II. Preparations: Surgical Face Mask

  1. Description
    1. Disposable, loose fitting physical barrier between the wearer's mouth and nose and the patient
    2. Some masks are also available with a Face Shield to protect the mid-face and eyes
    3. Blocks large-particle droplets, splashes, sprays or splatter (and the infectious agents they harbor)
  2. Indications
    1. Personal Protective Equipment during patient care (standard protection from low level exposure to body fluids)
    2. Sterile procedures (e.g. surgery) to protect the patient from the operating staff's oral and nasal secretions
  3. Limitations
    1. Does not filter small, aerosolized particles (e.g. cough, sneeze transmitted highly infectious agents)
    2. No significant protection against most toxins due to the loose fit

III. Preparations: N95 Mask

  1. Description
    1. Single-use, disposable, tightly fitting Face Mask offers protection against airborne particles
    2. Blocks small aerosolized particles, in addition to large particles, splashes and spray
    3. N95 Masks filter >=95% of particles <5 µm diameter
  2. Indications
    1. Protection against contagious, small aerosolized infectious agents (e.g. pandemic Influenza)
  3. Precautions
    1. Adequate respirator mask protection assumes that it is donned correctly and it is worn throughout contact exposure
    2. Mask must fit snugly without gaps (FIT testing needed)
  4. Limitations
    1. Requires special FIT Testing
    2. Not oil resistant
    3. Not designed for children or those with significant facial hair (beard)
    4. May be contraindicated in those with chronic lung disease (e.g. COPD or Severe Asthma)
    5. Not designed for toxin exposures ("hot zone") vapors or gases
      1. See Personal Protective Equipment
  5. Adverse Effects
    1. Headache
      1. Occurs in up to 70% of healthcare workers who remain in N95 Mask >6 hours per day
      2. Ong (2020) Headache 60(5): 864-77 [PubMed]

IV. Preparations: Powered Air Purifying Respirator (PAPR)

  1. Description
    1. Reusable battery-powered PPE device with HEPA Filters that are 99.97% effective against 0.3 micron particles
    2. Powered blower forces air through filter canisters and into an enclosed helmet, hood or Face Mask worn by user
  2. Indications
    1. Protection against dangerous, contagious, small aerosolized infectious agents (e.g. Ebola)
    2. Alternative device to N95 Mask for those who cannot adequately be fit (e.g. beard)
  3. Limitations
    1. Complicates the process of Donning and Doffing Personal Protection Equipment
    2. PAPR is reusable and requires careful cleaning procedures
    3. Interferes with communication
    4. Unable to use Stethoscope (no ear access in hood or helmet)

V. Preparations: M40 Mask (Chemical Defense Mask)

  1. Description
    1. Full face respirator
    2. External filter canister
      1. HEPA filter
      2. ASZ charcoal impregnated
  2. Indications
    1. Protects face and respiratory tract
    2. Volatile agents and aerosols
    3. Removes biological and toxin agents
  3. Limitations
    1. Does not protect in close space with Oxygen <19.5%
    2. Substances not filtered
      1. Ammonia
      2. Carbon Monoxide
      3. Nitric oxide
      4. Carbon dioxide

VI. Preparations: Cloth Mask (home use, patients)

  1. Indications
    1. These masks are primarily to protect others from the mask wearer
      1. When masks are used by everyone, the risk of contagious dispersion and exposure is reduced
    2. Risk of exposure to potential serious respiratory pathogen (e.g. COVID-19)
      1. Indoor environments outside home
      2. Outdoors when social distancing cannot be maintained
  2. Fit
    1. Masks should cover nose, mouth and chin
    2. Masks should fit relatively snugly around face
    3. Masks should have at least 2 layers of fabric
  3. Disadvantages
    1. Unlikely to be sufficient for exposures with close contact (at least N-95 is recommended)
    2. Misuse is common
      1. Avoid pulling mask down below chin (contaminates inner surface of mask)
      2. Avoid vented masks or breaching surface to allow for straws (defeats purpose of mask)
  4. Care
    1. Store masks in clean paper bag
    2. Wash hands when putting on, adjusting or removing mask
    3. Launder Cloth Masks in fragrance-free detergent when mask is soiled or damp or otherwise contaminated
  5. Adverse Effects
    1. Anxiety or Claustrophobia
      1. Reassure patients that masks do not decrease their oxygenation (may demonstrate with Oxygen Saturation)
      2. Encourage Relaxation Techniques (e.g. breathing Exercises)
    2. Heat Build-up
      1. Consider 100% cotton masks
      2. Decreases after first 30 minutes in mask
    3. Fogging Glasses
      1. Fogging is reduced when mask leaks less air at its upper boundary
        1. Consider taping mask to Nasal Bridge and cheeks
        2. Consider masks with moldable material over Nasal Bridge (e.g. surgical masks)
      2. Anti-fog solution (soapy water)
        1. May be applied to glasses and reduce fogging
    4. Ear Irritation
      1. May secure mask ties together in back of head (e.g. plastic device, paperclip) to keep strings off ears
    5. Headaches
      1. Maintain hydration
      2. Secure mask to avoid ear irritation (see above)
  6. (2020) Presc Lett 27(9): 49

