Potassium abnormalities in a pediatric intensive care unit: frequency and severity

Evaluation of Parenteral Potassium Supplementation in Pediatric Patients

OBJECTIVE

The primary objective was to evaluate the effect of parenteral potassium chloride (KCl) supplementation on potassium (K⁺) concentrations in a non-cardiac pediatric population. Secondary outcomes were to identify variables that may influence response to KCl supplementation (i.e., change in K⁺ concentration after KCl administration) and assess the incidence of hyperkalemia.

METHODS

This single-center, retrospective study evaluated infants and children who received parenteral KCl supplementation of 0.5 or 1 mEq/kg between January 2017 and December 2019.

RESULTS

The study included 102 patients with a median age of 1 year (IQR, 0.4-3.9) and weight of 9.1 kg (IQR, 4.9-14.2) who received 288 parenteral KCl administrations. One hundred seventy-three administrations were in the 1 mEq/kg group, and 115 administrations were in the 0.5 mEq/kg group. The median changes in K⁺ were 0.8 and 0.5 mEq/L in the 1 mEq/kg and 0.5 mEq/kg groups, respectively. Patients who had a repeat K⁺ concentration within 4 hours of the end of a 1 to 2-hour infusion had a higher median change in K⁺ compared with those who had a concentration drawn after this time frame (0.8 vs 0.6 mEq/L; p < 0.01).

CONCLUSIONS

There is a paucity of data on the correlation between parenteral KCl supplementation and change in K⁺ concentrations in pediatric patients. Our study demonstrated an association between KCl supplementation doses of 1 and 0.5 mEq/kg and changes in K⁺ of 0.8 and 0.5 mEq/L, respectively, in non-cardiac pediatric patients, with low observed incidence of hyperkalemia.

Early diagnosis of Gitelman syndrome in a young child: A case report

BACKGROUND

Gitelman syndrome (GS) is an autosomal recessive renal tubular disorder characterized by renal wasting hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. It is usually caused by mutations in the gene SLC12A3, which encodes the thiazide-sensitive Na-Cl cotransporter. GS is not usually diagnosed until late childhood or adulthood.

CASE SUMMARY

Here, we report the case of a one-year-old girl who was brought to the emergency department due to persistent vomiting for two days. On admission to our hospital, generalized weakness was observed, and laboratory investigations revealed severe hypokalemia (1.9 mmol/L). However, persistent hypokalemia was observed during outpatient follow-up. Suspicion of the GS phenotype was assessed via the patient’s clinical presentation, family history, and biochemical analysis of blood and urine. Further genetic analysis was performed for her and her family by exon-wide sequencing analysis of the gene SLC12A3. The genetic diagnosis of GS was established in the Taiwanese family with three affected individuals, two of whom were children (7 years/17 years) without obvious symptoms, with the youngest being only one year old (patient in our case).

CONCLUSION

We successfully demonstrated the early diagnosis of GS using family genetic analysis. Any instances of hypokalemia should not be neglected, as early detection of GS with suitable treatment can prevent patients from potentially life-threatening complications.

Incidence of Refeeding Syndrome in Critically Ill Children With Nutritional Support

INTRODUCTION

Early enteral nutrition is recommended for critically ill children, potentially exposing those who are undernourished to the risk of refeeding syndrome. However, data on its incidence is lacking, and the heterogeneity of diagnostic criteria and frequent electrolyte disorders in this population make its diagnosis complex. In 2020, the American Society for Parenteral and Enteral Nutrition (ASPEN) developed consensus recommendations for identifying patients at risk and with refeeding syndrome. These state that undernourished children are considered at risk of refeeding syndrome; those who develop one significant electrolyte disorder (decrease ≥ 10% in phosphorus, potassium, and/or magnesium) within the first five days of nutritional support, combined with a significant increase in energy intake, are considered to have refeeding syndrome. The aim of this study was to determine the incidence of refeeding syndrome according to the ASPEN definition in critically ill children on nutritional support.

