Influenza Pandemic and the Protection of Healthcare Workers with Personal Protective Equipment
Personal protective technology includes devices such as respirators, chemical-resistant clothing, hearing protectors, and safety goggles and glasses that provide a barrier between the worker and an occupational safety or health risk. NIOSH has a longstanding involvement in this field which was further solidified in 2001 with the formation of the National Personal Protective Technology Laboratory (NPPTL) in Pittsburgh, PA.
NIOSH is committed to ensuring that its research is relevant and making a difference in the lives of workers. As such, in 2005, NIOSH asked the Institute of Medicine (IOM) to form a standing committee to provide strategic guidance in addressing Personal Protective Equipment (PPE) issues for workers. One issue the committee deemed of high importance is PPE for healthcare workers in the event of pandemic influenza.
The IOM committee determined that there is an urgent need to address the lack of preparedness regarding effective PPE for use in an influenza pandemic. In September 2007, three critical areas were identified that require expeditious research and policy action:
- Influenza transmission research should become an immediate and short-term research priority so that effective prevention and control strategies can be developed and refined.
- Employer and employee commitment to worker safety and appropriate use of PPE should be strengthened.
- An integrated effort is needed to understand the PPE requirements of the worker and to develop and utilize innovative materials and technologies to create the next generation of PPE capable of meeting these needs.
Controlling the spread of a potential influenza pandemic is of critical importance to the more than 14 million healthcare workers in the United States (approximately 10 percent of the U.S. workforce) and their patients. Given that health care workers will be on the front lines during an influenza pandemic, protecting them with the best available prevention methods and PPE is imperative to reducing illness and death and preventing the progression of a pandemic. While PPE is the focus of this blog, it is only one way to protect workers and control the spread of the influenza virus. Engineering and administrative controls are an important part of this equation and NIOSH is also conducting research in these areas.
One step NIOSH is taking to address the IOM recommendations is the development of an action plan, which outlines current and future activities that should be considered for both near and long term implementation.
There are many complexities involved in protecting healthcare workers with PPE such as ensuring that workers appreciate the differences between medical masks and respirators. Medical masks are loose-fitting coverings of the nose and mouth designed to protect the patient from the cough or exhaled secretions of the physician, nurse, or other healthcare worker. Medical masks are not designed or certified to protect the wearer from exposure to airborne hazards. They may offer some limited, as yet largely undefined, protection as a barrier to splashes and large droplets. However, because of the loose-fitting design of medical masks and their lack of protective engineering, medical masks are not considered personal protective equipment.
Protection of the healthcare worker against infectious disease can also involve gloves, eye protection, face shields, gowns, and other protection. For the most part, these products are designed to provide a barrier to microbial transfer with particular attention to protecting the wearer's mucous membranes. Yet, they present the healthcare worker with other challenges that include difficulties in verbal communications and interaction with patients and family members, decreased tactile sensitivity through gloves, and physiological burdens such as difficulties in breathing while wearing a respirator. The extent of liquid penetration is a major issue with gowns and gloves. Comfort and wearability issues include the breathability of the fabric or material and biocompatibility or sensitivity to avoid contact dermatitis and other skin irritations.
Questions remain about the reusability of PPE as well as how long viruses survive on contaminated surfaces and what substances provide a protective barrier against viruses. Issues surrounding how best to integrate the various types of protective equipment (e.g., the respirator and eye protection) also need to be explored.
Additional questions addressed in the action plan include:
- What are the major modes of influenza transmission?
- What are the relevant sizes of aerosols?
- What is the infectivity of aerosols?
- Is high humidity an issue with wearing respirators?
- How does air flow exchange and ventilation affect transmission?
- What is the effectiveness of medical masks?
- What is the role of fomites (any object or substance capable of absorbing infectious organisms)?
- Should PPE other than respirators be certified? If so, who would be responsible for certification?
Comments to the draft action plan would be appreciated before June 1, 2008. NIOSH would also appreciate comments on our approach to addressing the IOM recommendations. The complete IOM report and the draft action plan can be viewed on the NIOSH website.
Edward F. Fries
Mr. Fries works in the Office of the Director of the NIOSH National Personal Protective Technology Laboratory.