VII. Prevent

  1. Mask Irritation
    1. Consider barrier cream (e.g. Desitin) at areas of pressure and irritation (e.g. bridge of nose, ears)
    2. Consider mask string holder that pulls the mask strings off the ears
    3. Consider Wound Dressing (e.g. Duoderm) in areas of pressure
    4. Consider topical irritant or allergans in the mask (e.g. latex)
    5. (2020) Presc Lett 27(6):31-2

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Related Studies

Ontology: Masks (C0024861)

Definition (UMD) Devices that cover the nose and mouth to maintain aseptic conditions or to administer inhaled anesthetics or other gases. They are typically composed of rubber, plastic or paper products.
Definition (NCI) A protective covering worn over the face, or an apparatus for administering anesthesia or oxygen through the nose or mouth.
Definition (MSH) Devices that cover the nose and mouth to maintain aseptic conditions or to administer inhaled anesthetics or other gases. (UMDNS, 1999)
Concepts Medical Device (T074)
MSH D008397
SnomedCT 261382003
English Face Masks, Masks, MASK, masks (treatment), masks, mask, face masks, Mask, Mask (physical object)
Swedish Munskydd
Czech masky
Finnish Naamarit
French Masques
Polish Maski ochronne
Norwegian Munnbind, Masker
Spanish Mascarillas, máscara (objeto físico), máscara, Máscaras
German Schutzmasken
Italian Maschere
Dutch Masker, Maskers
Portuguese Máscaras

Ontology: Respirators, Air-Purifying (C0035208)

Definition (UMD) Respirators designed to prevent the wearer from inhaling airborne particles, gases, and/or vapors by filtering the environmental air. These respirators typically consist of a filtering facepiece (e.g., mask) that includes air-purifying devices (e.g., filters, cartridges, canisters) that remove the contaminant before it reaches the user.
Concepts Medical Device (T074)
MSH D012134
SnomedCT 409533008
English Air-Purifying Respirator, Respirator, Air-Purifying, Respirators, Air Purifying, Masks, Air-Purifying, Air-Purifying Masks, Respirators, Air-Purifying, Air-Purifying Respirators, APR-Air-purifying respirator, Air-purifying respirator (physical object), Air-purifying respirator
Portuguese Respiradores de Ar Purificado
Spanish Respiradores de Aire Purificado, respirador purificador de aire (objeto físico), respirador purificador de aire
German Atemgeräte, Filter-
Norwegian APR-pusteapparater
Dutch Veiligheidsmaskers, respiratoire

Ontology: Respiratory Protective Devices (C0035233)

Definition (MSH) Respirators to protect individuals from breathing air contaminated with harmful dusts, fogs, fumes, mists, gases, smokes, sprays, or vapors.
Concepts Manufactured Object (T073)
MSH D012134
English Device, Respiratory Protective, Devices, Respiratory Protective, Protective Device, Respiratory, Protective Devices, Respiratory, Respiratory Protective Device, Respiratory Protective Devices
Swedish Skyddsmasker
Czech dýchací ochranné prostředky
Finnish Hengityssuojaimet
Japanese 人工呼吸器-工業用, 工業用人工呼吸器, 防毒面, 防毒マスク, 呼吸保護用具, レスピレータ-浄気式, レスピレーター-浄気式, 浄気式レスピレータ, 浄気式レスピレーター, ガスマスク, 呼吸保護具
French Respirateurs purificateurs d'air, Protecteurs respiratoires
Polish Ochraniacze dróg oddechowych
Norwegian Respirasjonsvern, Respirasjonsbeskyttelse, Pustebeskyttelse
German Atemschutzvorrichtungen
Italian Dispositivi di protezione respiratoria
Dutch Masker, veiligheids-, respiratoir, Respiratoir veiligheidsmasker
Portuguese Dispositivos de Proteção Respiratória
Spanish Dispositivos de Protección Respiratoria

Ontology: Surgical face mask (C0181758)

Definition (SPN) Surgical apparel are devices that are intended to be worn by operating room personnel during surgical procedures to protect both the surgical patient and the operating room personnel from transfer of microorganisms, body fluids, and particulate material. Examples include surgical caps, hoods, masks, gowns, operating room shoes and shoe covers, and isolation masks and gowns. Surgical suits and dresses, commonly known as scrub suits, are excluded.
Concepts Medical Device (T074)
SnomedCT 409528009
English MASK, SURGICAL, Masks, Operating Room, Masks, Surgical, Surgical Masks, Surgical face mask, surgical mask, surgical masks, mask surgical, Surgical mask, Surgical face mask (physical object)
Spanish máscara quirúrgica (objeto físico), máscara quirúrgica

Ontology: M40 Protective Masks (C1504101)

Concepts Medical Device (T074)
English M40 Protective Masks

Ontology: N95 Respirator, Disposable (C2746744)

Concepts Medical Device (T074)
English N95 Respirator, Disposable