MATERIALS AND METHODS

A secondary analysis of two prospective cohorts conducted in a tertiary pediatric intensive care unit in France was undertaken, and additional data were retrospectively collected. Children included were those (0-18 years) admitted to the pediatric intensive care unit with a minimum of one phosphorus, potassium, and/or magnesium assay and who received exclusive or supplemental nutritional support. Undernourished children (body mass index z-score < -2 standard deviations) were considered at risk of refeeding syndrome. The ASPEN critiera were used to identify those with probable refeeding syndrome.

RESULTS

A total of 1,261 children were included in the study, with 199 children (15.8%) classified as undernourished, who were at risk of refeeding syndrome. Of these, 93 children were identified as having probable refeeding syndrome, giving an overall incidence of 7.4%. The incidence rate among at-risk children was 46.7%. Most patients (58.1%) were classified as having severe refeeding syndrome.

CONCLUSION

Refeeding syndrome remains difficult to diagnose in critically ill children, due to frequent confounding factors impacting electrolyte plasma levels. These findings suggest that refeeding syndrome incidence may be high in undernourished children, and that refeeding syndromes can be severe. Further prospective studies using the ASPEN definition and risk criteria are required.

Reverse pseudohyperkalemia in a newly diagnosed pediatric patient with acute T-cell leukemia and hyperleukocytosis: a case report and literature review

Background

Hyperkalemia is a serious medical condition that requires immediate intervention. However, pseudohyperkalemia and reverse pseudohyperkalemia are misleading clinical manifestations that can result in incorrect diagnosis and consequent harmful intervention.

Case presentation

An 11-year-old girl manifested an incidental finding of hyperleukocytosis (WBC > 400 × 109/L), with 90% blast cells during routine pre-operative investigations for adenotonsillectomy. Initial investigations demonstrated elevated serum potassium levels (7.5 mmol/L), despite concomitantly normal levels in venous blood gas samples (3.9–4.4 mmol/L) and being clinically stable with normal 12-lead ECG. Surprisingly, plasma potassium level was exacerbated, in comparison to the serum level by > 1 mmol/L. This finding is consistent with reverse pseudohyperkalemia that is associated with hyperleukocytosis in acute leukemia that does not require any active intervention.

Conclusion

This case report emphasizes the significance of interpreting potassium levels accurately, preferably utilizing whole-blood potassium level over serum and plasma level in newly diagnosed leukemia cases with hyperleukocytosis. Additionally, having a high index for the possibility of reverse pseudohyperkalemia, secondary to leakage from fragile leukocytes, avoids unnecessary treatment that might cause harm to the patient.

Sulfamethoxazole-Trimethoprim and Hyperkalemia in an Infant

Hyperkalemia is a potentially life-threatening electrolyte abnormality in both children and adults. In the setting of elevated serum potassium concentrations, cardiac conduction disturbances and cardiac arrest may occur. In the pediatric intensive care unit (PICU) setting, the differential diagnosis of hyperkalemia may be extensive including increased potassium intake or administration, increased endogenous production, decreased renal excretion, and intracellular to extracellular shifts related to changes in acid-base status. We present a 4-month-old infant who developed hyperkalemia during the recovery phase of her PICU course for respiratory failure. A thorough investigation demonstrated that the hyperkalemia was most likely the result of the commonly used antibiotic, trimethoprim-sulfamethoxazole (Bactrim^®). Potential etiologies of hyperkalemia in the PICU patient are discussed and previous reports of hyperkalemia associated with trimethoprim-sulfamethoxazole presented.

Avoidable Serum Potassium Testing in the Cardiac ICU: Development and Testing of a Machine-Learning Model

OBJECTIVES

To create a machine-learning model identifying potentially avoidable blood draws for serum potassium among pediatric patients following cardiac surgery.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care center.

