Karen Nicolas, MD
Head of Radiology Division, MEIH
The diabetic patient needs a special handling during any appointment in Radiological department.
Patients with diabetes have a priority for an early appointment. Antidiabetic medication should not be taken in the morning before the exam to minimize the risk of hypoglycemic crises because of fasting.
Iodinated Contrast Injection And Renal Damage (Nephro-Toxicity)
If the creatinine level in the blood is within normal limits, the radiological exam with contrast injection can be done. If the creatinine value shows a slight increase above normal limits, the patient has to be prepared for the injection, meaning that he/she will have to increase the intake of liquids in order to hyper hydrate the kidneys and to accelerate the filtration rate of the kidney. This will speed up the elimination of the contrast agent after injection.
In longstanding diabetic conditions, progressive narrowing of the microcirculation vessels may lead to an impaired renal function.
CT-Scan, urography, angiography or other radiological investigations may require the intravenous injection of contrast material. If the patient has an impaired renal function, the contrast agent may increase the renal dysfunction. Therefore a blood test for the creatinine level is required before any injection. The creatinine is the most easily accessible indicator of renal function.
There is a widely accepted consensus that a creatinine level of 2mg/dl represents the cut-off value that contraindicates injection of iodinated contrast agents, except in several emergency cases.
In any case an increased fluid intake for 12 to 24 hours after the exam is recommended to every person after injection of iodinated contrast.
The oral antidiabetics of the metformin group have to be suspended the day of the exam and the following two days, because they may contribute to renal damage by the contrast agent. (This will be indicated to the patient depending on his medication).
If all these recommendations are respected, any radiological diagnostic procedure should not alterate renal function.
Longstanding diabetes has an impact on the various systems of the body defense. Patients and doctors must be aware that classical manifestations of various pathologies could be altered or even silent in a diabetic patient. This represents a continuous challenge for their diagnostic work up.