image by: AJKD

HWN Suggests

Contrast Nephropathy, myth thereof

The concept of contrast nephropathy was born in the 1950's, when it was observed that some patients developed renal failure following injection of IV contrast dye for intravenous pyelography.(13217726) This might have represented a true nephrotoxic reaction. The contrast dye used at that time probably was poisonous (50% diodone, a high-osmolar contrast dye which nobody would imagine using today). However, none of these early studies had adequate control groups, so it's impossible to know for sure. This was before the establishment of evidence-based medicine. Regardless, a myth was born. Over time, fear of contrast nephropathy blossomed and took root. Any renal failure which occurred following…

read full article

Featured

 Contrast Induced Nephropathy: A Modern-Day Medical Myth

If you have a septic patient, with a SCr <4.0 mg/dL and without a renal transplant, requiring contrast for diagnosis…Give the contrast!!!.

 Does contrast cause kidney injury? The evidence

At the current time, there is very little evidence that IV iodinated contrast material is an independent risk factor for AKI in patients with eGFR ≥30 mL / min/1.73m2.

Articles of Interest

Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury

The vast majority of patients having diagnostic tests and procedures with ICM will not experience a significant or permanent worsening of renal function, dialysis, or increased morbidity.

Contrast Induced Nephropathy

So for decades people have talked about Contrast Induced Nephropathy…or Contrast Induced Acute Kidney Injury – depending on the decade and location of discussion. The theory being that diuresis, increased urine viscosity and changes in vasoconstriction and vasodilation leads to a worsening of renal function following iv contrast administration.

Contrast Induced Nephropathy (CIN): Fact or Myth?

In the largest well-controlled study of acute kidney injury following contrast administration in the ED to date, intravenous contrast was not associated with an increased frequency of acute kidney injury.

Contrast Nephropathy – a medical myth getting busted?

The risk of AKI caused by intravascular contrast medium has been overstated.

Contrast-associated acute kidney injury is a myth: No

In summary, prior research has elucidated pathophysiologic effects of iodinated contrast on the kidneys in animal models and humans, while studies documenting associations of volume and osmolality of contrast media with risk for renal injury support their nephrotoxic potential. Recent studies questioning the existence of CA-AKI have important methodologic limitations that confound interpretation of their findings. While secular trends including the use of lower volumes of less nephrotoxic contrast along with the widespread use of preventive care including intravascular volume expansion have likely contributed to decreased rates of CA-AKI and rendered severe renal injury a relatively rare complication of contrast administration alone, these factors have not eliminated the existence of this iatrogenic condition. Continued vigilance and appropriation of evidence based preventive care in the highest risk patients remains essential.

Contrast-associated acute kidney injury is a myth: Yes

While a randomized controlled trial has not been conducted, there is now substantial evidence suggesting that CM contributes minimally, if at all, to the development of AKI. Despite the existence of such evidence, a pervasive preoccupation with what should be referred to as contrast-associated AKI (CA-AKI) persists in clinical practice, medical texts, and even among clinical researchers.

Contrast-associated acute kidney injury: does it really exist, and if so, what to do about it?

For decades, when contrast agents are administrated, physicians have been concerned because of the risk of inducing acute kidney injury (AKI). Recent literature questions the existence of AKI induced by contrast, but animal studies clearly showed harmful effects. The occurrence of contrast-associated AKI was likely overestimated in the past because of confounders for AKI.

Contrast-Induced Acute Kidney Injury: The Data and the Debate

Whether one believes CI-AKI is real or a myth, this debate is not merely theoretical because conclusions drawn have significant implications for the care of our patients who have CKD.

Contrast-Induced Nephropathy: Confounding Causation

The history of the study of CIN is just another example of evidence-based medicine successfully applied to the debunking of a common belief in a clinical syndrome. As ED physicians are faced with the challenge of rapidly diagnosing life-threatening conditions (i.e. aortic dissection/aneurysmal rupture, pulmonary embolism, occlusion or aneurysmal rupture of cerebral vessels, traumatic vascular injury), we should not delay emergent contrast-enhanced CT scans waiting for SCr.