PATIENTS

All patients admitted to the cardiac ICU at Boston Children's Hospital between January 2010 and December 2018 with a length of stay greater than or equal to 4 days and greater than or equal to two recorded serum potassium measurements.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We collected variables related to potassium homeostasis, including serum chemistry, hourly potassium intake, diuretics, and urine output. Using established machine-learning techniques, including random forest classifiers, and hyperparameter tuning, we created models predicting whether a patient's potassium would be normal or abnormal based on the most recent potassium level, medications administered, urine output, and markers of renal function. We developed multiple models based on different age-categories and temporal proximity of the most recent potassium measurement. We assessed the predictive performance of the models using an independent test set. Of the 7,269 admissions (6,196 patients) included, serum potassium was measured on average of 1 (interquartile range, 0-1) time per day. Approximately 96% of patients received at least one dose of IV diuretic and 83% received a form of potassium supplementation. Our models predicted a normal potassium value with a median positive predictive value of 0.900. A median percentage of 2.1% measurements (mean 2.5%; interquartile range, 1.3-3.7%) was incorrectly predicted as normal when they were abnormal. A median percentage of 0.0% (interquartile range, 0.0-0.4%) critically low or high measurements was incorrectly predicted as normal. A median of 27.2% (interquartile range, 7.8-32.4%) of samples was correctly predicted to be normal and could have been potentially avoided.

CONCLUSIONS

Machine-learning methods can be used to predict avoidable blood tests accurately for serum potassium in critically ill pediatric patients. A median of 27.2% of samples could have been saved, with decreased costs and risk of infection or anemia.

The Association of Laboratory Test Abnormalities With Mortality Risk in Pediatric Intensive Care

OBJECTIVES

To determine the bivariable associations between abnormalities of 28 common laboratory tests and hospital mortality and determine how mortality risks changes when the ranges are evaluated in the context of commonly used laboratory test panels.

DESIGN

A 2009-2016 cohort from the Health Facts (Cerner Corporation, Kansas City, MO) database.

SETTING

Hospitals caring for children in ICUs.

PATIENTS

Children cared for in ICUs with laboratory data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 2,987,515 laboratory measurements in 71,563 children. The distribution of laboratory test values in 10 groups defined by population percentiles demonstrated the midrange of tests was within the normal range except for those measured predominantly when significant abnormalities are suspected. Logistic regression analysis at the patient level combined the population-based groups into ranges with nonoverlapping mortality odds ratios. The most deviant test ranges associated with increased mortality risk (mortality odds ratios > 5.0) included variables associated with acidosis, coagulation abnormalities and blood loss, immune function, liver function, nutritional status, and the basic metabolic profile. The test ranges most associated with survival included normal values for chloride, pH, and bicarbonate/total Co2. When the significant test ranges from bivariable analyses were combined in commonly used test panels, they generally remained significant but were reduced as risk was distributed among the tests.

CONCLUSIONS

The relative importance of laboratory test ranges vary widely, with some ranges strongly associated with mortality and others strongly associated with survival. When evaluated in the context of test panels rather than isolated tests, the mortality odds ratios for the test ranges decreased but generally remained significant as risk was distributed among the components of the test panels. These data are useful to develop critical values for children in ICUs, to identify risk factors previously underappreciated, for education and training, and for future risk score development.

Risk of Electrolyte Disorders in Acutely Ill Children Receiving Commercially Available Plasmalike Isotonic Fluids: A Randomized Clinical Trial

IMPORTANCE

The use of isotonic fluid therapy is currently recommended in children, but there is limited evidence of optimal fluid therapy in acutely ill children.

OBJECTIVE

To evaluate the risk for electrolyte disorders, including hyponatremia, hypernatremia, and hypokalemia, and the risk of fluid retention in acutely ill children receiving commercially available plasmalike isotonic fluid therapy.

DESIGN, SETTING, AND PARTICIPANTS

This unblinded, randomized clinical pragmatic trial was conducted at the pediatric emergency department of Oulu University Hospital, Finland, from October 3, 2016, through April 15, 2019. Eligible study subjects (N = 614) were between 6 months and 12 years of age, required hospitalization due to an acute illness, and needed intravenous fluid therapy. Exclusion criteria included a plasma sodium concentration of less than 130 mmol/L or greater than 150 mmol/L on admission; a plasma potassium concentration of less than 3.0 mmol/L on admission; clinical need of fluid therapy with 10% glucose solution; a history of diabetes, diabetic ketoacidosis, or diabetes insipidus; a need for renal replacement therapy; severe liver disease; pediatric cancer requiring protocol-determined chemotherapy hydration; and inborn errors of metabolism. All outcomes and samples size were prespecified except those clearly marked as exploratory post hoc analyses. All analyses were intention to treat.

