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Background: Clinical decision support systems (CDSSs) enable the automated, real-time detection of situations associated with a risk of adverse drug events (ADEs). However, the effectiveness of CDSS in reducing ADEs has yet to be demonstrated. We have chosen to focus on the detection of ADE such as hyperkalemia and/or acute kidney injury (AKI), which are common among hospitalized older adults. The present study's primary objective is to use a CDSS to reduce the number of ADEs (such as AKI and/or hyperkalemia) that occur in hospitalized older adults., Methods: This is a multicenter, stepped-wedge, cluster-randomized study involving five hospitals. Each hospital will start with a control period (i.e., routine care, during which each center's CDSS is deactivated) and then switch to an intervention period (during which the CDSS is activated). The intervention will be the use of a CDSS and a strategy for managing and transmitting alerts to clinical pharmacists. The rules concerning AKI and hyperkalemia have been drafted and reviewed by a multidisciplinary group. Each rule created in the CDSS is associated with a standardized procedure, based on a review of the literature. Older patients (aged 65 or over) admitted to a participating general medicine ward, a surgical ward, or obstetrics ward will be eligible for inclusion after the provision of verbal informed consent., Discussion: This study will assess the effectiveness of the CDSS in reducing the incidence of AKI and hyperkalemia. The implementation of the CDSS can assist clinical pharmacists in their daily work and is expected to prevent ADEs., Trial Registration: ClinicalTrials.gov Identifier: NCT05923983. Registered February 02, 2023., Competing Interests: Declarations Ethics approval and consent to participate {24} The study protocol has been evaluated and authorized by the relevant institutional IEC/IRB (CPP Sud-Méditerranée IV, Montpellier, France; reference: 2021-A03211-40). The study sponsor (Lille University Hospital) is responsible for all administrative procedures. In accordance with French legislation, all the patients or their legal representative will be given verbal information about the study during the inclusion visit and will also receive a study information sheet. The patient can refuse to participate at any time. The study protocol has been registered with the French Consultative Committee on Information Processing in Medical Research and the French National Data Protection Commission. This trial was registered at ClinicalTrials.gov (NCT05923983) on February 9, 2023: with the title “DETECT-IP: a Clinical Decision Support System and Intelligent Procedures to Counter Some Adverse Drug Events in Older Hospital Patients”). Any substantial change in the protocol is subject to a written amendment submitted to the sponsor, who must seek approval from the IEC/IRB and authorization by the competent authority or authorities before implementation. All amendments to the protocol must be made known to all the study’s investigators. Consent for publication {32} Not applicable-The participant information materials and informed consent form are available from the corresponding author on request. Competing interests {28} The authors declare that they have no competing interests., (© 2024. The Author(s).)

Hyperkalemia is an electrolyte disorder defined as a plasma potassium concentration greater than 5 mmol/L. Plasma potassium represents approximately 2 % of the total body potassium, and its regulation depends mainly on renal excretion and transcellular shifts. Various pathologies can alter potassium homeostasis and lead to acute or chronic hyperkalemia. The rate of change in plasma potassium concentration is critical because the faster it occurs, the faster life-threatening symptoms develop. Therefore, acute hyperkalemia should be urgently treated. There is no «threshold» value defining the severity of the situation, but the electrocardiographic changes appear to be valuable indicators of severity. Several medical associations have issued recommendations regarding the emergency management of hyperkalemia, but there is no scientific consensus. In this article, we summarize the current knowledge and propose a practical management algorithm for the management of acute hyperkalemia.

Background: Pseudohyperkalemia (falsely elevated serum potassium) must be distinguished from true hyperkalemia to avoid unnecessary treatment. Some case reports suggest that pneumatic tube transportation may increase the risk of pseudohyperkalemia, but comprehensive research on the topic is lacking. Here, we aimed to assess the association between WBC levels, pneumatic tube transport, and pseudohyperkalemia prevalence., Methods: We analyzed 1188 samples collected from 240 patients between 2019 and 2022. Samples with elevated WBC counts (≥ 100 × 10 3 /μL) and potassium levels were included in this study. The method of specimen transportation was documented., Results: Pseudohyperkalemia was observed (7/390) in specimens transported using pneumatic tubes. No pseudohyperkalemia was identified with manually transported specimens (0/132). Every increase in WBC count by 100 × 10 3 /μL in the specimens multiplied the odds ratio of pseudohyperkalemia by 3.75 when delivered with pneumatic tube. The prevalence of pseudohyperkalemia increased as WBC count increased, especially at WBC counts greater than 200 × 10 3 /μL., Conclusion: Pneumatic tube transport poses a risk for pseudohyperkalemia in patients with extreme leukocytosis. Physicians should anticipate odd potassium levels when interpreting blood test results. Redrawing of blood samples, manual specimen transportation, or point-of-care testing are suggested to prevent further misdiagnosis., (© 2024. Japanese Society of Hematology.)

