CONTRAST
NEPHROPATHIES
1/2015
Samuel Lai
OBJECTIVES
 Understand the interaction between iodine, gadolinium and
CKD
 Know how to diagnose both contrast -induced nephropathy
(CIN) and nephrogenic systemic fibrosis (NSF)
 Know prevention options for CIN and NSF
CASE PRESENTATION
 55 y/o female with CKD Stage IV ( eGFR 15-29), DM II and HTN
presents with new onset L sided paralysis. She is admitted to
medicine after a CT Head Non -Contrast in the ED ruled out a
hemorrhagic stroke
 LABS: eGFR 20, Cr 2.3 (both at baseline)
 Neurology consult recommends an MRI/MRA Head/Neck with
and without contrast to rule out an ischemic stroke
 What should you be concerned about?
NEPHROGENIC SYSTEMIC FIBROSIS
 What is it?
 Thickening/hardening of skin, especially extremities and trunk
 Dermal fibrosis with CD 34+ fibrocytes
 2 to 18 months after gadolinium exposure
 Clinical Findings
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Symmetrical, bilateral, indurated papules
Possible erythema
Lower legs and forearms, most commonly
Systemic Symptoms
 Fibrosis of lungs (ILD-like picture), myocardium, pericardium and pleura
 Sclerodactyly, hyperpigmentation, epidermal atrophy
 Similar to scleroderma or scleromyxedema
NSF PICTURES
NSF PICTURES
NSF CONTINUED
 What causes it?
 Tissue deposition of gadolinium
 Activation of macrophages and fibroblasts
 Possible direct stimulation of bone marrow fibroblasts by gadolinium
 How do I diagnose it?
 Temporal relationship with gadolinium usage in CKD patient
 Punch biopsy of dermis
 Looking for CD34+ fibroblasts
NSF PREVENTION
 Who should avoid gadolinium?
 Patients with eGFR < 30 mL/min, dialysis or AKI should avoid
gadolinium
 What if I need to do use gadolinium anyway?
 Gadodiamide (Ominscan), Gadoversetamide (OptiMARK) and
Gadopentate (Magnevist) should be avoided
 Try Gadoteridol, Gadobutrol, Gadoterate
 Or ask your friendly radiologist!
 If HD access present, would dialyze within hours and repeat in 24h
 If no HD access?
 And eGFR < 15? Would initiate HD
 Otherwise, have a risk/benefit discussion about placing HD access
BACK TO OUR CASE
 You tell Neurology about the risk of NSF in this patient. The
consult resident says, “Oh wow, you’re right! I forgot about
that mini-lecture on the UCI website.”
 “Let’s get a CTA of her head/neck in about one week to see if
she had an ischemic stroke”
 What should you be concerned about?
CONTRAST INDUCED NEPHROPATHY
 What is it?
 AKI induced within 24-48 hours after iodinated contrast
 What causes it?
 Renal vasoconstriction
 Direct tubular cytotoxicity
 How do you diagnose it?
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60% patients oliguric with AKI symptoms (Hyper K and Ph, Acidosis)
FeNa generally < 1%, signaling pre-renal etiology
UA = ATN picture (muddy brown casts, epithelial casts)
Rule out other causes of AKI
Consider renal biopsy (however, CIN generally resolves quickly)
CIN CONTINUED
 How do I prevent this?
 At Risk Pts: Cr > 1.5 mg/dL or eGFR < 60 mL/min
 Utilize non-ionic, low or iso-osmolar agents (iopamidol)
 Ask your friendly radiologist!
 Use minimal contrast and space out studies (> 48 hours)
 Avoid nephrotoxic meds (NSAIDs) and hypovolemia
CIN CONTINUED
 FLUIDS
 Saline vs. Bicarbonate vs. NAC (not well established)
 Isotonic Saline
 1 mL/kg for six to twelve hours prior and post procedure or
 3 mL/kg one hour before and 1-1.5 ml/kg four to six after
 Isotonic Bicarbonate (3 AMPs of bicarb into 850 mL of sterile water)
 3 mL/kg one hour prior and 1 mL/kg six hours post procedure
 N-acetylcysteine (controversial)
 1200 mg PO BID the day before and day of procedure
CIN CONTINUED
 How about hemodialysis/hemofiltration?
 In patients with CKD Stage III to V, no benefit with hemodialysis
 Also, no need to dialyze in patients who are HD -dependent
 No studies support this
 What do I do if my patient gets CIN?
 Supportive care, which is expected to resolve in 3 -7 days regardless
of intervention
BACK TO THE CASE
 What should we do for our 55 y/o lady?
 If an ischemic stroke must be ruled out, need to discuss with patient
the risks/benefits of both studies
 Remember:
 NSF: recommendation is post-gadolinium HD, requiring access
 CIN: recommendation is IV Fluids +/- NAC and supportive care
 Initiate other risk-modifying treatments
 Lipid, Diabetes and HTN control
SUMMARY
 NSF
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High-risk if eGFR < 30 mL/min, AKI or on dialysis
Prevention = avoid types of gadolinium
Along with post-gadolinium dialysis if access already present
Consider initiating HD if eGFR < 15 mL/min
 CIN
 High risk if Cr > 1.5, eGFR < 60 mL/min or AKI
 Prevention = Fluids (Saline, Bicarbonate) and/or NAC
 Supportive care otherwise