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Our objective was to examine serum ferritin trends after conversion to permanent vascular access (PVA) among children who started hemodialysis (HD) using tunneled cuffed catheters (TCC). Retrospective chart reviews were completed on 98 subjects from 20 pediatric HD centers. Serum ferritin levels were collected at the creation of PVA and for two years thereafter. There were 11 (11%) arteriovenous grafts (AVG) and 87 (89%) arteriovenous fistulae (AVF). Their mean TCC use was 10.4 ± 17.3 months. Serum ferritin at PVA creation was elevated at 562.64 ± 492.34 ng/mL, increased to 753.84 ± 561.54 ng/mL (p = < 0.001) in the first year and remained at 759.60 ± 528.11 ng/mL in the second year (p = 0.004). The serum ferritin levels did not show a statistically significant linear association with respective serum hematocrit values. In a multiple linear regression model, there were three predictors of serum ferritin during the first year of follow-up: steroid-resistant nephrotic syndrome as primary etiology (p = 0.035), being from a center that enrolled >10 cases (p = 0.049) and baseline serum ferritin level (p = 0.017). Increasing serum ferritin after conversion to PVA is concerning. This increase is not associated with serum hematocrit trends. Future studies should investigate the correlation of serum transferrin saturation and ferritin levels in pediatric HD patients.

Background and objectives: Tunneled cuffed hemodialysis catheters (TCC) get colonized by microorganisms, increasing risk for catheter related bacteremia (CRB). Our objective was to detect the prevalence of bacterial colonization of TCC by using quantitative PCR (qPCR) targeting 16S rRNA and by determining the intraluminal adherent biological material (ABM) coverage. Methods: A total of 45 TCC were investigated. The 16S rRNA qPCR technique was used to detect bacterial colonization after scraping the intraluminal ABM. Proximal, middle, and distal TCC were evaluated by scanning electron microscopy (SEM) to determine the percentage (%) of intraluminal ABM coverage. All catheters were cultured following sonication. Results: A total of 45 TCC were removed: 7 due to CRB, 3 for suspected CRB and 35 were removed for non-infectious etiologies. Bacterial colonization was detected in 27 TCC by documenting 16S rRNA qPCR (+) results (60%). Seven of these 16S rRNA qPCR (+) catheters were removed due to CRB. There was no difference in demographic, clinical, or laboratory values between the 16S rRNA (+) versus (−) TCC. The 16S rRNA qPCR (−) outcome was highly associated with CRB-free status with negative predictive value of 100%. Bacterial colonization was documented in 10 TCC using catheter cultures (22%), which was significantly less compared to qPCR method ( p = 0.0002). ABM were detected in all catheter pieces, with mean intraluminal surface coverage (ABMC) of 68.4 ± 26.1%. ABM was unlikely to be microbial biofilm in at least 36% of removed TCC as their 16S rRNA qPCR and catheter culture results were both negative. Conclusions: Detecting bacterial colonization of TCC was significantly higher with 16S rRNA qPCR compared to catheter cultures. The 16S rRNA qPCR (−) cannot be predicted and was strongly associated with absence of CRB. Intraluminal ABM was not associated with microbial presence in about 1/3 of the TCC. These pieces of evidence may help to improve prophylactic strategies against CRB.

OBJECTIVE Acute kidney injury (AKI) is a complication encountered in 18% to 51% of pediatric critical care patients admitted for treatment of other primary diagnoses and is an independent risk factor for increased morbidity and mortality. Aminophylline has shown promise as a medication to treat AKI, but published studies have shown conflicting results. Our study seeks to assess the reversal of AKI following the administration of aminophylline in critically ill pediatric patients. METHODS We performed a single-institution retrospective chart review of pediatric inpatients who were diagnosed with AKI and subsequently treated with non-continuous dose aminophylline between January 2016 and December 2018. Data were collected beginning 2 days prior to the initial dose of aminophylline through completion of the 5-day aminophylline course. RESULTS Nineteen therapies among 17 patients were included in analysis. Twelve of the therapies resulted in resolution of AKI during the study period. We observed urine output increase of 19% (p = 0.0063) on the day following initiation of aminophylline therapy in the subset of patients whose AKI resolved. Trends toward decreased serum creatinine and lower inotropic support were also noted. CONCLUSIONS Based on these findings, aminophylline could be considered a potentially effective medication for use as rescue therapy in critically ill children with AKI. Limitations include small study population and retrospective nature. Further research in this area with a larger study population and a randomized control trial would allow for better characterization of the efficacy of aminophylline in reversal of AKI.

