Ira D. Davis

Cognitive functioning in children on dialysis and post‐transplantation

Abstract: We studied 124 children, 62 patient‐subjects who had end‐stage renal disease (ESRD) and 62 sibling‐controls who closely matched the patient‐subjects in terms of their ethnicity and their socioeconomic status, to discern whether children with ESRD would perform less well than their siblings on standardized achievement and intelligence quotient (IQ) tests, and to determine whether ethnicity would influence such results. The subjects were recruited from nine pediatric transplant and dialysis centers across the United States. Thirty‐one subjects were white (Euro‐American), 17 were African‐American, and 14 were categorized as ‘other’. The average age of the patient‐subjects was 13.7 ± 0.44 yr; and of the sibling‐controls 13.7 ± 0.38 yr. Most patients (61%) and siblings (84%) were in regular school classes, and most (87% and 92%, respectively) attended school full‐time. The average IQ percentile rank for the patients was significantly lower than their siblings (31 ± 4 vs. 44 ± 5, respectively, with normal = 50). Patients tended to score lower on achievement tests compared with their siblings (spelling: 88.7 ± 4 vs. 94.6 ± 2; arithmetic: 88.5 ± 2 vs. 94.0 ± 2; reading: 91.9 ± 2 vs. 100 ± 3, respectively). Patients scores on achievement tests were influenced by age at diagnosis and by the mother/caregivers lower achievement. Also, increased time on dialysis predicted lower scores on achievement tests. Neither dialysis/transplant status nor ethnicity significantly affected outcome. Our data suggest that ESRD, but not ethnicity or dialysis/transplant status, is a risk factor for lower IQ and academic achievement, especially in younger children, in children who spend more time living with ESRD, and in children whose mothers/caregivers have lower educational levels.

Survival of childhood polycystic kidney disease following renal transplantation: the impact of advanced hepatobiliary disease.

Abstract: Childhood PKD encompasses the diagnoses of AR and ADPKD, glomerulocystic disease, and syndromes such as tuberous sclerosis or Jeunes syndrome. Given the fact that a majority of PKD children with ESRD carry the diagnosis of ARPKD, natural history studies assessing the long‐term prognosis of PKD patients following renal transplantation must focus on morbidity and mortality issues related to complications from congenital hepatic fibrosis. Using the NAPRTCS registry, we analyzed the patient and graft survival rates of 203 PKD patients and 7044 non‐PKD patients undergoing renal transplantation between 1987 and 2001. Deceased PKD patients, all with a diagnosis of ARPKD, were further identified and characterized using a special questionnaire submitted to the principal investigators. Overall graft and patient survival rates were not significantly different between PKD and non‐PKD patients. No differences in rates of acute rejection or time to first rejection were noted between PKD and non‐PKD patients. The relative risk of living longer than 3 yr in the PKD patients was not significantly different from non‐PKD patients (RR = 0.70, p = 0.28). Sepsis was identified as a likely factor in the cause of death in nine (64%) ARPKD patients and was comfirmed with a positive blood culture in four patients. Despite similar graft and patient survival rates among PKD and non‐PKD children following renal transplantation, our results suggest that ARPKD transplant recipients appear to be at increased risk for sepsis that may be related to hepatic fibrosis and ascending cholangitis. The utility of early liver transplantation in ARPKD patients with significant hepatobiliary disease is discussed.

Urolithiasis with topiramate in nonambulatory children and young adults.

Urolithiasis occurs infrequently in the pediatric population, where metabolic factors play a primary role in the pathogenesis of stone formation. Topiramate, an antiepileptic drug, is associated with a kidney stone in 1.5% of patients in published clinical trials. However, this risk may be much higher in certain populations with multiple preexisting risk factors. We performed a retrospective review of all nonambulatory and neurologically impaired individuals in a long-term care facility. Three groups were involved: those with no exposure to antiepileptic drugs, those on antiepileptic drugs other than topiramate, and those who had been treated with topiramate. Thirteen of 24 (54%) individuals on topiramate monotherapy or polytherapy developed clinical evidence of urolithiasis after a mean duration of 36.4 months. Our results suggest that nonambulatory and neurologically impaired individuals in a long-term care facility appear to be at higher risk of developing kidney stones with topiramate than previously reported.

Prevalence of sleep disturbances in children and adolescents with chronic kidney disease

Although sleep disorders are common in adults with chronic kidney disease, little is known about the prevalence of sleep problems in children and adolescents with chronic kidney disease and their relationship to health-related quality of life measurements. We performed a clinic-based survey of sleep habits and common symptoms of sleep disturbances in 159 school-aged patients with chronic kidney disease. Three patient groups of chronic kidney disease were assessed: group 1, those not on dialysis and not transplanted; group 2, those on dialysis; and group 3, those with a functioning renal allograft. Four symptom domains for sleep disorders were assessed: excessive daytime sleepiness; sleep disordered breathing; restless legs syndrome symptoms; and insufficient sleep. Patients and the parent-proxy also completed the Pediatric Quality of Life Inventory Version 4.0 Generic Core Scales questionnaire. Ninety-three (93) patients (58.5%) had symptoms of a sleep disturbance. The presence of a sleep disturbance correlated with a decrease in health-related quality of life scores that was independent of the chronic kidney disease study group or estimated glomerular filtration rate. We conclude that sleep disturbances are common throughout the spectrum of chronic kidney disease in children and adolescents and are associated with diminished health-related quality of life scores.