Contrast-Induced Nephropathy: Does It Really Exist?

A single eGFR determination should not be the sole basis for risk classification for AKI following exposure to contrast media. This is particularly true for those with eGFRs of 30 to 45 mL/min/1.73 m2 and in some with eGFRs < 30 mL/min/1.73 m2. It is also important that the patient has a stable Scr level prior to exposure to contrast media. Physicians need to consider patients’ individual unique risk factors for CIN and balance the risks and benefits following exposure to contrast.

Contrast-Induced Nephropathy: Myth or Monster

While some older studies have demonstrated as increased incidence of AKI among patients receiving IV contrast when compared wiht controls (Heller 1991, Polena 2005) these studies have failed to control for potential confounders. Studies that have controlled for such confounder, typically using propensity score matching, have found no increased incidence of AKI, severe kidney failure, or death due to renal failure compared to patients not receiving contrast (mcDonald 2014, Hinson 2017). A meta-analysis of all such studies, performed in 2013, similarly failed to demonstrate a statistically significant increase in the incidence of AKI (McDonald 2013).

Evidence-based medicine and the misconception of contrast-induced kidney disease

To sum up, to the best of our knowledge, there is no point in withholding contrast media for fear of AKI irrespective of GFR/kidney status in any case that seems beneficial for patient (i.e. when the use of contrast is clinically indicated) in patients requiring urgent assessment in emergency departments and/or those with life threatening conditions such as sepsis.

IBCC chapter & cast: The myth of contrast nephropathy

Does contrast nephropathy exist? Vigorous debate has been ongoing about this dating back to 2013. Hundreds of studies on the topic ultimately reveal no convincing evidence that contrast nephropathy exists. However, it's unethical to perform a prospective RCT, so it's impossible to ever prove this. This has left us in an evidentiary limbo – we don't really believe that contrast nephropathy exists, but simultaneously we are also afraid of it.

Intravenous CT Contrast Media and Acute Kidney Injury: A Multicenter Emergency Department–based Study

Contrast-enhanced CT was associated with higher risk of acute kidney injury and further hemodialysis among Taiwanese patients with an estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73 m2 but not those with an eGFR of more than 45 mL/min/1.73 m2.

Just give the contrast? Appraisal of guidelines on intravenous iodinated contrast media use in patients with kidney disease

To summarize, the quality of the included guidelines was heterogeneous. The “Just give the contrast” slogan should be interpreted with caution. Most guidelines showed consistent recommended eGFR < 30 mL/min/1.73 m2 as the cutoff for referring patients to discuss the risk-benefit balance of ICM administration before a scan, use of iso-osmolar or low-osmolar ICM for scan, and hydration therapy after a scan

Kidney Boy on Acute Kidney Injury: Myths & Musings

Get a grip on acute kidney injury (AKI) with Dr. Joel Topf (AKA @kidney_boy), Kashlak’s Chief of Nephrology! We’ve put together an AKI highlight reel – focusing on practical tips and tricks to help you identify, diagnose and manage AKI, plus how to recognize AIN and random myths and musings on vancomycin, NSAIDS, contrast nephropathy, and the risk of NSF from gadolinium.

The Latest Myth: Contrast-Induced Nephropathy?

Here’s the simple explanation for why none of our observed treatments to prevent contrast-induced nephropathy – acetylcysteine, hydration, sodium bicarbonate – reliably work: CIN is a myth.

The myth and reality of contrast-induced nephropathy

Recent studies provide convincing evidence that nephrotoxicity after CECT is an unusual phenomenon in hospitalized patients. It is probably still more rare in outpatients who are generally healthier than hospitalized patients.

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Although the true risk of CI-AKI remains unknown, prophylaxis with intravenous normal saline is indicated for patients without contraindication (eg, heart failure) who have acute kidney injury (AKI) or an estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an eGFR of 30–44 mL/min/1.73 m2 at the discretion of the ordering clinician.