Reducing Unnecessary Imaging in Children With Multicystic Dysplastic Kidney or Solitary Kidney.

BACKGROUND AND OBJECTIVES: Children with isolated unilateral multicystic dysplastic kidney (MCDK) or congenital solitary kidney (CSK) undergo serial renal ultrasonography with variable frequency until they are transitioned to adult care. A growing body of literature suggests the value of frequent ultrasonography in this population is limited, providing no benefit to overall outcomes. Despite emerging evidence, ultrasound remains overused, resulting in avoidable health care expenditures and unnecessary use of resources. With our initiative, we aimed to improve quality of care by reducing avoidable ultrasounds in these children. METHODS: This was a single-center, prospective, interrupted time series of children <18 years with ultrasound-confirmed isolated unilateral MCDK or CSK in the outpatient nephrology clinic to evaluate the effect of a decision-making algorithm on the proportion of children receiving an avoidable ultrasound. An algorithm depicting a consensus, evidence-based protocol for managing pediatric MCDK or CSK was refined through content expert feedback and usability testing to standardize frequency of ultrasonography. Ultrasounds were deemed necessary after birth, at 6 months, and at 2, 5, 10, and 15 years. Differences pre- and postintervention were determined by using a U chart and t and F tests for significance. RESULTS: The algorithm resulted in a 47% reduction (P < .001) in the proportion of avoidable ultrasounds ordered in children with MCDK and CSK. This reduction was sustainable over a 6-month period and would result in at least $46 000 annual savings. CONCLUSIONS: Introduction of a clinical decision-making algorithm was associated with a reduction in avoidable ultrasound testing. Improving adherence across providers may allow for an even more pronounced reduction.

Kidney disease in children with heart or liver transplant.

Over the past few decades, there has been increasing recognition of kidney disease in children with non-kidney solid organ transplantation. The risk of kidney disease in children undergoing heart or liver transplantation is higher than the general population as the underlying disease and its associated management may directly impair kidney function. Both heart and liver failures contribute to hypoperfusion and kidney ischemia before patients reach the point of transplant. The transplant surgery itself can often be complicated by acute kidney injury (AKI), which may be further exacerbated by a complicated postoperative course. In the short- and long-term post-transplant period, these children are at risk of acute illness, exposed to nephrotoxic medications, and susceptible to rare but severe infections and immunologic insults that may contribute to AKI and chronic kidney disease (CKD). In some, CKD can progress to kidney failure with replacement therapy (KFRT). CKD and KFRT are associated with increased morbidity and mortality in this patient population. Therefore, it is critical to monitor for and recognize the risk factors for kidney injury in this population and mitigate these risks. In this paper, the authors provide an overview of kidney disease pertaining to heart and liver transplantation in children with guidance on monitoring, diagnosis, prevention, and management.

Persistent secondary hyperparathyroidism after renal transplantation in children.

Secondary hyperparathyroidism (HPTH) is a frequent complication of chronic kidney disease (CKD). Renal transplantation corrects the biochemical abnormalities that cause HPTH; however, HPTH persists in some patients. The factors that contribute to the persistence of HPTH after transplantation in children are poorly understood. We examined 57 children who underwent renal transplantation and determined whether baseline clinical and biochemical parameters could predict the persistence of HPTH at 1 year post-transplantation, using multivariate logistic regression. At the time of transplantation, serum parathyroid hormone (PTH) levels were >300 pg/ml in 60%, 150-300 pg/ml in 17%, and <150 pg/ml in 23% of recipients. HPTH (PTH >73 pg/ml) persisted in 78% of patients at 6 months and in 56% at 1 year after transplant. Older age at transplantation was the strongest predictor of HPTH at 1 year (OR=1.17, P<0.05). After adjustment for age, other baseline clinical or laboratory parameters were not predictive of HPTH at 1 year. The relationship between older age and persistent HPTH may be explained by longer duration of CKD. Given the potential morbidities associated with persistent HPTH, the role of interventions that would prevent or reverse persistent HPTH post-transplantation requires further investigation.

Nephrogenic syndrome of inappropriate antidiuresis.

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common cause of hyponatremia. We describe two infants whose clinical and laboratory evaluations were consistent with the presence of SIADH, yet who had undetectable arginine vasopressin (AVP) levels. We hypothesized that they had gain-of-function mutations in the V2 vasopressin receptor (V2R). DNA sequencing of each patient's V2R gene (AVPR2) identified missense mutations in both, with resultant changes in codon 137 from arginine to cysteine or leucine. These novel mutations cause constitutive activation of the receptor and are the likely cause of the patients' SIADH-like clinical picture, which we have termed "nephrogenic syndrome of inappropriate antidiuresis."