Clinical morbidity in pediatric dialysis patients: data from the Network 1 Clinical Indicators Project

Long-term complications of systemic oxalosis in children-a retrospective single-center cohort study

BACKGROUND

Systemic oxalosis is a severe complication seen in primary hyperoxaluria type I patients with kidney failure. Deposition of insoluble calcium oxalate crystals in multiple organs leads to significant morbidity and mortality.

METHODS

We describe a retrospective cohort of 11 patients with systemic oxalosis treated at our dialysis unit from 1982 to 1998 (group 1) and 2007-2019 (group 2). Clinical and demographic data were collected from medical records. Imaging studies were only available for patients in group 2 (n = 5).

RESULTS

Median age at dialysis initiation was 6.1 months (IQR 4-21.6), 64% were male. Dialysis modality was mostly peritoneal dialysis in group 1 and daily hemodialysis in group 2. Bone disease was the first manifestation of systemic oxalosis, starting with the appearance of sclerotic bands (mean 166 days, range 1-235), followed by pathological fractures in long bones (mean 200.4 days, range 173-235 days). Advanced disease was characterized by vertebral fractures with resulting kyphosis, worsening splenomegaly, and adynamic bone disease. Two patients developed pulmonary hypertension, 4 and 8 months prior to their death. Four of 11 patients developed hypothyroidism 0-60 months after dialysis initiation. Only one patient survived after a successful liver-kidney transplantation. Four patients died after liver or liver-kidney transplantation.

CONCLUSIONS

This is the first comprehensive description of the natural history of pediatric systemic oxalosis. We hope that our findings will provide basis for a quantitative severity score in future, larger studies.

Optimizing peritoneal dialysis prescription for volume control: the importance of varying dwell time and dwell volume

Not only adequate uremic toxin removal but also volume control is essential in peritoneal dialysis (PD) to improve patient outcome. Modification of dwell time impacts on both ultrafiltration (UF) and purification. A short dwell favors UF but preferentially removes small solutes such as urea. A long dwell favors uremic toxin removal but also peritoneal fluid reabsorption due to the time-dependent loss of the crystalloid osmotic gradient. In particular, the long daytime dwell in automated PD may result in significant water and sodium reabsorption, and in such cases icodextrin should be considered. Increasing dwell volume favors the removal of solutes such as sodium due to the increased volume of diffusion and the recruitment of peritoneal surface area. A very large fill volume with too high an intraperitoneal pressure (IPP) may, however, result in back-filtration and thus reduced UF and sodium clearance. Based on these principles and the individual transport and pressure kinetics obtained from peritoneal equilibration tests and IPP measurements, we suggest combining short dwells with a low fill volume to favor UF with long dwells and a large fill volume to favor solute removal. Results from a recent randomized cross-over trial and earlier observational data in children support this concept: the absolute UF and UF relative to the administered glucose increased and solute removal and blood pressure improved.

Long-term outcome of chronic dialysis in children

As the prevalence of children on renal replacement therapy (RRT) increases world wide and such therapy comprises at least 2% of any national dialysis or transplant programme, it is essential that paediatric nephrologists are able to advise families on the possible outcome for their child on dialysis. Most children start dialysis with the expectation that successful renal transplantation is an achievable goal and will provide the best survival and quality of life. However, some will require long-term dialysis or may return intermittently to dialysis during the course of their chronic kidney disease (CKD). This article reviews the available outcome data for children on chronic dialysis as well as extrapolating data from the larger adult dialysis experience to inform our paediatric practice. The multiple factors that may influence outcome, and, particularly, those that can potentially be modified, are discussed.

Serum albumin level and risk for mortality and hospitalization in adolescents on hemodialysis

BACKGROUND AND OBJECTIVES

National Kidney Foundation Dialysis Outcomes Quality Initiative practice guidelines recommend serum albumin > or = 4.0 g/dl for adults who are on hemodialysis. There is no established pediatric target for albumin and little evidence to support use of adult guidelines. This study examined the association between albumin and risk for death and hospitalization in adolescents who are on hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study linked data on patients aged 12 to 18 yr in 1999 and 2000 from the Centers for Medicare and Medicaid Services' End Stage Renal Disease Clinical Performance Measures Project with 4-yr hospitalization and mortality records in the United States Renal Data System. Albumin was categorized as < 3.5/3.2, > or = 3.5/3.2 and < 4.0/3.7, and > or = 4.0/3.7 g/dl.

RESULTS

Of 675 adolescents, 557 were hospitalized and 50 died. Albumin > or = 4.0/3.7 g/dl was associated with male gender, Hispanic ethnicity, and higher hemoglobin level. Those with albumin > or = 4.0/3.7 g/dl had fewer deaths per 100 patient-years and fewer hospitalizations per time at risk. In multivariate analysis, patients with albumin > or = 4.0/3.7 g/dl had 57% decreased risk for death. Poisson regression showed progressive decrease in hospitalization risk as albumin level increased; however, confidence intervals were similar between albumin > or = 4.0/3.7 g/dl and albumin > or = 3.5/3.2 and < 4.0/3.7 g/dl.

CONCLUSIONS

This study demonstrates decreased mortality and hospitalization risk with albumin > or = 3.5/3.2 g/dl and suggests that adolescent hemodialysis patients who are able to achieve serum albumin > or = 4.0/3.7 g/dl may have the lowest mortality risk.

