Sodium polystyrene sulfonate used to reduce the potassium content of a high-protein enteral formula: a quantitative analysis

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.

[Case report of an infant hyperkalemia: Suggestion of a hospital procedure for the milk pretreatment with sodium polystyrene sulfonate resin]

Sodium polystyrene sulfonate (SPS) is used to reduce intestinal potassium absorption in hyperkalemia during conservative management of chronic renal failure in infants. Milk can be pretreated by SPS to reduce the risk of enteropathy associated with oral or rectal administration. We report the case of an infant for whom this pre-treatment has been implemented. The objective of this work was to define the hospital procedure for the pre-treatment of milk by the SPS. This pre-treatment involves both a drug and infant milk. Each product has its own regulation and their processes do not normally cross each other. The roles of each contributor were therefore defined: prescription of pre-treated milk (dose of SPS and volume of milk) by the physician, dispensing of SPS by the pharmacist, delivery of milk by the milk kitchen staff, pre-treatment by a nurse and administration by a nursing auxiliary. The preparation of the bottles is as follows: placing approximately 1g of SPS per 100mL of milk in contact, stirring, resting in the refrigerator for one hour, taking the supernatant to be administered. In the reported case, serum potassium levels were reduced from 5.57mmol/L before treatment to 4.53mmol/L after treatment, in line with the 20% decrease found in the literature. This method of administration is beneficial in terms of tolerance and acceptability. The preparation is simple and allows going back home under treatment.

Let food be thy medicine and medicine be thy food?

Ensuring adequate nutrition in children with chronic kidney disease whilst avoiding hyperkalaemia can be a difficult balance to achieve. Pre-treatment of feeds, whether milk, formula or enteral nutrition, with sodium polystyrene sulfonate (SPS) is practiced in some paediatric centres internationally. Such treatments are purported to avoid the potentially serious complications of direct administration of SPS, such as intestinal necrosis, aspiration pneumonitis and metabolic alkalosis to name but a few. Although described some 45 years ago, this study by Palma et al. is only the second retrospective study to describe the clinical consequence of pre-treating feeds with SPS with the majority of earlier studies describing only the in vitro effects of this method. Whilst effective in reducing serum potassium, the authors justifiably highlight the high incidence of complications, such as hypokalaemia (31.6%) and hypernatraemia (26.3%). We have further highlighted this with a summary of the available literature on this subject demonstrating the gross alterations of the electrolyte composition of feeds following SPS pre-treatment and clinical complications in its application. We heartily agree and support the conclusion by Palma et al. that where this therapy is practiced, close monitoring of electrolytes is essential and much more work is needed to identify those patient cohorts for which this can indeed be considered a safe and effective intervention.

Pretreatment of enteral nutrition with sodium polystyrene sulfonate: effective, but beware the high prevalence of electrolyte derangements in clinical practice

Background

Current treatment options for chronic hyperkalemia in children with chronic kidney disease include dietary restrictions or enteral sodium polystyrene sulfonate (SPS); however, dietary restrictions may compromise adequate nutrition and enteral SPS may be limited by palatability, adverse effects and feeding tube obstruction. A potentially safer alternative is to pretreat enteral nutrition (EN) with SPS prior to consumption. The purpose of this study was to evaluate the efficacy and safety of pretreating EN with SPS in pediatric patients with hyperkalemia.

Methods

We performed a retrospective cohort study between September 2012 and May 2016 at the Children’s Hospital of Philadelphia. In all, 14 patients (age range 0.5–53.2 months) who received 19 courses of SPS pretreatment of EN were evaluated. Serum electrolytes were evaluated at baseline and within 1 week of initiating therapy. The primary endpoint was mean change in potassium at 7 days. Secondary endpoints included the mean change in serum sodium, chloride, bicarbonate, calcium, phosphorous and magnesium, as well as the percentage of patients who developed electrolyte abnormalities within the first week of treatment.