Background: Hyperkalemia is a frequent electrolyte alteration whose prevalence varies widely, depending on the adopted cutoff, the setting (inpatients versus outpatients), and the characteristics of the study population. Familial hyperkalemic hypertension (FHH) is a rare cause of hypertension, hyperkalemia, and hyperchloremic metabolic acidosis., Methods: In this retrospective observational study, we investigated the prevalence of hyperkalemia (serum K + >5.2 mmol/L on 2 repeated measurements) in 5100 referred patients affected by arterial hypertension, the potential causes, and the associated cardiovascular risk profile., Results: Overall, 374 (7.3%) patients had hyperkalemia. This was associated with drugs known to increase K + levels (74.6%), chronic kidney disease (33.7%), or both (24.3%). Among the 60 patients with unexplained hyperkalemia, 3 displayed a clinical and biochemical phenotype suggestive of FHH that was genetically confirmed in 2 of them (0.04% in the entire cohort). FHH prevalence rose to 3.3% in patients with unexplained hyperkalemia and up to 29% (2/7) if they had serum K + >5.8 mmol/L. The genetic cause of FHH was a missense variant affecting the acidic motif of WNK1 in 1 family and a rare CUL3 splicing variant, whose functional significance was confirmed by a minigene assay, in another. Finally, we observed a significant association between hyperkalemia and the occurrence of cardiovascular events, metabolic syndrome, and organ damage, independent of potential confounding factors., Conclusions: The identification of hyperkalemia in patients with hypertension has prognostic implications. A timely diagnosis of FHH is important for effective management of hypertension, electrolyte imbalance correction with tailored treatment, and genetic counseling., Competing Interests: P. Mulatero received fees for educational speech from Diasorin.

Dyskalemia is a common electrolyte abnormality. Since dyskalemia can cause fatal arrhythmias and cardiac arrest in severe cases, it is crucial to monitor serum potassium (K + ) levels on time. We developed deep learning models to detect hyperkalemia (K +  ≥ 5.5 mEq/L) and hypokalemia (K +  < 3.5 mEq/L) from electrocardiograms (ECGs), which are noninvasive and can be quickly measured. The retrospective cohort study was conducted at two hospitals from 2006 to 2020. The training set, validation set, internal testing cohort, and external validation cohort comprised 310,449, 15,828, 23,849, and 130,415 ECG-K + samples, respectively. Deep learning models demonstrated high diagnostic performance in detecting hyperkalemia (AUROC 0.929, 0.912, 0.887 with sensitivity 0.926, 0.924, 0.907 and specificity 0.706, 0.676, 0.635 for 12-lead, limb-lead, lead I ECGs) and hypokalemia (AUROC 0.925, 0.896, 0.885 with sensitivity 0.912, 0.896, 0.904 and specificity 0.790, 0.734, 0.694) in the internal testing cohort. The group predicted to be positive by the hyperkalemia model showed a lower 30-day survival rate compared to the negative group (p < 0.001), supporting the clinical efficacy of the model. We also compared the importance of ECG segments (P, QRS, and T) on dyskalemia prediction of the model for interpretability. By applying these models in clinical practice, it will be possible to diagnose dyskalemia simply and quickly, thereby contributing to the improvement of patient outcomes., (© 2024. The Author(s).)