Nutrition in children with CRF and on dialysis

The objectives of this study are: (1) to understand the importance of nutrition in normal growth; (2) to review the methods of assessing nutritional status; (3) to review the dietary requirements of normal children throughout childhood, including protein, energy, vitamins and minerals; (4) to review recommendations for the nutritional requirements of children with chronic renal failure (CRF) and on dialysis; (5) to review reports of spontaneous nutritional intake in children with CRF and on dialysis; (6) to review the epidemiology of nutritional disturbances in renal disease, including height, weight and body composition; (7) to review the pathological mechanisms underlying poor appetite, abnormal metabolic rate and endocrine disturbances in renal disease; (8) to review the evidence for the benefit of dietetic input, dietary supplementation, nasogastric and gastrostomy feeds and intradialytic nutrition; (9) to review the effect of dialysis adequacy on nutrition; (10) to review the effect of nutrition on outcome.

Advances in renal replacement therapy as a bridge to renal transplantation

While renal transplantation remains the most prevalent treatment for children with end-stage renal disease, the majority of children incident to ESRD receive dialytic therapy prior to receiving a renal allograft and 25% of children are still receiving dialytic therapy 36 months after achieving ESRD. The current review discusses the most recent advancements in both hemodialysis and PD therapies to provide optimal care for children as a bridge until renal transplantation. Areas covered include dialysis dose assessment, target dry weight assessment, vascular access and advancements in PD technology.

Anemia and growth status in pediatric patients receiving maintenance dialysis after a failed renal transplant course: an NAPRTCS report

We conducted a retrospective review of the North American Renal Transplant Cooperative Study (NAPRTCS) Registry transplant and dialysis arms to assess anemia and growth patterns in children who returned to dialysis after a failed renal transplant from January 1, 1992 to February 3, 2004. Of the 1807 potential study subjects, 1451 had transplant removal data (TxIn vs. TxOut) available for analysis. Four hundred and twenty-one of 1451 patients (29%) had a transplant nephrectomy at the time of entry into the NAPRTCS Registry Dialysis arm. Anemia rates steadily decreased from 72.2% at 30 days after dialysis initiation to 59.5% at 12 months after dialysis initiation. Factors associated with anemia at 30 days after dialysis initiation included hemodialysis, lack of Epo use, and patients who comprised earlier study era cohorts. At one yr after return to dialysis, earlier study cohort era was the only factor associated with anemia status. Patients did not demonstrate significant improvement in height SDS over the course of the study (-2.17 at day 30 to -2.32 at 24 months). The high anemia, poor growth, and low recombinant human growth hormone utilization rates in a group of patients followed longitudinally as they transition from renal transplant to dialysis should cause the pediatric nephrology community to reassess the processes in place to provide optimal care to pediatric end-stage renal disease patients.

Clinical outcomes and dialysis adequacy in adolescent hemodialysis patients

BACKGROUND

The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative guidelines recommend that adult hemodialysis (HD) patients receive a minimum dialysis dose by single-pooled Kt/V (spKt/V) of 1.2 or greater. There are no data to support a minimum spKt/V dose for children on HD therapy. We aim to determine the association of spKt/V with mortality and hospitalization in adolescents.

METHODS

Clinical characteristics of adolescent HD patients aged 12 to 18 years old included in the 2000/2001 End-Stage Renal Disease Clinical Performance Measures Project were linked to US Renal Data System data from October 1, 1999, to October 15, 2001. Hospitalization risks after adjustment for time on dialysis therapy, access, hemoglobin level, albumin level, and height were determined by means of Poisson regression. spKt/V was analyzed by the adult target (< versus > or = 1.2) and by intervals.

RESULTS

There were 613 patients with 477 patient-years of follow-up, during which there were 14 deaths and 185 hospitalizations covering 1,108 days. After adjustment, patients with an spKt/V less than 1.2 had increased hospitalization risk (1.59; 95% confidence interval, 0.98 to 2.56; P = 0.06) compared with those with an spKt/V of 1.2 or greater. Compared with patients with an spKt/V of 1.2 to 1.4, patients with an spKt/V less than 1.2 had increased adjusted risk for hospitalization (2.46; 95% confidence interval, 1.23 to 4.94; P = 0.01). Increases in spKt/V beyond 1.4 were not associated with improved outcomes.

CONCLUSION

Applying the current adequacy guideline to adolescent HD patients is justified by the increased hospitalization risk of those who fail to attain an spKt/V of 1.2 or greater. However, attaining an spKt/V in excess of 1.4 was not associated with greater benefit.

Noninvasive interventions to decrease hospitalization and associated costs for pediatric patients receiving hemodialysis

Minimal pediatric data describe hospitalization causes and associated costs for children who receive maintenance hemodialysis, and no data exist to evaluate methods to decrease hospitalization. In 1999, two common causes of hemodialysis patient hospitalization at Texas Children's Hospital were fluid overload/hypertension (FO/HTN) and vascular access thrombosis (VAT). Evaluated is the effect of two noninvasive monitoring programs, monitoring of hematocrit-guided ultrafiltration algorithm and vascular access flow using ultrasound dilution vascular access flow technology, on FO/HTN and VAT in the pediatric maintenance hemodialysis population. This prospective observational study reviewed all hospitalization data for all 51 patients who received maintenance hemodialysis from January 1999 through December 2001 obtained from unit monthly performance improvement meeting records. Hospitalization rates and related costs for FO/HTN and VAT were tracked before and after institution of the noninvasive monitoring programs. Application of the noninvasive monitoring of hematocrit-guided ultrafiltration algorithm since January 2000 significantly decreased hospitalization for FO/HTN (64 total days in 1999, 4 total days in 2000 and 2001 combined) while maintaining acceptable patient BP control and minimizing antihypertensive medication requirements. The vascular access monitoring program using ultrasound dilution vascular access flow technology to direct referral for angioplasty instituted in January 2001 led to a significant decrease in hospitalization for VAT (45 d in 2000 and 21 d in 2001). It is suggested that application of noninvasive technologies to assess patient target dry weight and access flow can significantly decrease pediatric maintenance dialysis patient morbidity and health care cost.