Question: At what creatinine level is it unsafe to give Gadolinium contrast in patients with kidney disease? Can dialysis prevent the complications?
Gadolinium based contrasts are widely used for MRI and until recently were considered relative nontoxic and a good alternative to iodinated contrast agents, especially in patients with kidney disease. However in the last few years, there has been a lot of literature indicating that gadolinium exposure causes a dermal fibrosing condition called ‘Nephrogenic Systemic Fibrosis’ (NSF). It first affects the skin as dermal hardening with tethering to deep dermal tissues giving the skin a wooden texture. These patients typically present with skin tightness, pruritus, arthralgias, and myalgias in affected areas. In advanced cases, it can lead to debilitating joint catractures and also involve skeletal muscle, bone, lungs, pleura, pericardium, myocardium, renal tubules, and dura mater. Diaphragmatic or pulmonary fibrosis may be implicated in respiratory failure and may cause features of restrictive lung disease. Interestingly all cases of NSF have been reported in patients having kidney disease, with nearly 80% in patients with ESRD on dialysis, and the rest with AKI, Stage 4 and stage 5 CKD. There seems to be little or no risk for patients with stages 1 through 3 CKD and patients with normal kidney function have no risk for NSF. The diagnosis is made on the basis of clinical findings, advanced renal dysfunction and temporal association with gadolinium exposure. Skin biopsy can be done to support the diagnosis.
There is no specific therapy for preventing or treating NSF. It has been found that in some cases, NSF improved with return of kidney function to normal. Studies have shown that 68% of gadolinium is eliminated after a 3-hour dialysis session and approximately 98% could be removed after three consecutive dialysis sessions. So intuitively, it would make sense to initiate dialysis in such patients after gadolinium exposure. But, most of the available evidence suggests that dialysis is not effective in preventing gadolinium-induced contrast injury. The reason behind this could be, that the Gd3+ ion dissociated from the parent dye compound deposits in tissue within dialysis-inaccessible compartment.
Bottomline:
1.Gadolinium should be avoided in patients with Stage 4-5 CKD (GFR under 30ml/min) , AKI and ESRD patients.
2.In patients, who absolutely need the imaging, informed consent should be obtained explaining the risk-benefit profile.
3.Contrast exposure should be minimal and preferably chelated gadolinium compounds (Gadoteridol in USA) , should be used.
4. Consider performing hemodialysis after the exposure (and the next 2 days) in patients who are already maintained on hemodialysis, recognizing that there are no data that support prevention of NSF with this modality.
If you want to read more, here are the links to two articles at CJASN and Nephrology Rounds
