Healthcare Total Barrier Management

2020 and 2021 have been especially complex in the Healthcare industry. COVID 19 has inflicted an enormous challenge globally, particularly in healthcare. Looking at the situation in the United States, hospitals faced the challenge of attending to an increasing number of COVID cases and, due to the extreme risk of infection, forced to stop most non-COVID care procedures. The effect of this impact is unknown, but it seems clear many hospitals across the country have suffered economic consequences and will need aggressive recovery plans to return to a normalized reality.

From a construction perspective, the global pandemic has raised many questions about designing and improving facilities to face similar future challenges while continuing to operate other care services for patients in local communities. Discussions have involved a large variety of topics including:

• Redesigning shared spaces for patients and relatives, but also medical and administrative staff within the facility. This means to rethink not only areas like waiting rooms or cafeterias but also break rooms and workstations. It is important to also consider the trajectory of a patient: entrance into the building, receiving care services, and exiting the building.
• Making hospitals and healthcare facilities flexible to accommodate more patients in case something similar happens again, without losing the ability to perform different care services
• Improving the isolation of critical spaces to maintain the negative pressure (i.e. patient rooms) or positive pressure (i.e. operating rooms), required to protect the patient and the staff from acquiring infections during these processes.

Implementation of these considerations are intended to help achieve the overarching goal of improving infection control. This topic is not new. The Center of Disease Control and Prevention (CDC) had already challenged Healthcare facilities with these goals prior to the COVID-19 pandemic. It is estimated that every day an average of 1 in 31 hospital patients has a healthcare associated infection (HAI). That results in an estimated 1.7 million infections every year with almost 100,000 associated deaths. 

Figure 1: CDC HAI impact. Most common airborne diseases transmission

Though CDC guidelines for Infection Control are extensive and broad, this article will focus on airflow and, more specifically, on pressurization. Important factors that impact airflow control include temperature, humidity, and ventilation.

There are many areas in a hospital that need to be considered for airflow control for infectious disease, including patient rooms, care units, or operating rooms that have requirements associated with pressurization. The CDC has two main recommendations to keep pressurization at acceptable levels:

• Implementation of risk assessment activities necessary in maintaining construction barriers. These include daily monitoring of negative airflow within construction and renovation areas within the different types of construction barriers
• Monitoring and documenting daily negative airflow rates in airborne infection isolation rooms and positive airflow rates in proactive environmental rooms, particularly when rooms are occupied with patients

The CDC concludes that in these spaces, excess air leakage beyond 125 cubic feet per minute does not allow for these recommendations to be implemented effectively, and as a result creates a questionable environment of care.

Some may think a good ventilation system will contribute to keeping a room at the needed pressurization level, while also providing proper air recycling. However, looking deeper at different systems that have to be integrated in these spaces, it can be observed there are multiple areas of concern when it comes to leakage. The following diagram reflects some of the systems associated with rooms that require wall or floor penetrations and, as a result possible risk of air leakage.

Figure 2: Elements of air leakage

It is important to consider these elements as there is evidence of how fast air travels through different compartments and areas. The following figure shows a real fire event in a hospital. In less than 20 seconds an entire hallway was full of smoke. 

Figure 3. Hospital surveillance cameras in the event of a fire

Smoke travels at around 400 feet per minute. It could be concluded that airborne infections can travel at a similar speed through the same areas as smoke in the event of a fire.

Is it possible that passive fire protection systems can help to mitigate airborne disease, as they are tested to limit smoke leakage?

“Total Barrier Management Reduces Airborne Infection Risk in Healthcare”, a white paper prepared by Andrew Streifel, Hospital Environment Specialist in the Department of Environmental Health and Safety at the University of Minnesota, contains a detailed study about the impact of air leakage when considering using a Firestop Total Barrier Management system in the relevant areas of a healthcare facility. 

Due to model building code regulations in the United States, many floors and wall barriers in hospitals typically require either fire resistance, smoke resistance, or both. Therefore, penetrations through these floors or walls, such as mechanical piping or electrical cabling, are required to be firestopped with tested systems to maintain the integrity of the barrier. The model building code requirements indicate these firestop systems must be tested in accordance with UL and ASTM standards, to prevent the spread of fire through openings in walls and floors. The following diagram shows the key ratings typically tested when conducting firestop systems tests: fire, temperature, water leakage, and air leakage. The passive fire protection industry is evolving to also conduct other performance tests such as mold and mildew resistance, sound transmission, and movement of joints and through penetrations.

Figure 4. Basics of Firestop

Air leakage can be specifically measured and tested by what is known as the L-rating or air leakage rating as highlighted in figure 4. As previously stated, CDC guideline require an air leakage measurement of less than 125 cubic feet per minute to help ensure a negative or a positive pressure room can provide an acceptable environment of care. It can become a challenge, however, to reach or maintain that pressure with so many possible opportunities for air leakage within the room from the areas identified in figure 2. 

With these considerations in mind, the “Total Barrier Management” white paper discusses a test conducted on a mocked Intensive Care unit by an independent 3rd party facility to establish leakage measurements following different UL standards, as shown in the following diagram:

Figure 5: ICU mocked built test according to UL standards

The study demonstrates that each application was tested within two different scenarios. In one test condition, penetrations were not sealed and in the other, penetrations were sealed with a code compliant firestop solution.

The following diagram shows the test results:

Figure 6: Medical Mock-up Room Application Test Series Overview

As shown in figure 6, conditions with unsealed through-penetrations resulted in air leakage measurements above the 125-cfm threshold recommended by the CDC. When properly sealed, the same through-penetrations show a significant reduction in air leakage, will all documented measurements well below the 125-cfm level.

As a result, the white paper concludes that it is reasonable to consider implementing Total Barrier Management to help maintain pressurization in certain areas. 

Infection control presents one of the biggest challenges in a healthcare environment, and in the current healthcare environment it has grown in importance. Passive Fire Protection is an important consideration in a typical life safety plan of a healthcare building. Firestop total barrier management contributes to reducing airborne infection risk making properly sealing critical applications crucial within healthcare facilities.

Learn more about Hilti’s solutions for healthcare facilities:

US: https://www.hilti.com/content/hilti/W1/US/en/engineering/industry-and-trade-solutions/engineering-solutions/health-and-safety/healthcare-solutions.html

CA: https://www.hilti.ca/content/hilti/W1/CA/en/engineering/industry---trade-solutions/engineering-solutions/health-and-safety/healthcare-solutions.html