How to Design for Improved Outbreak Response Capacity
Cohort isolation, in which infectious disease patients are treated together in an isolated unit, wing, floor or facility, is a frequently-used response model during a pandemic. Yet many hospitals are designed to treat infectious disease patients in distributed isolation rooms embedded within other patient care units. In this post, we assess the pros and cons of cohort vs. distributed isolation approaches.
Cohort isolation, in which infectious disease patients are treated together in an isolated unit, wing, floor or facility, has been a response model during the Covid-19 crisis and any pandemic. Yet many hospitals are designed to treat infectious disease patients in distributed isolation rooms embedded within other patient care units. As hospitals consider their current and longer term facility plans, it’s important to assess the pros and cons of cohort vs. distributed isolation approaches.
Benefits of Cohort Isolation
One benefit of cohort models is that staff on the unit are specially trained to work with Universal Precautions as well as additional isolation precautions, reducing the risk of caregiver infection. Cohort isolation unit staff can also function more efficiently, caring for only one type of patient, and potentially conserve personal protective equipment (PPE) if they’re treating patients with the same disease. In addition, cohort units consolidate airborne infectious inpatients into one area of the hospital, reducing the risk of spreading infection to other patients and staff, and can respond more rapidly during an epidemic, as all specialized staff and equipment are co-located.
A cohort isolation unit can in certain instances be set up on a temporary basis or scaled up or down depending on need. This requires specialized HVAC systems which can change the pressurization of the space from standard to negative. Many emergency departments, for example, have the capability of shutting airtight doors and creating negative airflow to create temporary airborne isolation units within the ED when required. A number of major hospitals also have the capability of creating airborne isolation suites within other units by changing the airflow. These suites can function as standard patient rooms when not needed for airborne isolation purposes.
While the mechanical requirements of creating negative air pressure within cohort units for airborne isolation increase costs, there may be economies of scale that accrue as infection prevention elements are consolidated in one cohort isolation location. For example, a consolidated airborne isolation unit may only require one airlock lobby or anteroom for staff to don and doff PPE and one infectious waste disposal system, whereas a distributed model might need multiple ones.
Benefits of Distributed Isolation
There are several reasons why hospitals may rely solely on distributed isolation rooms rather than have a consolidated cohort isolation unit, beyond the cost considerations. Perhaps the most important clinical benefit of distributed isolation is that infectious patients may have other underlying conditions that require specialized treatment. With distributed isolation rooms, these patients can be treated by specialized staff within the patient care unit, while in cohort units staff are trained primarily in infectious diseases and would require additional support to treat underlying conditions.
Another potential benefit of distributed models is that the caseload of isolation patients may be easier for nursing staff to sustain. The need to wear PPE continuously and maintain Universal Precautions in cohort units can be physically and psychologically demanding and contribute to staff burnout.
Like many cohort units, distributed isolation rooms are also used as standard patient units when not required for airborne infectious diseases. Care should be taken to conceal and minimize the visibility of antechambers and any other isolation infrastructure that may be present to alleviate patient concerns over potential infection.
Access is an important consideration for both cohort isolation units as well as distributed isolation rooms, as infectious patients need to be able to get to the unit or room while minimizing contact with the general hospital population. This requires a cohort isolation unit to be served by separate dedicated elevator, and requires dedicated entrances for both cohort and distributed rooms.
Hospitals will continue to evaluate their outbreak response capabilities during and after the current Covid-19 crisis, and many will more deeply consider the long-term need for expanded isolation capacity in distributed rooms or cohort units. The right approach will require a thorough consideration of the pros and cons of both models and the unique needs of individual healthcare systems.
