Continuous veno-venous hemodiafiltration in children after cardiac surgery

Objective: Acute renal failure (ARF) is still a frequent complication following extensive cardiac surgery. Renal replacement therapy (RRT) modality preferences to treat critically ill children have shifted from peritoneal dialysis to continuous renal replacement therapy (CRRT), although the experience with the latter is still highly limited in the infants. Methods: We describe our results with continuous veno-venous hemodiafiltration (CVVHDF) in 25 children (15 males, 10 females) who underwent CRRT from 2001 to 2006 and were retrospectively reviewed. Results: We performed continuous veno-venous hemodiafiltration (CVHDF) using PRISMA (Hospal). The mean age at the onset of CRRT was 26 months (ranging from 7 days to 11.2 years) and the mean body weight was 14 kg. The mean duration of RRT was 67 h (8–243 h) with ultrafiltration rate 4.9 ml/(h kg); the mean filter ‘lifetime’ was 31.5 h. Anticoagulation was achieved with non-fractioned heparin infusion (21/25 cases) and enoxaparin (2/16). The mean creatinine concentrations at the beginning, 24, 48 and 72 h were as follows: 171, 100, 65 and 88 μmol/l. Of these 25 treated children, 19 died in the postoperative period (8 during CVVHDF). The mortality rate for the entire group was 76%. The main cause of death was cardiac failure and sepsis with multiorgan dysfunction (MODS). The main complication during CRRT was bleeding, transient hypothermia, thrombocytopenia and filter clotting which occurred in about one-third of the patients. Conclusions: We conclude that CVVHDF may be an alternative method of renal support for critically ill children after cardiac surgery in experienced centers, but a significant number of specific complications should be taken into account.     

Continuous veno-venous hemodiafiltration using bicarbonate dialysate

We report our experience with 11 children treated by continuous veno-venous hemodiafiltration. The median age was 5.0 years (range 3 days to 14 years). Access was via dual-lumen subclavian or femoral vein catheters. Hemofilters were chosen on the basis of patient size and dialysis requirements. Bicarbonate-buffered dialysis solution was prepared shortly before use by supplementation of a specially prepared base solution with commercially available electrolyte solutions. The mean ultrafiltration rate was 37.4±27 ml/kg body weight per hour. Urea and creatinine clearances were 15.1±6.4 ml/kg body weight per min and 16.4±8.4 ml/kg body weight per min, respectively. Metabolic acidosis was readily controlled in all patients. Of the 11 patients, 7 ultimately recovered normal renal function. Received August 3, 1995; received in revised form February 19, 1997; accepted March 13, 1997     

Safety of perioperative hemodialysis and continuous hemodiafiltration for dialysis patients with cardiac surgery

Objective We have routinely used postoperative continuous hemodiafiltration (CHDF) combined with intraoperative hemodialysis (IHD) for dialysis patients undergoing open-heart surgery. This perioperative management could avoid any limitation of potassium concentration in the cardioplegic solution, strict restriction of fluid administration, or blood transfusion. Methods To evaluate the safety of this strategy, 22 dialysis patients who underwent open-heart surgery (Dialysis Group) were retrospectively compared with 30 patients with normal renal function selected from the same time period with rigorously matched clinical characteristics such as age, gender, and operative procedures (Matched Group). Results No significant difference was found in the operative variables such as the operative procedures, cardiopulmonary bypass time, and aortic cross-clamp time in both groups. There were two deaths (9.1%) in the Dialysis Group compared with Matched Group (0%). In the Dialysis Group, the levels of serum potassium and creatinine were well controlled in the perioperative period with a mean duration of IHD and CHDF of 243.7 ± 60.6 min and 2.7 ± 1.1 days, respectively. In particular, no significant difference between intraoperative and postoperative levels of serum potassium was observed in the Dialysis Group (P = 0.09), whereas there was a significant increase in the Matched Group (P = 0.004). Mean volume administered for the first 24 h after surgery was not different from the Matched Group. There were no vascular access-related complications in the Dialysis Group. Conclusions Postoperative CHDF combined with IHD can provide a similar management protocol for dialysis patients compared to patients with normal renal function.     

