CKD-EPI 2021 eGFR with contrast / metformin / gadolinium guidance, a steroid premedication scheduler, and breastfeeding guidance.
Renal function — eGFR
CKD-EPI 2021 creatinine equation (race-free).
mg/dL
—mL/min/1.73m²
Steroid premedication
For patients with a prior moderate/severe contrast reaction. Pick a regimen and the scan time.
Set a scan time to generate the schedule.
Breastfeeding after contrast
For a lactating parent asking whether to interrupt nursing. Pick the agent given.
eGFR thresholds (ACR Manual on Contrast Media).
Routine IV iodinated contrast in outpatients with eGFR ≥ 30 carries very low AKI risk and needs no special prophylaxis.
At eGFR < 30 (or AKI), weigh benefit vs. risk and consider IV volume expansion.
Metformin: no need to withhold if eGFR ≥ 30 and no AKI; withhold at the time of contrast and for 48 h if eGFR < 30, AKI, or the study is on the renal arteries / arterial study with possible emboli, then resume after renal function is confirmed stable.
Gadolinium (GBCA): group II agents (e.g., gadoterate, gadobutrol, gadobenate) carry very low NSF risk at any eGFR; group I agents are contraindicated at eGFR < 30.
Premedication. Elective (Greenberger): prednisone 50 mg PO at 13, 7 and 1 h before contrast + diphenhydramine 50 mg 1 h before.
Accelerated IV (urgent only, unproven benefit): methylprednisolone 40 mg IV (or hydrocortisone 200 mg IV) every 4 h until contrast + diphenhydramine 50 mg IV 1 h before; aim for ≥ 4–6 h of pretreatment when possible.
Breastfeeding. Patients may continue breastfeeding without interruption after both iodinated and gadolinium contrast; pump-and-dump is not required. Estimated infant dose < 0.01% of the maternal IV dose for iodinated agents; for gadolinium < 0.04% is excreted into milk in 24 h and < 1% of that is absorbed.
Reference only — not a substitute for clinical judgment or your local contrast policy. Based on the ACR Manual on Contrast Media.