Results

Serum potassium levels decreased from 6.0 to 4.4 mmol/L (P < 0.001) and serum sodium levels increased from 135.8 to 141.3 mmol/L (P = 0.008) 1 week after initiating SPS pretreatment. No significant differences in mean serum calcium or magnesium levels were noted. Nevertheless, more than half of the courses resulted in at least one electrolyte abnormality, with hypokalemia (31.6%), hypernatremia (26.3%) and hypocalcemia (21.1%) occurring most frequently.

Conclusions

Pretreatment of EN with SPS is an effective method for treating chronic hyperkalemia in pediatric patients; however, close monitoring of electrolytes is warranted.

Renal formulas pretreated with medications alters the nutrient profile

BACKGROUND

Pretreating renal formulas with medications to lower the potassium and phosphorus content is common in clinical practice; however, the effect of this treatment on other nutrients is relatively unstudied. We examine whether nutrient composition is affected by pretreating renal formulas with sodium polystyrene sulfonate (SPS) suspension and sevelamer carbonate.

METHODS

Fixed medication doses and treatment times were utilized to determine changes in the nutrient composition of Suplena® and Similac® PM 60/40. The effect of simultaneously adding both medications (co-administration) to the formula on the nutrient composition of Suplena® was also evaluated.

RESULTS

Pretreatment of Suplena® with SPS reduced the concentrations of calcium (11-38 %), copper (3-11 %), manganese (3-16 %), phosphorus (0-7 %), potassium (6-34 %), and zinc (5-20 %) and increased those of iron (9-34 %), sodium (89-260 %), and sulfur (19-45 %) and the pH (0.20-0.50 units). Pretreatment of Similac® PM 60/40 with SPS reduced the concentrations of calcium (8-29 %), copper (5-19 %), magnesium (3-26 %), and potassium (33-63 %) and increased those of iron (13-87 %) and sodium (86-247 %) and the pH (0.40-0.81 units). Pretreatment of both formulas with the SPS suspension led to significant increases in the aluminum concentration in both formulas (507-3957 %). No differences in potassium concentration were observed between treatment times. Unexpectedly, the levels of neither phosphorus nor potassium were effectively reduced in Suplena® pretreated with sevelamer carbonate alone or when co-administered with SPS.

CONCLUSIONS

Pretreating formula with medications alters nutrients other than the intended target(s). Future studies should be aimed at predicting the loss of these nutrients or identifying alternative methods for managing serum potassium and phosphorus levels in formula-fed infants. The safety of pretreating formula with SPS suspension should also be examined.

Design, synthesis and thermal behaviour of a series of well-defined clickable and triggerable sulfonate polymers

In the printing industry, the exploitation of triggerable materials that can have their surface properties altered on application of a post-deposition external stimulus has been crucial for the production of robust layers and patterns.

Pretreatment of formula or expressed breast milk with sodium polystyrene sulfonate (Kayexalate(®)) as a treatment for hyperkalemia in infants with acute or chronic renal insufficiency

OBJECTIVE

To evaluate the effect on serum potassium of treating infant formula or expressed breast milk (EBM) with sodium polystyrene sulfonate (SPS) before patient consumption.

DESIGN AND SETTING

Retrospective cohort study of patients at Seattle Children's Hospital who received SPS-treated formula or EBM.

SUBJECTS AND INTERVENTION

Thirteen patients less than 2 years of age with a diagnosis of hyperkalemia and acute kidney injury or chronic kidney disease that had received formula or EBM pretreated with SPS between September 2009 and May 2012 were identified. Hyperkalemia was defined as a serum potassium concentration greater than 5.5 mEq/L.

MAIN OUTCOME MEASURE

The primary endpoint was the mean change in serum potassium 48 hours after receiving pretreated formula or EBM. Serum potassium levels before and after patient consumption were averaged and compared using a paired t test.

