Luis Yu

Risk Factors for Development of Acute Renal Failure After Liver Transplantation

Background. Acute renal failure (ARF) is a common complication after liver transplantation (LTx). Identification of risk factors may prevent the development and attenuate the impact of ARF on patients outcome after LTX. Methods. Retrospective analysis of variables in the pre, intra, and postoperative periods of 92 patients submitted to LTx was performed in order to identify risk factors for development of ARF after LTx. ARF was defined as serum creatinine ≥2.0 mg/dL in the first 30 days after LTx. Univariate and multivariate analysis by logistic regression were performed. Results. ARF group comprised 56 patients (61%). Preoperative serum creatinine was higher in ARF group. During the intraoperative period, ARF group required more blood transfusions, developed more episodes of hypotension and presented longer anesthesia time. In the postoperative period, ARF group presented higher serum bilirubin and more episodes of hypotension. Dialysis was required in 10 patients (11%). The identified risk factors for development of ARF were: preoperative serum creatinine >1.0 mg/dL, more than five blood transfusions in the intraoperative period, hypotension during intra and postoperative periods. The identified mortality risk factors were hypotension in the postoperative period and no recovery of renal function after 30 days. Conclusions. Several factors are involved in the pathogenesis of ARF after LTx and may influence patients outcome and mortality. Pretransplant renal function and hemodynamic conditions in the operative and postoperative periods were identified as risk factors for development of ARF after LTx. Nonrenal function recovery and postoperative hypotension were identified as mortality risk factors after LTx.

Mycophenolate Mofetil Attenuates Renal Ischemia/Reperfusion Injury

Immunosuppressive agents may have an impact on ischemia/reperfusion (I/R) injury. The immunosuppressant mycophenolate mofetil (MMF) presents properties that can attenuate such injury. This study investigated the effects of MMF on renal I/R injury. Male Wistar rats received MMF (20 mg/kg per d) or vehicle by gavage beginning 2 d before ischemia and maintained during the entire study. Ischemic injury was induced by bilateral renal arteries occlusion for 60 min. Control rats received MMF and underwent sham operation. At days 1, 2, and 14, post-ischemia renal function was assessed and kidneys were removed for histologic and immunohistochemical studies. MMF given to nonischemic rats did not alter renal function. There was no functional protection at 24 h post-ischemia with MMF. At 2 d, post-ischemia rats pretreated with MMF presented higher inulin clearance compared with untreated rats (0.42 +/- 0.04 versus 0.15 +/- 0.02 ml/min per 100 g; P < 0.001) and attenuated renal blood flow decrease (5.23 +/- 0.28 versus 3.24 +/- 0.37 ml/min; P < 0.01). The immunostaining for intercellular adhesion molecule-1 (ICAM-1) was less intense in rats pretreated with MMF. These rats also presented an earlier decreased infiltrating macrophages/lymphocytes and cell proliferation at day 1 post-ischemia. The functional and immunohistochemical analyses performed at day 14 post-ischemia returned to values similar to controls in both groups of rats. To determine whether mycophenolic acid (MPA) could induce cytoprotection, the effects of MPA on normoxic and hypoxic/reoxygenated (H/R) isolated tubule suspensions were also investigated. MPA was not deleterious to normoxic tubules and it was not protective against H/R tubules. In conclusion, pretreatment with MMF attenuates I/R injury in rats and does not limit the recovery from ischemia. The protective effect of MMF by reducing inflammation precedes the hemodynamic changes and tubular injury.

Epidemiology of Acute Kidney Injury in Latin America

There is little reliable information on the epidemiology of acute kidney injury (AKI) in Latin America. It is generally assumed that AKI in the developing world affects mainly young and previously healthy people, with an etiologic spectrum relying on particular socioeconomic and environmental conditions. Transmissible diseases such as leptospirosis, malaria, dengue, diarrhea, among others, are recognized as important causes of AKI in these areas. On the other hand, in large cities and university hospitals in Latin American, the AKI spectrum is similar to that seen in developed countries. Large studies are needed to improve our knowledge to design preventive strategies for this potentially lethal disease that affects all population subgroups, from the socially and economically vulnerable to the wealthy. In this article the available information regarding AKI epidemiology in Latin America is reviewed. Data obtained by the Latin American Acute Renal Failure Commission from the Latin American Society of Nephrology through surveys performed in 1997, 2000, and 2004 are reported. Finally, 3 particular medical conditions frequently associated with AKI in Latin America are reviewed.

Snakebite-Induced Acute Kidney Injury in Latin America

There are 4 genera of venomous snakes in Latin America: Bothrops, Crotalus, Lachesis, and Micrurus. Acute kidney injury (AKI) has been reported consistently after Bothrops and Crotalus envenomations. In fact, these 2 genera of snakes are responsible, along with the Russells viper, for the majority of cases of snakebite-induced AKI reported worldwide. Although the Bothrops snakes are the leading cause of venomous snakebites in Latin America, the absolute number of AKI cases seen after Bothrops and Crotalus snakebites is similar. In this article the main characteristics of Bothrops and Crotalus snakes and their venoms, the clinical picture, and the pattern of accidents, risk factors, and mechanisms of renal injury are reviewed.

