Treatment of infant formula with patiromer dose dependently decreases potassium concentration

Assessment and management of magnesium and trace element status in children with CKD stages 2-5, on dialysis and post-transplantation: Clinical practice points from the Pediatric Renal Nutrition Taskforce

Children and young people with chronic kidney disease (CKD) are at risk for deficiency or excess of magnesium and trace elements. Kidney function, dialysis, medication, and dietary and supplemental intake can affect their biochemical status. There is much uncertainty about the requirements of magnesium and trace elements in CKD, which leads to variation in practice. The Pediatric Renal Nutrition Taskforce is an international team of pediatric kidney dietitians and pediatric nephrologists, formed to develop evidence-based clinical practice points to improve the nutritional care of children with CKD. PICO (patient, intervention, comparator, and outcomes) questions led the literature searches, which were conducted to ascertain current biochemical status, dietary intake, and factors leading to requirements differing from healthy peers, and to guide nutritional care of children with CKD stages 2-5, on dialysis, and post-transplantation. We address the assessment and intervention of magnesium and the trace elements chromium, copper, fluoride, iodine, manganese, selenium, and zinc. We suggest routine biochemical assessment of magnesium. Trace element assessment is based on clinical suspicion of deficiency or excess and their risk factors, including accumulation, losses, medications, nutrient interactions, and comorbidities. In particular, we suggest assessing magnesium, copper, iodine, and zinc when growth is poor, and evaluating magnesium, copper, selenium, and zinc in the presence of proteinuria. A structured approach to magnesium and trace element management, including biochemical, physical, and dietary assessment, is beneficial in the paucity of evidence. Research recommendations are suggested.

Predictors of hyperkalemia in pediatric patients on dialysis: international prospective observational study

BACKGROUND

Hyperkalemia is an important issue in kidney failure. The aim of the study was to investigate the predictors of hyperkalemia in children receiving maintenance dialysis.

METHODS

This was an international prospective cross-sectional observational study involving patients < 18 years receiving chronic hemodialysis or peritoneal dialysis. Hyperkalemia was defined as serum potassium (sK+) ≥ 5 mEq/L based on the Pediatric Renal Nutrition Taskforce recommendations. We recorded age, dialysis vintage, urine output (24-h urine collection); dietary K+, energy, protein and sodium intake (three-day diaries); office blood pressure (BP) in children < 5 years and 24-h ABPM in older patients; biochemistry (creatinine, urea, sodium, bicarbonate, hemoglobin, phosphate, albumin) and antihypertensive drugs.

RESULTS

Forty-one patients were enrolled (10 peritoneal dialysis, 31 hemodialysis), median age 13.3 (IQR 10.6-15.8) years; 15 of them (36.6%) showed hyperkalemia, and median sK+ was 4.7 (4.4-5.0) mEq/L. Renin-angiotensin-aldosterone system inhibitors (RAASi) were prescribed in 9/15 patients with hyperkalemia (60%) and 7/26 (26.9%) without hyperkalemia (p = 0.04). Patients with hyperkalemia were older and had higher urea and creatinine than those with normal sK+. A backward stepwise multivariable model showed that the only predictors of hyperkalemia were age (b = 0.53, p = 0.01), urea (b = 0.02, p = 0.03) and treatment with RAASi (b = 2.75, p = 0.021).

CONCLUSIONS

While higher age, higher urea levels and treatment with RAASi independently predicted the occurrence of hyperkalemia, K+ intake was not associated with sK+ in children on dialysis. This emphasizes the importance of considering non-dietary causes of hyperkalemia and considering the bioavailability of K+ more than the total dietary K+ intake.

Case report: Early molecular confirmation and sodium polystyrene sulfonate management of systemic pseudohypoaldosteronism type I

Introduction

Type 1 pseudohypoaldosteronism (PHA) consists of resistance to aldosterone. Neonatal presentation is characterized by salt wasting, hyperkalemia, and metabolic acidosis with high risk of mortality. Type 1 PHA can be autosomal dominant (renal type 1) or autosomal recessive (systemic type 1). Renal PHA type 1 can be feasibly managed with salt supplementation; however, systemic PHA type 1 tends to have more severe electrolyte imbalance and can be more refractory to treatment.