Hematopoietic cell transplantation (HCT) is a common therapy for the treatment of neoplastic and metabolic disorders, hematological diseases, and fatal immunological deficiencies. HCT can be subcategorized as autologous or allogeneic, with each modality being associated with their own benefits, risks, and post-transplant complications. One of the most common complications includes acute kidney injury (AKI). However, diagnosing HCT patients with AKI early on remains quite difficult. Therefore, this evidence-based guideline, compiled by the Pediatric Continuous Renal Replacement Therapy (PCRRT) working group, presents the various factors that contribute to AKI and recommendations regarding optimization of therapy with minimal complications in HCT patients.

BACKGROUND AND OBJECTIVES Arteriovenous fistulae (AVF) and grafts (AVG) are preferred permanent vascular access (PVA) for chronic hemodialysis (HD) patients. Our objective was to examine the change in markers of HD efficacy after successful establishment of a PVA among children who started HD with a tunneled cuffed catheter (TCC). MATERIALS AND METHODS Retrospective chart reviews were completed on patients from 20 pediatric dialysis centers. All patients used TCC prior to AVF/AVG, and each patient acted as his/her own control. Data on markers of HD efficacy (single-pool Kt/V, urea reduction ratio (URR), serum albumin and hematocrit (Hct)) were collected at the creation of AVF/AVG and for 2 years thereafter. Statistical methods included hypothesis testing and statistical modeling after adjusting for relevant demographic variables. RESULTS First PVA was created in 98 individual children: 87 (89%) were AVF and 11 (11%) were AVG. The mean TCC vintage prior to AVF/AVG was 10.4 ± 17.3 months. At 1-year follow-up, Kt/V improved by 0.15 ± 0.06 (p = 0.02) and URR improved by 4.54 ± 1.17% (p

Infections significantly complicate the care of children on hemodialysis and usually are associated with the use of a hemodialysis catheter for dialysis access. Infections of arteriovenous fistulae and arteriovenous grafts are uncommon, but many children on hemodialysis rely on a catheter, either while permanent access is being created or for long-term access. Catheter exit site infections most often occur independently of catheter-related bloodstream infections and are usually amenable to treatment with increased skin antisepsis and oral antibiotic provision. Tunnel infections can be more complicated and sometimes require surgical intervention and lead to catheter replacement. Catheter-related bloodstream infections are generally caused by skin flora and are often related to contamination of an open dialysis catheter hub during a dialysis treatment. Bacterial colonization of catheters and the development of biofilm also predispose to bloodstream infections. Broad-spectrum antibiotics such as vancomycin and ceftazidime are typically used for empiric antibiotic therapy. Antibiotic locks have been shown to reduce catheter infections and also augment cure rates. Catheter replacement or removal may be necessary, especially with infection with difficult-to-treat organisms or with persistent or recurrent infection.

There is no evidence-based definition for diagnosing crescentic glomerulonephritis. The prognostic implications of crescentic lesions on kidney biopsy have not been quantified. Our objective was to determine risk factors for end-stage kidney disease (ESKD) in patients with glomerulonephritis and crescents on kidney biopsy. A query of the Pediatric Nephrology Research Consortium&rsquo, s Pediatric Glomerulonephritis with Crescents registry identified 305 patients from 15 centers. A retrospective cohort study was performed with ESKD as the primary outcome. Median age at biopsy was 11 years (range 1&ndash, 21). The percentage of crescents was 3&ndash, 100% (median 20%). Etiologies included IgA nephropathy (23%), lupus (21%), IgA vasculitis (19%) and ANCA-associated GN (13%), post-infectious GN (5%), and anti-glomerular basement membrane disease (3%). The prevalence of ESKD was 12% at one year and 16% at last follow-up (median = 3 years, range 1&ndash, 11). Median time to ESKD was 100 days. Risk factors for ESKD included %crescents, presence of fibrous crescents, estimated GFR, and hypertension at biopsy. For each 1% increase in %crescents, there was a 3% decrease in log odds of 1-year renal survival (p = 0.003) and a 2% decrease in log odds of renal survival at last follow-up (p &lt, 0.001). These findings provide an evidence base for enrollment criteria for crescentic glomerulonephritis in future clinical trials.

Permanent vascular access (PVA) is preferred for long-term hemodialysis. Arteriovenous fistulae (AVF) have the best patency and the lowest complication rates compared to arteriovenous grafts (AVG) and tunneled cuffed catheters (TCC). However, AVF need time to mature. This study aimed to investigate predictors of time to first cannulation for AVF in pediatric hemodialysis patients. Data on first AVF and AVG of patients at 20 pediatric dialysis centers were collected retrospectively, including demographics, clinical information, dialysis markers, and surgical data. Statistical modeling was used to investigate predictors of outcome. First PVA was created in 117 children: 103 (88%) AVF and 14 (12%) AVG. Mean age at AVF creation was 15.0 ± 3.3 years. AVF successfully matured in 89 children (86.4%), and mean time to first cannulation was 3.6 ± 2.5 months. In a multivariable regression model, study center, age, duration of non-permanent vascular access (NPVA), and Kt/V at AVF creation predicted time to first cannulation, with study center as the strongest predictor (p < 0.01). Time to first cannulation decreased with increasing age (p = 0.03) and with increasing Kt/V (p = 0.01), and increased with duration of NPVA (p = 0.03). Secondary failure occurred in 10 AVF (11.8%). Time to first cannulation did not predict secondary failure (p = 0.29), but longer time to first cannulation tended towards longer secondary patency (p = 0.06). Study center is the strongest predictor of time to first cannulation for AVF and deserves further investigation. Time to first cannulation is significantly shorter in older children, with more efficient dialysis treatments, and increases with longer NPVA duration.