Continuous arteriovenous haemofiltration in critically ill children

We report 24 children with acute renal failure treated with continuous arteriovenous haemofiltration (CAVH) between 1987 and 1991. The median age was 2.9 years (range 3 days to 9 years). The main causes of the acute renal failure were: open heart surgery (n=11) and liver failure of different origins before and after liver transplantation (n=10). The indication for CAVH was oliguria or fluid overload in all children. The femoral vessels were used as vascular access in most instances. Different filters were used, depending on the size of the patient and an average ultrafiltration of 130±89 ml/h was achieved, which resulted in a fluid clearance of 4.0±2.6 ml/min per 1.73 m². In 18 patients uraemia was adequately controlled. Nine children survived after recovery of their renal function; 15 (62.5%) died as a consequence of multiorgan failure. We conclude that CAVH is an effective method to support critically ill children with acute renal failure.     

Continuous arteriovenous hemofiltration in children

Continuous arteriovenous hemofiltration (CAVH) is an extracorporeal technique for the treatment of hypervolemia and electrolyte disturbances in the critically ill patient with oligoanuria. The patient's cardiac output provides the blood flow through the circuit; no pumps are necessary. A range of hemofilters is now available extending the applicability of CAVH to the pediatric population, including premature newborns. In this report the treatment of 15 neonates and 8 older children is described. Fluid overload was reduced in all cases. Reflecting the very grave clinical conditions of these patients, 15 of the 23 treated children ultimately died. Due to failure to control uremia, four patients required treatment with dialysis. CAVH was found to be generally safe and effective even in the hemodynamically unstable critically ill child.Presented at the annual meeting of the American Society of Pediatric Nephrology, 5 May 1986, organized by Dr. R. N. Fine, Los Angeles.     

Urinary aprotinin as a predictor of acute kidney injury after cardiac surgery in children receiving aprotinin therapy

Proteomic analysis has revealed potential early biomarkers of acute kidney injury (AKI) in children undergoing cardiopulmonary bypass (CPB), the most prominent one with a mass-to-charge ratio of 6.4 kDa. The objective of this study was to identify this protein and test its utility as a biomarker of AKI. Trypsin-digested protein bands were analyzed by tandem mass spectrometry (MS/MS) to identify the protein in urine samples. Surface-enhanced laser desorption/ionization time-of-flight analysis and a functional activity assay were performed to quantify urinary levels in a pilot study of 106 pediatric patients undergoing CPB. The protein was identified as aprotinin. Urinary aprotinin levels 2 h after initiation of CPB were predictive of AKI (for functional assay: 92% sensitivity, 96% specificity, area under the curve of 0.98). By multivariate analysis, the urinary aprotinin level 2 h after CPB was an independent predictor of AKI (beta = 0.001, P < 0.0001). The 2 h urinary aprotinin level correlated with serum creatinine, duration of AKI, and length of hospital stay. We concluded that urinary aprotinin levels 2 h after initiation of CPB predict the development of AKI and adverse clinical outcomes.     

Metabonomics of acute kidney injury in children after cardiac surgery

Acute kidney injury (AKI) is a major complication in children who undergo cardiopulmonary bypass surgery. We performed metabonomic analyses of urine samples obtained from 40 children that underwent cardiac surgery for correction of congenital cardiac defects. Serial urine samples were obtained from each patient prior to surgery and at 4 h and 12 h after surgery. AKI, defined as a 50% or greater rise in baseline level of serum creatinine, was noted in 21 children at 48–72 h after cardiac surgery. The principal component analysis of liquid chromatography/mass spectrometry (LC/MS) negative ionization data of the urine samples obtained 4 h and 12 h after surgery from patients who develop AKI clustered away from patients who did not develop AKI. The LC/MS peak with mass-to-charge ratio (m/z) 261.01 and retention time (t_R) 4.92 min was further analyzed by tandem mass spectrometry (MS/MS) and identified as homovanillic acid sulfate (HVA-SO₄), a dopamine metabolite. By MS single-reaction monitoring, the sensitivity was 0.90 and specificity was 0.95 for a cut-off value of 24 ng/μl for HVA-SO₄ at 12 h after surgery. We concluded that urinary HVA-SO₄ represents a novel, sensitive, and predictive early biomarker of AKI after pediatric cardiac surgery.     

