Persistent Increase in Serum Ferritin Levels despite Converting to Permanent Vascular Access in Pediatric Hemodialysis Patients: Pediatric Nephrology Research Consortium Study.

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.

NSAID-associated acute kidney injury in hospitalized children - a prospective Pediatric Nephrology Research Consortium study.

BACKGROUND: Acute kidney injury (AKI) in children has serious short-term and long-term consequences. We sought 1) to prospectively describe NSAID-associated AKI in hospitalized children; 2) to determine if NSAID-associated AKI was more severe in younger children < 5 years; and 3) to follow outcomes after hospitalization for NSAID-associated AKI. METHODS: This was a prospective, multi-center study in hospitalized children 1 month to 18 years. Parents/guardians were given a brief questionnaire to determine the dosing, duration, and type of NSAIDs given. Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria were used to stage AKI severity. Patients with other causes of AKI were excluded (e.g., other nephrotoxins, sepsis, malignancy, etc.). RESULTS: We identified 25 patients with NSAID-associated AKI, accounting for 3.1% of AKI. All 25 had AKI upon hospital presentation. The median age was 15.5 years, and 20/25 (80%) had volume depletion. Median duration of NSAID use was 2 days, and 63% of patients took the normal recommended NSAID dose. Median hospital length of stay was 4 days, and none required dialysis. At the most recent estimated glomerular filtration rate (eGFR) after discharge (available in 17/25 patients), only 4/17 (24%) had eGFR ≥ 90 ml/min/1.73 m2, and 13/17 (76%) had eGFR 60 to < 90 ml/min/1.73 m2, indicative of abnormal kidney function. CONCLUSIONS: NSAID-associated AKI usually occurs with recommended NSAID dosing in the setting of dehydration. Follow-up after AKI showed a substantial rate of CKD. Therefore, we recommend that NSAIDs should not be used in dehydrated children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Conversion to permanent vascular access is associated with improved markers of hemodialysis efficacy in children: Pediatric nephrology research consortium study.

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 < 0.0001). Furthermore, PVA was associated with improved serum albumin by 0.31 ± 0.07 g/dL (p < 0.0001) and Hct by 2.80 ± 0.65% (p < 0.0001) at 1 year. These HD efficacy markers remained statistically significant at 2nd-year follow-up. These observations were further supported by the adjusted models. Conversion to AVF was associated with statistically significant improvement in all four markers of HD efficacy at 1-year follow-up. This trend was not demonstrated for subjects who were converted to AVG. CONCLUSION: Switching to PVA was associated with improved markers of HD efficacy, single-pool Kt/V, URR, serum albumin, and Hct. This improvement was mostly demonstrated at 1 year and maintained for the 2nd year. The potential differential impact of the type of PVA on the trajectory of markers of HD efficacy should be further investigated.

Predictors of time to first cannulation for arteriovenous fistula in pediatric hemodialysis patients: Midwest Pediatric Nephrology Consortium study.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Correction to: Predictors of patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients.

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.

Predictors of patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients.

BACKGROUND: 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. METHODS: Retrospective chart reviews were performed for first PVAs in 20 participating centers. Variables collected included patient demographics, complications, interventions, and final outcome. RESULTS: 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. CONCLUSIONS: 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.

Sport-related kidney injury among high school athletes.

BACKGROUND AND OBJECTIVE: The American Academy of Pediatrics recommends a "qualified yes" for participation by athletes with single kidneys in contact/collision sports. Despite this recommendation, most physicians continue to discourage participation in contact/collision sports for patients with single kidneys. A major concern is the lack of prospective data quantifying the incidence of sport-related kidney injury. The objective was to quantify the incidence of sport-related kidney injury among high school varsity athletes and compare it with sport-related injuries of other organ systems. METHODS: Data from the National Athletic Trainers' Association High School Injury Surveillance Study, an observational cohort study collected during the 1995-1997 academic years, were used. Incidence rates for sport-specific injuries to select organs were computed and compared. RESULTS: Over 4.4 million athlete-exposures, defined as 1 athlete participating in 1 game or practice, and 23,666 injuries were reported. Eighteen kidney injuries, none of which were catastrophic or required surgery, were reported compared with 3450 knee, 2069 head/neck/spine, 1219 mild traumatic brain, 148 eye, and 17 testicle injuries. Student athletes incurring kidney injuries were most often playing football (12 injuries) or girls' soccer (2 injuries). Sport-specific rates of kidney injury were significantly lower than sport-specific rates of mild traumatic brain, head/neck/spine, and knee injuries for all sports as well as rates of baseball- and basketball-specific eye injuries (P < .01). CONCLUSIONS: Kidney injuries occur significantly less often than other injuries during sport. These data do not support limiting sport participation by athletes with single kidneys.

At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension.

Hypertension affects 1-5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review.

Single kidney and sports participation: perception versus reality.

OBJECTIVES: Physician opinions and practice patterns regarding the participation of children and adolescents with single, normal kidneys in contact/collision sports are widely varied. We hypothesize that limitation of participation from play based only on the presence of a single kidney is not supported by available data. We sought to determine recommendations of pediatric nephrologists regarding the participation of patients with single, normal kidneys in contact/collision sports and review the literature to determine the rate of sports-related kidney injury compared with other organs. METHODS: Members of the American Society of Pediatric Nephrology were surveyed regarding their recommendations for participation of patients with single, normal kidneys in contact/collision sports. Medical and sports literature databases were searched to determine sports-related kidney, brain, spinal cord, and cardiac injury rates and the sports associated with kidney injury. RESULTS: Sixty-two percent of respondents would not allow contact/collision sports participation. Eighty-six percent of respondents barred participation in American football, whereas only 5% barred cycling. Most cited traumatic loss of function as the reason for discouraging participation. The literature search found an incidence of catastrophic sports-related kidney injury of 0.4 per 1 million children per year from all sports. Cycling was the most common cause of sports-related kidney injury causing > 3 times the kidney injuries as football. American football alone accounted for 0.9 to 5.3 fatal brain injuries and 4.9 to 7.3 irreversible spinal cord injuries per 1 million players per year. Commotio cordis causes 2.1 to 9.2 deaths per year. CONCLUSIONS: Most pediatric nephrologists prohibit contact/collision sports participation by athletes with a single kidney, particularly football. The available evidence suggests that cycling is far more likely to cause kidney injury. In addition, kidney injury from sports is much less common than catastrophic brain, spinal cord, or cardiac injury. Restricting participation of patients with a single, normal kidney from contact/collision sports is unwarranted.