Dialysis therapies: a National Dialogue.

The National Institute of Diabetes, Digestive, and Kidney Diseases-supported Kidney Research National Dialogue asked the scientific community to formulate and prioritize research objectives that would improve our understanding of kidney function and disease. Kidney Research National Dialogue participants identified the need to improve outcomes in ESRD by decreasing mortality and morbidity and enhancing quality of life as high priority areas in kidney research. To reach these goals, we must identify retained toxins in kidney disease, accelerate technologic advances in dialysate composition and devices to remove these toxins, advance vascular access, and identify measures that decrease the burden of disease in maintenance dialysis patients. Together, these research objectives provide a path forward for improving patient-centered outcomes in ESRD.

Nonrenal indications for continuous renal replacement therapy: A report from the Prospective Pediatric Continuous Renal Replacement Therapy Registry Group.

OBJECTIVE: Continuous renal replacement therapy is the most often implemented dialysis modality in the pediatric intensive care unit setting for patients with acute kidney injury. However, it also has a role in the management of patients with nonrenal indications such as clearance of drugs and intermediates of disordered cellular metabolism. MEASUREMENTS AND METHODS: Using data from the multicenter Prospective Pediatric Continuous Renal Replacement Therapy Registry, we report a cohort of pediatric patients receiving continuous renal replacement therapy for nonrenal indications. Nonrenal indications were obtained from the combination of "other" category for continuous renal replacement therapy initiation and patient diagnosis (both primary and secondary). This cohort was further divided into three subgroups: inborn errors of metabolism, drug toxicity, and tumor lysis syndrome. RESULTS: From 2000 to 2005, a total of 50 continuous renal replacement therapy events with nonrenal indications for therapy were included in the Prospective Pediatric Continuous Renal Replacement Therapy Registry. Indication-specific survival of the subgroups was 62% (inborn errors of metabolism), 82% (tumor lysis syndrome), and 95% (drug toxicity). The median small solute dose delivered among the subgroups ranged from 2125 to 8213 mL/1.73 m/hr, with 54%-59% receiving solely diffusion-based clearance as continuous venovenous hemodialysis. No association was established between survival and dose delivered, modality of continuous renal replacement therapy, or use of intermittent hemodialysis prior to continuous renal replacement therapy. CONCLUSIONS: Pediatric patients requiring continuous renal replacement therapy for nonrenal indications are a distinct cohort within the population receiving renal replacement therapy with little published experience of outcomes for this group. Survival within this cohort varies by indication for continuous renal replacement therapy and is not associated with continuous renal replacement therapy modality. Additionally, survival is not associated with small solute doses delivered within a cohort receiving >2000 mL/1.73 m/hr. Our data suggest metabolic control is established rapidly in pediatric patients and that acute detoxification may be provided with continuous renal replacement therapy for both the initial and maintenance phases of treatment using either convection or diffusion at appropriate doses.

Fluid overload and mortality in children receiving continuous renal replacement therapy: the prospective pediatric continuous renal replacement therapy registry.

BACKGROUND: Critically ill children with hemodynamic instability and acute kidney injury often develop fluid overload. Continuous renal replacement therapy (CRRT) has emerged as a favored modality in the management of such children. This study investigated the association between fluid overload and mortality in children receiving CRRT. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 297 children from 13 centers across the United States participating in the Prospective Pediatric CRRT Registry. PREDICTOR: Fluid overload from intensive care unit (ICU) admission to CRRT initiation, defined as a percentage equal to (fluid in [L] - fluid out [L])/(ICU admit weight [kg]) x 100%. OUTCOME & MEASUREMENTS: The primary outcome was survival to pediatric ICU discharge. Data were collected regarding demographics, CRRT parameters, underlying disease process, and severity of illness. RESULTS: 153 patients (51.5%) developed < 10% fluid overload, 51 patients (17.2%) developed 10%-20% fluid overload, and 93 patients (31.3%) developed > or = 20% fluid overload. Patients who developed > or = 20% fluid overload at CRRT initiation had significantly higher mortality (61/93; 65.6%) than those who had 10%-20% fluid overload (22/51; 43.1%) and those with < 10% fluid overload (45/153; 29.4%). The association between degree of fluid overload and mortality remained after adjusting for intergroup differences and severity of illness. The adjusted mortality OR was 1.03 (95% CI, 1.01-1.05), suggesting a 3% increase in mortality for each 1% increase in severity of fluid overload. When fluid overload was dichotomized to > or = 20% and < 20%, patients with > or = 20% fluid overload had an adjusted mortality OR of 8.5 (95% CI, 2.8-25.7). LIMITATIONS: This was an observational study; interventions were not standardized. The relationship between fluid overload and mortality remains an association without definitive evidence of causality. CONCLUSIONS: Critically ill children who develop greater fluid overload before initiation of CRRT experience higher mortality than those with less fluid overload. Further goal-directed research is required to accurately define optimal fluid overload thresholds for initiation of CRRT.

