Can Controlled or Powered Air Purifying Respirators be Safely Used in the Operating Room during the COVID-19 Pandemic? A Review Article

Disclaimer: We aim to present letters from our readership that may generate further discussion on managing patients with COVID-19. Given the novelty of COVID-19, best-available clinical evidence is limited and supported from anecdotal reports from China, South Korea, Italy and other sites, and from studies of previous epidemics like SARS and MERS. The opinions expressed are those of the authors and not the APSF. These materials are presented for informational and educational purposes only and do not establish a standard of care or constitute medical or legal advice. The APSF does not support or endorse any specific idea, product, equipment, or trademarked technique. We strongly promote consistency with your governing bodies and organizations such as the CDC, WHO, ASA, AANA, and AAAA. Readers are reminded to consult with their institutions and medical/legal advisors regarding any of the views and opinions expressed by the authors.

Introduction

According to the Center for Disease Control and Prevention (CDC), as of July 2020, there have been over 3.1 million people diagnosed with COVID-19 and over 132,000 deaths in the United States.¹ Since the nationwide and worldwide shortage of diagnostic tests for COVID-19 continues,² this statistic is likely an underestimate of the actual number. Additionally, there is rapidly emerging evidence demonstrating that asymptomatic and pre-symptomatic individuals transmit this virus,³ and per recent published literature, there is an alarming rate of hospital-associated transmissions,⁴ especially amongst healthcare professionals.³ A prospective international multicenter cohort study demonstrated that about 10% of healthcare professionals who performed tracheal intubation on patients with suspected or confirmed COVID-19 infection subsequently reported a COVID-19 illness themselves.⁵ Infection of just one health-care professional can severely reduce the capacity of an entire hospital.⁶ Therefore, it is essential that we continue to do everything we can to optimally protect each and every one in the healthcare community.

National Recommendations

The American Society of Anesthesiologists recommends that health care professionals utilize contact and airborne precautions when working with someone that may have COVID-19.⁷ N95 respirators are the most commonly used personal protective equipment to control airborne infectious exposures.⁸ According to the Occupational Safety and Health Administration, these respirators only protect individuals from infectious particles if the respirator fits properly.⁹ Healthcare professionals are required to be “fit tested” before safely using a N95 respirator. If an individual fails the mask fit test, then it is recommended that a Controlled Air Purifying Respirator (CAPR) or a Powered Air Purifying Respirator (PAPR) is worn for protection from aerosolized particles.

Personal Protective Equipment Controversy

Prior to the COVID-19 pandemic, the National Personal Protective Technology Laboratory and the Association of Perioperative Registered Nurses did not recommend the usage of a PAPR in the operating room due to a lack of scientific evidence regarding the safety of PAPRs and the possible and theoretical risk of a wearer’s exhalation contaminating the sterile field.¹⁰ Based on this, many hospitals made policies that prohibited the use of CAPRs and PAPRs in the operating room.

Historically, very few surgical patients requiring anesthesia carried a risk of transmitting a deadly airborne illness, and when this instance did occur, an anesthesia professional and surgeon who were properly fit for a N95 respirator could assume care of that patient. At the present time, it is nearly impossible to separate COVID-19 positive patients from others. This pandemic is of considerable magnitude in size and many COVID-19 patients are asymptomatic or pre-symptomatic. It is widely known that screening and diagnostic tests are sparse, and many of the tests that are available have an unreliably high rate of false-negatives results.¹⁰ We feel it is nearly impossible to prevent health-care professionals who are not wearing properly fitted protective equipment from being inadvertently exposed to COVID-19.

Review of Recent Scientific Literature

Within the last three years, new scientific literature has demonstrated the safety of using CAPRs and PAPRs in the operating room, but few people are aware of this. Many healthcare workers have already faced severe morbidity and mortality because of inadequate protection. Through this literature review, we hope to raise awareness of the recent scientific literature on CAPR and PAPR use in the operating room.

