Select members of the American Gastroenterological Association (AGA) Institute have rapidly developed new recommendations on how to implement severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing prior to endoscopy based on prevalence of asymptomatic SARS-CoV-2 infection. The guideline was published in Gastroenterology.
Because of the urgency associated with the coronavirus disease 2019 (COVID-19) pandemic and the need for recommendations for care of patients who require an endoscopy, the AGA Institute performed a rapid review of available data on diagnostic performance of tests for SARS-CoV-2 infection in the United States. The guideline was also developed based on responses to a survey of gastroenterologists.
The survey portion of the review was administered to practicing gastroenterologists/endoscopists to assess their risk aversion threshold, or their threshold for accepting risks associated with SARS-CoV-2 testing prior to endoscopy. In this survey, respondents were presented with a clinical scenario of an asymptomatic patient who tests negative for SARS-CoV-2 within 72 hours before their scheduled endoscopy procedure.
According to 74 responses to the survey, approximately 37.8% of gastroenterologists/endoscopists said they were willing to accept a risk of 1/40,000, suggesting that these clinicians are overwhelmingly not willing to open their centers unless N95 masks are available for both negative and positive COVID-19 cases. Around one-quarter of respondents (25.7%) said they were willing to accept a risk of 1/1000, suggesting they were willing to open their centers and rely on surgical masks regardless of infection testing. Approximately 36.5% of respondents said they were willing to accept risks between 1/2500 to 1/10,000.
Based on available evidence, the guideline committee from the AGA Institute first made recommendations for endoscopy centers with intermediate prevalence of asymptomatic SARS-CoV-2 infection (0.5-2%). For these centers, the AGA recommends implementing a pre-testing strategy, as it would likely exert a minimal burden on patients. The use of surgical masks is recommended for endoscopists and staff for patients who test negative and who are undergoing upper and lower endoscopies. In addition, the AGA recommends N95/N99 respiratory or powered air purifying respirators (PAPRs) for clinicians and staff unwilling to accept the possible small infection risk from false negatives.
Among centers with low prevalence (<0.5%) of asymptomatic SARS-CoV-2 infection, the AGA made a conditional recommendation against using a pre-testing strategy. Based on very low certainty evidence, a pre-testing strategy in centers with low prevalence may not inform clinicians in regard to triage, primarily because of the high number of false positives.
Additionally, a pre-testing strategy may be more burdensome in low-prevalence settings, both for the center as well as for the patient, many of whom will need to cancel their procedure and self-quarantine for 14 days if they receive a false positive for SARS-CoV-2. Gastroenterologists in these settings may use N95/N99 respiratory or PAPRs if personal protective equipment (PPE) is available. Surgical masks are also suggested for clinicians and staff with a low risk aversion threshold.
For endoscopy centers located in high prevalence areas (>2%), the guideline members from the AGA Institute also recommend against implementing a pre-testing strategy. This is because a pre-testing strategy may not inform clinicians about decisions regarding PPE use because there are likely a substantial number of false negatives. For all upper and lower endoscopies in high-prevalence settings, the guideline recommends the use of N95/N99 respirators or PAPRs, if available. The guideline authors suggest that the resumption of outpatient endoscopy in centers in COVID-19 hotspots may depend on the availability of PPE.
The AGA Institute made a strong recommendation against serologic testing as a pre-testing strategy for all endoscopic centers. This recommendation is based on the fact that serology testing seeks to identify the presence of antibodies and detects past infection, which does not play an important role in the diagnosis of SARS-CoV-2 infection in asymptomatic patients scheduled to undergo an endoscopy. The guideline authors also wrote that there is lacking evidence as to whether seroconversion can be supported for return to work or to inform hospital staffing policies.
A primary limitation of the guideline was the lack of a robust resource of data about the prevalence of asymptomatic individuals among endoscopy centers. Additionally, only small clinical studies were available to help the investigators estimate prevalence rates.
In their summary, the guideline authors wrote that if an endoscopy does implement a pre-testing strategy, these centers should “consider the logistics of testing (for patients and endoscopy centers), the informative value of the test, and downstream consequences with respect to triaging of patients, ensuring safety with endoscopy, and PPE use.”
Sultan S, Siddique SM, Altayar O, et al. AGA Institute rapid review and recommendations on the role of pre-procedure SARS-CoV2 testing and endoscopy [published online July 28, 2020]. Gastroenterology. doi: 10.1053/j.gastro.2020.07.043