RESULTS

Pretreatment of formula or EBM with SPS resulted in a 24% decrease in serum potassium levels (6.3 mEq/L to 4.8 mEq/L; P < .0001). There was a significant difference in before and after calcium and creatinine levels (P < .05), and no significant differences in blood urea nitrogen, sodium, magnesium, phosphorus, chloride, or bicarbonate levels.

CONCLUSION

Pretreatment of formula or EBM with SPS before consumption is an effective treatment for hyperkalemia in infants. Caution needs to be taken in patients who have sodium restrictions because the exchange for potassium produces a sodium-rich formula.

Pretreatment of infant formula with sodium polystyrene sulfonate : focus on optimal amount and contact time

BACKGROUND

In pediatric patients at risk of hyperkalemia there are limited treatment or preventive alternatives for this electrolyte imbalance. Oral or rectal sodium polystyrene sulfonate (SPS) has several potential adverse effects, and dietary potassium restriction may compromise nutrition. Pretreatment of infant formula with SPS has been previously studied with promising efficacy. The optimal dosing and contact time has not been fully elucidated for this practice, nor have brand and generic products been compared.

OBJECTIVE

The present study aimed to evaluate the effectiveness of varying amounts of brand and generic SPS for the removal of potassium from formula after 1 and 24 hours.

METHODS

SPS was added to infant formula in four different amounts measured in milliliters to reflect how a parent or caregiver would measure this product at home. After 1 and 24 hours samples were withdrawn and potassium and sodium levels were measured.

RESULTS

Potassium decreased in all samples, with the greatest reduction after the addition of 10 mL of SPS. Sodium levels increased in all pretreated samples to a greater extent than the potassium reduction. Contact time of either 1 or 24 hours did not impact the amount of potassium removed or the increase in sodium concentration. There were also no differences found between generic and brand SPS products.

CONCLUSION

The effectiveness of SPS for formula pretreatment appears to have a plateau effect beyond the addition of 20 mL (16.47 g of brand name product, 19.5 g of generic product). This study demonstrates an effective protocol for pretreatment of formula.

Comparison of antiplatelet effect and tolerability of clopidogrel resinate with clopidogrel bisulfate in patients with coronary heart disease (CHD) or CHD-equivalent risks: a phase IV, prospective, double-dummy, parallel-group, 4-week noninferiority trial

BACKGROUND

Clopidogrel resinate is a resinate complex of (+)-clopidogrel optical isomer, wherein the (+)-clopidogrel isomer binds to a water-soluble cation exchange resin via sulfonic acid groups. It was approved by the Korean Food and Drug Administration on the basis of a Phase I study that demonstrated the bioequivalence of clopidogrel resinate and clopidogrel bisulfate. However, there are no available data regarding efficacy and tolerability in patients with vascular disease.

OBJECTIVE

The goal of this study was to investigate the antiplatelet efficacy and tolerability of clopidogrel resinate in patients with coronary heart disease (CHD) or CHD-equivalent risks.

METHODS

This study was a Phase IV, randomized, double-blind, double-dummy, parallel-group, noninferiority trial. We prospectively recruited patients in 10 centers between March 2008 and July 2008. Patients who had documented CHD or CHD-equivalent risks were randomly assigned to 1 of 3 groups: group A, aspirin (100 mg) + clopidogrel bisulfate placebo + clopidogrel resinate placebo; group B, aspirin (100 mg) + clopidogrel bisulfate placebo + clopidogrel resinate (75 mg); or group C, aspirin (100 mg) + clopidogrel bisulfate (75 mg) + clopidogrel resinate placebo. The primary outcome was the percent P2Y(12) inhibition after medication, assessed by using a point-of-care assay. If the 1-sided 90% upper confidence limit for the difference was less than the prespecified delta value (-5.7), clopidogrel resinate would be considered noninferior to clopidogrel bisulfate. The secondary outcome, the prevalence of adverse events (AEs) associated with study medications, was assessed at each visit by direct interview.