Infants with a congenital anomaly of the kidney and urinary tract sometimes present with hyponatremia, hyperkalemia, and metabolic acidosis due to under-responsiveness to aldosterone, hereafter referred to as secondary pseudo-hypoaldosteronism. The purpose of this report is to investigate pseudo-hypoaldosteronism in infant urinary tract infection. A systematic review was conducted following PRISMA guidelines after PROSPERO (CRD42022364210) registration. The National Library of Medicine, Excerpta Medica, Web of Science, and Google Scholar without limitations were used. Inclusion criteria involved pediatric cases with documented overt pseudo-hypoaldosteronism linked to urinary tract infection. Data extraction included demographics, clinical features, laboratory parameters, management, and course. Fifty-seven reports were selected, detailing 124 cases: 95 boys and 29 girls, 10 months or less of age (80% of cases were 4 months or less of age). The cases exhibited hyponatremia, hyperkalemia, acidosis, and activated renin-angiotensin II-aldosterone system. An impaired kidney function was found in approximately every third case. Management included antibiotics, fluids, and, occasionally, emergency treatment of hyperkalemia, hyponatremia, or acidosis. The recovery time averaged 1 week for electrolyte, acid-base imbalance, and kidney function. Notably, anomalies of the kidney and urinary tract were identified in 105 (85%) cases., Conclusions: This review expands the understanding of overt transient pseudo-hypoaldosteronism complicating urinary tract infection. Management involves antimicrobials, fluid replacement, and consideration of electrolyte imbalances. Raising awareness of this condition within pediatric hospitalists is desirable., What Is Known: • Infants affected by a congenital anomaly of the kidney and urinary tract may present with clinical and laboratory features resembling primary pseudo-hypoaldosteronism. • Identical features occasionally occur in infant urinary tract infection., What Is New: • Most cases of secondary pseudo-hypoaldosteronism associated with a urinary tract infection are concurrently affected by a congenital anomaly of the kidney and urinary tract. • Treatment with antibiotics and parenteral fluids typically results in the normalization of sodium, potassium, bicarbonate, and creatinine within approximately 1 week., (© 2024. The Author(s).)

Patients with newly diagnosed hematological malignancies often present with a considerable cellular burden, leading to complications including hyperkalemia. However, pseudohyperkalemia, arising from in vitro cell lysis, can pose challenges in clinical practice. Although pseudohyperkalemia is frequently reported in adult hematological malignancies, its occurrence in pediatric patients is underreported, and its incidence in this demographic remains unclear. We retrospectively reviewed the medical records of pediatric patients who received a new diagnosis of hematological malignancies from 2011 to 2022 at Taichung Veterans General Hospital. Hyperkalemia was defined by a serum or plasma potassium level exceeding 5.5 mEq/L. Pseudohyperkalemia was defined by 1) a potassium decrease of over 1 mEq/L in within 4 h without intervention or 2) the absence of electrocardiography changes indicative of hyperkalemia. Cases with apparent red blood cell hemolysis were excluded. A total of 157 pediatric patients with a new diagnosis of hematological malignancies were included, 14 of whom exhibited hyperkalemia. Among these 14 cases, 7 cases (4.5%) were of pseudohyperkalemia. This rate increased to 21.2% in patients with initial hyperleukocytosis. Pseudohyperkalemia was associated with a higher initial white blood cell count and lower serum sodium level. All episodes of pseudohyperkalemia occurred in the pediatric emergency department, where samples were obtained as plasma, whereas all true hyperkalemia cases were observed in the ordinary ward or intensive care unit, where samples were obtained as serum. Timely recognition of pseudohyperkalemia is crucial to avoiding unnecessary potassium-lowering interventions in pediatric patients with newly diagnosed hematological malignancies.

Background: Both mineralocorticoid receptor antagonists (MRAs) and sodium-glucose co-transporter type 2 inhibitors (SGLT2is) have demonstrated beneficial reductions in cardiovascular outcomes. However, the risk of precipitating hyperkalemia with their concomitant usage remains unclear., Methods: MEDLINE and Cochrane were searched from inception through March 2022. Randomized controlled trials on patients with heart failure (HF) evaluating the effect of SGLT2is on clinical outcomes between MRA users and non-users were considered for inclusion. Outcomes of interest were mild and moderate/severe hyperkalemia, for which hazard ratios (HR) were pooled using a random effects model., Results: From the 972 articles retrieved from the initial search, three RCTs (n = 14,462 patients) were included in our meta-analysis. Pooled analysis demonstrated no significant difference in the incidence of mild hyperkalemia between MRA users (HR 0.82 [0.70-0.97]) and non-users (HR 0.95 [0.77-1.17]) (P-interaction = 0.28). The risk of severe hyperkalemia was significantly decreased in MRA users (HR 0.59 [0.44-0.78]; p = 0.0002; I 2 = 0%) but not in non-users (HR 0.76 [0.56-1.02]; p = 0.07; I 2 = 0%) (P-interaction = 0.22). Sensitivity analysis including patients with HF with reduced ejection fraction (HFrEF) revealed similar results across all subgroups, but no significant reduction in the incidence of mild hyperkalemia (HR 0.89 [0.76-1.04] was noted in MRA users with HFrEF., Conclusion: MRAs reduced the risk of mild or moderate/severe hyperkalemia, when added to SGLT2is. Future clinical trials should target scrupulous assessment of the risk of mild and moderate/severe hyperkalemia when used concomitantly with MRAs., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

