating medical procedure such as endotracheal intubation, where an N95 respirator is required, follow facility procedures for taking off their mask and face shield (to be reprocessed or disposed of as per facility infection prevention and control guidance), and then putting on an N95 respirator, with meticulous hand hygiene performed at all steps
- If subsequent encounters do not require the use of an N95 respirator, this can be removed and changed back to a non-respirator mask following facility procedures for putting on and removing PPE
- Maintain a 2 metre distance between themselves and others when possible in all settings, and always when masks and shields are removed (e.g., during breaks or when changing masks)
It is a foundational concept in infection prevention and control practice, that disposable masks should not be re-worn. However, in the context of the COVID-19 pandemic and PPE shortages, please refer to jurisdictional guidance with regard to mask use, re-use, and reprocessing policies.
- Example approach:
- A policy of masking for the full duration of shifts is one strategy aimed at protecting staff and patients while trying to conserve supplies of PPE
- If re-use of masks is recommended, staff must remove their mask by the ear loops or elastics taking care not to touch front of mask, and carefully store the mask in a clean dry area and in accordance with institutional and jurisdictional public health guidance, taking care to avoid contamination of the inner surface of the mask
- Hand hygiene must occur before and after removal of mask and prior to putting it on again
- Masks should be disposed of and replaced when they become damaged, wet, damp, or soiled (from the wearer's breathing or external splash), or when they come in direct contact with a patient
- Masks do not necessarily need to be replaced after seeing a patient on Droplet and Contact precautions if a full face shield is worn over this
- Staff should be informed of how to access additional masks if needed
This technical brief was prepared by: Cheryl Volling, Marina Salvadori, and James Brooks on behalf of the COVID-19 Clinical Issues Task Group
The authors gratefully acknowledge the contributions of: Allison McGeer, Gerald Evans, Kathryn Suh, Elizabeth Brodkin, Sandra Callery, Gordon Dow, Barb Catt on behalf of Infection Prevention and Control (IPAC)-Canada, and Linda Pelude and Robyn Mitchell, on behalf of the Canadian Nosocomial Infection Surveillance Program (CNISP).
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