Sleep Disturbances in Children and Adolescents With Non-Dialysis-Dependent Chronic Kidney Disease

BACKGROUND While studies have shown sleep disorders to be common in adults with chronic kidney disease (CKD), pediatric data are scarce. OBJECTIVE To characterize the prevalence of sleep disorders among children and adolescents with non-dialysis-dependent CKD. DESIGN Prospective, questionnaire-based, cross-sectional study. SETTING Tertiary pediatric nephrology center. PARTICIPANTS Children aged 6 to 18 years with non-dialysis-dependent CKD. Those with renal transplants were also considered to have CKD and were included, provided it was at least 3 months after the transplant. INTERVENTIONS A validated pediatric sleep questionnaire. OUTCOME MEASURES Four domains of sleep disturbance were assessed: sleep-disordered breathing, restless leg syndrome/paroxysmal leg movement (RLS/PLM), insomnia, and excessive daytime sleepiness. Positive responses to any of these signified the presence of a sleep disorder. RESULTS A total of 49 non-dialysis-dependent children (30 with non-renal transplant CKD and 19 with post-renal transplant CKD; median age, 14 years; interquartile range, 6-18 years) were administered the pediatric sleep questionnaire; 71% (n = 35) of the patients were male; 37% (n = 18) were identified as having a sleep disorder; 40% (n = 12) were in the nontransplant CKD group and 32% (n = 6) in the transplant CKD group. The most common type of sleep disorder was RLS/PLM, affecting 27% (n = 8) in the nontransplant CKD group and 32% (n = 6) in the transplant CKD group. There was no correlation between stage of CKD and prevalence of sleep problems (P = .22). CONCLUSIONS Disordered sleep was identified in more than one-third of our study population, and the most common type was RLS/PLM. Pediatricians should be aware of the relatively high incidence of sleep disorder among children and adolescents with CKD.

Pediatric renal biopsy: should this procedure be performed in an outpatient setting?

Abstract. Although several retrospective reports suggest that pediatric outpatient renal biopsies may be done in a safe and cost-effective manner, risk factors and the natural history of major complications following this procedure have not been clearly delineated. In an effort to determine the minimal observation period required to detect major post-renal biopsy complications in children and to establish clinical parameters predictive of these complications, a retrospective review of 177 percutaneous renal biopsies was performed. The overall major complication rate was 3.4%, while the minor complication rate was 14.1%. The mean percentage change in hemoglobin 4 – 10 h postbiopsy in patients with major bleeding complications was significantly greater than patients with minor bleeding complications. Using a 16% drop in hemoglobin 4 – 10 h postbiopsy, the sensitivity and specificity of identifying a major bleeding complication was 100% and 98%, respectively, while the positive and negative predictive value was 68% and 100%, respectively. All patients with major complications due to excess sedation or immediate bleeding were diagnosed within 11 h of the biopsy. Automated renal biopsies offered several safety and efficiency advantages compared with non-automated methods. Our results suggest that outpatient pediatric renal biopsies should be encouraged provided certain precautions are taken to reduce the risk of developing major complications.

Complications of peritoneal dialysis in children with Eagle-Barrett syndrome

Abstract.Eagle Barrett syndrome (EBS) is characterized by the triad of abdominal muscle deficiency, urinary tract abnormalities, and cryptorchidism. Approximately 25% of patients with EBS progress to end-stage renal disease. It is speculated that the abdominal muscular defects in EBS pose technical problems in achieving successful peritoneal dialysis (PD). In this retrospective analysis, we reviewed the medical records of EBS and non-EBS PD patients cared for at Rainbow Babies and Childrens Hospital from 1985 to 2002; 5 EBS and 9 non-EBS patients were analyzed. PD duration, total complication rates, and catheter usage rates in the two groups were not significantly different. The two most frequent complications were peritonitis and catheter mechanical malfunction during 103 patient-months in EBS patients and 296 patient-months in non-EBS patients. Peritonitis occurred 1 episode every 20.6 patient-months and 14.8 patient-months in EBS and non-EBS patients, respectively. The time from PD initiation to onset of any complication, including first peritonitis, was not significantly different in the two groups. Although the age at PD initiation was significantly different between the groups, there was no correlation between age at onset of PD and complication rates or time to first complication. Despite their abdominal muscle defects, EBS patients do not have more-frequent PD complications.