INTERVENTIONS

Acutely ill children were randomized to receive commercially available plasmalike isotonic fluid therapy (140 mmol/L of sodium and 5 mmol/L potassium in 5% dextrose) or moderately hypotonic fluid therapy (80 mmol/L sodium and 20 mmol/L potassium in 5% dextrose).

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of children with any clinically significant electrolyte disorder, defined as hypokalemia less than 3.5 mmol/L, hypernatremia greater than 148 mmol/L, or hyponatremia less than 132 mmol/L during hospitalization due to acute illness. The main secondary outcomes were the proportion of children with severe hypokalemia and weight change.

RESULTS

There were 614 total study subjects (mean [SD] age, 4.0 [3.1] years; 315 children were boys [51%] and all 614 were Finnish speaking [100%]). Clinically significant electrolyte disorder was more common in children receiving plasmalike isotonic fluid therapy (61 of 308 patients [20%]) compared with those receiving moderately hypotonic fluid therapy (9 of 306 patients [2.9%]; 95% CI of the difference, 12%-22%; P < .001). The risk of developing electrolyte disorder was 6.7-fold greater in children receiving isotonic fluid therapy. Hypokalemia developed in 57 patients (19%) and hypernatremia developed in 4 patients (1.3%) receiving plasmalike isotonic fluid therapy. Weight change was greater in children receiving isotonic, plasmalike fluid therapy compared with those receiving mildly hypotonic fluids (mean weight gain, 279 vs 195 g; 95% CI, 16-154 g; P = .02).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, commercially available plasmalike isotonic fluid therapy markedly increased the risk for clinically significant electrolyte disorders, mostly due to hypokalemia, in acutely ill children compared with previously widely used moderately hypotonic fluid therapy containing 20 mmol/L of potassium.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02926989.

Extracorporeal potassium binding for the management of hyperkalemia in an anephric model of crush injury

BACKGROUND

Potassium-binding polymers have shown promising results in an anephric porcine hyperkalemia model. The benefits of the polymer in a clinically relevant injury model remain unknown. We hypothesized that potassium-binding cartridges would control serum potassium concentration in a porcine hemorrhagic shock model with supraceliac aortic occlusion and a limb crush injury.

METHODS

Ten Yorkshire-cross swine were anesthetized and instrumented. Pigs underwent splenectomy and bilateral nephrectomy. Hemorrhagic shock was induced for 30 minutes while a leg compression device was applied. Pigs underwent supraceliac aortic occlusion for 60 minutes and were resuscitated with shed blood. The leg compression device was removed 20 minutes after balloon deflation. After 20 minutes of reperfusion, animals were randomized to extracorporeal circulation with (treatment) or without (control) the potassium binding cartridges. In both groups, blood was circulated through a hemodialyzer with a peristaltic pump. In the treatment group, the ultrafiltrate was diverted from the hemodialyzer through cartridges containing the polymer and returned to the extracorporeal circuit. Animals were resuscitated with 0.9% saline boluses and a norepinephrine infusion. The change in serum potassium concentration (ΔK) was calculated as serum [K]T390 - serum [K]T0.

RESULTS

There was a significant difference in serum potassium concentration between groups (p < 0.001). ΔK was significantly higher in the control than the treatment group (3.75 [3.27-4.42] and 1.15 [0.62-1.59] mmol/L, respectively; p = 0.03). There were no differences in mean arterial pressure (p = 0.14), isotonic crystalloids requirement (p = 0.51), or norepinephrine dose (p = 0.83) between groups. Serum lactate concentration was significantly higher in the control group (p < 0.001). At the end of the experiment, the [K] was reduced by 25% (24.9%-27.8%) across the cartridges.

CONCLUSION

The cartridges controlled serum potassium concentrations without dialysate and retained potassium binding capabilities over 4 hours. There were no deleterious effects on hemodynamic parameters. Those cartridges might be beneficial adjuncts for hyperkalemia management in austere environments.

