key: cord-0948405-gl8pm0bh
authors: Ismail, Ahmed; Sarkar, Priya; Muthiah, Balasundaram; Yassin, Nuha
title: Computerized tomography of the Thorax for surgical patients during the COVID‐19 pandemic: Was it useful?
date: 2021-09-12
journal: Int J Clin Pract
DOI: 10.1111/ijcp.14774
sha: d15802810f6760f73770f891e7d0e6ef7050ba20
doc_id: 948405
cord_uid: gl8pm0bh

OBJECTIVES: Diagnostic challenges during the corona virus disease (COVID‐19) pandemic forced the radiology regulating body to adopt the use of CT Chest as a triage and diagnostic tool, which was subsequently abandoned. The Royal Wolverhampton hospital followed both protocols. Here, we investigate the evidence behind this decision within the context of surgical admissions during the COVID‐19 peak in our hospital. METHODS: Retrospective data collection and analysis of all surgical admissions between the 1st of March to the 31st of May. Data were collected from the radiology and electronic portal looking into patients undergoing CT chest to diagnose the presence of COVID‐19 as well as swab results. RESULTS: Seventy‐eight patients fulfilled our inclusion criteria. The scan either confirmed the presence or absence (4, 63 patients) of COVID‐19 but was sometimes inconclusive (11 patients). Comparing these to the results of the swabs; CT showed sensitivity 42.86%, Specificity 97.92%, and accuracy 90.91%. In the inconclusive CT report group, chances of having a positive swab result were 45%: None of the scan results changed any of the surgical planning. Lymphocyte count in the context of surgical presentation did not have any statistical significance to predict the presence of COVID‐19 (P = .7). Cost implications on our cohort of patients for adding the chest CT is estimated to be around £31 000. CONCLUSION: CT Thorax during the pandemic was a good negative predictor but had limited diagnostic value and did not change patient management. Newer, faster techniques of PCR swabs and antibody testing would be a better and cheaper alternative.

Every medical institution around the world was compelled to rise to the immense challenges posed by the corona virus disease The British Society of Thoracic Imaging (BSTI) issued their first statement on 11th March 2020 stating, 1 "BSTI have been discussing this with NHS England. The current position is that there is no recommended use of CT, beyond 'routine clinical care'. We are reassured that this has so far also been the position taken by the American College of Radiology, in recommendations published on 22nd/March/2020. In a situation where numbers rise very rapidly, with increasingly ill patients requiring hospital admission, the role of CT may turn towards risk stratification and assessment of disease burden. Again, these discussions are ongoing with the Royal College of Radiologists and NHS England. We also have dialogue with our Italian colleagues.'' However, the following statement was released on 22nd May 2020, stating "As community prevalence of COVID-19 has dropped; and availability of RT-PCR has improved (including rapid tests generating results in 45-90 minutes), [so] the need for an alternative (ie, CT chest) has diminished. Most acute hospitals will now receive RT-PCR results before the decision regarding operative management. Acute abdominopelvic CT already includes the lung bases; the incremental benefit of full thoracic scanning where RT-PCR is negative and community prevalence is dropping is likely to be negligible. We therefore suggest that there is no longer a need for routine CT of the entire thorax for patients undergoing acute abdominopelvic imaging. 1 The Royal College of Radiology had similar views to those mentioned above and they released their own statement. 2

The surgical department at the Royal Wolverhampton NHS Trust decided to investigate our own outcomes during the COVID-19 pandemic to see if CT Thorax added any value to the management of patients with general surgical conditions.

Retrospective data were collected and analysed from all admissions between 1st March 2020 and 31st May 2020, that is, starting from the rise of the pandemic in Royal Wolverhampton Hospital and the implementation of the new guidelines regarding CT scanning of the chest as a tool to triage or to investigate patient for possible COVID-19. Our inclusion criteria included all surgical admissions, emergency or elective, any gender and any age, those with a scan of their thorax, with or without a scan of the abdomen and pelvis to investigate their surgical pathology. The exclusion criterion was patients not undergoing CT Thorax. Data were collected from our electronic clinical portal and scanned documents.

