Contrast Agents in Renal Insufficiency

[Redpancreas]

I know IV CT contrast (iodinated agents) are bad for the kidneys but other things seem to be a gray line. Can someone weigh in on the following. Assume the patient is CKD3B plus. I know w/ ESRD with dialysis you can just dialyze it out if the imaging isn't urgent.

1.) Oral CT contrast?
2.) Gadolinium (MRI) contrast?

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[whoknows2012]

I know IV CT contrast (iodinated agents) are bad for the kidneys but other things seem to be a gray line. Can someone weigh in on the following. Assume the patient is CKD3B plus. I know w/ ESRD with dialysis you can just dialyze it out if the imaging isn't urgent.

1.) Oral CT contrast?
2.) Gadolinium (MRI) contrast?

Oral is fine (as far as I can tell)
Gadolinium I avoid if crcl<30

 

[anonperson]

I know IV CT contrast (iodinated agents) are bad for the kidneys but other things seem to be a gray line. Can someone weigh in on the following. Assume the patient is CKD3B plus. I know w/ ESRD with dialysis you can just dialyze it out if the imaging isn't urgent.

1.) Oral CT contrast?
2.) Gadolinium (MRI) contrast?

Gadolinium-contrast toxicity in patients with kidney disease: nephrotoxicity and nephrogenic systemic fibrosis - PubMed

Gadolinium is widely employed as a contrast agent for magnetic resonance imaging (MRI) and has generally been considered to be safe. As with iodinated radiocontrast, concern for contrast-induced nephropathy existed with gadolinium-contrast as it possessed many similar qualities (hyperosmolar...

pubmed.ncbi.nlm.nih.gov

 

[Redpancreas]

Oral is fine (as far as I can tell)
Gadolinium I avoid if crcl<30

I guess the whole controversy behind this to expand further is many centers have better Gadolinium now which makes NSF less of a concern. Was curious to see what everyone's doing at their institutions.

 

[chessknt]

Contrast Nephropathy, myth thereof

CONTENTS Venous injection of contrast (e.g. for CT scan) The birth of the contrast nephropathy myth Current lack of evidence regarding contrast nephropathy Weighing the risks vs. benefits of using contrast (Renalism) The attention given to contrast nephropathy is insane Intra-arterial contrast...

emcrit.org

A bit reductive but a good argument against agonizing over the use of IV contrast in patients with AKI. The worst outcome from a CT scan isn't an AKI it is a non-diagnostic study.

 

[Chemist0157]

I know IV CT contrast (iodinated agents) are bad for the kidneys but other things seem to be a gray line. Can someone weigh in on the following. Assume the patient is CKD3B plus. I know w/ ESRD with dialysis you can just dialyze it out if the imaging isn't urgent.

1.) Oral CT contrast?
2.) Gadolinium (MRI) contrast?

1. Oral contrast should be fine.
2. Gadolinium is typically avoided with GFR < 30. NSF is rare but very terrible. Hemodialysis is a suggestion after shortly after administration of class I and III agents, but it does NOT have a proven benefit. There is a world where the benefit of having a gadolinium study with a class II agent outweighs risk of NSF. It seems quite rare that someone just HAS to have an MRI with gadolinium, but it will come up from time to time.

 

[Chemist0157]

Contrast Nephropathy, myth thereof

CONTENTS Venous injection of contrast (e.g. for CT scan) The birth of the contrast nephropathy myth Current lack of evidence regarding contrast nephropathy Weighing the risks vs. benefits of using contrast (Renalism) The attention given to contrast nephropathy is insane Intra-arterial contrast...

emcrit.org

A bit reductive but a good argument against agonizing over the use of IV contrast in patients with AKI. The worst outcome from a CT scan isn't an AKI it is a non-diagnostic study.

I tend to tell people "do what you have to do." I can start dialysis if need be, but most of the people you are seeing are sick for other reasons, and they (and their kidneys!) are not getting better without the underlying cause being diagnosed and addressed.

Though I would probably not be as cavalier as that webpage. It is reductive. CIN is real, but it is rare in normal kidney function. It is rare in stable CKD. Loss of residual renal function in ESRD is rare. It is less common with the newer agents. It is less common now with cardiac procedures as interventionalists can really get by with little contrast. It is more likely in the setting of AKI from other cause. Creatinine bump could be more hemodynamically mediated within the kidneys than true damage, but if I see someone who has a contrast study, and creatinine rises 2-3 days after a study, and there is no other obvious cause of kidney injury, and the urine shows granular casts, that is probably going to be called CIN.

