Renal Function and Iodinated Contrast

Prevent contrast induced nephropathy.

• Hold metformin prior and 2 days after
• Hold diuretics 1 day prior
• hydrate with IV normal saline
• Mucomyst 1200mg IV prior to CT or 600mg PO BID before and after scan, or…
• Bicarb 3ml/kg/hr x 1hr prior and 1ml/kg/hr x 6hrs afterwards (mix 3 amps in 1L of D5 water, bolus 500cc prior to ct, then 100cc per hour until its gone)

Cr less than 1.4 = full dose contrast
Cr 1.5-2.0 = do above.
Cr greater than 2.0 = consider alternative test

ALL patients over 40 years old require BUN and Creatinine check prior to getting IV contrast.

Nephrogenic Systemic Fibrosis

Omniscan (and other Gadolinium-based contrast) contraindicated in patients with severe renal impairment (GFR less than 30), unless benefits cleary out weigh the risks. Strongly consider alternative imaging for moderate renal impairment (if GFR less than 60). Hemodialysis suggested for patients already on dialysis.

http://www.ctisus.com/GE_White_paper_on_NSF.pdf
http://www.radiologytoday.net/archive/rt05072007p12.shtml
http://www.schmidtandclark.com/Gadolinium/Dialysis-Recommended-to-Prevent-NSF-After-Gadolinium-Based-Imaging-in-Severe-Renal-Failure.pdf

Contrast Nephropathy

Acute decline in renal function 24-48 hours after expose to contrast agents. Risk factors:

• Pre-existing renal insufficiency
• Diabetes mellitus
• Decreased effective arterial volume (CHF, dehydration, cirrhosis)
• Patients receiving nephrotoxic drugs (NSAIDS, diuretics)
• High volume of contrast

Prophylaxis:

• IVF 24 hours prior, 12-24 hours post
• For CHF patients, hold diuretics 24 hours prior
• For DM patients, hold metformin 24 hours prior, 48 hours post
• Mucomyst 1200mg IV prior to CT or 600 PO BID before and after scan, or
• Bicarb 3ml/kg/hr x 1hr prior and 1ml/kg/hr x 6hrs afterwards (mix 3 amps in 1L of D5 water, bolus 500cc prior to ct, then 100cc per hour until its gone)

Contrast Allergy

• Symptoms: hives, respiratory, GI
• “Shellfish or ‘iodine allergy’ is not a contraindication to use of IV contrast and does not mandate a pretreatment regimen” ~ eMedicine.

Pre-medicate for non-emergent studies:

• Prednisone 50mg PO 13 hours prior# Prednisone 50mg PO 7 hrs prior# Prednisone 50mg PO + Benadryl 50mg PO/IM 1 hour prior

Emergent studies, administer the following meds and wait 15 minutes.

• 100 mg of Solumedrol I.V.# 50 mg Benadryl I.V.