The protocol used was non-contrast material-enhanced chest CT, unless CT pulmonary angiography was required to detect pulmonary embolism (PE). Reports on the scan was stratified into either 1-positive for COVID-19 and these usually showed consolidation with ground glass opacities either in one or both lungs, 2-Negative for COVID-19 where no abnormalities were found or 3-Inconclusive where the radiological changes were not able to confirm the presence or absence of COVID-19.

Seventy-eight patients fulfilled the inclusion criteria, our age range was 26-92 years, with a median of 72.5. All patients admitted had a suspected surgical pathology. Seventy-two patients were emergency admissions while only 6 were elective, for cancer resection.

Data collected investigated patient's comorbidities including hypertension, diabetes and ischaemic heart disease (Chart 1).

COVID-19 nasopharyngeal swabs were sent on admission for 66 patients with available results. 12 patients did not have a swab (with no documented reason) and 21 patients (26.9%) had clinical and radiological signs of chest infection during their surgical admission. All these 21 patients had COVID-19 swabs sent except one who died and was not for escalation because of frailty (Table 1) .

CT Thorax offered to the 78 patients were reported by radiologists of varying grades, but all were counter-checked by a consultant within 24 hours if reported initially by a registrar. Reports reviewed by the collecting team were categorised into confirmed negative, confirmed positive and inconclusive (Table 2) .

All the results were compared with the results of the swabs (Table 3) , excluding the 12 patients who did not have swabs sent, testing for sensitivity, specificity, and accuracy (Table 4) . Forty-five percent of patients with CT reports that were inconclusive had a positive COVID-19 swab.

The number of patients requiring surgical intervention in our data capture were 22 (28%). Out of these, seven patients were positive for COVID-19 and CT failed to identify all of them, although six were reported as inconclusive. Ten of these patients required ITU admission post-operatively, but only one was because of COVID-19 pneumonia. One patient died a few days after surgical intervention, but he was COVID-19 negative on PCR and CT (Table 5) .

Assessing mortality in our cohort of patients, 6 patients (7%) died in the first 30 days from admission, out of which one was related to COVID-19 pneumonia confirmed by CT Chest and swab. However, their management did not require surgical intervention. The rest had normal CT Chest findings, three had negative swabs results and two had no swabs sent at all (Table 6) .

Exploring whether lymphocyte count plays a role in the context of surgical admission to predict COVID-19 status, they were found to be below the normal range in 56 patients (71%). From these, eight C H A R T 1 Comorbidities CI 58%-80%), consolidation (47%, 35%-60%) and "air bronchogram sign" (46%,25%-66%) were more common than the atypical lesion of "crazy-paving pattern" (15%, 8%-22%). Seventy percent (95% CI 46%-95%) of cases showed a location preference for the right lower lobe, 65% (58%-73%) of patients presented with more or equal 3 lobes involvement. Meanwhile, 42% (32%-53%) of patients had all five lobes involved, and 67% (55%-78%) showed a predominant peripheral distribution. 6 In conclusion, as proven in our cohort of surgical patients, CT is an expensive tool that is good to rule out SARS-CoV-2 virus but is not advisable to be used as a diagnostic tool. PCR swabs, especially the new generation, is a quick, safe test with no exposure to radiation.

Data available on request from the authors. 

An update on COVID-19 for the radiologist -A British society of Thoracic Imaging statement

Chest computed tomography for the diagnosis of patients with coronavirus disease 2019 (COVID-19): a rapid review and meta-analysis

Diagnostic performance of CT and reverse transcriptase-polymerase chain reaction for coronavirus disease 2019: a meta-analysis

CT imaging features of 4121 patients with COVID-19: a meta-analysis

CT manifestations and clinical characteristics of 1115 patients with coronavirus disease 2019 (COVID-19): a systematic review and meta-analysis