Mortality Risk Factors and Validation of Severity Scoring Systems in Critically Ill Patients with Acute Renal Failure

Background. Risk stratification and prediction of outcome in acute renal failure patients in the intensive care unit are important determinants for improvement of patient care and design of clinical trials. Methods. In order to identify mortality risks factors and validate general and specific predictive models for acute renal failure (ARF) patients in the intensive care unit (ICU), 324 patients were prospectively evaluated. Multivariate analysis by logistic regression was utilized for identification of mortality risk factors. Discrimination and calibration were used to evaluate the performance of the following models at referral to nephrologist and at initiation of renal replacement therapy: APACHE II, SAPS II, LODS, and ATN-ISI. Organ failure was assessed by SOFA and OSF. Results. The hospital mortality rate was 85%. The identified mortality risk factors were: age ≥ 65 yr, BUN ≥ 70 mg/dL, ARF of septic origin, and previous hypertension. Serum creatinine ≥ 3.5 mg/dL, systolic blood pressure ≥ 100 mm Hg, and normal consciousness were associated with mortality risk reduction. Performance of all prognostic models was disappointing with unsatisfactory calibration and underestimation of mortality on the day of referral to the nephrologist and at initiation of renal replacement therapy. Conclusions. Cross-validation of prognostic models for ARF resulted in poor performance of all studied scores. Therefore, a specific model is still warranted for the design of clinical trials, comparison of studies, and for prediction of outcome in ARF patients, especially in the ICU.

Anuric Acute Renal Failure Caused by Dextran 40 Administration

Dextran 40 is largely used in clinical medicine as a plasma substitute because of its beneficial effects on the microcirculation and antithrombogenic properties. An unusual adverse reaction of dextran administration is oligoanuric acute renal failure. We report two cases of anuric ARF induced by dextran 40. Diuresis and renal function were quickly resumed after plasma-pheresis treatment. Renal biopsy revealed normal kidneys except for swelling and vacuolation of renal tubules suggestive of osmotic nephrosis.

Positive fluid balance is associated with reduced survival in critically ill patients with cancer

There are no studies that describe the impact of the cumulative fluid balance on the outcomes of cancer patients admitted to intensive care units ICUs. The aim of our study was to evaluate the relationship between fluid balance and clinical outcomes in these patients.

Performance of the third generation models of severity scoring systems (APACHE IV, SAPS 3 and MPM-III) in acute kidney injury critically ill patients

BACKGROUND Severity scores are useful to guarantee similar disease severity among groups in clinical trials and to enable comparison between different studies. The aim of this study was to assess the performance of the third generation models of severity scoring systems [simplified acute physiology score (SAPS) 3, acute physiology and chronic health evaluation (APACHE) IV and mortality probability model (MPM)-III] in acute kidney injury (AKI) patients in the intensive care unit (ICU). METHODS Three hundred and sixty-six consecutive AKI critically ill patients were prospectively assessed in six ICUs of an academic tertiary care center. Scores were applied on AKI diagnosis day (DD) and on the day of nephrology consultation (NCD). Discrimination was assessed by area under the receiver operating characteristic curve (AUCROC) and calibration by Hosmer-Lemeshow (HL) goodness-of-fit test. RESULTS Hospital mortality rate was 67.8%. SAPS 3 general and Central and South America (CSA) customized equations presented identical good discrimination (AUCROC curve: 0.80 on NCD) and satisfactory HL tests on both analyzed days (P > 0.100). CSA SAPS 3 equation predicted mortality more accurately [standardized mortality ratio (SMR) on NCD = 1.00 (95% confidence interval (CI) 0.84-1.34)]. APACHE IV and MPM-III scores presented similar discrimination compared to SAPS 3 on both analyzed days (P > 0.05). APACHE IV presented satisfactory HL tests over time (P > 0.100) but underestimated mortality [SMR on DD = 1.92 (95% CI 1.61-2.23); SMR on NCD = 1.46 (95% CI 1.48-1.96)]. MPM-III showed unsatisfactory HL test results (P = 0.027 on DD; P = 0.045 on NCD) and underestimated mortality [SMR on NCD = 2.09 (95% CI 1.48-1.96)]. CONCLUSIONS SAPS 3, especially the geographical customized equation, presented good discrimination and calibration performances, accurately predicting mortality in this group of AKI critically ill patients.

Impact of mild acute kidney injury (AKI) on outcome after open repair of aortic aneurysms.

Recently, mild AKI has been considered as a risk factor for mortality in different scenarios. We conducted a retrospective analysis of the risk factors for two distinct definitions of AKI after elective repair of aortic aneurysms. Logistic regression was carried out to identify independent risk factors for AKI (defined as

Biopsy Proven Acute Tubular Necrosis Due to Rhabdomyolysis in a Dengue Fever Patient: a Case Report and Review of Literature

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