Diagnosing the acute abdomen during a global contrast shortage: a single centre experience.

Background: The COVID-19 pandemic led to a global shortage of iodinated contrast media (ICM) in early 2022. ICM is used in more than half of the computed tomography of the abdomen and pelvis (CTAP) performed to diagnose an acute abdomen (AA). In response to the shortage, the RANZCR published contrast-conserving recommendations. This study aimed to compare AA diagnostic outcomes of non-contrast CTs performed before and during the shortage.

Methods: A single-centre retrospective observational cohort study of all adult patients presenting with an AA who underwent a CTAP was conducted during the contrast shortage period from May to July 2022. The pre-shortage control comparison group was from January to March 2022; key demographics, imaging modality indication and diagnostic outcomes were collected and analysed using SPSS v27.

Results: Nine hundred and sixty-two cases met the inclusion criteria, of which n = 502, 52.2% were in the shortage period group. There was a significant increase of 464% in the number of non-contrast CTAPs performed during the shortage period (P < 0.001). For the six AA pathologies, only n = 3, 1.8% of non-contrast CTAPs had equivocal findings requiring further imaging with a contrast CTAP. Of the total CTs performed, n = 464, 48.2% were negative.

Conclusion: This study showed that when non-contrast CTs are selected appropriately, they appear to be non-inferior to contrast-enhanced CTAPs in diagnosing acute appendicitis, colitis, diverticulitis, hernia, collection, and obstruction. This study highlights the need for further research into utilizing non-contrast scans for assessing the AA to minimize contrast-associated complications.