An 83-year-old man diagnosed with multiple myeloma presented with renal failure and hyperkalemia. The patient was treated with calcium polystyrene sulfonate (CPS: kalimate) for hyperkalemia. On the 10th day after starting CPS, airway obstruction due to the presence of a mass was observed, and the patient died on that same day. Autopsy revealed that the mass was located between the trachea and epiglottis and it was determined to consist of CPS-related mosaic crystals. There was a protrusion within the trachea surrounding the CPS crystals, inflammatory cells, and granulation tissue. This case suggests that CPS is associated with not only gastrointestinal complications, but also with airway complications.

This article provides a comprehensive overview of electrolyte and water homeostasis in pediatric patients, focusing on some of the common serum electrolyte abnormalities encountered in clinical practice. Understanding pathophysiology, taking a detailed history, performing comprehensive physical examinations, and ordering basic laboratory investigations are essential for the timely proper management of these conditions. We will discuss the pathophysiology, clinical manifestations, diagnostic approaches, and treatment strategies for each electrolyte disorder. This article aims to enhance the clinical approach to pediatric patients with electrolyte imbalance-related emergencies, ultimately improving patient outcomes.Trial registration This manuscript does not include a clinical trial; instead, it provides an updated review of literature., (© 2024. The Author(s).)

Background: Artificial intelligence (AI) electrocardiogram (ECG) analysis can enable detection of hyperkalemia. In this validation, we assessed the algorithm's performance in two high acuity settings., Methods: An emergency department (ED) cohort (February to August 2021) and a mixed intensive care unit (ICU) cohort (August 2017 to February 2018) were identified and analyzed separately. For each group, pairs of laboratory-collected potassium and 12 lead ECGs obtained within 4 hours of each other were identified. The previously developed AI ECG algorithm was subsequently applied to leads 1 and 2 of the 12 lead ECGs to screen for hyperkalemia (potassium >6.0 mEq/L)., Results: The ED cohort (N=40,128) had a mean age of 60 years, 48% were male, and 1% (N=351) had hyperkalemia. The area under the curve (AUC) of the AI-enhanced ECG (AI-ECG) to detect hyperkalemia was 0.88, with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR+) of 80%, 80%, 3%, 99.8%, and 4.0, respectively, in the ED cohort. Low-eGFR (<30 ml/min) subanalysis yielded AUC, sensitivity, specificity, PPV, NPV, and LR+ of 0.83, 86%, 60%, 15%, 98%, and 2.2, respectively, in the ED cohort. The ICU cohort (N=2636) had a mean age of 65 years, 60% were male, and 3% (N=87) had hyperkalemia. The AUC for the AI-ECG was 0.88 and yielded sensitivity, specificity, PPV, NPV, and LR+ of 82%, 82%, 14%, 99%, and 4.6, respectively in the ICU cohort. Low-eGFR subanalysis yielded AUC, sensitivity, specificity, PPV, NPV, and LR+ of 0.85, 88%, 67%, 29%, 97%, and 2.7, respectively in the ICU cohort., Conclusions: The AI-ECG algorithm demonstrated a high NPV, suggesting that it is useful for ruling out hyperkalemia, but a low PPV, suggesting that it is insufficient for treating hyperkalemia.