Peritoneal dialysis for acute renal failure in children

Fifty infants and children with acute renal failure were treated with acute peritoneal dialysis between 1987 and 1990. The patients were dialyzed using either a catheter introduced percutaneously over a guide-wire (n=40) or a Tenckhoff catheter (n=10). The cause of the acute renal failure was primary renal disease in 17 children, cardiac disease in 19, and trauma/sepsis in 14. Peritoneal dialysis succeeded in controlling metabolic abnormalities, improving fluid balance, and relieving the complications of uremia. The procedure had few major complications. Overall mortality was 50%, reflecting the serious nature of the underlying diseases. We conclude that acute peritoneal dialysis is a safe and effective treatment in most pediatric patients with acute renal failure. Our series of patients treated with acute peritoneal dialysis serves as a basis of comparison for the evaluation of new modalities of therapy in childhood acute renal failure.     

Significance of hemolysis on extracorporeal life support after cardiac surgery in children

Hemolysis is common during extracorporeal life support (ECLS). Elevated levels of circulating plasma free hemoglobin (FHb) has been linked to the development of hemoglobinuria nephropathy. Its clinical significance in patients receiving ECLS remains unknown. Medical records of 104 children <3 years old who required ECLS after repair of congenital heart disease were reviewed. Forty-two patients required continuous renal replacement therapy (CRRT) during ECLS (CRRT group), and 62 patients did not (no-CRRT group). For all patients, FHb level and the degree of fluid overload at the end of ECLS predicted the mortality rate during ECLS. Compared with the no-CRRT group, the CRRT group had a higher mortality rate during ECLS, a higher peak FHb level during ECLS, a higher FHb level at the end of ECLS, and more days of ECLS. In the CRRT group, the FHb level at the end of ECLS predicted death during ECLS. In the no-CRRT group, the peak FHb level was associated with a worse renal function. In conclusion, elevated FHb levels were associated with renal dysfunction and death during ECLS in children undergoing cardiac surgery. Further studies are needed to elucidate the cause–effect relationship in our findings.     

Continuous renal replacement therapy (CRRT) after stem cell transplantation. A report from the prospective pediatric CRRT Registry Group

Pediatric stem cell transplant (SCT) recipients commonly develop acute renal failure (ARF). We report the demographic and survival data of pediatric SCT patients enrolled in the Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry. Since 1 January 2001, 51/370 (13.8%) patients entered in the ppCRRT Registry had received a SCT. Median age was 13.63 (0.53–23.52) years. The primary reasons for the initiation of continuous renal replacement therapy (CRRT) were treatment of fluid overload (FO) and electrolyte imbalance (49%), FO only (39%), electrolyte imbalance only (8%) and other reasons (4%). The CRRT modalities included continuous veno-veno hemodialysis (CVVHD), 43%, continuous veno-veno hemofiltration (CVVH), 37% and continuous veno-veno hemodiafiltration (CVVHDF), 20%. Seventy-six percent had multi-organ dysfunction syndrome (MODS), 72% received ventilatory support and the mean FO was 12.41 ± 3.70%. Forty-five percent of patients survived. Patients receiving convective therapies had better survival rates (59% vs 27%, P < 0.05). Patients requiring ventilatory support had worse survival (35% vs 71%, P < 0.05). Mean airway pressure (Paw) at the end of CRRT was lower in survivors (8.7 ± 2.94 vs 25.76 ± 2.03 mmH₂O, P < 0.05). Development of high mean airway pressure in non-survivors is likely related to non-fluid injury, as it was not prevented by early and aggressive fluid management by CRRT therapy.     

持续肾替代治疗在肝移植术后急性肾损伤的应用

目的 探讨持续肾替代治疗(CRRT)对肝移植术后急性肾损伤的治疗效果.方法 回顾性分析82例肝移植围手术期应用CRRT患者的肾功能情况,对其治疗前后的主要指标进行检测.结果 与治疗前比较,治疗后患者丙氨酸氨基转移酶(ALT)、总胆红素(TBil)、血尿素氮(BUN)、肌酐(Cr)、肌酸磷酸激酶(CPK)、C反应蛋白(CPR)、肌酐下降,差异均有统计学意义(P＜0.05).与治疗前比较,CRRT治疗后患者血K+、Na+、Cl-、HCO3-、中心静脉压(CVP)显著好转,差异亦具有统计学意义(P＜0.05).其他生化指标与治疗前比较变化不大,差异无统计学意义(P＞0.05).对开始血滤治疗的时机进行研究显示,在急性肾损伤RIFLE分级Ⅰ级开始血滤治疗的患者肾功能恢复的比例明显高于在F级开始血滤治疗的患者(P＜0.05).结论 CRRT治疗能明显改善肝移植术后急性肾损伤患者的预后.     