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Comments
The article presents valid points. However, coming from an EMS pre-hospital setting where most units are required to have N-95 masks, I wonder if any consideration was taken to outline the potential inneffectiveness of the masks in less than desirable environments.
Example, If N-95's are not the oil resistant type, and you are in an oily area, such as a machine shop, how effective are the masks if the oil is in the air. Just a point for future comment because I see alot of false sense of security out there regularly. Thanks.
Posted 3/31/08 at 5:32 pm
Thank you for your comment. You make a good point about the appropriate use of PPE in less than desirable environments. It is always important for PPE users to use PPE appropriate for the hazards to which they are exposed in accordance with published guidance, recommendations, and regulations. (For respirator guidance see the respirator page on the NIOSH website.) This can be a challenge for EMS workers whose job takes them into different environments. Under the Action Plan, NIOSH plans on establishing measures to assess and compare the effectiveness of PPE.
Posted 4/8/08 at 8:30 am
No matter how much PPE we have to use, The worker (EMTs, Nursing, Fire Fighters, Doctors) have to assume a certain amount of risk. For that matter any person on any proffesion has to assume some risk. We can only wear so much equipment and complete our job to the best of our abilities, and the safety of the victom as well. There will always be factors that are not able to be over come.
Posted 4/1/08 at 5:09 am
Thank you for your comment. NIOSH is committed to reducing risk as much as possible in all occupations. As you reference, there are barriers to using PPE and the Healthcare Worker Action Plan addresses this through training and best practices. Additionally, state of the art equipment design can help reduce the burden on the user and will be explored in a PPT workshop being planned for fall 2008.
Posted 4/8/08 at 8:30 am
Thanks for a good plan for needed research into this important area. This nation must do the best possible to insure the safety and health of our healthcare workers. It is not acceptable to ask them to assume risks that can be controlled. We'll need our brave healthcare workers to provide care in a flu pandemic, which they can't do if they are sick themslves or if they fear working because their employers have not planned to protect their health.
Posted 4/6/08 at 9:55 am
I agree Timothy, but I'm seeing in our hospitals in Atlanta, that nurses do not wear much PPE...
Posted 4/7/08 at 2:31 pm
Have you discovered a better mask filtration system in your research? If so, we would like to know about it.
Posted 4/11/08 at 4:05 pm
Thank you for your comment. Current NIOSH certified respirators effectively protect the users at filtration efficiency levels of 95%, 99%, or 99.97% depending on the respirator type. These three efficiency levels were determined by testing with the most penetrating aerosol size until a maximum loading of 200 mg was reached.
The filters capture both smaller- and larger-sized particles more efficiently than the most penetrating particle size. Recent research demonstrates a shift in the most penetrating particle size:
However, NIOSH research demonstrates the protection expected to be provided by certified respirators will not change significantly. We are concentrating our current research on comfort and overall efficiency. Overall efficiency is determined as Total Inward Leakage (TIL) by considering the particles passing through the filter and faceseal fit. Also, other research we are conducting with filtering facepiece respirators focuses on studying various antimicrobial products and decontamination methods on the efficacy on respirators.
Posted 4/16/08 at 12:22 pm
I also commend the effort reflected in this reearch. I believe an interesting and essential question is a biological corollary to the industrial hygiene concept of "dose-response". Our bodies have a natural defense against some pathogens, in the form our our immune system, as opposed to many chemical and physical agents. As we go about our daily lives, we are routinely exposed to organisms related to the "ordinary diseases of life", and yet we do not get ill every time we come in contact with a limited number of these pathogens.
Understanding, as possible, some range of exposure for persons with average, healthy immune systems may illuminate what a reasonable level of protection is, that workers will use as opposed to rejecting because it is too uncomfortable or involves too much additional respiratory burden. I know infectious disease specialists have some broad ideas along these lines, and may be very helpful in this analysis.
Posted 4/15/08 at 8:27 am
Thank you for your comment. NIOSH is committed to reducing risks to exposure in all occupations. Determining the minimum level of respiratory protection for protection against infectious aerosols is an imprecise science, based on the estimated exposure hazard level and the infectious dose for the general worker population. Recommendations are established based on typically expected exposure and infectivity parameters. Factors such as the airborne concentration, aerodynamic size, and pathogen viability in exposure scenarios are considered in assessing the hazard level. The ability of the normal human immune system to resist infection and illness from a pathogen is one of the factors considered in estimating the infectious dose. It would be impractical to determine the effectiveness of each individual's immunity system to resist infection by a given pathogen, or to develop recommended minimum levels of respiratory protection based on individual variations in exposure scenarios and immunity system status.