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 mmH(2)O, 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.

Incidence of postoperative hyponatremia and complications in critically-ill children treated with hypotonic and normotonic solutions.

OBJECTIVE: To determine the incidence and clinical consequences of postoperative hyponatremia in children. STUDY DESIGN: We performed a retrospective analysis of postoperative admissions to the pediatric intensive care unit (excluding cardiac, neurosurgical, and renal). The incidence of severe (serum sodium < 125 mmol/L or symptoms) and moderate (serum sodium < 130 mmol/L) hyponatremia in children receiving hypotonic (HT) and normotonic (NT) fluids was calculated. RESULTS: Out of a total of 145 children (568 sodium measurements; 116 HT and 29 NT), we identified 16 with hyponatremia (11%). The incidences of moderate (10.3% vs 3.4%, P = .258) and severe (2.6% vs 0%; P = .881) hyponatremia were not significantly different in the HT and NT groups. There were no neurologic sequelae or deaths related to hyponatremia. CONCLUSIONS: In our study group, hyponatremia was common, but morbidity and death were not observed. Careful monitoring of serum sodium level may be responsible for this lack of adverse outcomes. Larger, prospective studies are needed to determine whether the incidence of hyponatremia differs between the HT and NT groups.

Demographic characteristics of pediatric continuous renal replacement therapy: a report of the prospective pediatric continuous renal replacement therapy registry.

BACKGROUND: This article reports demographic characteristics and intensive care unit survival for 344 patients from the Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry, a voluntary multicenter observational network. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Ages were newborn to 25 yr, 58% were male, and weights were 1.3 to 160 kg. Patients spent a median of 2 d in the intensive care unit before CRRT (range 0 to 135). At CRRT initiation, 48% received diuretics and 66% received vasoactive drugs. Mean blood flow was 97.9 ml/min (range 10 to 350 ml/min; median 100 ml/min); mean blood flow per body weight was 5 ml/min per kg (range 0.6 to 53.6 ml/min per kg; median 4.1 ml/min per kg). Days on CRRT were <1 to 83 (mean 9.1; median 6). A total of 56% of circuits had citrate anticoagulation, 37% had heparin, and 7% had no anticoagulation. RESULTS: Overall survival was 58%; survival differed across participating centers. Survival was lowest (51%) when CRRT was started for combined fluid overload and electrolyte imbalance. There was better survival in patients with principal diagnoses of drug intoxication (100%), renal disease (84%), tumor lysis syndrome (83%), and inborn errors of metabolism (73%); survival was lowest in liver disease/transplant (31%), pulmonary disease/transplant (45%), and bone marrow transplant (45%). Overall survival was better for children who weighed >10 kg (63 versus 43%; P = 0.001) and for those who were older than 1 yr (62 versus 44%; P = 0.007). CONCLUSIONS: CRRT can be used successfully for a wide range of critically ill children. Survival is best for those who have acute, specific abnormalities and lack multiple organ involvement; sicker patients with selected diagnoses may have lower survival. Center differences might suggest opportunities to define best practices with future study.

Phenylacetate and benzoate clearance in a hyperammonemic infant on sequential hemodialysis and hemofiltration.

An infant with a suspected inborn metabolism error was treated with a metabolic cocktail of intravenous sodium phenylacetate (NaPh) and sodium benzoate (NaBz) for hyperammonemia. Sequential hemodialysis (HD) then hemofiltration (HF) was performed due to hyperammonemia. Dialytic and convective clearance (K; ml/min) of ammonia, NaPh, and NaBz was measured. The K of ammonia was 57 and 37 for HD and HF, respectively. The K of NaBz was 37 and 12 for HD and HF, respectively. The K of NaPh was 38 and 14 ml/min for HD and HF, respectively. Despite high clearance of both NaPh and NaBz by HD and HF, the hyperammonemia was corrected.

Renal replacement therapy in the treatment of confirmed or suspected inborn errors of metabolism.

