To the Editor—The Infectious Diseases Society of America (IDSA) recommends preprocedural severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) testing prior to major surgery only to prevent adverse patient outcomes, ^{Reference Hanson, Altayar and Caliendo1} as long as personal protective equipment (PPE) is readily available for all participating healthcare workers. In reality, testing is conducted much more broadly. Consequences of such testing include costs and inconvenience incurred by patients and postponement of necessary procedures due to either a positive test (which may represent remote infection) or inability to obtain timely results.

One concern that has made scaling back universal preprocedural testing difficult is the potential for transmission of the virus between patients in the postanesthesia care unit (PACU), which is nearly always an open unit. To address this specific issue while allowing for a reduction in otherwise unnecessary preprocedure testing in patients who were low risk for adverse postprocedure outcomes in the event of unrecognized severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) infection, we implemented the ventilated headboard developed by the Centers for Disease Control (CDC) and National Institute for Occupational Safety and Health (NIOSH). ²

Tufts Medical Center (TMC) is a 415-bed hospital in Boston, Massachusetts. From April 1, 2020, to July 1, 2021, preprocedural SARS-CoV-2 nasopharyngeal real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing was performed within 72 hours of scheduled surgery for all patients expected to undergo a procedure utilizing general anesthesia or conscious sedation. The protocol was then changed given the widespread availability of PPE and the efficacy of vaccinations at preventing severe coronavirus disease 2019 (COVID-19), limiting preprocedural testing to patients undergoing a procedure utilizing general anesthesia who were either not fully vaccinated or were severely immunocompromised.

Hospital protocol dictated that aerosol-generating procedures (AGPs, which according to our state public health guidance included intubation, nebulizers, or noninvasive ventilation), when required by a postoperative patient who had tested negative or who had not been tested, could be performed either (1) in an operating room, (2) in the single negative-pressure isolation room in our PACU, or (3) in the main PACU while utilizing a ventilated headboard. The numbers and proportions of patients cared for using each approach were not tracked, which limited our analysis. Ventilated headboards were constructed at TMC utilizing specifications provided by NIOSH (Fig. 1). ^2,3 Ventilated headboards were utilized ∼2–3 times per week.

Fig. 1. Ventilated headboard device utilized at Tufts Medical Center (TMC), designed utilizing NIOSH specifications and utilized in the postanesthesia care unit (PACU).

COVID-19 cases with symptom onset (or if asymptomatic, positive test) on or after day 8 of a hospital admission are investigated by infection prevention specialists as potential nosocomial infections. Cases are classified as nonnosocomial, possibly or probably nosocomial, or definitively nosocomial.

From April 1, 2020, to March 31, 2022, there were 95 positive tests among 10,888 preprocedural tests performed, corresponding to an overall test positivity of 0.87%. This rate increased to 7.9% (14 of 177) during the SARS-CoV-2 ο omicron variant era beginning December 1, 2022. During this same 2-year period, 30 cases of potential nosocomial COVID-19 were investigated, of which 15 were classified as possibly/probably or should be definitively nosocomial infections. No cases were traced to PACU exposure. Although potential PACU-acquired infections occurring in outpatients would not have been picked up by our surveillance systems, which is another limitation of this ecologic study, no such cases were brought to the attention of the infection prevention specialists.

These findings highlight 2 important points: (1) preprocedural SARs-CoV-2 test positivity is low and (2) nosocomial SARS-CoV-2 cases traceable to exposures in the PACU are rare. This success should be considered as hospitals re-evaluate preprocedural testing protocols ^{Reference Penney and Doron4} considering adequate PPE supplies for healthcare workers as well as effective vaccinations, which protect patients against the adverse consequences of undergoing a procedure while having unrecognized SARS-CoV-2 infection.

The goal of hospital infection prevention measures is to protect both patients and healthcare workers, including the potential for transmission during AGPs, ^{Reference Cheng, Wong and Chan5} especially in space-limited units such as the PACU. To mitigate this risk, novel infection prevention strategies, including the use of HEPA filters ^{Reference Liu, Phillips, Speth, Besser, Mueller and Sedaghat6} and plastic head covers, ^{Reference Yuan, Tseng, Hsu, Feng, Lin and Lin7} have been implemented worldwide. Designed for use in field hospitals in the event of a respiratory pathogen pandemic, the ventilated headboard is another strategy, and utilizes a canopy type structure to direct aerosols to an attached HEPA filter aerosol containment and air scrubbing unit. ² The ventilated headboard provides near-instant capture of patient generated aerosol and thus increases surge isolation capacity. ³ This infection prevention strategy has also been demonstrated to be effective in real-world settings such as ours, and one study reported that ventilated headboards eliminated all evidence of the SARS-CoV-2 virus spreading to the environment. ^{Reference Landry, Barr and MacDonald8}

Without an experimental control, we cannot know whether the use of the ventilated headboard contributed to the low rate of transmission seen, but, as with many preventative interventions carried out in the absence of data over the course of the pandemic, this intervention provided reassurance to those working in the PACU setting that precautions were being taken. As COVID-19 prevention strategies evolve, it will be critical to continue to balance safety against the potential for delayed and deferred care, which have negatively affected public health throughout the pandemic. It is now time to practice harm reduction by limiting testing to facilitate expedient procedures for patients who need them.