Role of complementary Ct chest in patients presenting with acute abdominal symptoms during covid-19 pandemic: a UK experience

Background: In March 2020, the UK Intercollegiate General Surgery Guidance on COVID-19 recommended that patients undergoing emergency abdominal CT should have a complementary CT chest for COVID-19 screening.

Purpose: To establish if complementary CT chest was performed as recommended, and if CT chest influenced surgical intervention decision. To assess detection rate of COVID-19 on CT and its correlation with RT-PCR swab results. To determine if COVID-19 changes is reliably detected within the lung bases which are usually imaged in standard abdominal CT.

Methods: Patients with acute abdominal symptoms presenting to a single institution between 1st and 30th April 2020 who had abdominal CT and complementary CT chest were retrospectively extracted from Computerised Radiology Information System. CT COVID-19 changes were categorised according to British Society of Thoracic Radiology reporting guidance. Patient demographics (age and gender), RT-PCR swab results and management pathway (conservative or intervention) were recorded from electronic patient records. Statistical analyses were performed to evaluate any significant association between variables. p values ≤0.05 were regarded as statistically significant.

Results: Compliancy rate in performing complementary CT chest was 92.5% (148/160). Thirty-five patients (35/148,23.6%) underwent intervention during admission. There was no significant association (p = 0.9085) between acquisition of CT chest and management pathway (conservative vs intervention). CT chest had 57% sensitivity (CI 18.41% to 90.1%) and 100% specificity (CI 92% to 100%) in COVID-19 diagnosis. Three of ten patients who had classic COVID-19 changes on CT chest did not have corresponding changes in lung bases.

Conclusion: Compliance with performing complementary CT chest in acute abdomen patients for COVID-19 screening was high and it did not influence subsequent surgical or interventional management.