Clinic risk scores as indicative of contrast nephropathy prophylaxis need

Abstract

Contrast-induced nephropathy is an important cause of acute renal injury in the hospital setting and it is widely documented in patients undergoing exams or procedures with iodinated contrast agents, especially in subgroups at high risk for the disease (chronic kidney disease, cardiac dysfunction, diabetes, among others). A series of prophylactic measures to reduce the incidence of renal damage in these groups is known, the main ones being volume expansion with crystalloid solution and administration of anti-oxidants, such as n-acetyl-cysteine.Recently, however, contrast-induced nephropathy has been questioned in the medical community because of some studies that have shown a low prevalence of renal damage in patients undergoing iodine contrast. These studies, however, were performed in populations with low renal risk, and after medical knowledgement of contrast-induced nephropathy prophylaxis in populations at high risk, which reduces the incidence of the disease. The prophylaxis itself has been questioned by some groups in studies that do not demonstrate a difference in renal injury in patients who have used precautionary measures. Again, these studies were conducted in populations at low risk for contrast-induced nephropathy, making difficult this conclusion.There are clinical risk scores that evaluate the chance of a particular person developing nephropathy induced by iodine contrast, the best known being the Mehran index. There are no studies in the literature that use clinical risk scores to divide patients into high- and low-risk groups by comparing the efficacy of prophylaxis measures for contrast-induced nephropathy in the actual high-risk population.Thus, the objective of the present study is to assess the risk of Mehran's score in hospitalized patients who underwent intravenous iodine contrast over one year at the Hospital das Clínicas, Medical School, University of São Paulo, and to analyze which of them were given nephroprophylaxis measures and which developed contrast-induced nephropathy. It is intended to demonstrate that in patients at high risk, prophylactic measures may be important, unlike what we expect to find in the low-risk population.