OBJECTIVE: Analysis of mortality and risk factors for mortality in the use of renal replacement therapy to correct metabolic disturbances associated with confirmed or suspected inborn errors of metabolism. STUDY DESIGN: A retrospective review of an institutional review board-approved pediatric acute renal failure data base at the University of Michigan. Eighteen patients underwent 21 renal replacement therapy treatments for metabolic disturbances caused by urea cycle defects (n = 14), organic acidemias (n = 5), idiopathic hyperammonemia (n = 1), and Reye syndrome (n = 1). RESULTS: There were 14 boys (74%) and 4 girls (26%), with a mean age and weight of 56.2 +/- 71.0 months and 18.5 +/- 19.2 kg, respectively, at the initiation of renal replacement therapy. Overall treatment mortality rate was 57.2% (12 of 21 treatments), with 11 of the 18 patients (61.1%) dying before hospital discharge. Two-year follow-up on those patients demonstrated that 5 patients (71.4%) remained alive. Initial therapy with hemodialysis was associated with improved survival. Ten treatments (47.6%) required transition to another form of renal replacement therapy to maintain ongoing metabolic control, with a mean duration of 6.1 +/- 9.8 days. Time to renal replacement therapy >24 hours was associated with an increased risk of mortality, whereas a blood pressure >5th percentile for age at the initiation of therapy and the use of anticoagulation were associated with a decreased risk of mortality. CONCLUSIONS: Renal replacement therapy can correct the metabolic disturbances that accompany suspected or confirmed inborn errors of metabolism. Our experience demonstrates an approximately 60% mortality rate associated with renal replacement treatment, with more than 70% of survivors living longer than 2 years.

Hyperphosphatemia due to fosphenytoin in a pediatric ESRD patient.

Fosphenytoin is indicated for the treatment of generalized convulsions and seizures occurring during neurosurgery. Metabolites of fosphenytoin include phenytoin, phosphate, and formaldehyde. The drug monograph recommends caution in administering fosphenytoin to patients in whom phosphate restriction is necessary. Additionally, fosphenytoin has altered pharmacokinetics in end-stage renal disease patients. We report a 17-year old African-American male with end-stage renal disease who developed acute hyperphosphatemia to 3.9 mmol/L (12.1 mg/dL) following the intravenous administration of 1000 mg of fosphenytoin for an idiopathic complex partial seizure. To our knowledge, this is the first report of acute hyperphosphatemia due to fosphenytoin administration. Due to this risk of hyperphosphatemia, we recommend that fosphenytoin should be used with caution in the end-stage renal disease population.

Hyperosmolar solutions in continuous renal replacement therapy for hyperosmolar acute renal failure: a preliminary report.

OBJECTIVE: To demonstrate the efficacy of hyperosmolar dialysis and prefilter replacement fluid solutions for continuous renal replacement therapies in the correction of hyperosmolar disorders in acute renal failure. DATA SOURCE: An Institutional Review Board-approved pediatric acute renal failure database at the University of Michigan C. S. Mott Children's Hospital. STUDY SELECTION: Three patients were identified meeting the inclusion criteria. The mean serum sodium concentration and plasma osmolality were 158 mmol/L and 357 mOsm/kg, respectively, at the time of initiation of renal replacement therapy. The sodium and/or dextrose concentrations of the dialysate or replacement fluids initially were increased and subsequently decreased to affect the solutions' calculated osmolalities in an effort to control the rate of decline of the patients' measured plasma osmolalities. DATA EXTRACTION: The case patients' serum sodium concentrations and plasma osmolalities were measured. Additionally, the sodium and dextrose concentrations of the dialysate or replacement fluid were recorded and the solutions' osmolalities calculated. DATA SYNTHESIS: The three patients experienced a mean rate of reduction of their serum sodium concentration and plasma osmolality of 0.5 mmol/L/hr and 1.6 mOsm/kg/hr, respectively. CONCLUSIONS: Hyperosmolar dialysis or prefilter replacement fluid solutions can affect a slow decline in both the serum sodium and plasma osmolality in cases of hyperosmolar acute renal failure.

Clearance of amino acids by hemodialysis in argininosuccinate synthetase deficiency.

We determined the dialytic clearance of amino acids involved in ammoniagenesis and nitrogen excretion in a neonate with argininosuccinate synthetase deficiency who underwent acute hemodialysis. Plasma ammonia and plasma and dialysate amino acid concentrations were obtained at baseline, 30-minute intervals during hemodialysis, and 30 minutes after the completion of hemodialysis. Plasma ammonia concentrations declined by 56% during the 90-minute hemodialysis treatment, whereas arginine, citrulline, glutamine, and glycine concentrations decreased by 65%, 55%, 40%, and 34%, respectively. Mean dialytic clearances for arginine, citrulline, glutamine, and glycine were 24, 282, 263, and 189 mL/min per 1.73 m(2), respectively. The high dialytic clearance of citrulline suggests a novel mechanism of hemodialysis removal of nitrogen. Dialytic clearances of glutamine and glycine may prevent further ammoniagenesis in hyperammonemic patients. However, our data suggest that hemodialysis affects the precursors of alternative pathway removal of ammonia. Further study is needed to optimize the intradialytic and interdialytic dosing of substrates.