Renal oxygen content is increased in healthy subjects after angiotensin-converting enzyme inhibition

OBJECTIVE: The association between renal hypoxia and the development of renal injury is well established. However, no adequate method currently exists to non-invasively measure functional changes in renal oxygenation in normal and injured patients. METHOD: R2* quantification was performed using renal blood oxygen level-dependent properties. Five healthy normotensive women (50±5.3 years) underwent magnetic resonance imaging in a 1.5T Signa Excite HDx scanner (GE Healthcare, Waukesha, WI). A multiple fast gradient-echo sequence was used to acquire R2*/T2* images (sixteen echoes from 2.1 ms/slice to 49.6 ms/slice in a single breath hold per location). The images were post-processed to generate R2* maps for quantification. Data were recorded before and at 30 minutes after the oral administration of an angiotensin II-converting enzyme inhibitor (captopril, 25 mg). The results were compared using an ANOVA for repeated measurements (mean + standard deviation) followed by the Tukey test. ClinicalTrials.gov: NCT01545479. RESULTS: A significant difference (

Fluid overload and changes in serum creatinine after cardiac surgery: predictors of mortality and longer intensive care stay. A prospective cohort study

Introduction: Fluid overload is a clinical problem frequently related to cardiac and renal dysfunction. the aim of this study was to evaluate fluid overload and changes in serum creatinine as predictors of cardiovascular mortality and morbidity after cardiac surgery.Methods: Patients submitted to heart surgery were prospectively enrolled in this study from September 2010 through August 2011. Clinical and laboratory data were collected from each patient at preoperative and trans-operative moments and fluid overload and creatinine levels were recorded daily after cardiac surgery during their ICU stay. Fluid overload was calculated according to the following formula: (Sum of daily fluid received (L) - total amount of fluid eliminated (L)/preoperative weight (kg) x 100). Preoperative demographic and risk indicators, intra-operative parameters and postoperative information were obtained from medical records. Patients were monitored from surgery until death or discharge from the ICU. We also evaluated the survival status at discharge from the ICU and the length of ICU stay (days) of each patient.Results: A total of 502 patients were enrolled in this study. Both fluid overload and changes in serum creatinine correlated with mortality (odds ratio (OR) 1.59; confidence interval (CI): 95% 1.18 to 2.14, P = 0.002 and OR 2.91; CI: 95% 1.92 to 4.40, P <0.001, respectively). Fluid overload played a more important role in the length of intensive care stay than changes in serum creatinine. Fluid overload (%): b coefficient = 0.17; beta coefficient = 0.55, P <0.001); change in creatinine (mg/dL): b coefficient = 0.01; beta coefficient = 0.11, P = 0.003).Conclusions: Although both fluid overload and changes in serum creatinine are prognostic markers after cardiac surgery, it seems that progressive fluid overload may be an earlier and more sensitive marker of renal dysfunction affecting heart function and, as such, it would allow earlier intervention and more effective control in post cardiac surgery patients.Fundacao Univ Cardiol IC FUC, Inst Cardiol Rio Grande Sul, Intens Care Unit, BR-90620001 Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Med, Div Nephrol, BR-04021001 São Paulo, BrazilHeart Inst INCOR, Hypertens Unit, BR-05403900 São Paulo, BrazilNove de Julho Univ, Med Pos Grad Program, BR-01504001 São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Med, Div Nephrol, BR-04021001 São Paulo, BrazilWeb of Scienc

Renal oxygen content is increased in healthy subjects after angiotensin-converting enzyme inhibition

OBJECTIVE: the association between renal hypoxia and the development of renal injury is well established. However, no adequate method currently exists to non-invasively measure functional changes in renal oxygenation in normal and injured patients.METHOD: R2(star) quantification was performed using renal blood oxygen level-dependent properties. Five healthy normotensive women (50 +/- 5.3 years) underwent magnetic resonance imaging in a 1.5T Signa Excite HDx scanner (GE Healthcare, Waukesha, WI). A multiple fast gradient-echo sequence was used to acquire R2(star)/T-2(star) images (sixteen echoes from 2.1 ms/slice to 49.6 ms/slice in a single breath hold per location). the images were post-processed to generate R2(star) maps for quantification. Data were recorded before and at 30 minutes after the oral administration of an angiotensin II-converting enzyme inhibitor (captopril, 25 mg). the results were compared using an ANOVA for repeated measurements (mean +/- standard deviation) followed by the Tukey test. ClinicalTrials.gov: NCT01545479.RESULTS: A significant difference (p<0.001) in renal oxygenation (R2(star)) was observed in the cortex and medulla before and after captopril administration: right kidney, cortex = 11.08 +/- 0.56ms, medulla = 17.21 +/- 1.47ms and cortex = 10.30 +/- 0.44ms, medulla = 16.06 +/- 1.74ms, respectively; and left kidney, cortex = 11.79 +/- 1.85ms, medulla = 17.03 +/- 0.88ms and cortex = 10.89 +/- 0.91ms, medulla = 16.43 +/- 1.49ms, respectively.CONCLUSIONS: This result suggests that the technique efficiently measured alterations in renal blood oxygenation after angiotensin II-converting enzyme inhibition and that it may provide a new strategy for identifying the early stages of renal disease and perhaps new therapeutic targets.Fundacao Univ Cardiol IC FUC, Inst Cardiol Rio Grande do Sul, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilServ Invest Diagnost SIDI, Porto Alegre, RS, BrazilMR Res Latin Amer GE Healthcare, São Paulo, BrazilUFCSPA, Dept Ciencias Basicas Saude, Porto Alegre, RS, BrazilUniv São Paulo, Fac Med, Hosp Clin, Inst Coracao InCor USP, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilWeb of Scienc

Successful management of acute renal failure after high-dose methotrexate in a patient with relapsed osteosarcoma

High-dose methotrexate (MTX) is frequently included in the treatment of osteosarcoma [1]. Following intravenous high dosages, approximately 50 to 60% of this drug is bound to plasma proteins and more than 50% of MTX is excreted unchanged in the urine [2]. The most common side effects of MTX are mucositis of varying degrees and liver toxicity. Leukopenia, thrombocytopenia, severe mucositis, diarrhea, skin rash or renal dysfunction are not usually observed if prevention based on hydration and urine alkalization are adequately administrated [2, 3]. The reported incidence of acute renal failure (ARF) due to MTX is about 1.8% [4]. The mechanism of renal damage seems to be the intratubular precipitation of crystals produced by MTX and the consequence is usually a persistence of high serum levels of the drug [5]. The aim of this report is to describe the management of a patient who developed ARF following high dose MTX administration