Verification of two Alternative Do-it-yourself Equipment Respirators Seal as COVID-19 Protection (VADERS-CoV): a quality assessment pilot study

Pettinger, M.; Momeni, M.; Michaud, C.; Van Dyck, M.; Kahn, D.; Lemaire, G.

Background During the ongoing COVID-19 pandemic, healthcare workers are facing shortage in personal protective equipment, especially adequate respirators. Alternative do-it-yourself respirators (ADR) emerge, without any proof of protection. Objective Verify seal potential of two ADR compared to a common FFP2 respirator. Design Quality assessment pilot study. Setting Tertiary Care Hospital. Participants Ten anaesthesiology residents. Interventions Participants performed quantitative face-fit tests (QNFT) with three respirators to evaluate seal. A common FFP2 respirator was used as baseline (control group). ADR tested in this study are an Anaesthesia Face Mask (AFM) and a full-face Modified Snorkelling Mask (MSM) with a 3D-printed connector, both in conjunction with a breathing system filter. Main outcome measures Non-inferior seal performance of ADR over FFP2, assessed by calculated QNFT based on measured individual fit factors, as defined by the Occupational Safety and Health Administration. Results For each respirator a total of 90 individual fit factor measurements were taken. Within the control group, seal failed in 37 (41%) measurements but only in 10 (11%) within the AFM group and in 6 (7%) within the MSM group (P < 0.001 respectively). However, when calculating the final, mean QNFT results, no statistically significant difference was found between respirators. Successful QNFT were determined for 5 out of 10 participants in the control group, for 8 in the AFM group (P = 0.25) and for 7 in the MSM group (P = 0.69). Conclusion Both ADR do have the potential to provide non inferior seal compared to a common FFP2 respirator. While AFM respirators are easily assembled, snorkelling masks must undergo significant but feasible modifications. Our results suggest that those ADR masks might be further investigated as they seem to be viable alternatives for situations when certified respirators are not available.