Airborne Infection Isolation Rooms (AIIRs) & COVID-19: Ensuring Patient Containment

Airborne Infection Isolation Rooms (AIIRs)

All U.S. hospitals should be prepared for the possible arrival of patients with Coronavirus Disease 2019 (COVID-19). All hospitals should ensure their staff are trained, equipped and capable of practices needed to:

  • Prevent the spread of respiratory diseases; including COVID-19 within the facility
  • Promptly identify and isolate patients with possible COVID-19 and inform the correct facility staff and public health authorities
  • Care for a limited number of patients with confirmed or suspected COVID-19 as part of routine operations
  • Potentially care for a larger number of patients due to an escalating outbreak
  • Monitor and manage any healthcare personnel that might be exposed to COVID-19
  • Communicate effectively within the facility and plan for appropriate external communication related to COVID-19

The following checklist highlights important areas for hospitals to review in preparation for potential arrivals of COVID-19 patients.

__Confirm the number and location of Airborne Infection Isolation Rooms (AIIRs) available in the facility (ideally AIIRs will be available in the emergency department and on inpatient units).

__ Document that each AIIR has been tested and confirmed to be effective (e.g., sufficient air exchanges, negative pressure, exhaust handling) within the last month. The AIIR should be checked for negative pressure before occupancy. If the instrument used to monitor negative pressure provides logging capabilities, it is ideal for healthcare staff to review them to verify the room stability before, during and after infected patient occupancy.

Verify each AIIR meets the following criteria:

__ Minimum of 6 air changes per hour (12 air changes per hour are recommended for new construction or renovation).

__ Air from these rooms should be exhausted directly to the outside or be filtered through a high-efficiency particulate air (HEPA) filter before re-circulation.

__ Room doors should be kept closed except when entering or leaving the room, and entry and exit should be minimized.

__ When occupied by a patient, the AIIR must be checked at least daily for negative pressure.

__ A protocol is established, which specifies that aerosol-generating procedures that are likely to induce coughing (e.g., sputum induction, open suctioning of airways) are to be performed in an AIIR using appropriate PPE.

__ Facility has plans to minimize the number of HCP who enter the room. Only essential personnel enter the AIIR. Facilities should consider caring for these patients with dedicated HCP to minimize risk of transmission and exposure to other patients and HCP.

__ Facility has a process (e.g., a log, electronic tracking, dual-purpose data logger and room pressure variable monitor) for documenting HCP entering and exiting the patient room.

__ Facility has policies for dedicating noncritical patient-care equipment to the patient.

__ Patient movement outside of the AIIR will be limited to medically-essential purposes

__ Patients transported outside of their AIIR will be asked to wear a facemask and be covered with a clean sheet during transport.

Airborne Isolation Room Specifications as per CDC

This is a single patient room equipped with special air handling (able to maintain negative pressure) and ventilation capacity. The negative pressure room is also known as an Airborne Isolation Room. This negative pressure room is usually a single-occupancy patient-care room frequently used to isolated individuals with confirmed or suspected airborne infection.

Elements of an Airborne Isolation Room 

  • Negative pressure ventilation that creates inward directional airflow from corners of the room. Ideally, this room is prefaced by an anteroom (see below)
  • The airborne isolation room should have a toilet and sink for the patient, and a designated hand washing sink for healthcare workers.
  • Have monitoring equipment including alarms; ideally an instrument capable of providing real-time feedback, current room pressure values, and alerts/alarms if pressures become unstable/unsafe. 
  • Transmit exhaust of air from the hospital room to the outside of the building
  • Recirculate air through a HEPA filter if not expelled to the outside before being returned to the general circulation
  • The door to the room must be kept closed to maintain negative pressure even if the patient is not in the room.
  • The windows in the room should remain closed at all times; opening the window may cause the reversal of airflow, which counters the benefits of a negative pressure room.
  • All healthcare providers who enter the isolated negative pressure room must be fit tested for an N95 respirator, and should take notice of room pressure to ensure that they are within acceptable ranges.
  • Only healthcare providers immunized to the organism in question should enter a room where airborne precautions are in place for varicella or measles or varicella. A respirator is not necessary for immunized individuals but is required for non-immunized workers who provide care.
  • The negative pressure room should have dedicated personal hygiene facilities including a toilet and bathing facilities.
  • One should also have a point of care evaluation for every patient interaction so that one can determine the need for additional precautions.

What is an Anteroom?

This is relatively clean and frequently used area to transition patients/healthcare workers in and out of the airborne isolation room when it is under negative pressure. An anteroom is frequently used as a transitional space between the airborne isolation room and the hallway. It is in this transition area where healthcare workers store their PPE and put on their PPE before entering the airborne isolation room. Ideally, an instrument or monitoring device will display differential pressure values between the anteroom and the Airborne Isolation Room (AIIR) as well as between the anteroom and the hallway.

  1. The laundry hamper is usually located inside the patient room.
  2. The HCP sink is usually in the anteroom location.
  3. The only items that are stored in the anteroom are the procedure or surgical masks, N95 respirator, eye protection devices, gloves, and gowns.
  4. At the hand washing sink, an alcohol-based hand sanitizer and disinfectant wipes should be available.
  5. Posters showing how to perform hand washing must be placed at the sink.

Additional Precautions – Performing Aerosol-Generating Procedures (AGPs)

  • Some procedures performed on patient with known or suspected COVID-19 could generate infectious aerosols. In particular, procedures that are likely to induce coughing (e.g., sputum induction, open suctioning of airways) should be performed cautiously and avoided if possible.
  • If performed, the following should occur:
    • HCP in the isolation room should wear an N95 or higher-level respirator, eye protection, gloves, and a gown, and ensure negative pressure is being maintained at all times via a visual indicator displaying negative pressure values.
    • The number of HCP present during the procedure should be limited to only those essential for patient care and procedure support. Visitors should not be present for the procedure.
    • AGPs should ideally take place in an AIIR.
    • Clean and disinfect procedure room surfaces promptly as described in the section on environmental infection control below.

Cautionary Statement

In most hospital Airborne Isolation Room (AIIRs), negative pressure monitoring is accomplished through antiquated and non-specific gauges like the ball in tube (Ball In The Wall), or Magnehelic gauges. These gauges offer the most basic in isolation room pressure monitoring. Caregivers relying on these antiquated instruments will not know exact pressures, have the option to monitor both negative and positive pressure differentials, receive alerts in advance when pressure levels become unsafe, no ability to view logged data, no ability to chart data, etc.

More technologically advanced instruments such as the TV2 Room pressure monitor provide patients, staff and the general public with a more comprehensive barrier of protection via an advanced alert system, visual alarms and the access to stored data points for detailed room values 24/7. With pandemics like COVID-19, patient and public safety should not be left up to chance; relying on outdated hospital equipment like a ping pong ball in a plastic tube. View a comparison between ball in the wall type instruments and more advanced, complete solutions.