Factors affecting the incidence of contrast-induced nephropathy in patients undergoing computed tomography. / Incidencia de nefropatía por contraste en pacientes sometidos a tomografía computarizada: ¿qué factores la condicionan?

OBJECTIVE: To analyze the incidence of contrast-induced nephropathy in a cohort of patients undergoing computed tomography (CT) with intravenous iodinated contrast material. To evaluate the efficacy of N-acetylcysteine in preventing contrast-induced nephropathy. PATIENTS AND METHODS: This prospective observational study was carried out in the months comprising March 2016 through July 2016. We selected the first five patients scheduled to undergo CT examination each day who agreed to participate and signed the informed consent form. We recorded patients' cardiovascular histories, chronic treatments, and indications for the CT examination. We measured blood levels of creatinine and urea before and after the CT examination. We used the Modification of Diet in Renal Disease (MDRD-4) equation to estimate the glomerular filtration rate. We analyzed the type and dose of contrast material. We recorded whether N-acetylcysteine was administered before the CT examination. We used SPSS 15.0® to compare means and proportions. Statistical significance was set at p < 0.05. RESULTS: No incidents of contrast-induced nephropathy were detected in any of the 202 patients included [mean age, 63.92 ± 12 years (range 22-87); 57.4% male; 21.8% diabetic; 39.6% hypertensive; 87.1% had MDRD4 ≥ 60 ml/min/1.73 m2 (89.45 ± 14, range 62.36-134.14) and 12.9% had MDRD4 < 60 ml/min/1.73 m2 (45.38 ± 11, range 9.16-58.90)]. The most common indication for CT examinations was oncologic (81.2%). The only contrast agent administered was iopamidol; the mean dose was 107.83 ± 11 ml (range 70-140). The mean interval between pre-CT and post-CT laboratory tests was 4.06 ± 1 days. Only 13 patients received N-acetylcysteine; 9 of these had MDRD < 60 ml/min/1.73 m2 and 4 had MDRD4 ≥ 60 ml/min/1.73 m2 (p = 0.000). CONCLUSIONS: The incidence of contrast-induced nephropathy was not significant in patients with glomerular filtration rates greater than 30 ml/min/1.73 m2: these favorable results might be due to analyzing only scheduled examinations and to using relatively low doses of a "nonionic" iodinated contrast agent.

[Elderly patients with Chronic Kidney Disease: what is their course at one year?]. / Ancianos con enfermedad renal crónica: ¿Cuál es su evolución al cabo de un año?

INTRODUCTION: Aging is associated to several structural and functional kidney changes. Recently, there is a great interest in the detection of Chronic Kidney Disease (CKD) in the general population. A classification of CKD, based on several stages of the estimated glomerular filtration rate (eGFR), has been established. In this study we followed up, clinically and biochemically, during one year eighty patients older than 65 years so as to ascertain the applicability and utility of such classification to those patients. PATIENTS AND METHODS: 80 clinically stable patients, with a median age of 83 years, recruited within January and April 2006, were followed up during one year. We separated them in two groups: Group 1: 38 patients with serum creatinine pound sterling 1,1 mg/dl (range 0,7-1,1) and with no proteinuria; and Group 2: 42 patients with serum creatinine > or =1.1 mg/dl (range 1,2-3) and with proteinuria <3 grs/24 hours. Clinically we registered morbimortality and treatments received, and biochemically we measured serum creatinine and eGFR at the time of recruitment and after one year of follow up using two equations: Cockroft and abbreviated MDRD. Statistical comparisons were made using the general lineal model for repeated measures of the SPSS 11.0 program. RESULTS: 10% of the patients died during the follow up. Cardiac problems were the kind of morbidity more frequently found. Only a small proportion (23%) of group 2 patients were receiving erythropoietin (EPO) treatment. Estimated GFR and proteinuria remained stable at the end of one year independently of basal GFR; we found no significant differences between groups in the rest of analytical parameters. CONCLUSION: in old patients with no significant proteinuria, the similarity of their clinical evolution and the stability of their eGFR (independently of its basal value), as well as the lack of differences in other analytical parameters, appears not to confer any advantages to the use of mathematical formulae to classified them according to their eGFR.