A major US hospital that was an early adopter of elastomeric masks
In mid-January 2020, Yale New Haven Hospital, a large Yale university affiliated healthcare system, in Connecticut decided that they would provide N95 respirators for their staff seeing COVID suspected and confirmed patients but knew that they would struggle to meet demand. Their solution was to purchase re-usable elastomeric masks initially buying 1,200 immediately, which has now increased to 9,000 for a workforce of 33,000 spread over 7 hospitals with 4400 beds.
A/Prof Martinello who championed this decision (discussed in this NY times article) had previously worked in the US Veterans Affairs system and recalled their stockpile of 130,000 elastomeric masks after the SARS epidemic of 2003. It was this experience that motivated him to go early with rolling out elastomerics. When asked how they made they calculations at the beginning he says,
“Early on we were slowed down by the need for precise calculations. All I’ll say is buy a lot and don’t worry too much the estimates because you are investing in the safety of your staff”.
They predominantly use the Honeywell 7700 and 3M 6000 brand of elastomeric for high risk COVID zones being the COVID wards, ED, ICU, respiratory units and anaesthesia. Some staff members have their own device which they take home but the usual protocol is to remove the reusable filter which is put into a paper bag and kept by the HCW while the mask is sent for a disinfection clean. A recent advisory from the CDC is to now wear a surgical mask with tie backs over the exhalation valves to prevent unsuspecting HCWs breathing out virus. This directive hasn’t put a strain on surgical mask supply.
The disinfection protocol is straight forward. At the end of the shift, the masks are wiped down after use with a disinfectant wipe and then sent for central processing. The elastomerics are detergent washed in a 80-90 degree Celsius cycle and air dried. It is a similar process used for initial cleaning of surgical instruments without the autoclave step because the aim is to kill COVID-19 without sterilisation being necessary. Staff also wear goggles or face-shields (without googles).
Has it made a difference to HCW infections? A/Prof Martinello thinks so. He says that they’ve had around 973 HCW infections among a workforce of 33,000 with no junior medical staff requiring hospitalisation. A survey of 13,706 symptom-free HCWs during the peak of the surge in May-June revealed a PCR positivity rate of 0.22%. On further questioning, symptoms were actually present in 13 of these 30 positive HCWs, but were so mild that they barely recognised them (e.g. cough thought to be allergy related, new headache) emphasising the importance of source control in healthcare settings with universal mask use.
The elastomeric has been a useful addition to the single use N95 respirator which remains the workhorse device used 80-90% of the time. Extended use of the N95 respirators is the norm in US hospitals. The Yale New Haven Health System reprocesses their N95 respirators using vaporised hydrogen peroxide.
In addition to the elastomerics, the hospital invested in powered respirators going from 230 to 900 devices. Once fully deployed, every 20-30 bed unit will have 2 PAPRs and the hospital is not too prescriptive about what HCWs choose to use with N95 respirators, elastomerics and PAPRs considered equivalent. It’s a common-sense approach that has served them well through the worst period of the US surge. The elastomerics have helped preserve N95 respirators and this hospital has successfully integrated them into the routine care of COVID-19 patients.