It's always hard to tease out in the hospital as patients may have tubular injury from multiple causes. Practically speaking, you're not going to find anyone with ESRD from contrast alone.

 

[chessknt]

I tend to tell people "do what you have to do." I can start dialysis if need be, but most of the people you are seeing are sick for other reasons, and they (and their kidneys!) are not getting better without the underlying cause being diagnosed and addressed.

Though I would probably not be as cavalier as that webpage. It is reductive. CIN is real, but it is rare in normal kidney function. It is rare in stable CKD. Loss of residual renal function in ESRD is rare. It is less common with the newer agents. It is less common now with cardiac procedures as interventionalists can really get by with little contrast. It is more likely in the setting of AKI from other cause. Creatinine bump could be more hemodynamically mediated within the kidneys than true damage, but if I see someone who has a contrast study, and creatinine rises 2-3 days after a study, and there is no other obvious cause of kidney injury, and the urine shows granular casts, that is probably going to be called CIN.

It's always hard to tease out in the hospital as patients may have tubular injury from multiple causes. Practically speaking, you're not going to find anyone with ESRD from contrast alone.

Yep. If I have a pt with sepsis physiology and kidneys in the ****ter and I can't find a source they are going to get contrast because I can't road trip sick people back and forth to the scanner if there is questionable findings that can be better assessed with contrast.

 

[HariboGoldbears]

Contrast induced AKI seems to be a controversial topic right now. I agree that if contrast is needed to make a diagnosis that is treatment plan chaning, we should not be swayed by the patient's Cr.

 

[qxrt]

I'm a radiologist. Specifically, an IR, so I personally inject contrast into patients routinely. I hate how everyone is so afraid of iodinated contrast that many exams that should be performed with contrast are performed without. I hate how I get calls from the ordering doc asking for the radiologist's permission to do a CT angio neck in a trauma case for suspected arterial injury because the patient got a contrast enhanced CT moments before. It's like IV contrast is a boogeyman to many physicians. Just give the damn contrast! I would not be surprised if far more harm was caused by missed diagnoses from lack of IV contrast than contrast ever caused to kidneys.

 

[chessknt]

I'm a radiologist. Specifically, an IR, so I personally inject contrast into patients routinely. I hate how everyone is so afraid of iodinated contrast that many exams that should be performed with contrast are performed without. I hate how I get calls from the ordering doc asking for the radiologist's permission to do a CT angio neck in a trauma case for suspected arterial injury because the patient got a contrast enhanced CT moments before. It's like IV contrast is a boogeyman to many physicians. Just give the damn contrast! I would not be surprised if far more harm was caused by missed diagnoses from lack of IV contrast than contrast ever caused to kidneys.

This is why the true cost of defensive medicine can never be quantified. People are afraid of being sued not of AKI risk.

'Your client, with complete disregard for Mrs. Smith's 87 year old stage IV CKD kidneys, gave her contrast to look for a pulmonary embolus when she was having a COPD attack from smoking and now she is on dialysis. How can you explain this breach of the standard of care where a VQ scan 24 hours later should have been obtained ??!!!ONE!'

 

[turkeyjerky]

I'm a radiologist. Specifically, an IR, so I personally inject contrast into patients routinely. I hate how everyone is so afraid of iodinated contrast that many exams that should be performed with contrast are performed without. I hate how I get calls from the ordering doc asking for the radiologist's permission to do a CT angio neck in a trauma case for suspected arterial injury because the patient got a contrast enhanced CT moments before. It's like IV contrast is a boogeyman to many physicians. Just give the damn contrast! I would not be surprised if far more harm was caused by missed diagnoses from lack of IV contrast than contrast ever caused to kidneys.

Honest Q--how much contrast do you use in a given interventional study or procedure as compared to what's given in a CT?

 

[qxrt]

Honest Q--how much contrast do you use in a given interventional study or procedure as compared to what's given in a CT?

There's such a wide variety of IR procedures that there is no single answer. But some of the more complex or difficult procedures such as some angiography procedures can easily use more contrast than a contrast-enhanced CT.