Components of a Protective Environment

Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (2007)

Appendix A: Table 5.

(Adapted from MMWR 2003; 52 [RR-10])

Edit [July 2023]

Edit: An ~ indicates text that was edited for clarity. The edit does not constitute change to the intent of the recommendations.

I. Patients: allogeneic hematopoeitic stem cell transplant (HSCT) only

  • Maintain in PE room except for required diagnostic or therapeutic procedures that cannot be performed in the room, e.g., radiology, operating room
  • Respiratory protection e.g., N95 respirator, for the patient when leaving PE during periods of construction

II. Standard and Expanded Precautions

  • Hand hygiene observed before and after patient contact
  • ~ Barrier precautions (e.g., masks, gowns, gloves) are not required for healthcare personnel in the absence of suspected or confirmed infection unless indicated according to Standard Precautions or if recommended for source control (e.g., mask) for any individual entering the protective environment room.

III. Engineering

  • Central or point-of-use HEPA (99.97% efficiency) filters capable of removing particles 0.3 μm in diameter for supply (incoming) air
  • Well-sealed rooms
    • Proper construction of windows, doors, and intake and exhaust ports
    • Ceilings: smooth, free of fissures, open joints, crevices
    • Walls sealed above and below the ceiling
    • If leakage detected, locate source and make necessary repairs
  • Ventilation to maintain ≥12 ACH
  • Directed air flow: air supply and exhaust grills located so that clean, filtered air enters from one side of the room, flows across the patient’s bed, exits on opposite side of the room
  • Positive room air pressure in relation to the corridor
    • Pressure differential of >2.5 Pa [0.01” water gauge]
  • Monitor and document results of air flow patterns daily using visual methods (e.g., flutter strips, smoke tubes) or a hand held pressure gauge
  • Self-closing door on all room exits
  • Maintain back-up ventilation equipment (e.g., portable units for fans or filters) for emergency provision of ventilation requirements for PE areas and take immediate steps to restore the fixed ventilation system
  • For patients who require both a PE and Airborne Infection Isolation, use an anteroom to ensure proper air balance relationships and provide independent exhaust of contaminated air to the outside or place a HEPA filter in the exhaust duct. If an anteroom is not available, place patient in an AIIR and use portable ventilation units, industrial-grade HEPA filters to enhance filtration of spores.

IV. Surfaces

  • Daily wet-dusting of horizontal surfaces using cloths moistened with EPA-registered hospital disinfectant/detergent
  • Avoid dusting methods that disperse dust
  • No carpeting in patient rooms or hallways
  • No upholstered furniture and furnishings

V. Other

  • No flowers (fresh or dried) or potted plants in PE rooms or areas
  • Use vacuum cleaner equipped with HEPA filters when vacuum cleaning is necessary