Post-contrast acute kidney injury between dogma and real life: case of computed tomography with intravenous injection of contrast medium in the emergency department

Since the 1930s, it has been widely recognized that intravenous injection of iodine-based contrast media (CM) during imaging carries a risk of post-contrast acute kidney injury (PC-AKI). However, advancements in the development of these CM over the last five decades, particularly the gradual reduction in their osmolarity, have led to improved tolerance of modern contrast agents, which are now iso-osmotic with plasma. Despite this progress, studies have raised questions about CM iatrogenic effect. Clinical evidence suggests the existence of criteria that permit the performance of contrast-enhanced CT scans without waiting for serum creatinine levels in the majority of cases. It is crucial to identify independent risk factors for PC-AKI, such as age, diabetes, dehydration, or nephrotoxic medications, which can exacerbate acute kidney injury and, consequently, PC-AKI. However, these factors should not hinder or delay the administration of a CT scan, especially in emergency situations. The population most vulnerable to PC-AKI appears to be those with chronic kidney disease and a glomerular filtration rate (GFR) less than 30 ml.min-1.1.73m-2,-1 .1.73m- 2 , followed by patients with hypertension. Therefore, nephroprotection measures should be prioritized for this population. This literature review aims to provide a pragmatic approach for the everyday practice of emergency physicians.