Case Presentation

We present a case of a 3-year-old girl with systemic PHA type 1, diagnosed and confirmed molecularly in infancy, who has been successfully managed with sodium polystyrene sulfonate decanted into feeds along with sodium supplementation. On day 5 of life, a full-term female infant presented to the ED for 2 days of non-bloody, non-bilious emesis, along with hypothermia to 94°F. Laboratory results were notable for hyponatremia (Na) of 127, hyperkalemia (K) of 7.9, and acidosis with bicarbonate level of 11.2. Genetic testing ordered within a week of life confirmed PHA type 1 with a homozygous pathogenic frameshift variant in SCNN1A c.575delA (p.Arg192GlyfsX57). Sodium polystyrene sulfonate and feeds were decanted until the age of 16 months, and she was also continued on NaCl supplementation. She was gradually transitioned to directly administered sodium polystyrene sulfonate without any electrolyte issues. She has overall done well after gastrostomy-tube (G-tube) placement without severe hyperkalemia even with several hospitalizations for gastrointestinal or respiratory illnesses.

Discussion/Conclusion

A treatment approach to systemic PHA and sodium polystyrene sulfonate administration in neonates and infants is described.

Nutritional management of the infant with chronic kidney disease stages 2-5 and on dialysis

The nutritional management of children with chronic kidney disease (CKD) is of prime importance in meeting the challenge of maintaining normal growth and development in this population. The objective of this review is to integrate the Pediatric Renal Nutrition Taskforce clinical practice recommendations for children with CKD stages 2-5 and on dialysis, as they relate to the infant from full term birth up to 1 year of age, for healthcare professionals, including dietitians, physicians, and nurses. It addresses nutritional assessment, energy and protein requirements, delivery of the nutritional prescription, and necessary dietary modifications in the case of abnormal serum levels of calcium, phosphate, and potassium. We focus on the particular nutritional needs of infants with CKD for whom dietary recommendations for energy and protein, based on body weight, are higher compared with children over 1 year of age in order to support both linear and brain growth, which are normally maximal in the first 6 months of life. Attention to nutrition during infancy is important given that growth is predominantly nutrition dependent in the infantile phase and the growth of infants is acutely impaired by disruption to their nutritional intake, particularly during the first 6 months. Inadequate nutritional intake can result in the failure to achieve full adult height potential and an increased risk for abnormal neurodevelopment. We strongly suggest that physicians work closely with pediatric renal dietitians to ensure that the infant with CKD receives the best possible nutritional management to optimize their growth and development.

A case of 1-month-old female infant delaying peritoneal dialysis introduction by low-potassium anti-allergic formula treated with sodium polystyrene sulfonate

The 8806H formula is the only renal formula available for pediatric patients with chronic kidney disease in Japan. A 1-month-old female infant could not be administered 8806H because of milk allergy. Administration of low-potassium anti-allergic formula treated with sodium polystyrene sulfonate maintained adequate serum potassium levels, and introduction of peritoneal dialysis could be delayed. The patient had severe renal dysfunction secondary to bilateral hypoplastic and multi-cystic kidneys. Although she received the 8806H formula, this product was switched to hydrolyzed casein formula because she developed allergy to 8806H at 28 days of age, which led to hyperkalemia. We initiated treatment with sodium polystyrene sulfonate at 40 days of age to lower the potassium concentration in milk, which prevented hyperkalemia and maintained the patient's nutritional status to ensure appropriate increase in body weight. We monitored electrolyte levels in milk and confirmed reduction in potassium levels before feeding. Although such condition is rare and there are few reports of potassium reduction in anti-allergic formulas, this strategy may be useful for pediatric patients with renal insufficiency who cannot be treated with renal formulas because of milk allergy.

The dietary management of potassium in children with CKD stages 2-5 and on dialysis-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Dyskalemias are often seen in children with chronic kidney disease (CKD). While hyperkalemia is common, with an increasing prevalence as glomerular filtration rate declines, hypokalemia may also occur, particularly in children with renal tubular disorders and those on intensive dialysis regimens. Dietary assessment and adjustment of potassium intake is critically important in children with CKD as hyperkalemia can be life-threatening. Manipulation of dietary potassium can be challenging as it may affect the intake of other nutrients and reduce palatability. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations (CPRs) for the dietary management of potassium in children with CKD stages 2-5 and on dialysis (CKD2-5D). We describe the assessment of dietary potassium intake, requirements for potassium in healthy children, and the dietary management of hypo- and hyperkalemia in children with CKD2-5D. Common potassium containing foods are described and approaches to adjusting potassium intake that can be incorporated into everyday practice discussed. Given the poor quality of evidence available, a Delphi survey was conducted to seek consensus from international experts. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs, based on the clinical judgment of the treating physician and dietitian. These CPRs will be regularly audited and updated by the PRNT.