408 - Evaluation of the negative predictive value of the SARS-CoV-2 PCR respiratory assays in asymptomatic children undergoing surgery

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Presenting Author(s)

Suchitra Rao

Associate Professor
University of Colorado School of Medicine
Aurora, CO
Disclosure: BioFire (Grant/Research Support)

Co-Author(s)

LA

Lilliam Ambroggio

Associate Professor
Children’s Hospital Colorado
Denver, CO
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
EA

Edwin J. Asturias

Professor
CU School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
LB

Lalit Bajaj

Professor
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
MC

Michelle Corrado

Resident
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
TI

Thomas Inge

Professor
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Sarah A. Jung

Scientific Director of Clinical Microbiology
Children's Hospital Colorado
Denver, CO
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
TM

Tyler Morrissey

Fellow
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
CO

Christina M. Osborne

Fellow
Children’s Hospital Colorado and University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Justin B. Searns

Assistant Professor
Children’s Hospital Colorado, University of Colorado
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
GW

Gina Whitney

Associate Professor
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Samuel R. Dominguez

Professor
University of Colorado School of Medicine
Aurora, Colorado
Disclosure: BioFire (Consultant, Research Grant or Support)

Background: Universal pre-operative screening with SARS-CoV-2 PCR has been adopted by institutions to mitigate risk to healthcare workers (HCW) during aerosol-generating procedures such as intubation. However, there remains uncertainty regarding rates of false negative results and optimal sampling type.  The objective was to determine the reliability of single, pre-operative SARS-CoV-2 testing from the nasopharynx in children undergoing general anesthesia.

Methods: Children < 18 years of age who underwent intubation for a procedure received pre-operative testing 24-48 hours prior with a nasopharyngeal (NP) swab or wash, in conjunction with intra-operative nasal wash (NW) and tracheal aspirate (TA) sampling. All paired samples underwent testing using the Simplexa DiaSorin platform or a modified Centers for Disease Control assay. Cohen’s Kappa was used for interrater reliability of each sample result. McNemar’s Test was used to compare result proportions by sample type. Positive and negative predictive values (PPV, NPV) were calculated based on the intraoperative NW as the reference standard. Analyses were conducted using SAS (v 9.4).

Results: We collected full sample sets from 364 children from April 14 to May 15; 66% of pre-operative samples were NP swabs. The median age was 6 years (IQR 2,13), 55% were male, 68% were white and 41% of children had a high-risk comorbidity. Most surgeries were conducted by general surgery (23%), followed by orthopedics (19%). Only 2.5% of children had respiratory symptoms, and 4.8% had a documented fever within a week of the procedure.  SARS-CoV-2 positive samples occurred in 4/364 (1%) of pre-operative samples, 8/363 (2.2%) of intra-operative samples, and 8/348 (2.3%) of TA samples. The pre-operative test had 100% PPV and 99% NPV, and the TA had 100% PPV and 98.6% NPV (Table 1). There was very good agreement (Figure) between pre- and intraoperative upper respiratory sampling, with a Kappa of 0.66, (95% CI 0.35-0.97). There was no statistical difference in results by sample type.   Table 1. Comparison of intra-operative and pre-operative nasopharyngeal sample results, test characteristics and test concordance

Table 2. Comparison of intra-operative nasopharyngeal and tracheal aspirate sample results, test characteristics and test concordance

Figure 1 Percent agreement between pre-operative and intra-operative samples

Conclusion: There is a high PPV and NPV of pre-operative SARS-CoV-2 PCR testing among children undergoing anesthesia. These data can help inform guidelines regarding appropriate precautions for HCW performing high risk procedures in asymptomatic pediatric patients.