Background: New trials indicated a potential of sodium-glucose cotransporter-2 inhibitors (SGLT2i) to reduce hyperkalemia, which might have important clinical implications, but real-world data are limited. Therefore, we examined the effect of SGLT2i on hyper- and hypokalemia occurrence using the FDA adverse event reporting system (FAERS)., Methods: The FAERS database was retrospectively queried from 2004q1 to 2021q3. Disproportionality analyses were performed based on the reporting odds ratio (ROR) and 95% confidence interval (CI)., Results: There were 84 601 adverse event reports for SGLT2i and 1 321 186 reports for other glucose-lowering medications. The hyperkalemia reporting incidence was significantly lower with SGLT2i than with other glucose-lowering medications (ROR, 0.83; 95% CI, 0.79-0.86). Reductions in hyperkalemia reports did not change across a series of sensitivity analyses. Compared with that with renin-angiotensin-aldosterone system inhibitors (RAASi) alone (ROR, 4.40; 95% CI, 4.31-4.49), the hyperkalemia reporting incidence was disproportionally lower among individuals using RAASi with SGLT2i (ROR, 3.25; 95% CI, 3.06-3.45). Compared with that with mineralocorticoid receptor antagonists (MRAs) alone, the hyperkalemia reporting incidence was also slightly lower among individuals using MRAs with SGLT-2i. The reporting incidence of hypokalemia was lower with SGLT2i than with other antihyperglycemic agents (ROR, 0.79; 95% CI, 0.75-0.83)., Conclusion: In a real-world setting, hyperkalemia and hypokalemia were robustly and consistently reported less frequently with SGLT2i than with other diabetes medications. There were disproportionally fewer hyperkalemia reports among those using SGLT-2is with RAASi or MRAs than among those using RAASi or MRAs alone., (Copyright © 2024 Italian Federation of Cardiology - I.F.C. All rights reserved.)

This study aims to develop and validate a machine learning (ML) predictive model for assessing mortality in patients with malignant tumors and hyperkalemia (MTH). We extracted data on patients with MTH from the Medical Information Mart for Intensive Care-IV, version 2.2 (MIMIC-IV v2.2) database. The dataset was split into a training set (75%) and a validation set (25%). We used the Least Absolute Shrinkage and Selection Operator (LASSO) regression to identify potential predictors, which included clinical laboratory indicators and vital signs. Pearson correlation analysis tested the correlation between predictors. In-hospital death was the prediction target. The Area Under the Curve (AUC) and accuracy of the training and validation sets of 7 ML algorithms were compared, and the optimal 1 was selected to develop the model. The calibration curve was used to evaluate the prediction accuracy of the model further. SHapley Additive exPlanations (SHAP) and Local Interpretable Model-agnostic Explanations (LIME) enhanced model interpretability. 496 patients with MTH in the Intensive Care Unit (ICU) were included. After screening, 17 clinical features were included in the construction of the ML model, and the Pearson correlation coefficient was <0.8, indicating that the correlation between the clinical features was small. eXtreme Gradient Boosting (XGBoost) outperformed other algorithms, achieving perfect scores in the training set (accuracy: 1.000, AUC: 1.000) and high scores in the validation set (accuracy: 0.734, AUC: 0.733). The calibration curves indicated good predictive calibration of the model. SHAP analysis identified the top 8 predictive factors: urine output, mean heart rate, maximum urea nitrogen, minimum oxygen saturation, minimum mean blood pressure, maximum total bilirubin, mean respiratory rate, and minimum pH. In addition, SHAP and LIME performed in-depth individual case analyses. This study demonstrates the effectiveness of ML methods in predicting mortality risk in ICU patients with MTH. It highlights the importance of predictors like urine output and mean heart rate. SHAP and LIME significantly enhanced the model's interpretability., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Addison's disease is known to cause hyperkalemia. However, heart block as a result of such hyperkalemia is very rare. We report one such case where Addison's disease presented with hyperkalemia and resultant heart block and Stokes-Adam's syndrome along with other features of hypoadrenalism., (Copyright © 2024 Copyright: © 2024 Annals of African Medicine.)

