Risk of Acute Kidney Injury Following IV Iodinated Contrast Media Exposure: 2023 Update, From the AJR Special Series on Contrast Media

Iodinated contrast material (ICM) has revolutionized the field of diagnostic radiology through improvements in diagnostic performance and the expansion of clinical indications for radiographic and CT examinations. Historically, nephrotoxicity was a feared complication of ICM use, thought to be associated with a significant risk of morbidity and mortality. Such fears often precluded the use of ICM in imaging evaluations, commonly at the expense of diagnostic performance and timely diagnosis. Over the past 20 years, the nephrotoxic risk of ICM has become a topic of debate, as more recent evidence from higher-quality studies now suggests that many cases of what was considered contrast-induced acute kidney injury (CI-AKI) likely were cases of mistaken causal attribution; most of these cases represented either acute kidney injury (AKI) caused by any of myriad other known factors that can adversely affect renal function and were coincidentally present at the time of contrast media exposure (termed "contrast-associated AKI" [CA-AKI]) or a manifestation of the normal variation in renal function that increases with worsening renal function. This Special Series Review discusses the current state of knowledge regarding CI-AKI and CA-AKI, including the incidence, risk factors, outcomes, and prophylactic strategies in the identification and management of these clinical conditions.

[ESUR recommendations on the use of contrast media: Practice survey, review and commentary by CJN, FIRN and SFNDT]

Contrast media administration is classically considered to cause or worsen kidney failure. Recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. The present work evaluates the practice of French nephrologists, and provides a commentary on these recommendations based on an updated review of the literature. We conducted survey among French nephrologists, using an electronic questionnaire distributed by the Société Francophone de Néphrologie, Dialyse et Transplantation, the French Intensive care Renal Network and the Club des Jeunes Néphrologues. 266 responses were collected. The European Society of Urogenital Radiology guidelines are poorly known among the panel of nephrologists. Their practices differ from the guidelines by the more frequent and earlier implementation of measures to prevent renal failure post contrast media. In accordance with the guidelines, hydration is prescribed as a first-line preventive measure, mainly with saline and bicarbonate. Inhibitors of the renin-angiotensin-aldosterone system are frequently discontinued before an injection of contrast media, contrary to what is recommended. In conclusion, the European Society of Urogenital Radiology guidelines, which the working group endorses, but which are still too little known and applied in clinical nephrology in France, prompt nephrologists to lift some of the restrictions on the use of PCI as well as on the continuation of ARS inhibitors before injecting PCI.

Kidney and contrast media: Common viewpoint of the French Nephrology societies (SFNDT, FIRN, CJN) and the French Radiological Society (SFR) following ESUR guidelines

Contrast medium administration is classically considered to cause or worsen kidney failure, but recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. Kidney injury does not constitute a contra-indication to the administration of iodinated contrast medium, as long as the benefit-risk ratio justifies it. Intravenous hydration with 0.9% NaCl or 1.4% sodium bicarbonate is the only validated measure for the prevention of post-iodine contrast nephropathy. This is necessary for intravenous or intra-arterial administration of iodinated contrast agent without first renal pass when the glomerular filtration rate is less than 30mL/min/1.73m², for intra-arterial administration of iodinated contrast agent with first renal passage when the glomerular filtration rate is less than 45mL/min/1.73m², or in patients with acute renal failure. The use of iodinated contrast medium should allow the carrying out of relevant examinations based on an analysis of the benefit-risk ratio and the implementation of measures to prevent toxicity when necessary.