Primary aldosteronism, a common cause of severe hypertension 1 , features constitutive production of the adrenal steroid aldosterone. We analyzed a multiplex family with familial hyperaldosteronism type II (FH-II) 2 and 80 additional probands with unsolved early-onset primary aldosteronism. Eight probands had novel heterozygous variants in CLCN2, including two de novo mutations and four independent occurrences of a mutation encoding an identical p.Arg172Gln substitution; all relatives with early-onset primary aldosteronism carried the CLCN2 variant found in the proband. CLCN2 encodes a voltage-gated chloride channel expressed in adrenal glomerulosa that opens at hyperpolarized membrane potentials. Channel opening depolarizes glomerulosa cells and induces expression of aldosterone synthase, the rate-limiting enzyme for aldosterone biosynthesis. Mutant channels show gain of function, with higher open probabilities at the glomerulosa resting potential. These findings for the first time demonstrate a role of anion channels in glomerulosa membrane potential determination, aldosterone production and hypertension. They establish the cause of a substantial fraction of early-onset primary aldosteronism.

Hemodialysis (HD) guidelines recommend permanent vascular access (PVA) in children unlikely to receive kidney transplant within 1 year of starting HD. We aimed to determine predictors of primary and secondary patency of PVA in pediatric HD patients. Retrospective chart reviews were performed for first PVAs in 20 participating centers. Variables collected included patient demographics, complications, interventions, and final outcome. There were 103 arterio-venous fistulae (AVF) and 14 AV grafts (AVG). AVF demonstrated superior primary (p = 0.0391) and secondary patency (p = 0.0227) compared to AVG. Primary failure occurred in 16 PVA (13.6%) and secondary failure in 14 PVA (12.2%). AVF were more likely to have primary failure (odds ratio (OR) = 2.10) and AVG had more secondary failure (OR = 3.33). No demographic, clinical, or laboratory variable predicted primary failure of PVA. Anatomical location of PVA was predictive of secondary failure, with radial having the lowest risk compared to brachial (OR = 12.425) or femoral PVA (OR = 118.618). Intervention-free survival was predictive of secondary patency for all PVA (p = 0.0252) and directly correlated with overall survival of AVF (p = 0.0197) but not AVG. Study center demonstrated statistically significant effect only on intervention-free AVF survival (p = 0.0082), but not number of complications or interventions, or outcomes. In this multi-center pediatric HD cohort, AVF demonstrated primary and secondary patency advantages over AVG. Radial PVA was least likely to develop secondary failure. Intervention-free survival was the only predictor of secondary patency for AVF and directly correlated with overall access survival. The study center effect on intervention-free survival of AVF deserves further investigation.

Objectives Fetuses continue to be exposed to renin angiotensin system (RAS) blockers despite their known teratogenicity and a black box warning. We hypothesized that fetopathy from in utero exposure to RAS blockers has a broader spectrum of clinical manifestations than described previously and that there are a variety of clinical scenarios leading to such exposures. Study design This was a retrospective study performed through the Midwest Pediatric Nephrology Consortium. Cases of RAS blocker fetopathy were identified, with determination of renal and extrarenal manifestations, timing of exposure, and the explanation for the fetal exposure. Results Twenty-four cases were identified. RAS blocker exposure after the first trimester was associated with more severe renal manifestations. Chronic dialysis or kidney transplantation was required in 8 of 17 (47%) patients with RAS blocker exposure after the first trimester and 0 of 7 patients with exposure restricted to the first trimester ( P = .05). Extrarenal manifestations, some not previously noted in the literature, included central nervous system anomalies (cystic encephalomalacia, cortical blindness, sensorineural hearing loss, arachnoid cysts) and pulmonary complications (pneumothorax, pneumomediastinum). RAS blocker exposure usually was secondary to absent or poor prenatal care or undiagnosed pregnancy. Conclusion RAS blocker fetopathy continues to be a cause of considerable morbidity, with more severe renal manifestations associated with exposure after the first trimester. A variety of significant extrarenal manifestations occur in these patients. Clinicians should emphasize the risk of fetopathy when prescribing RAS blockers to women of childbearing age.