RESULTS

A total of 314 patients (mean [SD] age, 62.2 [9.0] years; male 63.7%; weight, 67.3 [13.6] kg [range, 45-102 kg]; all Asian) were enrolled, and 287 patients finished the study (group A, n = 97; group B, n = 90; and group C, n = 100). Eight patients took no study medications and were excluded from the tolerability and efficacy analyses. Nineteen patients discontinued the study because of protocol violation (n = 15), adverse events (n = 3), or voluntary withdrawal (n = 1) and were excluded from the efficacy analysis. There were no significant differences in baseline clinical characteristics among the groups except for the frequency of a history of CHD (group A, 85.4%; group B, 73.0%; and group C, 88.3%; P = 0.01). Patients treated with either type of clopidogrel showed significant inhibition (mean [SD]) of P2Y(12) (group A, -5.9% [15.1%]; group B, 23.4% [21.9%]; and group C, 19.5% [23.8%]; P < 0.001). Differences between clopidogrel resinate and clopidogrel bisulfate in the inhibition of P2Y(12) did not exceed the predetermined value for inferiority (P for noninferiority, 0.02; 90% CI, -0.9 to 10.3). In the tolerability analysis, there was no mortality during the study period and no significant differences between groups in the frequency of AEs and serious AEs (AEs: group A, 33.0%; group B, 26.0%; and group C, 23.3% [P = 0.27]; serious AEs: group A, 1.0%; group B, 3.0%; and group C, 1.0% [P = 0.42]). One patient in group B underwent coronary stent implantation for treatment of stable angina.

CONCLUSIONS

In this small, selected Asian patient population, differences in the platelet inhibition efficacies of clopidogrel resinate and clopidogrel bisulfate did not exceed the predetermined limits for noninferiority. The differences in tolerability between the 2 drugs did not reach statistical significance.

Nutritional management of hyperkalemic infants with chronic kidney disease, using adult renal formulas

OBJECTIVE

This study sought to evaluate the use of adult renal formulas in hyperkalemic infants with chronic kidney disease (CKD).

DESIGN

This was a retrospective, single-center cohort study.

SETTING

This study took place at the Department of Pediatric Nephrology, Dialysis, and Transplantation at Helen DeVos Children's Hospital (Grand Rapids, MI).

PATIENTS

Seven hyperkalemic infants (mean age, 6.9 months) comprised the study population: 29% with stage 3 CKD, 29% with stage 4 CKD, and 42% with stage 5 CKD.

INTERVENTION

Infants were empirically treated with adult renal formulas for an average duration of 9.6 months. Six of seven infants were started on breast milk or infant formula (Similac PM 60/40, Abbott Laboratories, Columbus, OH), but because of inadequate growth and hyperkalemia, were transitioned to adult renal formulas (Suplena, Abbott Laboratories, Columbus, OH; Nepro, Abbott Laboratories, Columbus, OH; and/or Renalcal, Nestle Nutrition, Minnetonka, MN). One infant received adult renal formula at birth.

MAIN OUTCOME MEASURES

The outcome measures included amount of potassium delivered by infant and adult renal formulas, level of serum potassium, and anthropometric measurements adjusted for age and gender (z-scores).

RESULTS

The transition from infant to adult renal formula resulted in a decrease in mean amount of potassium delivered by formula (from 2.6 to 1.0 mEq/kg/day, P < .001) and a decrease in mean serum potassium (from 5.1 to 4.0 mmol/L, P < .01). During treatment with adult renal formula, the infants demonstrated a significant increase in mean weight z-score (from -1.0 to 0.5, P < .01), height z-score (from -1.9 to -0.5, P < .01), and head-circumference z-score (from -1.5 to -1.0, P=.03). Adult renal formulas were well-tolerated.

CONCLUSIONS

Hyperkalemic infants with CKD can be nutritionally managed on adult renal formula.