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Background: Hyperkalemia is a potentially life-threatening complication of chronic kidney disease (CKD). Dietary potassium restriction is challenging in infants despite low-potassium formulas. Decreasing potassium in formula using patiromer, a new calcium-based cation exchange polymer may be one option to accomplish this; however, data confirming efficacy is lacking., Methods: Varying doses of patiromer were added to prepared Similac Advance and Similac PM 60/40. Measurements of potassium, calcium, sodium, magnesium, and phosphorus were obtained at baseline and at 30 min, 60 min, and 24 h following patiromer administration., Results: Following pre-treatment with patiromer, the potassium concentration of both formulas decreased. This effect was mild with the lowest dose but increased in a dose-dependent fashion. Treating for 60 min or 24 h did not yield substantially greater effects than treating for 30 min. Calcium levels increased in both formula groups, mostly in a dose-dependent fashion. Changes in magnesium, sodium, and phosphorus were also seen after patiromer pre-treatment., Conclusions: Pre-treatment with patiromer decreases the potassium concentration of infant formula. Calcium levels increased after treatment as expected with the majority of ion exchange occurring in 30 min. Treatment of formula with patiromer shows promise as a unique option for managing hyperkalemia.

The kidney plays an essential role in maintaining homeostasis of ion concentrations in the blood. Because the concentration gradient of potassium across the cell membrane is a key determinant of the membrane potential of cells, even small deviations in serum potassium level from the normal setpoint can lead to severe muscle dysfunction, resulting in respiratory failure and cardiac arrest. Less severe hypo- and hyperkalemia are also associated with morbidity and mortality across various patient populations. In addition, deficiencies in potassium intake have been associated with hypertension and adverse cardiovascular and renal outcomes, likely due in part to the interrelated handling of sodium and potassium by the kidney. Here, data on the beneficial effects of potassium on blood pressure and cardiovascular and renal outcomes will be reviewed, along with the physiological basis for these effects. In some patient populations, however, potassium excess is deleterious. Risk factors for the development of hyperkalemia will be reviewed, as well as the risks and benefits of existing and emerging therapies for hyperkalemia.

Objective: To describe the safety and efficacy of sodium polystyrene sulfonate (SPS) in pediatric patients with acute hyperkalemia., Methods: A retrospective chart review of all patients less than 18 years of age administered SPS for acute hyperkalemia at Texas Children's Hospital between 2011 and 2014., Results: Our cohort consisted of 156 patients (mean age 6.8 ± 6.1 years). The peak mean potassium concentration observed was 6.5 ± 0.77 mmol/l prior to administration of SPS. The mean SPS dose was 0.64 ± 0.32 g/kg. The majority (91 %) of the SPS doses were given orally. The nadir mean potassium concentration in the 48 h post-SPS was 4.7 ± 1.2 mEq/l, which occurred at 16.7 ± 14.7 h post-dose. In the 48 h following SPS administration, 68 (43 %) patients required at least one additional intervention after SPS dose. Patients who required an additional intervention after initial SPS dose differed significantly in weight, baseline serum potassium, and were more likely to have received SPS treatment via the rectal route. A gastrointestinal adverse event was documented in 24 (15 %) patients., Conclusions: SPS was used effectively and safely in the majority of patients in this report. However, it may not be appropriate as a first single-line agent in patients with severe acute hyperkalemia who require a greater than 25 % reduction in serum potassium levels or those at a high risk for cardiac arrhythmias.

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.

Background: The predictive factors to regain a heartbeat following emergency department resuscitative thoracotomy (EDT) for trauma are poorly understood. The objective of the present study was to prospectively assess the electrolyte profile, coagulation parameters, and acid-base status from intracardiac blood samples in trauma patients subjected to open cardiopulmonary resuscitation (CPR) in the presence of established cardiac arrest., Methods: All patients who underwent EDT following trauma were considered for inclusion. Prior to the injection of any resuscitative medications, a sample of intracardiac blood from the right ventricle was obtained for analysis., Results: During the study period, a total of 22 patients had intracardiac blood samples obtained and were eligible for analysis. Twelve patients never regained cardiac activity, and 10 patients transiently regained a heartbeat for a mean of 51 ± 69 min, but ultimately died. Some 91 % (20/22) of patients presented with severe acidosis (pH < 7.20). The pCO(2) was <45 mmHg in 68 % (15/22) of patients, and the pO(2) level was >75 mmHg in 77 % (17/22) of patients. Patients who never regained cardiac activity had a significantly higher lactate level than those with a return of cardiac rhythm (17.1 ± 2.6 vs. 10.6 ± 4.9 mmol/L, p = 0.018). The sodium and potassium levels were higher for those who never regained a rhythm than for those who did regain a pulse (sodium: 155 ± 14 vs. 147 ± 9 mmol/L, p = 0.094; potassium: 6.0 ± 1.1 vs. 4.6 ± 1.0 mmol/L, p = 0.014). Severe hyperkalemia (potassium > 5.5 mmol/L) occurred significantly more often in patients who did not regain a heart beat (p = 0.030). Coagulopathy (INR > 1.2 and/or prothrombin time >15 s and/or platelet count <100,000/μL) was noted in 96 % of patients., Conclusions: Most patients undergoing open CPR have normal blood gas levels. Severe lactic acidosis, hyperkalemia, and hypernatremia are associated with decreased probability for return of cardiac function. Calcium and magnesium levels were not significantly different between the two groups, making the therapeutic role of these electrolytes very questionable.