Acute kidney injury (AKI) is a common adverse event after hematopoietic cell transplantation (HCT). AKI is associated with early death or chronic kidney disease among transplant survivors. However, large-scale pediatric studies based on standardized criteria are lacking. We performed a retrospective analysis of 1057 pediatric patients who received allogeneic HCT to evaluate the incidence and risk factors of AKI according to AKI Network criteria within the first 100 days of HCT. We also determined the effect of AKI on patient survival. The 100-day cumulative incidences of all stages of AKI, stage 3 AKI, and AKI requiring renal replacement therapy (RRT) were 68.2% ± 1.4%, 25.0% ± 1.3%, and 7.6% ± .8%, respectively. Overall survival at 1 year was not different between patients without AKI and those with stage 1 or 2 AKI (66.1% versus 73.4% versus 63.9%, respectively) but was significantly different between patients without AKI and patients with stage 3 AKI with or without RRT requirement (66.1% versus 47.3% versus 7.5%, respectively; P .001). Age, year of transplantation, donor type, sinusoidal obstruction syndrome (SOS), and acute graft-versus-host disease (GVHD) were independent risk factors for stages 1 through 3 AKI. Age, donor, conditioning regimen, number of HCTs, SOS, and acute GVHD were independent risk factors for AKI requiring RRT. Our study revealed that AKI was a prevalent adverse event, and severe stage 3 AKI, which was associated with reduced survival, was common after pediatric allogeneic HCT. All patients receiving allogeneic HCT, especially those with multiple risk factors, require careful renal monitoring according to standardized criteria to minimize nephrotoxic insults.

The original version of this article unfortunately contained a mistake. The name of Vimal Chadha was presented incorrectly. The corrected author list is given above.

There are current concerns that antibiotic lock solutions (ABL) can induce antimicrobial resistance in long-term hemodialysis patients. Retrospective chart review of 157 children on hemodialysis between January 1997 and June 2006 was performed. In ERA I, only systemic antibiotics were used. In ERA II, ABL were added to systemic antibiotics when needed. In ERA III, ABL were used for treatment of all cases of catheter-related bacteremia (CRB) and for CRB prophylaxis in high-risk patients. The study includes 111,325 catheter days. The CRB incidence was 3.9 CRB/1000 catheter days. There was significant decrease for the total systemic antibiotic exposure (P = 0.0484) and the percentage of catheters lost to malfunction (P = 0.001) in ERA III. Protocol ABL exposure was associated with a trend to increased tobramycin-gentamicin resistance for gram-positive CRBs (P = 0.2586) but with improved tobramycin-gentamicin resistance for gram-negative (P = 0.0949) and polymicrobial CRBs (P = 0.1776) and improved vancomycin resistance for gram-positive CRBs (P = 0.0985). This retrospective analysis does not support the premise that ABL use will promote antimicrobial resistance in the hemodialysis population. The decreased exposure to systemic antibiotics by vigorous ABL use may even improve the antimicrobial resistance patterns in this population in the long term.

The aim of this retrospective study was to investigate if the application of chlorhexidine-based solutions (ChloraPrep®) to the exit site and the hub of long-term hemodialysis catheters could prevent catheter-related bacteremia (CRB) and prolong catheter survival when compared with povidone–iodine solutions. There were 20,784 catheter days observed. Povidone–iodine solutions (Betadine®) were used in the first half of the study and ChloraPrep® was used in the second half for all the patients. Both groups received chlorhexidine-impregnated dressings at the exit sites. The use of Chloraprep® significantly decreased the incidence of CRB (1.0 vs 2.2/1,000 catheter days, respectively, P = 0.0415), and hospitalization due to CRB (1.8 days vs 4.1 days/1,000 catheter days, respectively, P = 0.0416). The incidence of exit site infection was similar for the two groups. Both the period of overall catheter survival (207.6 days vs 161.1 days, P = 0.0535) and that of infection-free catheter survival (122.0 days vs 106.9 days, P = 0.1100) tended to be longer for the catheters cleansed with ChloraPrep®, with no statistical significance. In conclusion, chlorhexidine-based solutions are more effective for the prevention of CRB than povidone–iodine solutions. This positive impact cannot be explained by decreased number of exit site infections. This study supports the notion that the catheter hub is the entry site for CRB.

