Iodinated Imaging Contrast Media and GFR
Chapter: Contrast Media
Policy Number: RAD 17
Publication Date: December 18, 2015
The decision to use iodinated ICM must be based on an assessment of the patient’s health status, with particular attention to renal function. In cases of compromised renal function, a CIN prophylaxis protocol may be used.
To define guidelines evaluating patient renal function prior to iodinated ICM administration and define protocol for pre-hydration
Contrast-induced nephropathy (CIN): A sudden deterioration in renal function following the recent administration of iodinated ICM in the absence of another nephrotoxic event.
Estimated Glomerular Filtration Rate (eGFR): Calculated assessment of renal function based on laboratory testing (serum creatinine) and patient age, gender, and race.
Imaging Contrast Media (ICM): radiographic iodinated contrast compounds administered intravascularly for medical imaging purposes.
All patients, except as defined by the exception below, should have renal function assessed prior to the administration of iodinated ICM. If eGFR is required:
- The eGFR value must be obtained within 30 days of iodinated ICM administration AND
- The patient must not have had an intervening major illness or change in medication since the time of the eGFR test
Exceptions to eGFR testing requirement:
- Patient’s age is <60 and there is no history of:
- Renal disease, including insufficiency, prior dialysis treatment, transplant, single kidney, renal tumor, or renal surgery
- Hypertension requiring medical therapy
- Diabetes mellitus
- Recent episode of acute hypotension / sepsis
- Diuretic medication
- Emergent studies may be performed without prior eGFR testing if deemed necessary by the referring Attending Physician and/or the Radiologist. The name of the authorizing physician should be noted on the contrast pre-screening form. Renal function testing in these patients is preferred but may not be possible due to the urgency of the test.
For Non-Dialysis patients:
- eGFR ≥ 45 Patient may receive iodinated ICM
- 30 ≤ eGFR < 45 Renal impairment; review study for indications, reduce iodinated ICM dose if possible within the constraints of the required examination, switch to non-contrast imaging alternatives if feasible. Check with radiologist (or other physician overseeing the medical imaging procedure) for decision regarding administration of iodinated ICM. In general, these patients should only receive iodinated ICM if necessary. If iodinated ICM is deemed medically necessary, CIN prophylaxis (see below) may be arranged prior to administration.
- eGFR < 30 Renal consult should be strongly considered, and CIN prophylaxis (see below) should be performed prior to administration of iodinated ICM, unless the study is deemed emergent.
Patients on Hemodialysis:
- Patients with anuric end-stage renal disease may receive intravenous contrast without risk of further renal damage because the kidneys are no longer functioning. Nephrology may be consulted to confirm anuric status and to consider the need for urgent hemodialysis following contrast administration if there is concern about the theoretical possibility of complications from the osmotic load of the contrast itself.
- Patients with end-stage renal disease who have residual urine output should be treated with extreme caution and managed in conjunction with Nephrology.
Patients on Metformin or Metformin-containing Medications:
- Check for use of metformin (Glucophage®) or other metformin-containing medications. Patients on metformin may receive iodinated ICM as per above but if they have pre-existing renal insufficiency (eGFR<45) should hold the medication for 48 hours following the contrast procedure and resume only after repeat renal function testing and approval from the referring physician.
CIN Prophylaxis Protocol:
- Although the major preventative action against CIN is adequate hydration, there is no compelling evidence to support the use of any particular hydration protocol. The protocols offered below are suggested options.
- For all patients:
- Consider holding diuretics (e.g., furosemide [Lasix], HCTZ, spironolactone) on the day prior and the day of the examination if clinically appropriate
- Discontinue potentially nephrotoxic medications 24 hours prior to the use of contrast if clinically appropriate, resuming after renal function testing. These medications include non-steroidal anti-inflammatory agents (NSAIDs), ACE Inhibitors, angiotensin receptor blockers, cisplatin-based chemotherapy agents, and aminoglyoside antibiotics.
- Encourage oral hydration before, during, and after the administration of contrast.
- CIN Prophylaxis Hydration Protocol suggestions, which may be altered or modified based on the clinical situation:
- Inpatient setting:
- Protocol 1: Sodium Bicarbonate (NaHCO3) solution [150Meqof NaHCO3 to 1L of 5% dextrose in H2O] administered IV 3ml/kg 1hr prior to the procedure, at 1mL/kg during the procedure, and 1mL/kg per hour for 6h after the procedure.
- Protocol 2: 0.9% sodium chloride at 100 ml/hr, beginning 6 to 12 hours before and continuing 4 to 12 hours after iodinated ICM administration.
- Outpatient setting:
- Protocol 1: Sodium Bicarbonate (NaHCO3) solution 150Meq of NaHCO3 to 1L of 5% dextrose in H2O] administered IV 3ml/kg 1hr prior to the procedure, at 1mL/kg during the procedure, and 1mL/kg for 1h after the procedure.
- Protocol 2: Sodium Chloride 0.9% 250ml IV before and after the procedure.
- Protocol 3: Sodium Chloride 0.9% 100-200ml/hr for 2-3 hours prior to the procedure and 100-200ml/hr for 1 hour after the procedure.
- Inpatient setting:
- If available, Acetylcysteine (Mucomyst) 600mg PO BID day before and day of exam may be administered but is of uncertain benefit.
- Patient history and clinical assessment should guide use and modifications of this protocol, specifically to avoid the possibility of pulmonary edema.
- If a recent serum carbon dioxide level is available and exceeds 26 mmol/L, then the hydration protocol may be altered to utilize normal saline instead of sodium bicarbonate solution.
- Follow up renal function testing (serum BUN, creatinine, eGFR) may be ordered 48-72 hours after the exam and the results should be checked by the ordering physician.
American College of Radiology (ACR) Contrast Manual Version 10.3 (2017)
Review and Approval
The following Steward Health Care personnel originated and approved this policy:
|Approved by||Steward Health Care System – Radiology Enterprise Group, Steward Clinical Excellence Committee|
|DCN: For office use only||7/15/2016 10:46:57 AM 3 C 2|