LEVEL OF EVIDENCE

Translational science study, level I.

Potassium disorders in pediatric emergency department: Clinical spectrum and management

INTRODUCTION

Potassium abnormalities are frequent in intensive care but their incidence in the emergency department is unknown.

AIM

We describe the spectrum of potassium abnormalities in our tertiary-level pediatric emergency department.

METHODS

Retrospective case-control study of all the patients admitted to a single-center tertiary emergency department over a 2.5-year period. We compared patients with hypokalemia (<3.0mEq/L) and patients with hyperkalemia (>6.0mEq/L) against a normal randomized population recruited on a 3:1 ratio with potassium levels between 3.5 and 5mEq/L.

RESULTS

Between January 1, 2013 and August 31, 2016 we admitted 108,209 patients to our emergency department. A total of 9342 blood samples were tested and the following potassium measurements were found: 60 cases of hypokalemia (2.8±0.2mEq/L) and 55 cases of hyperkalemia (6.4±0.6mEq/L). In total, 200 patients with normokalemia were recruited (4.1±0.3mEq/L). The main causes of the disorders were non-specific: lower respiratory tract infection (23%) and fracture (15%) for hypokalemia, lower respiratory tract (21.8%) and ear-nose-throat infections (20.0%) for hyperkalemia. Patients with hyperkalemia had an elevated creatinine level (0.72±1.6 vs. 0.40±0.16mg/dL, P<0.0001) with lower bicarbonate (19.4±3.8 vs. 21.8±2.8mmol/L, P=0.0001) and higher phosphorus levels (1.95±0.6 vs. 1.42±0.27mg/dL, P=0.0001). Patients with hypokalemia had an elevated creatinine level (0.66±0.71 vs. 0.40±0.16mg/dL, P<0.0001) and a lower phosphorus level (1.12±0.31 vs. 1.42±0.27mg/dL, P=0.0001). We did not observe significant differences in pH, PCO₂, base excess and lactate, or in the mean duration of hospitalization in general wards and pediatric intensive care units according to the PIM and PRISM scores.

DISCUSSION

Dyskalemia is rare in emergency department patients: 0.64% for hypokalemia and 0.58% for hyperkalemia. This condition could be explained by a degree of renal failure due to transient volume disturbance. The main mechanism is dehydration due to digestive losses, polypnea in young patients, and poor intake. In the case of hypokalemia, poor intake and digestive losses could be the main explanation. These disorders resolve easily with feeding or perfusion and do not impair development.

CONCLUSION

Dyskalemia is rare in emergency department patients and is easily resolved with feeding or perfusion. A plausible etiological mechanism is a transient volume disturbance. Dyskalemia is not predictive of poor development in the emergency pediatric population.

Insight into potassium's role in childhood mortality due to severe acute malnutrition

Hypokalaemia is associated with an increase in mortality in children with severe acute malnutrition (SAM) and diarrhoea. This is a descriptive cross-sectional retrospective study conducted in the Nutritional Ward at Mohamed Alamin Hamid Pediatrics Hospital in Omdurman, Sudan. It aimed to assess the frequency of hypokalaemia among children with SAM to understand the influence of hypokalaemia and potassium supplementations contributed on the children survival rates (January-December 2015). It included 215 patients with SAM and acute diarrhoea. The potassium levels of all the patients were assessed upon hospital admission and this correlated with the mortality according to the degree of hypokalaemia and treatment initiated. Hypokalaemia was evident in 70.2% of the patients. Mortality was 3.1% in normokalaemic and 13.9% in hypokalaemic patients. The patients' survival was significantly associated with their serum potassium levels and the treatment received. The survival rates have been assessed via the Multinomial Logistic Model, which reveals that normokalaemic children had a chance of 157.349 (95% confidence interval 18.479-1,339.811) times higher than that compared to the baseline children with advanced hypokalaemia with serum levels <2 mEq/l (p-value < 0.001). Children with mild hypokalaemia within the serum levels of 3.0-3.4 mEq/ml showed an increased survival chance of 549.970 (95% CI 19.293-3,238.716) times compared to the baseline children (p-value = 0.000). In patients with SAM, who presented with acute diarrhoea, there was an increase in mortality in patients with hypokalaemia compared with patients who presented with normal potassium levels. Corresponding mortality rates increased significantly with the severity of hypokalaemia. In severe hypokalaemia, there is a significant difference in mortality between patients treated with oral rehydration solutions for malnutrition in relation to patients treated with oral potassium supplements or with intravenous potassium.

