ACHRNEWS

Minimizing The Spread Of Infection

May 27, 2004
[Editor's note: This is the third installment of a three-part series on the role of HVAC in health care environments. This article focuses on the spread of infections in hospitals.]

TAMPA, Fla. - It's a sad irony that while people go to the hospital in order to regain their health, many times they get another illness while they are there. The term "nosocomial infections" refers specifically to infections that begin in the hospital. The spread of infectious diseases in hospitals can be made better or worse with certain airflow and moisture conditions. That's why two professional organizations teamed up at the Tampa Convention Center to examine the growing problem posed by nosocomial infections.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and the American Society for Healthcare Engineering (ASHE) put their heads together to discuss growing concerns over "super bugs" (drug-resistant diseases), airborne infections, and the role of IAQ in the health care setting.

John F. McCarthy, Sc.D., CIH, of Environmental Health and Engineering, Newton, Mass., explained what the healing environment is, who it includes, and what its latest challenges are, in his lecture "Defining the Healing Environment."

"ASHRAE is moving forward to standardize hospitals," he stated. The framework of this standardization must take into consideration the breadth of the hospital IAQ problem and how standards for mechanical systems may support the healing environment.

Who It Affects

The hospital environment, McCarthy said, includes multiple constituents: patients, clinical and operational staff, local and global communities, and regulators. Every hospital's mission, he added, is "Excellence in clinical practice ... creating an environment of care."

New and evolving medical practices, the need to increase system efficiencies, and the overriding need to create this environment of care must be supported by infrastructure. "Getting that budget increase is very difficult," McCarthy said.

The benefits of creating an efficient, healthy environment offers increased productivity and energy efficiency - in short, profitability, he said. Good practices are also critical to achieving a maximum mechanical plant life.

Several factors are making hospital environments of greater concern, he said. For example, health care facilities include several diverse building types. New construction can make buildings "less environmentally forgiving," he said. "We need to take extreme measures."

Then there are the budget restraints. Operations and maintenance tend to fall to the bottom of the list, McCarthy said, until there is an emergency situation.

Priorities for the mechanical system usually divide up thus:

  • In the design phase, priorities usually are divided 50-50 between mechanical system cost and performance.

  • In the construction phase, cost and schedule take precedence.

  • In the operation phase, building performance becomes most important.

    It's important to note that 80 percent of a typical, 30-year-old building's cost goes to operations and maintenance, McCarthy pointed out; 20 percent goes to first-cost expenditures.

    HVAC Under The Microscope

    McCarthy said the following areas need to be considered in hospital and health care environments:

  • Controlled air movement.

  • Ventilation and filtration strategies.

  • Temperature and rh control.

  • Sophisticated maintenance practices.

  • Supportive environment.

    "Even in noncompliant buildings, you can still have 20 to 30 percent comments of dry eyes, headache, and tiredness," he said. "In a hospital, this can have a tremendously negative impact."

    Specific environmental risks include carcinogens (cancer-causing agents), mutagens (agents that can induce or increase the frequency of mutation in an organism), and teratogens (agents that cause physical defects in a developing embryo); toxins; sensitizers and aerosols; and infectious agents.

    HVAC Wellness Program

    It is critical to study the dynamic interactions between the mechanical systems, these agents, and how they may be introduced to the environment, McCarthy said, before they become big problems.

    In short, they need to be addressed as a high priority while their priority is otherwise low. He called this an "IEQ [indoor environmental quality] paradox."

    Emergency issues, he said, are generally technically difficult, but the simple motivation of the critical need to solve them brings various departments together.

    In order to address problems, hospital teams need to match symptoms with multiple causes and "understand the motivation of complainers," McCarthy said. It also may be helpful to create a relative risk assessment model following the path presented in Figure 1.

    Figure 1. Filling out a relative risk assessment flow chart can help a hospital’s mechanical staff and directors stay one step ahead of emergent indoor environmental quality situations.


    Possible sources include outdoor air intakes, construction activities, cleaning, and mold.

    Microenvironment exposures are those that can cover a limited, 3-foot radius, essentially one room. This could include aerosolized drug delivery (a new medical technology under development) and laser plumes. Such agents may cause irritation, odors, decreased visibility, mutagens, carcinogens, and infectious agents (in plumes).

    Then there's the ubiquitous latex, which is released in particle form and then transported through air movement, resuspension, inhalation, and contact. It can cause asthmatic reactions in staff as well as patients, McCarthy said. "Trying to get people working together to solve the problem is going to be very, very important."

    Microbiological contaminants include biological-source aerosols such as aspergillus and outdoor air contaminants. They can be affected by air movement, filtration, and dilution. Left untreated, their in-halation or surface impaction can cause infections and growth.

    Barriers to proactive responses, he said, include a lack of resources, distributed responsibility ("where many are in charge, none are"), customer approval, and the necessity of staff retraining.

    Incentives include an improved environment, inside and outside, improved outcomes, cost savings, reduced regulatory requirements, and reduced liability.

    In order to plan successfully, McCarthy advised the following:

  • Centralize the costs (true costs).

  • Train proactively.

  • Involve the directors.

  • Use the relative risk scale.

  • Present the ideas in an atmosphere of "experts helping experts."

  • Develop common goals, vocabulary, and key performance indicators (KPIs); demonstrate the value of IEQ through KPIs.

  • Support the mission of the hospital.

  • Speak in the universal language of money.

  • Integrate the physical structure with the outcome.

    Publication date: 05/31/2004