CDC adds respirators to Ebola regalia for health care workers to increase 'margin of safety'

March 18th, 2015

While emphasizing that Ebola does not spread by the airborne route, the Centers for Disease Control and Prevention is advising in new infection control guidelines that health care workers wear N95 respirators or powered air purifying respirators (PAPRs) for treating patients stricken with the deadly virus.

“We are recommending either of those options -- but not a face mask.” said CDC Director Tom Frieden, MD, MPH. “That’s not because we think that Ebola is airborne, but rather because we think that [procedures] in American hospitals can be so risky, whether that is suctioning or intubation or other things that may not be done in other parts of the world such as Africa. We want to add the extra margin of safety.”

Respiratory protection was one of the bigger points of discussion in the development of the new “consensus” guidelines for Ebola personal protective equipment (PPE), which included input from clinicians who are currently treating Ebola patients at Emory University Hospital, Nebraska Medical Center and the National Institutes of Health Clinical Center, he said.

‘‘These guidelines represent a consensus and an increased margin of safety for health care workers,” Frieden said at a hastily called evening press conference on Oct. 20.

Though it was starting to appear that many hospitals were going to err on the side of caution and use respirators regardless, the CDC argued in earlier Ebola guidelines that a surgical mask and face shield were sufficient to contain contact and droplet spread of the virus unless procedures were likely to generate aerosols that could be inhaled. Despite persistent questions, concerns and the occasional conspiracy theory, the CDC held to that recommendation for months.

The agency was likely trying to head off public misperceptions – and the ensuing panic – that Ebola could transmit through the air like measles. That is still not the case, but health care workers could use as much reassurance as possible if they are going to be asked to walk into the isolation room of an Ebola patient. A single exposure could mean death. And as a practical matter, the old guidelines could lead to situations where clinicians may decide the patient could benefit from an aerosol-generating procedure, but they would have to leave the room and re-garb to don a respirator.

“We don’t want the health care worker who is already suited up – and it takes a while to suit up – saying, ‘[I need] to suction this patient and that might [create] aerosol generation, so I’m going to leave -- take all of this off -- and put on an N95 or PAPR and come back,’” Frieden said. “So we’ve [decided] that we are not going to recommend that face masks be used, but either N95s or PAPRs. For other countries [in Africa] that may be less relevant, but it’s because of the kind of [aerosol generating] procedures that are done here.”

The new CDC guidance focuses on specific PPE that health care workers should use, providing detailed instructions on how to remove equipment safely. “The greatest risk in Ebola care is in the taking off of whatever equipment the health care worker has put on” Frieden said. “One of the critical aspects of these guidelines is a very structured way of doing that step-by-step which is supervised, and in a way ritualized, so that it is done the same way every time.”

The CDC Ebola guidelines are centered on three principles:

• All healthcare workers undergo rigorous training and are practiced and competent with PPE, including taking it on and off in a systematic manner
• No skin exposure when PPE is worn
• All workers are supervised by a trained monitor who watches each worker taking PPE on and off. This is to ensure each worker follows the step by step processes, especially to disinfect visibly contaminated PPE. The trained monitor can spot any missteps in real-time and immediately address.

The CDC is essentially recommending the same PPE included in its August 1, 2014 guidance, with the addition of respirators, coveralls and single-use, disposable hoods and face shields. Goggles are no longer recommended, as they may not provide complete skin coverage in comparison to a full face shield. Additionally, goggles are not disposable, may fog after extended use, and healthcare workers may be tempted to manipulate them with contaminated gloved hands, the CDC noted.

The new CDC recommendations for PPE use by health care workers caring for Ebola patients include:

• Double gloves
• Boot covers that are waterproof and go to at least mid-calf or leg covers
• Single use fluid resistant or impermeable gown that extends to at least mid-calf or coverall without integrated hood.
• Respirators, including either N95 respirators or powered air purifying respirator (PAPR)
• Single-use, full-face shield that is disposable
• Surgical hoods to ensure complete coverage of the head and neck
• Apron that is waterproof and covers the torso to the level of the mid-calf should be used if Ebola patients have vomiting or diarrhea