Background: Pseudohyperkalaemia is relatively uncommon in children, but needs to be considered in cases where extreme hyperkalaemia is associated with normal renal function., Case: A previously well 12 year-old boy presented with new onset T cell acute lymphoblastic leukaemia associated with a high peripheral blood white cell count. Plasma biochemistry tests on a blood sample sent to the laboratory using a pneumatic tube system showed a high plasma potassium level of 16.6 mmol/l, with otherwise normal electrolytes and renal function. A 12-lead electrocardiogram was normal, with no changes suggestive of hyperkalaemia. Pseudohyperkalaemia was suspected, and further samples transported to the laboratory by foot showed normal plasma potassium levels. It was subsequently demonstrated that the pseudohyperkalemia was due to the lysis of leukaemic white cells during the transport of blood samples from the ward to the laboratory within the pneumatic tube system., Conclusions: Paediatricians caring for children with haematological malignancies need to be aware of this cause of pseudohyperkalaemia so that unnecessary treatment, including the commencement of acute dialysis, is avoided. We recommend that blood samples collected from children with high white cell count malignancies are transported to the laboratory by foot rather than in pneumatic tube systems.

Background: Classic teaching states that chronic adrenal insufficiency is associated with hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and eosinophilia. We hypothesize that these diagnostic markers do not predict relative adrenal insufficiency (RAI) in the critically ill or injured patient., Methods: Chart review of surgical, trauma, and medical patients admitted over 7 years to a critical care unit was performed to evaluate cortisol levels drawn for suspicion of RAI, which was defined as a cortisol concentration <25 mcg/dl. Laboratory parameters were defined as hyponatremia <135 mmol/l, hyperkalemia >5.3 mmol/l, hypercalcemia >2.55 mmol/l (10.2 mg/dl), hypoglycemia <3.89 mmol/l (70 mg/dl), and eosinophilia >5%., Results: A total of 212 patients had cortisol levels drawn. Fifty-seven percent were male and their mean age was 59 years. Fifty-three percent had RAI. Average cortisol level was 30.5 μg/dl. No significant differences were seen in mean potassium, sodium, calcium, or glucose levels between RAI and non-RAI patients. Few patients had laboratory values consistent with RAI. In fact, many with RAI had opposite findings: 75% had hypernatremia, 90% had hypokalemia, 100% had hypocalcemia, and 97% had hyperglycemia. Eosinophilia was statistically significant (P = 0.026)., Conclusion: Hyponatremia, hyperkalemia, hypercalcemia, and hypoglycemia do not predominate in RAI and laboratory values are of minimal value in predicting patients with RAI.

Hyperkalemia is a potentially life-threatening condition in which serum potassium exceeds 5.5 mmol/l. It can be caused by reduced renal excretion, excessive intake or leakage of potassium from the intracellular space. In addition to acute and chronic renal failure, hypoaldosteronism, and massive tissue breakdown as in rhabdomyolysis, are typical conditions leading to hyperkalemia. Symptoms are non-specific and predominantly related to muscular or cardiac dysfunction. Treatment has to be initiated immediately using different therapeutic strategies to increase potassium shift into the intracellular space or to increase elimination, together with reduction of intake. Knowledge of the physiological mechanisms of potassium handling is essential in understanding the causes of hyperkalemia as well as its treatment. This article reviews the pathomechanisms leading to hyperkalemic states, its symptoms, and different treatment options.

Eight boys aged 2-12 weeks with urinary tract malformations (UTMs) exhibited features of transient type 1 pseudo-hypoaldosteronism (TPHA1) in the course of urinary tract infection (UTI). Hyponatremia (120.9+/-5.8 mmol/l), hyperkalemia (6.9+/-0.9 mmol/l), metabolic acidosis (plasma bicarbonate 11+/-1.4 mmol/l), and a rise in serum creatinine levels (145+/-101 micromol/l) were associated with high urinary sodium (Na) and low potassium (K) excretion. Tubular resistance to aldosterone was indicated by high plasma aldosterone concentrations (170.4+/-100.5 ng/dl), high levels of the plasma aldosterone to potassium ratio (25.2+/-15.6), and diminished urinary K/Na values (0.31+/-0.19). With appropriate therapy, serum electrolytes, creatinine, and acid-base balance normalized within 2 weeks. A Medline search revealed another 85 cases of TPHA1 reported to date. All of the 93 patients were less than 7 months of age and 90% were less than 3 months of age, 90.3% suffered from UTM, with associated UTI in 89% of them, 11% had UTMin the absence of UTI, and 9.7% showed isolated UTI. These findings indicate that early infancy is the main contributing factor for TPHA1 to occur and that UTI and UTMare additional factors, with at least one being required for its development.

In critically ill children weighing <10 kg, it is necessary to use blood as a priming solution for the extracorporeal continuous renal replacement therapy (CRRT) circuit before initiating CRRT to prevent hemodilution and maintain adequate oxygenation. However, blood bank blood usually contains supra-physiological electrolyte concentrations and a non-physiological acid-base balance that may exacerbate the patient's condition. The objective of this trial was to develop a simple protocol to pre-treat blood bank-derived blood to yield a more physiological blood priming solution. Expired human blood in a recirculating in vitro CRRT circuit was dialyzed prior to the initiation of CRRT using a physiological dialysate solution. Serial blood samples were assessed for electrolyte and pH content. Regimens using maximal blood flow rates (180-200 ml/min) and aggressive dialysate flow rates (33-42 ml/min) were able to correct severely hyperkalemic and acidemic blood within 7.5 min. Initially elevated blood potassium concentrations >20 mEq/l were normalized to below 5 mEq/l within 7.5 min of dialysis in all cases. Blood bank-derived blood can be "conditioned" quickly to physiological pH and electrolyte concentrations using these simple pre-dialysis regimens. Unlike some blood preparation regimens that have been published, the technique used in this trial requires no special equipment or added medications that are not already used in CRRT.