Iodinated contrast medium: Is there a re(n)al problem? A clinical vignette-based review

As we were taught, for decades, that iodinated contrast-induced acute kidney injury should be dreaded, considerable efforts were made to find out effective measures in mitigating the renal risk of iodinated contrast media. Imaging procedures were frequently either downgraded (unenhanced imaging) or deferred as clinicians felt that the renal risk pertaining to contrast administration outweighed the benefits of an enhanced imaging. However, could we have missed the point? Among the abundant literature about iodinated contrast-associated acute kidney injury, recent meaningful advances may help sort out facts from false beliefs. Hence, there is increasing evidence that the nephrotoxicity directly attributable to modern iodinated CM has been exaggerated. Failure to demonstrate a clear benefit from most of the tested prophylactic measures might be an indirect consequence. However, the toxic potential of iodinated contrast media is well established experimentally and should not be overlooked completely when making clinical decisions. We herein review these advances in disease and pathophysiologic understanding and the associated clinical crossroads through a typical case vignette in the critical care setting.

Post-contrast acute kidney injury. Part 2: risk stratification, role of hydration and other prophylactic measures, patients taking metformin and chronic dialysis patients : Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

OBJECTIVES

The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. AREAS COVERED IN PART 2: Topics reviewed include stratification of PC-AKI risk, the need to withdraw nephrotoxic medication, PC-AKI prophylaxis with hydration or drugs, the use of metformin in diabetic patients receiving contrast medium and the need to alter dialysis schedules in patients receiving contrast medium.

KEY POINTS

• In CKD, hydration reduces the PC-AKI risk • Intravenous normal saline and intravenous sodium bicarbonate provide equally effective prophylaxis • No drugs have been consistently shown to reduce the risk of PC-AKI • Stop metformin from the time of contrast medium administration if eGFR < 30 ml/min/1.73 m 2 • Dialysis schedules need not change when intravascular contrast medium is given.

Intravenous radiographic contrast administered prior to high-dose methotrexate and subsequent toxicity requiring the use of glucarpidase

Methotrexate is a dihydrofolate reductase inhibitor that interferes with DNA synthesis, DNA repair, and cellular replication. We present the first adult case of a patient who received intravenous contrast prior to administration of high-dose methotrexate, who subsequently experienced delayed methotrexate clearance and renal impairment necessitating the use of glucarpidase. This case displays a possible correlation between intravenous radiographic contrast administration and resulting toxicity due to delayed methotrexate clearance.

Incidences of acute kidney injury, dialysis, and graft loss following intravenous administration of low-osmolality iodinated contrast in patients with kidney transplants

PURPOSE

To determine the incidence of acute kidney injury (AKI), need for emergent dialysis, and renal graft loss in patients with kidney transplants, who underwent CT examinations with low-osmolality iodine-based contrast material (IBCM).

MATERIALS AND METHODS

Our institutional review board approved this retrospective Health Insurance Portability and Accountability Act compliant study. From January 2005 to April 2015, a total of 224 CT examinations were performed using low-osmolality IBCM in patients with kidney transplants. Six patients who had septic or cardiogenic shock and 30 patients with documented, failed transplants were excluded from our analysis, yielding a total of 188 examinations. Of these, pre- and post-CT serum creatinine (SCr) values were available for 104 examinations, to allow evaluation of AKI. The mean baseline SCr and estimated glomerular filtration rate (eGFR) in this subgroup were 1.37 mg/dL (median 1.18, range 0.5-6.05) and 65.8 mL/min/1.73 m², respectively (median 65, range 9-114). AKI was defined as a rise in SCr of either (a) ≥0.3 mg/dL or (b) ≥0.5 mg/dL in the 24- to 72-h period following IBCM administration. For all patients undergoing the 188 examinations, need for dialysis and graft loss 30 days after contrast administration were evaluated.

RESULTS

In patients with pre- and post-CT SCr values, the incidence of AKI was 7% (7/104) based on a rise of ≥0.3 mg/dL and 3% (3/104) based on a rise of ≥0.5 mg/dL. All three patients with the more strict definition (≥0.5 mg/dL) had a pre-CT eGFR <60 mL/min/1.73 m². No patient required dialysis or had renal graft loss 30 days after contrast administration.

CONCLUSION

The incidence of AKI after administration of low-osmolality IBCM administration in renal transplant recipients is low, with no instances of emergent dialysis or graft loss at 30 days post contrast.