A pilot study, conducted in 2017, found no measurable differences in the particulate counts on the surgical field when the PAPR-hood system was activated versus when the PAPR-hood system was turned off. The authors concluded that for the operating room staff that have failed the mask fit test, wearing a PAPR could be an acceptable and safe alternative.¹¹

In 2019, as part of the Occupational Health and Industrial Hygiene Commons, a study was conducted that compared the bacterial contamination of three different models of PAPRs (3M^TM Versaflo^TM TR-600-ECK, 3M^TM Air-Mate^TM, and MAXAIR CAPR 710) to a N95 respirator and to a surgical mask. To mimic the operating room environment, the setting of this study was a small room that had no ventilation. Experiments were replicated on each respirator and surgical mask a total of ten times (five times with the door open and five times with the door closed). Data was collected in colony forming units on agar plates that were placed in the testing room. All respirators that were tested generated less contamination compared to the surgical mask. The contamination that the CAPRs produced was comparable to that of the N95 respirator. Furthermore, all the PAPRs tested generated less contamination than the N95.¹²

In February 2020 the CDC published a similar paper. Settling plates were placed in a sterile field and contamination was collected from participants who were performing particulate-generating actions. Aerosolized contamination level generation was compared amongst participants who were performing the particulate-generating actions while wearing different forms of protective equipment, including: (1) full facepiece PAPR, (2) full facepiece PAPR with shoulder length hood, (3) surgical mask, and (4) no facial covering (control). Surgical masks reduced aerosolized contamination level by 98.48%, while both PAPRs reduced the contamination level by 100%, when compared with the usage of no facial covering. No statistically significant difference was found between the effectiveness of surgical mask versus both PAPRs (P-value = 0.588) and full facepiece PAPR versus full facepiece PAPR with shoulder length hood (P-value > 0.999). The authors concluded that the tested PAPR configurations were effective at reducing aerosolized contamination into a sterile field.¹⁰

In April 2020, a systematic review further supported the use of PAPRs in the operating room and advised that a PAPR should be used “if the surgeons fail the mask fit test.”⁶

Joint Recommendations

A Joint Statement was published by the American Society of Anesthesiologists, Anesthesia Patient Safety Foundation, American Academy of Anesthesiologist Assistants, and American Association of Nurse Anesthetists in June 2020 that states that the optimal practice for all anesthesia professionals is to utilize appropriate personal protective equipment when interacting with all patients in the operating room, which includes: fitted N95 respirators, PAPRs, and other CDC or NIOSH approved respirators. Although the authors of the Joint Statement did not feel that the use of a CAPRs/PAPRs can contaminate the surgical field, they advise wearing a regular surgical mask under the CAPR/PAPR if that makes clinicians feel more comfortable. Wearing the regular surgical mask under the CAPR/PAPR provides patients the standard protection from exhaled contaminates in the operating room.¹³

Conclusion

Based on these latest scientific publications, it appears that CAPR and PAPR use in the operating room is safe and recommended. To ensure the safety of all of our healthcare workers during the COVID-19 pandemic, we ask institutions to consider amending policies to support the perioperative use of CAPR/PAPR protective equipment for individuals who have failed the fit test. Please do not hesitate to write back with any comments and/or questions. We hope to keep as many people safe as possible!

 

Danielle Levin, MD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Jorge Fleisher, MD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Michael Schoor, MD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Satrajit Bose, MD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Mark Lovich, MD, PhD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Hans P. Van Lancker MD
St. Elizabeth’s Medical Center, Brighton, Massachusetts, United States of America

Acknowledgements: We would like to first thank the leaders of APSF, ASA, AORN, AAAA, AANA, CDC, and FDA for constantly updating their recommendations to ensure all health care professionals are as safe as possible. We also express our sincere gratitude to our institution for amending our hospital policies to support the perioperative use of CAPR/PAPR protective equipment for individuals who have failed the fit test.

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The authors have no conflicts of interest.

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