- CHOP —
- Children’s Hospital of Philadelphia
- COVID-19 —
- coronavirus disease 2019
- RT-PCR —
- reverse transcriptase polymerase chain reaction
- SARS-CoV-2 —
- severe acute respiratory syndrome coronavirus 2
Surgery in patients with coronavirus disease 2019 (COVID-19) is associated with increased mortality and complications.1 Procedures may generate aerosols or require endotracheal intubation, increasing risk of occupational exposure of health care workers. As medical centers navigate aerosol-generating procedures, preprocedure testing is important for patient and provider safety. Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immediately before the procedure would yield the most accurate results. However, scheduling logistics and inadequate turnaround times often necessitate preprocedure testing several days in advance. Thus, patients may have negative preprocedure testing results, yet have active viral replication at the time of surgery. Although patients are instructed to monitor for symptoms after testing, symptom reporting is likely to be insensitive in children because most have mild or no symptoms.2–4 The purpose of this study was to determine if preprocedure testing up to 3 days before surgery was concordant with testing performed at the time of surgery in children.
Methods
Children presenting for surgery at the Children’s Hospital of Philadelphia (CHOP) are required to have a reverse transcriptase polymerase chain reaction (RT-PCR)–based nasopharyngeal SARS-CoV-2 test within 3 days of surgery. From July 10, 2020, to October 9, 2020, a convenience sample of patients aged <18 years who had negative preprocedure testing results and lacked symptoms of COVID-19 had nasopharyngeal samples taken after anesthesia induction. Preprocedural samples taken 1 to 3 days before surgery, as well as at the time of surgery, were analyzed for the presence of SARS-CoV-2 with a CHOP in-house laboratory–developed RT-PCR assay, which has a 6- to 10-hour turnaround time. The N2 primer and probe used in the assay are the same as the Centers for Disease Control–developed assay and authorized by the United States Food and Drug Administration. The cycle threshold for a positive test result was 40. The limit of detection for this assay is ∼20 000 copies per milliliter, and the specificity was 100%, as determined through wet testing against common respiratory pathogens and by in silico analysis. Preprocedural samples taken on the day of surgery were analyzed by our in-house laboratory for the presence of SARS-CoV-2 with the Xpert Xpress SARS-CoV-2 assay from Cepheid Inc (Sunnyvale, CA), an RT-PCR rapid assay with a 45-minute turnaround time. This test is used to target the E and y genes of SARS-CoV-2 and contains an exogenous processing control. It has a limit of detection of 0.01 plaque-forming units per milliliter, with a reported negative percentage agreement of 95.6%.5
The study was approved by the institutional review board (IRB 20-017635), and informed consent was obtained from guardians. Race and ethnicity were self-reported by parents and guardians during surgery registration. Race and ethnicity of this cohort is described because minorities have higher reported rates of SARS-CoV-2 infection,6 and racial and ethnic composition may affect overall positivity rates and likelihood of exposure to SARS-CoV-2 between time of preprocedural testing and time of surgery. Time-of-surgery test results were compared with preprocedure results by using Pearson’s χ2 test.
Results
Two hundred forty-one pediatric surgical patients were included in this study, with a mean (SD) age of 7.2 (5.5) years (range 7 d–18 y). Sex, race, and ethnicity are described in Table 1. Twelve surgical procedure types were identified. In total, 10.8% of patients had preprocedure testing on day of surgery, 27.4% had it 1 day before, 54.8% had it 2 days before, and 7.1% had it 3 days before surgery (Table 1). There was 100% concordance of testing, with all subjects with negative preprocedure testing results having negative time-of-surgery SARS-CoV-2 RT-PCR results (P < .01).
Demographics
Discussion
In this cohort of asymptomatic children with negative preprocedure testing, there was 100% concordance with time-of-surgery testing. The vast majority (93%) of subjects had testing performed within 2 days of their surgery. These data should be interpreted in the context of community prevalence.7 With any test, the negative predictive value will decrease with increased prevalence. During the 3-month period of this study, inpatient and outpatient testing positivity rates in our pediatric health care network ranged from 1.1% to 4.5%. In an area of relatively low community transmission, preprocedure testing of children within 2 days of surgery appears to be a reasonable strategy for balancing the safety of patients and staff with logistic testing and surgical scheduling issues.
There are several limitations to our study. Because of need for consent and testing resource availability, we retested a subset of patients undergoing surgery. However, we believe we captured a representative cross-section of ages and surgical procedure types. Our study also does not address the sensitivity of nasopharyngeal RT-PCR testing for SARS-CoV-2.
As pediatric specialists grapple with how to make procedures safer in the setting of COVID-19, testing guidelines must evolve on the basis of the patient population, community prevalence, and logistic realities. A negative test result cannot rule out SARS-CoV-2 infection, and use of appropriate personal protective equipment remains essential.
Acknowledgments
We acknowledge Allison M. Blatz, MD, and William R. Otto, MD, for their assistance in enrolling subjects for this study. No compensation was received for their role in this investigation.
Footnotes
- Accepted January 27, 2021.
- Address correspondence to Audrey R. Odom John, MD, PhD, 907C ARC/Children’s Hospital of Philadelphia, 3615 Civic Center Blvd, Philadelphia, PA 19104-4318. E-mail: johna3{at}email.chop.edu
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
FUNDING: Dr Odom John is supported by National Institutes of Health National Institute of Allergy and Infectious Diseases grants R01-AI103280, R21-AI123808, and R21-AI130584 and is an investigator in the Pathogenesis of Infectious Diseases of the Burroughs Wellcome Fund. The sponsor or funder did not participate in the work. Funded by the National Institutes of Health (NIH).
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
- Copyright © 2021 by the American Academy of Pediatrics