Preprocedural fasting for contrast-enhanced CT: when experience meets evidence

Abstract

Traditional preparatory fasting policy prior to iodinated contrast media (ICM) assisted contrast-enhanced CT (CECT) examinations lacks methodologically acceptable evidence. Considering the possible negative effects of preprocedural fasting, the latest European Society of Urogenital Radiology guidelines V10.0 and American Committee of Radiology 2021 guidelines clearly state that preprocedural fasting is not recommended prior to routine intravenous ICM administration. This comprehensive and detailed Review presents the current global dietary preparation policies, potential harm of excessive fasting, and a systematical and well-bedded description of practice advancements of dietary preparation. The evidences revealed that there has been no single instance of vomiting-associated aspiration pneumonia due to the undemanding implementation of preparatory fasting prior to CECT yet. Non-fasting would not increase the incidence of emetic symptoms and the risk of aspiration pneumonia. Not every patient should undergo all CECT examinations without preparatory fasting. There is still much more refinement to be done on the preparatory fasting policy. Changes in traditional preparatory fasting policy will make positive and significant implications on clinical practice. This Review aims to provide operational guidance and suggestions for practitioners and policymakers, motivate efficient, reasonable, safe and normative ICM usage, and achieve optimal patient clinical benefits and high-quality radiological care practices.

Pediatric Cardiovascular Computed Tomography

“…Therefore, fasting protocols for pediatric cardiovascular CT may differ among institutions. Notably, excessive fasting is not recommended, particularly in infants and young children, because of the detrimental effects of dehydration and hypoglycemia 43 …”

Change the preprocedural fasting policy for contrast-enhanced CT: results of 127,200 cases

“…As a time-honored tradition, preprocedural fasting for 4–6 h is typically required prior to contrast-enhanced CT (CECT) in most medical institutions worldwide, to reduce the possibility of adverse consequences (e.g., emetic complications and aspiration) after injection of iodinated contrast media (ICM) [ 1 – 3 ]. Although this policy lacks methodologically acceptable evidence, and the fasting time durations and contents vary considerably in different medical institutions, preprocedural fasting is still a fairly common request worldwide [ 3 ]. Nowadays, with the extensive applications of non-ionic ICM, the incidence of emetic complications has reduced to an extremely low level (nausea 0.013%, vomiting 0.059%) [ 4 ], which is much lower than that reported by Katayama et al about 30 years ago [ 5 ].…”

“…Nowadays, with the extensive applications of non-ionic ICM, the incidence of emetic complications has reduced to an extremely low level (nausea 0.013%, vomiting 0.059%) [ 4 ], which is much lower than that reported by Katayama et al about 30 years ago [ 5 ]. According to our rigorous and extensive literature review [ 3 ], no aspiration pneumonia has been reported due to the lenient implementation of preparatory fasting. Non-fasting would not increase the risk of aspiration pneumonia and the incidence of emetic complications [ 3 ].…”

“…According to our rigorous and extensive literature review [ 3 ], no aspiration pneumonia has been reported due to the lenient implementation of preparatory fasting. Non-fasting would not increase the risk of aspiration pneumonia and the incidence of emetic complications [ 3 ]. Furthermore, preprocedural fasting may bring negative effects, including but not limited to general discomfort (e.g., hunger, thirst, dehydration, anxiety, irritability), hypoglycemic risk in diabetic patients, and may even increase the risk of adverse events [ 3 ].…”

“…Non-fasting would not increase the risk of aspiration pneumonia and the incidence of emetic complications [ 3 ]. Furthermore, preprocedural fasting may bring negative effects, including but not limited to general discomfort (e.g., hunger, thirst, dehydration, anxiety, irritability), hypoglycemic risk in diabetic patients, and may even increase the risk of adverse events [ 3 ]. Therefore, it seems not prudent to fast without distinction for every patient without evidence-based considerations, and the existing fasting strategies can reasonably be less restrictive.…”