This retrospective study was designed to investigate the effectiveness of tissue plasminogen activator-tobramycin antibiotic lock solutions (TPA/tobra ABLs) for prophylaxis of catheter-related bacteremia (CRB) in high-risk children on long-term hemodialysis. During the first 6 months (Era 1), the high-risk group was defined. These patients received TPA/tobra ABL prophylaxis after every hemodialysis treatment for the next 6 months (Era 2). The prophylaxis regimen was applied once a week for the third 6-months period (Era 3). Primary endpoints were CRB and infection-free catheter survival. There were 16,412 catheter days, and 95 cases of CRB in 43 children. The incidence of CRB was 5.8/1,000 catheter days. Significant decrease in the incidence of CRB was observed when prophylactic TPA/tobra ABL was used in the high-risk group (P = 0.0201). There was a tendency for less CRB when prophylactic ABL was applied after every hemodialysis session compared with once a week (P = 0.0947). The catheters in the high-risk group had shorter survival times than those in the average-risk group in Era 1 (P < 0.0001). However, both the overall and infection-free survival of the catheters in the high-risk group significantly improved while the patients were receiving TPA/tobra ABL prophylaxis, becoming similar to the outcomes of the catheters in the average-risk group and exhibiting statistically non-significant differences (P = 0.5571 and P = 0.9711, respectively). In conclusion, the TPA/tobra ABLs may effectively reduce the rate of CRB, and this may prolong both the overall and infection-free survival times of the catheters in the high-risk group.

Background and objectives: This retrospective study compared the effectiveness of the timing of the antibiotic locks to clear catheter-related bacteremia in children on chronic hemodialysis. Design, setting, participants, & measurements: The early antibiotic lock group received antibiotic locks along with systemic antibiotics from the very beginning of catheter-related bacteremia. The late antibiotic lock group was given only systemic antibiotics initially, and antibiotic locks were used late in the infection if the catheter-related bacteremia could not be cleared after resolution of symptoms. Results: There were 264 catheter-related bacteremias in 79 children during 6 yr of observation. Early antibiotic locks were able to clear catheter-related bacteremia and resolve the symptoms more effectively without the need for catheter exchange when compared with late antibiotic locks. A total of 84 catheter-related bacteremias required wire-guided exchange of the catheters. Late antibiotic locks required wire-guided catheter exchange more frequently than the early antibiotic locks. The post–catheter-related bacteremia infection–free survival of the catheters after wire-guided exchange were significantly longer than those of both antibiotic lock groups. Recurrence of catheter-related bacteremia within 45 d after wire-guided exchange occurred at similar rates compared with the antibiotic lock groups. Conclusion: Antibiotic locks are significantly more effective in clearing catheter-related bacteremia when used early in infection, diminishing the need for catheter exchange. Wire-guided exchange has a late-onset advantage for infection-free survival compared with catheter in situ treatment. The recurrence rates in the first 45 d after catheter-related bacteremia are similar regardless of the treatment strategy.

This retrospective study was completed to investigate the effectiveness of tissue plasminogen activator (TPA) antibiotic locks (ABL) along with systemic antibiotics (AB) to clear catheter-related bacteremia (CRB) in children on chronic hemodialysis. There were 76 CRBs in 37 children. CRBs were successfully cleared with AB/ABL in 63/76 (83%) cases. Ten of 76 (13%) CRBs were symptomatic at 48 h of treatment. These were seven polymicrobial, two gram-negative, and one Candida CRB. 13/76 (17%) episodes required catheter exchange, and all were wire-guided exchanges. TPA-ABL/AB cleared gram-positive and gram-negative CRBs significantly better than polymicrobial CRBs (p < 0.01). The infection-free survival and the rate of recurrence at 45 days was not statistically different between the TPA-ABL/AB group and the catheter-exchange group. If CRB was symptomatic at 48 h of treatment, recurrence at 6 weeks was more frequent with persistent use of TPA-ABL/AB (p < 0.05). There were no episodes of metastatic infections, catheter malfunction from occlusion, or catheter breakdown during the course of TPA-ABL treatments. In conclusion, TPA-ABL can be safely and effectively used in the management of CRB, increasing the probability of catheter survival and preserving the vascular access site. With the exception of polymicrobial CRB, there is no disadvantage in using TPA-ABL/AB over catheter exchange, as the infection-free survival and the rate of recurrence are comparable.

This retrospective study was done to compare the infection-free and overall survival of first and subsequent tunneled cuffed hemodialysis catheters in children. Subsequent catheters were exchanged by two different methods (a) removal and replacement (RR), or (b) wire-guided exchange (WGE) using the same tunnel and vessel. The study involved 59 children (27 male, 32 female; mean age 13.9 +/- 4.6 years) undergoing maintenance hemodialysis in a pediatric unit over a period of 60 months. From a total of 175 catheters (57 first catheters, 81 WGE, 37 RR) and 38,888 catheter days, 74/175 (42%) catheters were exchanged because of catheter-related bacteremia (CRB) and 43/175 (25%) for malfunction or cuff extrusion. One-year survival rates for first and consecutive catheters was 26% and 21%, respectively. The overall survival of first catheters, and those exchanged by WGE and RR for both infectious and non-infectious reasons, was not statistically different. However, infection-free survival of first catheters was significantly prolonged in comparison with that of subsequent catheters (P0.001). The infection-free survival and the overall survival were not affected by etiology of primary disease, gender, serum albumin, or hemoglobin. Overall catheter survival increased with age10 years. There was a significant association between gram-negative and polymicrobial CRB and requirement for RR (P0.02). Our findings suggest that WGE is safe in a clinically stable child if the tunnel and the exit site are not infected and has the potential benefit of preserving the vascular access site. The shorter infection-free survival in subsequent catheters suggests a cumulative disadvantage with prolonged catheter use.

