Yield of Screening for COVID-19 in Asymptomatic Patients Before Elective or Emergency Surgery Using Chest CT and RT-PCR (SCOUT)

Abstract

Objective: To determine the yield of preoperative screening for COVID-19 with chest CT and RT-PCR in patients without COVID-19 symptoms. Summary of Background Data: Many centers are currently screening surgical patients for COVID-19 using either chest CT, RT-PCR or both, due to the risk for worsened surgical outcomes and nosocomial spread. The optimal design and yield of such a strategy are currently unknown. Methods: This multicenter study included consecutive adult patients without COVID-19 symptoms who underwent preoperative screening using chest CT and RT-PCR before elective or emergency surgery under general anesthesia. Results: A total of 2093 patients without COVID-19 symptoms were included in 14 participating centers; 1224 were screened by CT and RT-PCR and 869 by chest CT only. The positive yield of screening using a combination of chest CT and RT-PCR was 1.5% [95% confidence interval (CI): 0.8–2.1]. Individual yields were 0.7% (95% CI: 0.2–1.1) for chest CT and 1.1% (95% CI: 0.6–1.7) for RT-PCR; the incremental yield of chest CT was 0.4%. In relation to COVID-19 community prevalence, up to ∼6% positive RT-PCR was found for a daily hospital admission rate >1.5 per 100,000 inhabitants, and around 1.0% for lower prevalence. Conclusions: One in every 100 patients without COVID-19 symptoms tested positive for SARS-CoV-2 with RT-PCR; this yield increased in conjunction with community prevalence. The added value of chest CT was limited. Preoperative screening allowed us to take adequate precautions for SARS-CoV-2 positive patients in a surgical population, whereas negative patients needed only routine procedures.

Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic

“…This study showed no additional benefit to performing CT in addition to a single swab test, meaning that the additional cost and organizational burden of CT as a screening test in asymptomatic patients is unlikely to be justified. This corroborates the findings of a multicentre study of 2093 patients undergoing surgery in the Netherlands, in which the incremental yield of thoracic CT in asymptomatic patients was slight, at 0.4 per cent 9 . Similarly, in a small series 22 , high-resolution CT chest added very little additional value and a high resource cost, with just 3 of 386 patients with a negative swab who had thoracic CT having surgery postponed.…”

“…On the other, there is a time and cost burden of testing, with uncertainty around the best strategy and variable global availability 4–6 . The mainstay of testing is nasopharyngeal swab test with quantitative reverse transcriptase–PCR (RT–qPCR) to detect SARS-CoV-2 viral RNA 7 , 8 , although preoperative CT has also been suggested, especially before major surgery 9 .…”

The role of chest CT in management of asymptomatic SARS-CoV-2 infections: A longitudinal multi-center study in Chongqing, China

“…Recently, several studies have reported chest CT of asymptomatic SARS-CoV-2 infections. However, most of these asymptomatic studies were cross-sectional and focused on summarizing of CT features or screening 25 , 37 - 39 . A comprehensive and longitudinal study (including screening, CT features and evolution of asymptomatic SARS-CoV-2 infections) was scarcely reported.…”

Preoperative screening and testing for COVID‐19 during Victoria's second wave

“…Nurses, anaesthetists and surgeons were certainly infected in the course of their work during Victoria's second wave, despite none being in the preoperative testing cohort reported by the eight Victorian hospitals 6 . There were also 596 non‐clinical staff infected, 343 (58%) of them were acquired in the workplace 8 . The third risk is to other patients who may contract coronavirus disease in hospital by coming into contact with infected patients.…”

“…Other countries, far worse afflicted by their waves of coronavirus disease than Victoria, have reported rates of preoperative testing exceeding 1%. 8 There are three reasons to identify which patients being admitted to hospital for elective surgery have coronavirus disease. The first is to minimize their risk of morbidity and mortality in the postoperative period.…”