Continuous arteriovenous haemofiltration in the newlyborn with acute renal failure and congenital heart disease

Newlyborn infants with congenital heart disease who develop acute renal failure are particularly difficult to treat. There are often complex associated medical problems and the mortality is high. Continuous arteriovenous haemofiltration (CAVH) provides a slow and gentle removal of fluid, together with the possibility of correcting metabolic abnormalities. We used CAVH in six newlyborn infants all with severe congenital heart disease, who developed acute renal failure early in life. In four patients it was necessary to insert a blood pump into the circuit to maintain adequate blood flow. CAVH alone, with or without a blood pump, was unable to reduce the plasma urea and creatinine, and in three of the infants, dialysis across the filter was required. CAVH was effective in controlling fluid balance. Although mortality remains high we feel CAVH has an important role in selected patients.     

Nosocomial infections in infants and children after cardiac surgery

Objective  To identify the incidence, characteristics and risk factors of nosocomial infections (NIs) in infants and children undergoing open heart surgery, a prospective observational study. Methods  One hundred consecutive infants and children < 2 yrs of age undergoing open heart surgery (OHS) between March 2007 and December 2007 were included in the study. Samples for blood, endotracheal and urine culture were drawn daily during intensive care unit (ICU) stay. Cultures from endotracheal tube, central venous catheter, arterial cannula, chest tube, urinary catheter and other invasive lines were also obtained. Centers for Disease Control and Prevention criteria were used for defining NIs. A number of possible risk factors predisposing to NI were analyzed. Results  32% patients developed NI. The NI rate was 49%. Common NIs were bloodstream infection (19%), respiratory tract infection (17%), catheter site infection (7%) and urinary tract infection (6%). Common pathogens were Acinetobacter (22.5%), Pseudomonas aeruginosa (20.4%), Klebsiella pneumoniae (16.3%) and Staphylococcus aureus (12.2%). Major risk factors for NI were length of ICU stay (p < 0.001), duration of intubation (p < 0.001), reintubation (p < 0.001), duration of central venous catheterization (p = 0.001), preoperative congestive heart failure (p = 0.002), tracheostomy (p = 0.003), duration of preoperative stay (p = 0.01), blood transfusion (p = 0.01), preoperative balloon atrial septostomy (p = 0.02), duration of surgery (p = 0.03), surgical complexity score (p = 0.03) and hypothermia (p = 0.03). The mortality rate was 11% with significant association between NI and death (p = 0.002). Conclusion  NIs develop frequently in infants and children after OHS. This study may serve as a reference point for further development and implementation of interventions aimed at reducing NI rates and improving patient outcome.     

A new model to predict acute kidney injury after cardiac surgery in patients with renal insufficiency

ObjectiveTo establish a simple model for predicting postoperative acute kidney injury (AKI) requiring renal replacement therapy (RRT) in patients with renal insufficiency (CKD stages 3–4) who underwent cardiac surgery.MethodsA total of 330 patients were enrolled. Among them, 226 were randomly selected for the development group and the remaining 104 for the validation group. The primary outcome was AKI requiring RRT. A nomogram was constructed based on the multivariate analysis with variables selected by the application of the least absolute shrinkage and selection operator. Meanwhile, the discrimination, calibration, and clinical power of the new model were assessed and compared with those of the Cleveland Clinic score and Simplified Renal Index (SRI) score in the validation group. Results: The rate of RRT in the development group was 10.6% (n = 24), while the rate in the validation group was 14.4% (n = 15). The new model included four variables such as postoperative creatinine, aortic cross‐clamping time, emergency, and preoperative cystatin C, with a C-index of 0.851 (95% CI, 0.779–0.924). In the validation group, the areas under the receiver operating characteristic curves for the new model, SRI score, and Cleveland Clinic score were 0.813, 0.791, and 0.786, respectively. Furthermore, the new model demonstrated greater clinical net benefits compared with the Cleveland Clinic score or SRI score.ConclusionsWe developed and validated a powerful predictive model for predicting severe AKI after cardiac surgery in patients with renal insufficiency, which would be helpful to assess the risk for severe AKI requiring RRT.     