Posterior reversible leukoencephalopathy syndrome (PRES) clinically presents with seizures, severe headaches, and mental and visual changes. Our goal was to describe the clinical features, triggering factors, neuro-imaging findings, and electroencephalogram (EEG) findings in a pediatric cohort with renal disease. We retrospectively analyzed the records of 18 children with the diagnosis of PRES between January 2001 and June 2006 at the University of Miami/Holtz Children’s Hospital, USA. There were 22 PRES episodes. The most common clinical presentation was generalized tonic–clonic seizures in 59% (13/22). The most common identified trigger of PRES was hypertensive crisis in 59% (13/22). Almost half of the children had no evidence of on-going uncontrolled hypertension; 44% (8/18) had normal funduscopic examination findings, and 50% (9/18) had no or mild left ventricular hypertrophy. Two of the 18 patients had recurrent PRES episodes, three episodes each. Diffuse slowing was the most common finding on the EEGs. Atypical magnetic resonance imaging (MRI) findings were more prevalent in the imaged cases (62% vs 25%, P < 0.05). All the computerized tomography (CT) scans were normal, despite the positive MRI findings in four cases when both types of imaging was used. All the episodes had total clinical resolution. In conclusion, despite the diverse initial trigger, acute hypertension seems to be the common pathogenic pathway for pediatric PRES. MRI seems superior to CT, with better sensitivity due to its high resolution and diffusion-weighted imaging. The lesions do not necessarily have to be in the posterior white matter and may not be totally reversible.

Catheter-related bacteremia (CRB), along with liver failure is the leading cause of mortality and morbidity in parenteral nutrition dependent children. Immunosuppressant therapy following transplantation increases the risk of CRB. Previous reports in pediatric cancer patients have described the use of antibiotic lock solutions (ABL) for prophylaxis of CRB. In our institution, we evaluated five children (ages between one and four yr old), three with intestinal transplantation and two with short gut syndrome, who were high risk for recurrent CRB defined by their incidence of bacteremias in the observation period (>2 CRB/six months or life-threatening CRB). These children received the prophylactic ABL protocol with tobramycin-tissue plasminogen activator, four h per day, on alternating ports for six to eight months. Each patient was his/her own historical control. We observed decreased incidence of CRB's (p

The genetics of renal tumors in children is widely recognized. However, most of the studies published to date emphasize the association between Wilms tumor and the WT-1 gene. Recently, a unique translocation between the X chromosome and chromosome 1 or t(X;1) has been described in several reports of renal cell carcinomas (RCCs) diagnosed in children and adolescents that results in PRCC-TFE3 gene fusion. We report here a 9-year old African-American boy with a history of a right congenital mesoblastic nephroma treated with nephrectomy and followed by annual checkups. After 9 years, he was diagnosed with a mass at the hilum of the left kidney during the work-up of new-onset hypertension. A limited biopsy revealed densely hyalinized connective tissue that was initially interpreted to be a hyalinized contralateral mesoblastic nephroma. The child received chemotherapy, but the mass continued to grow. He underwent a left nephrectomy, and the pathology was diagnostic for a clear cell RCC. Chromosomal analysis disclosed a t(X;1)(p11.2;q21) translocation, which is known to result in a PRCC-TFE3 gene fusion. The tumor showed nuclear labeling for TFE3 protein by immunohistochemistry, supporting the above diagnosis. He has been on hemodialysis, is tumor free, and has not been receiving chemotherapy for 24 months. This is the first report of a RCC as a second malignant neoplasm in a child treated for a congenital mesoblastic nephroma.

This study was designed to characterize proteinuria in children with kidney disease. Random urine samples from 250 pediatric patients were examined by quantitative measures of total protein (pr), albumin (Alb), and creatinine (cr). Patient diagnoses were subjectively categorized as "Glomerular" (GD) or "Tubulo-interstitial" disease (TD) in origin. Proteinuria was quantitated by the random urine protein-to-creatinine (Upr/cr) ratio, and glomerular proteinuria was assessed as the albumin-to-creatinine ratio (Ualb/cr) and percentage albuminuria (%Alb=Alb/pr*100). The non-albumin fraction (1-Alb/pr) includes low-molecular-weight proteins and micro- and macroglobulins. Of the 250 patients, 112 (45%) had GD and 138 (55%) had TD. Both proteinuria and albuminuria correlated with a decline in glomerular filtration rate (GFR) (r=-0.4; p0.0001). Those with GD averaged significantly greater %Alb than those with TD at all levels of proteinuria (p0.0001). With loss in GFR, %Alb increased significantly in patients with TD (18+/-13 to 47+/-30%; p0.001) and GD (56+/-26 to 74+/-15%; p0.01), respectively. The %Alb at all levels of GFR averaged50% in those with TD and50% in those with GD. In conclusion, random Ualb/cr, Upr/cr, and %Alb provide a simple and inexpensive assessment of proteinuria and may profile renal disease activity and response to therapy in pediatric patients.

