Respiratory protection is of paramount concern when discussing pandemic influenza, avian influenza, and the start of the seasonal flu period, particularly in the Northeastern part of the United States. For most practical purposes there are four kinds of respiratory-protection devices used by U.S. first responders: the self-contained breathing apparatus (SCBA); the powered-air purifying respirator, or PAPR; high-efficiency masks; and procedure masks.
The last-named, procedure masks, serve basically as filters that fit over the mouth and nose and catch most droplets. According to the federal Centers for Disease Control and Prevention (CDC) publication Interim Guidance for the Use of Masks to Control Influenza Transmission, the procedure masks provide the effective level of protection needed for most medical contacts (described as being within three feet) with influenza patients.
High-efficiency masks such as what is called the N95 are used in health care to protect against staph infections when working with patients who are ill with a respiratory-transmissible disease. These masks differ from procedure masks in that they are form-fitting (to reduce air leaks around the filter) and have been rated for their ability to filter out droplets the size of those expelled when a person coughs.
A PAPR is a filtration mask that is equipped with a fan to draw ambient air through the filter, thus overcoming the physical limitations of the user’s lungs. An SCBA provides a clean air supply from a tank that feeds into a full face mask.
The EMS (Emergency Medical Services) Role
The scene of an emergency is often both chaotic and uncontrolled, with hazards that do not exist in the clinical setting. An ambulance, although generally more controlled, is also a confined environment. Many ambulances do not have sufficient space for a patient to be more than three feet away from the care provider.
To further complicate the situation, patients in an ambulance often have not been diagnosed to the degree necessary to make the respiratory-protection decisions that are needed. Because of these multiple unknowns, EMS personnel should be using the most conservative protection practical; there is no way after a diagnosis has been made to go back in time and upgrade the protection used.
Both the SCBA and the PAPR are poorly suited for use by EMS staff. Any tight-fitting mask requires not only training but also fit testing. The latter is not normally provided to EMS staff for the SCBA or PAPR, but it is typically provided for N95 masks. Moreover, the bulkiness and inconvenience of these devices may lead some wearers to forgo these respirators in favor of an N95 or procedure mask, making outlays for training and fit testing wasted.
According to the Occupational Health and Safety Administration (OSHA) guidance update on Protecting Employees from Avian Influenza, N95 is the desired standard for protection; however, it is likely that there will be shortages of these devices during a pandemic. Unfortunately, the same tight face seal that makes the N95 so desirable also makes it almost impossible to fashion, even if a suitable filter material is available.
Researchers at the University of Pittsburgh have suggested that, in an emergency, an effective procedure mask can be fashioned from a cotton tee-shirt. Relying on that option may sound extreme, of course. But the reality is that, in an environment where there are no better options, something – almost anything, really – is better than nothing.
Links for Additional Research:
OSHA Avian Flu Respiratory page (including guidance)
NIOSH Respirator page
Homemade surgical-mask instructions
NIOSH-approved suppliers of N95 masks
James Mason is a pen name used by an EMS professional with over 25 years of service; he has worked as an EMT and Paramedic in 3 of the 100 largest EMS systems in the United States as well as some that operate a single unit. In addition he has served as a medic on a transport jet, DMAT team, emergency room, and in a hyperbaric chamber. He has been an instructor at NYC*EMS Academy, Philadelphia Fire Academy and other world training program. He is the author of over 50 articles on EMS and emergency management.