NCLEX-RNReduction of Risk PotentialMedium
A client with type 2 diabetes and chronic kidney disease is scheduled for a CT scan with IV contrast. The client currently takes metformin. What is the nurse's priority action?
- AAdminister the metformin dose as scheduled before the procedure
- BHold the metformin for 48 hours before and after the contrast study
- CIncrease the metformin dose to prevent hyperglycemia during the procedure
- DSwitch the client to an insulin sliding scale only on the day of the procedure
Show answer & explanationAnswer & explanation
Correct answer: B. Hold the metformin for 48 hours before and after the contrast study
Metformin combined with IV contrast dye increases the risk of contrast-induced nephropathy and lactic acidosis, especially in a client with existing kidney disease. The standard practice is to hold metformin for 48 hours before and after contrast administration until renal function is confirmed stable.
Why the other options are wrong
- A. Giving metformin before contrast increases lactic acidosis risk.
- C. Increasing the dose would further increase toxicity risk.
- D. A full switch to insulin isn't necessary; only the metformin needs to be held temporarily.
Metformin & Contrast Dye Interaction
IV contrast can precipitate acute kidney injury, which combined with metformin increases lactic acidosis risk.
- Hold metformin 48 hours before and after contrast studies
- Check renal function (creatinine/eGFR) before resuming
- Contrast-induced nephropathy risk higher in CKD, diabetes, dehydration
Memory trick: 'Metformin + dye = lactic acid alert' — hold 48 hours.