# 2502
Earlier this week CIDRAP News reported on a recently published study, in the Journal of Infection Control, on the usage of PPEs (Personal Protective Equipment) during a 24-hour pandemic simulation in the UK.
Hospital pandemic drill reveals major supply challenges
Robert Roos
News Editor
Nov 25, 2008 (CIDRAP News) – Hospital workers who followed official infection control guidelines for pandemic influenza for 1 day used 10 times as many gloves as usual, generated three times as much clinical waste, and found that many tasks took longer than normal, according to a new report.
None of these findings should come as any surprise, although they do help to quantify things a bit. This drill took place in November of 2006, and used infection control guidelines issued in 2005, which required:
"Healthcare workers (HCWs) to wear gloves, a plastic apron or gown, and a surgical mask when coming within 3 feet of pandemic flu patients.
They recommend the use of an FFP3 respirator (equivalent to a US N-99 respirator, designed to stop 99% of small airborne particles) and eye protection during aerosol-generating procedures"
One of the key findings was that basic PPE (surgical masks, gowns, gloves) use was higher than expected, but the quantity of high-level PPEs used was much lower than expected.
A finding that may be driven more by the arbitrary rules of this exercise, than by reality.
Quite frankly, the level of protective gear worn by many of the participants in this exercise (surgical mask, gloves, gown) was considerably lower than many HCW's would expect in a pandemic.
The question becomes, when it comes to PPE's for HCW's during a pandemic. How much is enough?
What little science we have on this issue does little to support the notion that medical/surgical masks are reasonably protective against airborne viruses.
The following is from the NIOSH Science blog, Influenza Pandemic and the Protection of Healthcare Workers with Personal Protective Equipment, published on March 31st of this year. (Slightly reformatted for readability)
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.
The take away point here is that NIOSH, the National Institute for Occupational Safety and Health, doesn't consider medical masks to be PPE's.
In the aftermath of SARS, where a number of HCW's became infected (and several died) as a result of tending to patients, the CDC issued interim guidance on the use of PPEs when dealing with SARS patients.
A NIOSH-certified, disposable N95 respirator is sufficient for routine airborne isolation precautions. Use of a higher level of respiratory protection may be considered for certain aerosol-generating procedures (see Infection Control Precautions for Aerosol-Generating Procedures on Patients Who Have SARS).
SARS, which had a R0 (basic reproductive number) of roughly 3.0, was about as infectious as influenza. The CDC's minimum recommendation is for an N95 mask, along with gown, gloves, eye protection and hand hygiene.
Personal protective equipment appropriate for standard, contact, and airborne precautions (e.g., hand hygiene, gown, gloves, and N95 respirators) in addition to eye protection, have been recommended for health-care workers to prevent transmission of SARS in health-care settings (see the Infection Control and Exposure Management page).
And in this after-action study of the SARS outbreak in Toronto, we learn that HCW's had about a 6% chance of infection for every shift they had contact with SARS patients.
Loeb M, McGeer A, Henry B, Ofner M, Rose D, Hlywka T, et al. SARS among critical care nurses, Toronto. Emerg Infect Dis [serial online] 2004 Feb 2004 [date cited]. http://www.cdc.gov/ncidod/EID/vol10no2/03-0838.htm
To determine factors that predispose or protect healthcare workers from severe acute respiratory syndrome (SARS), we conducted a retrospective cohort study among 43 nurses who worked in two Toronto critical care units with SARS patients.
Eight of 32 nurses who entered a SARS patient’s room were infected. The probability of SARS infection was 6% per shift worked.
Assisting during intubation, suctioning before intubation, and manipulating the oxygen mask were high-risk activities. Consistently wearing a mask (either surgical or particulate respirator type N95) while caring for a SARS patient was protective for the nurses, and consistent use of the N95 mask was more protective than not wearing a mask.
Risk was reduced by consistent use of a surgical mask, but not significantly. Risk was lower with consistent use of a N95 mask than with consistent use of a surgical mask. We conclude that activities related to intubation increase SARS risk and use of a mask (particularly a N95 mask) is protective.
And lastly, the CDC's Interim guidance on the use and purchase of facemasks and respirators by individuals and families for pandemic influenza preparedness, where aerosol generating procedures like intubation are unlikely to occur, we get this:
Settings where respirators and facemasks should be used will depend on the potential for exposure to infectious persons:
- A facemask is recommended when exposure in a crowded setting occurs with persons not known to be ill. An example would be exposure on a crowded bus or subway while commuting to work during a pandemic. Because ill persons are advised to stay home during a pandemic, contacts in most public settings will be with persons who are not ill. However, it is prudent to wear a facemask because one may encounter people who are infectious but not yet ill.
- A facemask also is recommended for use by ill persons when they must be in close contact with others. <snip>
-
A respirator is recommended for use in settings that involve close contact (less than about 6 feet) with someone who has known or suspected influenza illness. <snip>
Here in the United States, the question of what constitutes adequate PPE's for HCW's during a pandemic is a question being addressed by the CDC, NIOSH, OSHA, and other agencies.
A final determination has yet to be issued.
Whatever they decide, the perception of HCW's about the effectiveness of these measures will ultimately determine how willing they are going to be to work during a pandemic.
Frankly, given the evidence, reserving respirators (like N95, N99, or FFP3) and eye protection only for aerosol-generating procedures isn't likely to be viewed positively by most HCW's.
And even if you could convince HCWs to accept surgical/medical masks as PPE's, the likely attrition rate due to illness among HCW's would probably be a show-stopper.
The problem, of course is, PPE's are expensive, bulky to warehouse, and are uncomfortable to wear for long periods of time.
Surgical/Medical masks are relatively cheap, and don't restrict breathing like the N95 and N99 masks do.
Few hospitals keep more than a week or two worth of PPE's on hand. They've followed the J-I-T (just in time) Inventory system that everyone else has.
When they run low, they order more. It saves money, and is a system that works great as long as the supply chain remains intact.
Getting health care facilities to invest in adequate PPE's, before a pandemic erupts, is a difficult `sell'. They believe they can wait until a pandemic is imminent, before taking action.
Most PPE's, however, are manufactured offshore. A great many come from China, and the Far East. During a pandemic, the global demand for these supplies will far outstrip their manufacturing capacity, and supply line issues are likely to further restrict their availability.
The study that led off this blog indicates that PPE usage could be 10x's normal during a pandemic. Unless greater supplies are stockpiled before a pandemic, many facilities will run short in a matter of days.
Today, the issue is dollars and cents.
Once a pandemic begins, the issues will become HCW's lives, and the ability of many health care facilities to operate.
If we wait until that happens to try to solve this problem, it may be too late to do anything about it.