Dent disease is an X-linked proximal tubulopathy that typically presents with hypercalciuria, low-molecular-weight proteinuria and slow progression to endstage renal disease. We report the case of a 5-year-old boy who presented with asymptomatic nephrotic range proteinuria and was later diagnosed with Dent disease. Absence of specific glomerular pathology in the first kidney biopsy led to erroneous treatment for presumably unsampled primary focal segmental glomerulosclerosis. Aggressive angiotensin blockade and immunosuppression resulted in significant side effects with marginal benefit. The continued nonspecific findings after a second kidney biopsy 2 years later led to the suspicion of a congenital tubulopathy. We detected a novel CLCN5 gene mutation, c.1396G > C, that creates a G466R missense change in the ClC-5 protein. Dent disease should be considered in the differential diagnosis of asymptomatic proteinuria for male patients. Profiling proteinuria in these patients by spot urine albumin/creatinine ratio may give the first clue to a tubulopathy. Determining the extent to which the clinical work-up should proceed for females with Dent phenotype or asymptomatic proteinuria remains to be a challenging clinical dilemma.

There are current concerns that antibiotic lock solutions (ABL) can induce antimicrobial resistance in long-term hemodialysis patients. Retrospective chart review of 157 children on hemodialysis between January 1997 and June 2006 was performed. In ERA I, only systemic antibiotics were used. In ERA II, ABL were added to systemic antibiotics when needed. In ERA III, ABL were used for treatment of all cases of catheter-related bacteremia (CRB) and for CRB prophylaxis in high-risk patients. The study includes 111,325 catheter days. The CRB incidence was 3.9 CRB/1000 catheter days. There was significant decrease for the total systemic antibiotic exposure (P = 0.0484) and the percentage of catheters lost to malfunction (P = 0.001) in ERA III. Protocol ABL exposure was associated with a trend to increased tobramycin-gentamicin resistance for gram-positive CRBs (P = 0.2586) but with improved tobramycin-gentamicin resistance for gram-negative (P = 0.0949) and polymicrobial CRBs (P = 0.1776) and improved vancomycin resistance for gram-positive CRBs (P = 0.0985). This retrospective analysis does not support the premise that ABL use will promote antimicrobial resistance in the hemodialysis population. The decreased exposure to systemic antibiotics by vigorous ABL use may even improve the antimicrobial resistance patterns in this population in the long term.

Background. Antibiotic lock (ABL) solutions can effectively treat catheter-related bacteraemia (CRB) without the need for catheter exchange. This approach does not increase secondary infectious complications. We evaluated the risk factors that contribute to failure when CRB is treated with ABLs and systemic antibiotics in paediatric haemodialysis patients. Methods. A retrospective chart review of 72 children on haemodialysis between January 2004 and June 2006 was performed. We evaluated risk factors for ABL treatment using patients' characteristics, CRB/catheter characteristics and patients' biochemical profiles. The first CRB of each catheter was included in the statistical analysis. Our end points were outcome at 2 weeks of treatment and at 6 weeks following treatment. Compound symmetry covariance structure was employed for statistical analysis. Results. We treated 149 CRB in 50 patients. The incidence was 3.4 CRB/1000 catheter days. Thirty CRB failed to be cleared with the use of ABL and systemic antibiotics at 2 weeks of treatment (30/149, 20 vs 80%, P < 0.001). Twenty-four of these catheters required exchange. Thirty-nine of the treated catheters got re-infected within the next 6 weeks (39/125, 31 vs 69%, P < 0.001). CRB aetiology was the only statistically significant independent variable for 2-week outcome (P = 0.033). Coagulase-negative Staphylococcus CRB had higher odds of being cleared at 2 weeks compared with other CRB aetiologies. For the 6-week outcome, the statistically significant independent variables in the final model included age (P = 0.048) and serum phosphorous level (P < 0.001). Younger age and higher serum phosphorous levels were independent risk factors for failure at 6 weeks with re-infection. Area under the receiver operating characteristic (ROC) curve for the model of the 2-week outcome was 0.736 with the percentage of correct predictions at 81.2%. Area under the ROC curve for the model of the 6-week outcome was 0.689 with the percentage of correct predictions at 75.5%. Conclusions. CRB can effectively be treated with ABLs and systemic antibiotics. CRB aetiology is the only independent variable of early treatment failure. Younger age and higher serum phosphorous levels are independent risk factors for re-infection at 6 weeks.