Treatment of Acute Renal Failure in the Intensive Care Unit: Lower Costs by Intermittent Dialysis Than Continuous Venovenous Hemodiafiltration

Intermittent and continuous renal replacement therapies (RRTs) are available for the treatment of acute renal failure (ARF) in the intensive care unit (ICU). Although at present there are no adequately powered survival studies, available data suggest that both methods are equal with respect to patient outcome. Therefore, cost comparison between techniques is important for selecting the modality. Expenditures were prospectively assessed as a secondary end point during a controlled, randomized trial comparing intermittent hemodialysis (IHD) with continuous venovenous hemodiafiltration (CVVHDF). The outcome of the primary end points of this trial, that is, ICU and in-hospital mortality, has been previously published. One hundred twenty-five patients from a Swiss university hospital ICU were randomized either to CVVHDF or IHD. Out of these, 42 (CVVHDF) and 34 (IHD) were available for cost analysis. Patients' characteristics, delivered dialysis dose, duration of stay in the ICU or hospital, mortality rates, and recovery of renal function were not different between the two groups. Detailed 24-h time and material consumption protocols were available for 369 (CVVHDF) and 195 (IHD) treatment days. The mean daily duration of CVVHDF was 19.5 ± 3.2 h/day, resulting in total expenditures of €436 ± 21 (21% for human resources and 79% for technical devices). For IHD (mean 3.0 ±  0.4 h/treatment), the costs were lower (€268 ± 26), with a larger proportion for human resources (45%). Nursing time spent for CVVHDF was 113 ± 50 min, and 198 ± 63 min per IHD treatment. Total costs for RRT in ICU patients with ARF were lower when treated with IHD than with CVVHDF, and have to be taken into account for the selection of the method of RRT in ARF on the ICU.     

Pharmacokinetics and drug dosing adjustments during continuous venovenous hemofiltration or hemodiafiltration in critically ill patients

Continuous renal replacement therapy (CRRT) in critically ill patients with renal failure may significantly increase drug clearance, requiring drug dosing adjustments. Drugs significantly eliminated by the kidney often undergo substantial removal during CRRT, and a supplemental dose corresponding to the amount of drug removed by CRRT should be administered. Clearance by CRRT can either be measured or estimated. The high-flux membranes used in CRRT make no filtration barrier to most drugs, and the filtrate concentration can be estimated by the unbound fraction of the drug in plasma. When adding dialysis to filtration, this approach overestimates drug clearance, and a correcting factor should be used. A method for estimating drug clearance as a function of creatinine clearance is also suggested, but it has the same limitations in overestimating drug clearance when dialysis is combined with filtration. For non-toxic drugs, doses can safely be increased 30% above actual estimates to ensure adequate dosing. For drugs with a narrow therapeutical margin, monitoring plasma concentrations are mandatory. When appropriate, the use of a readily available reference for drug dosing is recommended.     

Pharmacokinetics of vancomycin in patients with multiple organ failure during continuous hemodiafiltration

Background. Some pharmacokinetic data for vancomycin (VCM) during continuous arteriovenous hemofiltration have been reported, but reports on the effect of continuous venovenous hemodiafiltration (CVVHDF), which is more commonly performed in patients with multiple organ failure (MOF), on VCM pharmacokinetics are scanty. Method. We selected five patients with MOF with serious infection with methicillin-resistant Staphylococcus aureus who needed treatment with VCM during CVVHDF. Blood flow rate was 80 ml/min, and dialysis fluid flow rate and filtration flow rate were both 0.5 l/h. A hemofilter made of polysulfon was used. After administration of 0.5–1.0 g of VCM, serial samples of blood and dialysate/filtrate outflow were obtained during CVVHDF. Pharmacokinetic parameters were calculated by a standard model-independent method. Results. Mean ± SE values for the pharmacokinetic parameters of VCM were: elimination rate constant, 0.0369 ± 0.0124/h; systemic clearance, 25.6 ± 5.0 ml/min; CVVHDF clearance, 15.9 ± 3.4 ml/min; non-CVVHDF clearance, 9.6 ± 8.4 ml/min; and distribution volume, 51.1 ± 21.6 l. The harmonic mean of half-life was 18.9 h. Conclusion. The systemic clearance of VCM during CVVHDF was relatively higher than anticipated. The pharmacokinetic parameters obtained in the present study will be useful to optimize the dose schedule of VCM in patients with MOF being treated with CVVHDF. Received: January 5, 1999 / Accepted: May 27, 1999     

Continuous venovenous hemofiltration

Continuous venovenous hemofiltration (CVVH) is a technique characterized by a venovenous circuit and a pump to perfuse the hemofilter. CVVH is suited to individualization of ultrafiltration and solute clearance in patients with acute renal failure and volume overload, specifically when there is impaired cardiovascular function or where arterial access is problematic. Examples, indications and relative advantages of this and other dialytic modalities are discussed.     

