Use of oral contrast for CT scanning and time to diagnosis and treatment of acute appendicitis.

BACKGROUND
The aim of this study was to investigate whether there is a delay in treatment for patients having pre-operative CT imaging with both intravenous and oral contrast (CTIVO) compared to intravenous contrast alone (CTIV).


METHODS
A retrospective review of patients who underwent emergency appendicectomy at a single hospital during a two-year period (1/1/2019-31/12/2020) was performed. Demographic details, imaging timing/modality; biochemical markers; American Society of Anaesthesiologists (ASA) physical status classification, anaesthetic induction time; operative report findings; histopathology, peri-operative complications, admission/discharge times were recorded. The Sunshine Appendicitis Grading System (SAGS) score was used for severity of appendicitis.


RESULTS
Pre-operative CT was performed in 294 patients; CTIVO: 159 (54%), CTIV: 135 (46%). Both groups were comparable for age, sex, ASA status and inflammatory markers. The median time from CT request to scanning was longer with CTIVO (CTIVO: 170 min, CTIV: 65 min, P < 0.0001). The median time from CT request to induction of anaesthesia was also longer with CTIVO (CTIVO: 780 minutes, CTIV: 406 min, P < 0.0001). A delay to theatre was not significantly associated with severity of appendicitis (SAGS score). The diagnostic accuracy was not reduced in the CTIV group compared to the CTIVO group.


CONCLUSION
CTIVO scans significantly delay CT diagnosis and surgical treatment of appendicitis compared to CTIV. Omitting oral contrast does not result in a reduction in diagnostic accuracy for appendicitis.