The aim of this retrospective study was to investigate whether the application of a chlorhexidine-impregnated dressing (Biopatch) at the exit site of tunneled-cuffed hemodialysis catheters has any effect on the incidence and etiology of catheter-related bacteremia (CRB). This study was carried out over a 5-year period in a single center, where, in the first 2(1/2) years, the exit sites were cleansed with betadine at every hemodialysis session and then covered with a transparent dressing (pre-Biopatch Era). During the next 2(1/2) years, Biopatch was applied to the exit site once a week after cleansing with betadine, and then covered with a transparent dressing (Biopatch Era). The application of Biopatch significantly decreased the incidence of exit site infections (ESI) (P

BACKGROUND An accepted pathogenesis of catheter-related bacteraemia (CRB) is the seeding of microorganisms from the intraluminal biofilm of central venous catheters. Antibiotic locks (ABL) are solutions containing high concentrations of antimicrobials with or without anticoagulants that aim to destroy the biofilm. METHODS In this study, two different ABL solutions, tissue plasminogen activator (TPA)-based and heparin-based ABL, used in conjunction with systemic antibiotics, were prospectively compared in the treatment of CRB. RESULTS A total of 42 children on chronic haemodialysis with 11,016 catheter-days were observed for signs and symptoms of CRB over a period of 10 months. Twenty-four CRBs were diagnosed in 18 children (2.2 CRB/1000 catheter-days) and were treated with the protocol. Symptoms of CRB resolved in 83% within 48 h of treatment. None of the infected catheters required early emergent exchange or removal for poorly controlled CRB. Six children had recurrence of CRB within 6 weeks, of which four required catheter exchange. There was no specific microorganism or type of CRB that predisposed to higher recurrence rates. The mean infection-free survival of the catheters following TPA-ABL treatment was shorter than that following heparin-ABL treatment, but was not statistically significant by the log-rank test (126.8 +/- 81.6 days versus 154.5 +/- 70.4 days). CONCLUSION Both TPA-ABL and heparin-ABL used in conjunction with systemic antibiotics can effectively clear CRB without significant late recurrence at 6 weeks. Early use of ABL for management of CRB can potentially decrease the need for catheter removal, thus salvaging vascular access sites.

Phenazopyridine (Pyridium) is a commonly used urinary tract analgesic. It has been associated with yellow skin discoloration, hemolytic anemia, methemoglobinemia, and acute renal failure, especially in patients with preexisting kidney disease. We report a 17-year-old female with vertically transmitted human immunodeficiency virus (HIV) infection, presenting with acute renal failure and methemoglobinemia following a suicidal attempt with a single 1,200 mg ingestion of Pyridium. She had no prior evidence of HIV nephropathy. The patient had a progressive nonoliguric renal failure on the 3rd day following the ingestion. She was treated with N-acetylcysteine, intravenous carnitine, and alkalinization of the urine. Her kidney biopsy revealed acute tubular necrosis with no glomerular changes. After 7 days of conservative management, she was discharged home with normal kidney function. To our knowledge, this is the second smallest amount of Pyridium overdose resulting in acute renal failure with no previous history of kidney disease.

Tunneled central venous catheters are often used in children on chronic hemodialysis. This study was done to evaluate the spectrum of catheter-related bacteremia (CRB) and to determine predictors of recurrent CRB in children on hemodialysis. Chart review was performed in 59 children from a pediatric dialysis unit with chronic, tunneled, cuffed hemodialysis catheters between January 1999 and December 2003. CRB was diagnosed in 48 of 59 (81%) patients. The incidence of CRB was 4.8/1,000 catheter days. Overall catheter survival (290+/-216 days) was significantly longer than infection-free catheter survival (210+/-167 days, p0.05). Organisms isolated were gram-positive in 67%, gram-negative in 14%, and polymicrobial in 19%. Systemic antibiotics cleared CRB in 34% and an additional 23% cleared with the inclusion of antibiotic-heparin locks; 43% required catheter exchange. There was a significant likelihood of early catheter exchange with polymicrobial CRB (p0.01). Catheter loss occurred from infection in 63%. Risk factors for CRB included young age (10 years) and presence of human immunodeficiency virus (HIV) infection. Patients with2 initial positive blood cultures (p0.0001) had a significantly higher rate of recurrence after 6 weeks of initial treatment. In conclusion, CRB remains a major determinant of catheter loss. However, overall catheter survival is longer than infection-free catheter survival, suggesting that systemic antibiotics with antibiotic-heparin locks should be the initial step in the management of CRB and this approach may salvage some catheters.