Periodically, I field questions from folks that require a little bit (well, perhaps sometimes more than a little) of conjecture. Recently, I received a question regarding the requirements in ASHRAE 170-2008 regarding appropriate pressure relationships in emergency department and radiology waiting rooms (ASHRAE 170-2008 says those areas would be under negative pressure, with the caveat that the requirement applies only to “waiting rooms programmed to hold patients awaiting chest x-rays for diagnosis of respiratory disease”).
Right now, that particular question is kind of the elephant in the room from a regulatory perspective; there is every indication that The Joint Commission/CMS are working their way through ASHRAE 170-2008 and have yet to make landfall on this particular requirement—as far as I know—feel free to disabuse me of that notion. The intent of the requirement (as I interpret it) is to have some fundamental protections in place to ensure that an isolated respiratory contagion does not have the capacity of becoming a legitimate outbreak because of inadequate ventilation. Now, you could certainly use the annual infection control program risk assessment to identify whether your waiting rooms are “programmed to hold patients awaiting chest x-rays for diagnosis of respiratory disease” based on the respiratory disease data from the local community (and you might be able to obtain data from a larger geographic area, which one might consider a “buffer zone”).
Best case scenario results in you being able to take this completely off the table from a risk standpoint, next best would be that you introduce protocols for respiratory patients that remove them from the general waiting rooms (depending on the potential numbers, you may not have the space for it), worst case being that you have to modify the current environment to provide appropriate levels of protection. The notation for this requirement does provide some relief for folks with a recirculating air system in these areas, which allows for HEPA filters to be used instead of exhausting the air from these spaces to the outdoors, providing the return air passes through the HEPA filters before it introduced into any other spaces.
Knowing what I do about some of the ventilation challenges folks have, I suspect that it may make more sense to pursue the HEPA filtration setup than it would be to try to bring each of the spaces under negative pressure, but (going out on a limb here) that might be a question best answered by a group of knowledgeable folks (including an individual of the mechanical engineering persuasion) as a function of the (wait for it…) risk assessment process.
Ultimately, it comes down to what the Authority Having Jurisdiction chooses to enforce; that said, it might be worth having someone work through your state channels or by putting the question to the Standards Interpretation Group at Joint Commission (I suspect that their response would not be not particularly instructive beyond the usual “do a risk assessment” strategy, but there is a new person running the Engineering group at TJC, so perhaps something a little more helpful might be forthcoming). At any rate, as noted above, I’ve not heard of this being cited, but I also know that if there’s an outbreak tied to inadequate ventilation somewhere, this could become a hot topic pretty quickly (probably not as hot as ligature risks at the moment, but you never know…).