14 May 2020
Please see the latest RCR statement on the role of CT in screening elective pre-operative patients, which replaces the statement below from 30 April 2020.
30 April 2020
Concerns have been expressed over an increase in requests for pre-operative chest CT as a routine screen to exclude asymptomatic COVID-19.
The RCR supports the agreed intercollegiate statements from the Surgical Royal Colleges. CT screening for COVID-19 in asymptomatic COVID-19 positive patients has a low pick up rate and a 20% false negative rate in symptomatic patients. The guidance was drafted in light of the acknowledged low sensitivity and specificity of chest CT for the diagnosis of COVID-19.
Patients presenting as acute abdominal emergencies who require immediate surgical management
Pre-operative low-dose CT of the chest in patients presenting as abdominal emergencies, who are having an abdominal CT in their diagnostic investigations, has been agreed. Emerging evidence, unpublished, suggests that for those patients with previously undiagnosed COVID-19, the pulmonary changes are visible on the upper slices of the abdominal CT. This may obviate the requirement to undertake additional CT of the chest in these patients in future so this guidance will be updated as evidence emerges.
Guidance for pre-operative chest CT imaging for elective cancer surgery during the COVID-19 pandemic
Intercollegiate guidance for pre-operative chest CT imaging for elective cancer surgery during the COVID-19 pandemic, developed in discussion with the RCR, recommends that CT should only be deployed in very specific circumstances.
- Preoperative chest CT scanning should be undertaken in patients whose preoperative assessment indicates that they will need level II/III critical care in their postoperative recovery
- This particularly applies to thoracic surgery and complex upper abdominal surgery (oesophageal, gastric, hepatic and pancreatic)
- Screening for other complex, high risk surgeries should be determined by careful discussion with the duty radiologist by the individual treating teams, based on the likelihood of respiratory compromise and / or critical care support postoperatively.
- It should only be considered if positive CT findings would change the patient’s immediate surgical management.
Routine pre-operative chest CT to screen for COVID-19 is NOT indicated
The relatively low pick up rate of COVID-19 in asymptomatic patients with positive RT-PCR and a 20% false negative rate in symptomatic patients indicates that pre-operative CT chest is of limited utility.
Routine COVID-19 precautions are recommended: negative RT-PCR within 48 hours, no symptoms for seven days and self-isolation for 14 days.
If, despite a negative swab and patient isolation, there is still concern about possible COVID-19 infection in asymptomatic patients, there should be discussion between the clinical team and the duty radiologist to determine whether further imaging is justified. Consideration should be given to local disease prevalence but pre-operative CT chest should be not be performed unless a positive scan means the operation would be postponed.
Requests for routine scanning of pre-operative patients will be rejected.
There are significant implications on scanner capacity which is required to scan urgent patients and elective patients whose imaging has been delayed due to the COVID-19 crisis.