Enhanced and increased respiratory protection with improved user comfort and reduced physiological burden can be achieved with the use of novel and innovative technologies. For example, advancements in filter media technologies have allowed the introduction of high efficiency (HE or 100-level) particulate filter respirators with lower breathing resistance using electrostatic media developed since the implementation of 42 CFR 84 in 1995. Also, Powered Air Purifying Respirators (PAPRs) offer users lower breathing resistance and improved comfort from the airflow, while providing higher protection levels than non-powered or negative pressure respirators.
Your concern regarding the barriers to using respiratory protection such as comfort and physiological burden are being explored in some of our research activities. In one research project, physiological burden is being explored by investigating the effects on inhaled carbon dioxide, inhaled oxygen, and inhalation/exhalation pressures from the Automatic Breathing Machine Simulator with the treatment of N95 particulate filtering respirators, with and without surgical masks and under light, medium and heavy work rates (see http://www.cdc.gov/niosh/nas/ppt/QUADCharts07/Z6PV_FY07_QC.htm). An article entitled "Effect on breathing resistance of a surgical mask worn over an N95 filtering facepiece respirator" is currently in press at The Journal of the International Society for Respiratory Protection. Also, you may want to participate in a workshop being planned for Fall 2008 to address technology issues regarding respiratory protection. This workshop (November 2008 timeframe) should address comfort issues and innovative technologies available to improve comfort. Finally, NIOSH recently partnered with the Veterans Health Administration to initiate Project BREATHE (Better Respiratory Equipment using Advanced Technologies for Healthcare Employees). This project seeks to determine the ideal characteristics that would be required for healthcare worker specific respirator. These research initiatives should provide insight to some of the questions you raise and better inform us of the stakeholder needs and research possibilities.
Posted 5/12/08 at 12:49 pm
The article seems to reflect a real and necessary effort to address key points, & it is much appreciated. It is however important to remember that wearing an N95 mask for any length of time or in a high energy level activity is problematic for some patient care providers and would provide additional stress in an already stressful situation. Route of transmission (droplet versus airborne) therefor becomes critical for this as well as a number of other reasons.
Since flu viruses are likely to be on the outside surface of any mask when worn in the vicinity of a flu patient it is likely not appropriate to re-use them, unless another protective mask is worn on top. This may lead to additional breathing problems for staff.
Posted 4/15/08 at 11:41 am
NIOSH agrees that current research has not, at this time, provided sufficient data to support the reuse of disposable filtering facepiece respirators. NIOSH is conducting research to examine the efficacy and effect of simple decontamination procedures for filtering facepiece respirators and to examine the risks associated with handling an FFR exposed to viral aerosols. NIOSH is using a breathing simulator to investigate the recommendation made by the Institute of Medicine (IOM) to examine the effects of the placement of a surgical mask over an N95 particulate filtering respirator. A subset of respirators and surgical masks will be tested to compare with a companion field study by the Department of Veterans Affairs.
Posted 4/16/08 at 10:02 am
The Association of Occupational Health Professionals in Healthcare (AOHP) supports NIOSH in the development and implementation of an action plan to address the PPE issues related to pandemic influenza. There are many unanswered questions and concerns among healthcare workers as to the type of PPE, especially respiratory protection for influenza. Implementation of the action plan as well as researching the additional questions that were identified would provide significant valuable information that can be used to support a safer work environment for healthcare workers during a pandemic.
Posted 5/30/08 at 7:18 am
Alterations in respiratory patterns in workplace define the approaches and parameters for worker protection. The advantages of respiratory protective devices (Personal protective equipment) are well documented. Their importance is increasing and will continue with the increase of enforcement policies as well as governmental regulations for safety in the workplace. The challenge is the need to ensure continuing compatibity between the health of workers and the conditions at work to institute preventive measures and to reduce absenteism and loss of productivity.
Posted 6/17/08 at 6:49 pm