Effects on renal haemodynamics and tubular function of the contrast medium Ioxaglate in renal transplant patients

Conflicting and new risk factors for contrast induced nephropathy

PURPOSE

Iodinated contrast medium is commonly used in diagnostic or interventional procedures in uroradiology. Procedures requiring the intravascular administration of iodinated contrast medium are becoming a great source of an iatrogenic disease known as contrast induced nephropathy. Identifying patients at high risk is the first step to minimize the overall risk of contrast induced nephropathy. This review describes conflicting and new risk factors for contrast induced nephropathy.

MATERIALS AND METHODS

A MEDLINE/PubMed search from 1966 to 2006 was performed. All articles related to the use of contrast medium and the risk factors for contrast induced nephropathy were reviewed.

RESULTS

The classic risk factors for contrast induced nephropathy are preexisting renal failure, diabetes mellitus, advanced age, nephrotoxic agent administration, hypovolemia, use of a large amount of contrast medium or an ionic hyperosmolar contrast medium and congestive heart failure. Metabolic syndrome, prediabetes and hyperuricemia have been identified as new risk factors for contrast induced nephropathy. The use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, renal transplantation, diabetes mellitus with normal renal function, low osmolar contrast medium in patients at high risk for contrast induced nephropathy, multiple myeloma, female gender and cirrhosis have been classified as conflicting risk factors for contrast induced nephropathy.

CONCLUSIONS

Patients at risk for contrast induced nephropathy should be identified before urological procedures requiring contrast administration. In addition to the classic risk factors for contrast induced nephropathy, determining the metabolic syndrome, hyperuricemia and prediabetes as well as the use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers before performing procedures using contrast medium seems to be a useful guide to assess the risk of contrast induced nephropathy.

High-risk situations and procedures

With the wider use of imaging and interventional techniques that require the use of iodinated contrast media in seriously ill patients, many clinical situations occur where patients may be at increased risk for contrast-induced nephropathy (CIN). There is little guidance for clinicians in these areas. The aim of this review is to assess the available literature. Acute renal failure is a common complication following coronary artery bypass surgery, and exposure to contrast medium may increase the risk for this condition, although there is insufficient evidence to make a definitive statement. Evidence is also limited for patients with liver disease: in those undergoing transarterial chemoembolization, cirrhosis may be a risk factor for renal failure. There is some evidence that periprocedural hypotension may be a risk factor for CIN after percutaneous coronary intervention, but no published information was identified on the significance of shock or hypotension in other groups of patients. The published evidence on the risk of CIN in renal transplant recipients is inconsistent. In emergency situations, the course of action is usually dictated by clinical circumstances; the renal status of a patient is likely to be unknown and it is important to ensure adequate volume expansion, especially after the procedure. In all clinical situations that are potentially associated with a high risk for CIN, the decision to administer contrast medium is a matter for clinical judgment, based on the clinical status of the patient and the expected benefits of the investigation or procedure.