Continuous venovenous hemodiafiltration trace element clearance in pediatric patients: a case series

Continuous renal replacement therapy (CRRT) is used to treat critically ill children with acute kidney injury. The effect of CRRT on trace element clearance is poorly characterized. The purpose of this study was to quantify the transmembrane clearance of chromium, copper, manganese, selenium and zinc during continuous venovenous hemodiafiltration (CVVHDF). The transmembrane clearance of trace elements was assessed prospectively in five critically ill children receiving CVVHDF at the pediatric intensive care unit of a tertiary care university hospital. Pre-filter blood and effluent samples were measured for trace element concentrations. Transmembrane clearance of trace elements was calculated, and daily loss of each trace element was determined. Daily trace element loss via CVVHDF was compared with daily standard supplementation of trace elements in pediatric parenteral nutrition. Five patients (age range 23 months to 15 years) with a body weight range of 10.5–53 kg completed the study. The median transmembrane clearance of chromium, copper, manganese, selenium and zinc during CVVHDF was calculated as 0 ml, 0.59 ml, 2.48 ml, 1.22 ml, and 1.90 ml, respectively, per 1.73 m² body surface area per minute. The calculated CVVHDF losses were substantially smaller than the daily parenteral supplementation for all trace elements. These data were presented in poster form at the 2006 International Continuous Renal Replacement Therapy Meeting, San Diego, CA, USA. Abstract reference: Pasko DA, Churchwell MD, Btaiche IF, Jain JC, Mueller BA (2006) Trace element clearance in pediatric patients supported by continuous venovenous hemodiafiltration (CVVHDF). Blood Purif 24:269 (abstract no. 49). This study was funded in part by a grant from the University of Michigan College of Pharmacy Clinical Research Resources Fund.     

Fenoldopam infusion for renal protection in high-risk cardiac surgery patients: a randomized clinical study

OBJECTIVE: The purpose of this study was to evaluate the renoprotective effects of fenoldopam in patients at high risk of postoperative acute kidney injury undergoing elective cardiac surgery requiring cardiopulmonary bypass. DESIGN: A double-blind randomized clinical trial. Setting: Hospital. Participants: One hundred ninety-three patients. Interventions: Patients undergoing cardiac surgery were randomly assigned to receive a continuous infusion of fenoldopam, 0.1 microg/kg/min (95 patients), or placebo (98 patients) for 24 hours. Patients were included if at least 1 of the following risk factors was present: preoperative serum creatinine > or =1.5 mg/dL, age >70 years, diabetes mellitus, or prior cardiac surgery. Serum creatinine and urinary output were measured at baseline (T1), 24 hours (T2), and 48 hours after surgery (T3). Acute kidney injury was defined as a postoperative serum creatinine level of > or =2 mg/dL with an increase in serum creatinine level of 0.7 mg/dL or greater from preoperative to maximum postoperative values. MEASUREMENTS AND MAIN RESULTS: Acute kidney injury developed in 12 of 95 (12.6%) patients receiving fenoldopam and in 27 of 98 (27.6%) patients receiving placebo (p = 0.02), whereas renal replacement therapy was started in 0 of 95 and 8 of 98 (8.2%) patients, respectively (p = 0.004). Serum creatinine was similar at baseline (1.8 +/- 0.4 mg/dL v 1.9 +/- 0.3 mg/dL) in the fenoldopam and placebo groups but differed significantly (p < 0.001 and p < 0.001) 24 hours (1.6 +/- 0.2 mg/dL v 2.5 +/- 0.6 mg/dL) and 48 hours (1.5 +/- 0.3 mg/dL v 2.8 +/- 0.4 mg/dL) after the operation. CONCLUSIONS: A 24-hour infusion of 0.1 mug/kg/min of fenoldopam prevented acute kidney injury in a high-risk population undergoing cardiac surgery.