Use of Powered Air-Purifying Respirator(PAPR) as part of protective equipment against SARS-CoV-2-a narrative review and critical appraisal of evidence.

Abstract

The last two decades have seen an increasing frequency of zoonotic origin viral diseases including Severe Acute Respiratory Syndrome Coronaviruses, SARS-CoV-2. Respiratory component of the infectious disease program against SARS-CoV-2 incorporates use of protective airborne respiratory equipment. In this narrative review, we explore the features of Powered Air Purifying Respirators (PAPR) as well as logistical and evidence based advantages and disadvantages. Simulation study findings support increased heat tolerance and wearer comfort with a PAPR. Although PAPRs have been recommended for high risk procedures on suspected or confirmed COVID-19 patients, this recommendation remains controversial due to lack of evidence. International regulatory bodies do not mandate the use of PAPR for high risk aerosol generating procedures in patients with SARS-CoV-2. Current reports of the choice of protective respiratory technology during the SARS-CoV-2 pandemic are disparate. Patterns of use appear to be related to geographical locations. Field observational studies do not indicate a difference in healthcare worker infection utilizing PAPR devices versus other compliant respiratory equipment in healthcare workers performing AGPs. Whether a higher PAPR filtration factor translates to decreased infection rates of HCWs remains to be elucidated. Utilization of PAPR with high filtration efficiency may represent an example of "precautionary principle". Action taken to reduce risk may be guided by logistical advantages of the PAPR system, rather than high level evidence.