1/2015 Samuel Lai CONTRAST NEPHROPATHIES

 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 OBJECTIVES

 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? CASE PRESENTATION

 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  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 NEPHROGENIC SYSTEMIC FIBROSIS

NSF PICTURES

 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 CONTINUED

 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 NSF PREVENTION

 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? BACK TO OUR CASE

 What is it?  AKI induced within hours after iodinated contrast  What causes it?  Renal vasoconstriction  Direct tubular cytotoxicity  How do you diagnose it?  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) CONTRAST INDUCED NEPHROPATHY

 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 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 CIN CONTINUED

 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 BACK TO THE CASE

 NSF  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 SUMMARY