Evaluation of the rationale for concurrent use of N95 filtering facepiece respirators with loose-fitting powered air-purifying respirators during aerosol-generating medical procedures

Abstract

The concurrent use of N95 filtering facepiece respirators with powered air-purifying respirators during aerosol-generating medical procedures in patients with severe respiratory pathogens has been promoted as offering additional protection against infectious agents. The purpose of this article is to examine the impact of this additional respiratory equipment upon protection and personal performance. The presumed additive protective effect of an N95 filtering facepiece respirator used concurrently with a powered air-purifying respirator has not been subjected to rigorous scientific investigation. The burden imposed by additional respiratory protective equipment should not be discounted, and the potentially minor contribution to protection may be offset by the negative impact on personal performance. Novel uses of protective equipment occasionally are spawned during crisis situations, but their generalized applicability to healthcare workers should ultimately be evidence-based.

Preparing for a COVID-19 pandemic: a review of operating room outbreak response measures in a large tertiary hospital in Singapore

“…36 The concurrent use of N95 respirators with PAPR to further decrease the risk of viral transmission may sound tempting, but there is no strong evidence of an added protective effect. 64 Disadvantages of such concurrent use include increased communication difficulties, 65 claustrophobic reactions, 66 and increased risk of infection from doffing the additional layers of PPE ( Table 2). 67 It is more important to emphasize proper doffing and cleaning of PAPR for re-use to prevent contamination and cross-infection.…”

Physiological Burden Associated with the Use of Filtering Facepiece Respirators (N95 Masks) during Pregnancy

“…Use of a surgical mask as an outer barrier over such respirators might prevent dissemination of some of the pathogens expelled via the exhalation valve, but this combination is not currently NIOSH approved. 51 …”

“…49,50 The increase in breathing resistance brought about by the use of some respirators can lead to a decrease in tidal volume and hypoventilation. 51 Although the breathing resistance offered by N95 FFR is low, 43 its effect on tidal volume is unknown at present. This is an important issue because the pregnancy-related loss of residual volume (which serves as an oxygen reservoir) increases the risk of hypoxia from hypoventilation, 46,47 and any respirator-related hypoventilation theoretically could also offset the progesterone-induced hyperventilation and lead to increased carbon dioxide retention.…”

Efeitos da alteração do limite de exposição ocupacional à sílica cristalina no processo de seleção de respiradores

“…O uso impróprio do EPI pode comprometer o desempenho, a segurança, o conforto físico-emocional e a comunicação dos trabalhadores (Roberge, 2008). Os profi ssionais responsáveis pela escolha dos EPIs, como os integrantes do Serviço Especializado em Engenharia de Segurança e Medicina do Trabalho (SESMT) e da Comissão Interna de Prevenção de Acidentes (CIPA), acumulam muitas outras tarefas (identifi car agentes nos processos de trabalho, participar da implementação e do controle da qualidade das medidas de prevenção necessárias, etc.).…”