Electrolyte imbalance in critically ill paediatric patients

Objective:

To determine the frequency and outcome of electrolyte imbalance in seriously ill children admitted in Paediatric Intensive Care Unit (PICU) of a public sector hospital in Karachi.

Methods:

All children between the ages of one month to 12 years admitted in PICU from May 2017 to October 2017 were included. Blood samples were drawn to determine the baseline sodium, potassium, calcium, magnesium and phosphorous and followed 24 hourly or earlier, if needed (Those who had imbalance at admission or on subsequent repeat labs as per protocol).

Results:

A total of 101 children were included in the study. Electrolyte imbalance was seen in 84%. A single electrolyte imbalance was noted in 30.58%. Hypocalcemia was the most frequent abnormality noted in 57.6%. Among the total expiries during the study period 91% had electrolyte imbalance. Mortality within 48 hours and duration of stay was also increased in these patients.

Conclusion:

Electrolyte imbalance is an important prognostic indicator in critically ill patients.

Severe hypokalemia secondary to abuse of β-adrenergic agonists in a pediatric patient: Case report

This study reports a case of a 13-year-old male with a 3-year history of severe and intermittent hypokalemia episodes of unknown origin, requiring admission to the intensive care unit (ICU) for long QT syndrome (LQTS), finally diagnosed of redistributive hypokalemia secondary to the abuse of β-adrenergic agonists in the context of a probable factitious disorder.

Safety, Efficacy, and Timeliness of Intravenous Potassium Chloride Replacement Protocols in a Pediatric Cardiothoracic Intensive Care Unit

OBJECTIVE

Hypokalemia in children following cardiac surgery occurs frequently, placing them at risk of life-threatening arrhythmias. However, renal insufficiency after cardiopulmonary bypass warrants careful administration of potassium (K⁺). Two different nurse-driven protocols (high dose and tiered dosing) were implemented to identify an optimal K⁺ replacement regimen, compared to an historical low-dose protocol. Our objective was to evaluate the safety, efficacy, and timeliness of these protocols.

DESIGN

A retrospective cohort review of pediatric patients placed on intravenous K⁺ replacement protocols over 1 year was used to determine efficacy and safety of the protocols. A prospective single-blinded review of K⁺ repletion was used to determine timeliness.

PATIENTS

Pediatric patients with congenital or acquired cardiac disease.

SETTING

Twenty-four-bed cardiothoracic intensive care unit in a tertiary children's hospital.

INTERVENTIONS

Efficacy was defined as fewer supplemental potassium chloride (KCl) doses, as well as a higher protocol to total doses ratio per patient. Safety was defined as a lower percentage of serum K⁺ levels ≥4.8 mEq/L after a dose of KCl. Between-group differences were assessed by nonparametric univariate analysis.

RESULTS

There were 138 patients with a median age of 3.0 (interquartile range: 0.23-10.0) months. The incidence of K⁺ levels ≥4.8 mEq/L after a protocol dose was higher in the high-dose protocol versus the tiered-dosing protocol but not different between the low-dose and tiered-dosing protocols (high dose = 2.2% vs tiered dosing = 0.5%, P = .05). The ratio of protocol doses to total doses per patient was lower in the low-dose protocol compared to the tiered-dosing protocol (P < .05). Protocol doses were administered 45 minutes faster (P < .001).

CONCLUSION

The tiered-dosed, nurse-driven K⁺ replacement protocol was associated with decreased supplemental K⁺ doses without increased risk of hyperkalemia, administering doses faster than individually ordered doses; the protocol was effective, safe, and timely in the treatment of hypokalemia in pediatric patients after cardiac surgery.