Hyperkalemia is a common electrolyte disturbance in both inpatient and outpatient clinical practice. The severity and associated risk depends on the underlying cause and rate of potassium (K+) increase. Acute hyperkalemia requires immediate attention due to potentially life-threatening manifestations resulting from the rapid increase in plasma K+ concentration. Treatment is initially focused on stabilizing the cardiac membrane, followed by maneuvers to shift K+ into the cells, and ultimately initiating strategies to decrease total body K+ content. Chronic hyperkalemia develops over a more extended period of time and manifestations tend to be less severe. Nevertheless, the disorder is not benign since chronic hyperkalemia is associated with increased morbidity and mortality. The approach to patients with chronic hyperkalemia begins with a review of medications potentially responsible for the disorder, ensuring effective diuretic therapy and correcting metabolic acidosis if present. The practice of restricting foods high in K+ to manage hyperkalemia is being reassessed since the evidence supporting the effectiveness of this strategy is lacking. Rather, dietary restriction should be more nuanced, focusing on reducing the intake of nonplant sources of K+. Down-titration and/or discontinuation of renin-angiotensin-aldosterone inhibitors should be discouraged since these drugs improve outcomes in patients with heart failure and proteinuric kidney disease. In addition to other conservative measures, K+ binding drugs and sodium-glucose cotransporter 2 inhibitors can assist in maintaining the use of these drugs., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Hyperkalaemia is an electrolyte imbalance that impairs muscle function and myocardial excitability, and can potentially lead to fatal arrhythmias and sudden cardiac death. The prevalence of hyperkalaemia is estimated to be 6%-7% worldwide and 7%-10% in Asia. Hyperkalaemia frequently affects patients with chronic kidney disease, heart failure, and diabetes mellitus, particularly those receiving treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors. Both hyperkalaemia and interruption of RAAS inhibitor therapy are associated with increased risks for cardiovascular events, hospitalisations, and death, highlighting a clinical dilemma in high-risk patients. Conventional potassium-binding resins are widely used for the treatment of hyperkalaemia; however, caveats such as the unpalatable taste and the risk of gastrointestinal side effects limit their chronic use. Recent evidence suggests that, with a rapid onset of action and improved gastrointestinal tolerability, novel oral potassium binders (e.g., patiromer and sodium zirconium cyclosilicate) are alternative treatment options for both acute and chronic hyperkalaemia. To optimise the care for patients with hyperkalaemia in the Asia-Pacific region, a multidisciplinary expert panel was convened to review published literature, share clinical experiences, and ultimately formulate 25 consensus statements, covering three clinical areas: (i) risk factors of hyperkalaemia and risk stratification in susceptible patients; (ii) prevention of hyperkalaemia for at-risk individuals; and (iii) correction of hyperkalaemia for at-risk individuals with cardiorenal disease. These statements were expected to serve as useful guidance in the management of hyperkalaemia for health care providers in the region., (© 2024 The Authors. Nephrology published by John Wiley & Sons Australia, Ltd on behalf of Asian Pacific Society of Nephrology.)

The World Health Organization estimates that 31 foodborne pathogen account for 600 million cases of illness annually. This study, conducted in a pediatric emergency department in Turkey, addresses the limited research on pediatric foodborne diseases (FD) in the country, exposing a significant knowledge gap. Analyzing 17,091 pediatric cases, 106 FD cases were identified, predominantly affecting boys (94.3%) with an average age of 7.65 ± 6.51 years. Remarkably, no patients required pediatric intensive care admission, and no mortalities were recorded. Hyponatremia emerged as a prevalent electrolyte disorder in pediatric FD, while hyperkalemia was notably observed in children under 5. The study emphasizes the severity of FD in children under 5, reflected in longer hospital stays, underscoring the urgent need for targeted interventions and improved detection methods in pediatric FD.

The quantitative systems pharmacology (QSP) approach is widely applied to address various essential questions in drug discovery and development, such as identification of the mechanism of action of a therapeutic agent, patient stratification, and the mechanistic understanding of the progression of disease. In this review article, we show the current landscape of the application of QSP modeling using a survey of QSP publications over 10 years from 2013 to 2022. We also present a use case for the risk assessment of hyperkalemia in patients with diabetic nephropathy treated with mineralocorticoid receptor antagonists (MRAs, renin-angiotensin-aldosterone system inhibitors), as a prospective simulation of late clinical development. A QSP model for generating virtual patients with diabetic nephropathy was used to quantitatively assess that the nonsteroidal MRAs, finerenone and apararenone, have a lower risk of hyperkalemia than the steroidal MRA, eplerenone. Prospective simulation studies using a QSP model are useful to prioritize pharmaceutical candidates in clinical development and validate mechanism-based pharmacological concepts related to the risk-benefit, before conducting large-scale clinical trials., Competing Interests: Declaration of competing interest Ryuta Saito and Tomohisa Nakada are an employee of Mitsubishi Tanabe Pharma Corporation., (Copyright © 2024 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.)

Hyperkalemia is common in everyday clinical practice, and is a major risk factor for mortality. It mainly affects patients with chronic renal failure (CKD), diabetes or receiving treatment with inhibitors of the renin-angiotensin-aldosterone system (iRAAS). Therapeutic management aims not only to avoid the complications of hyperkalemia, but also to avoid discontinuation of cardio- and nephroprotective treatments such as iRAAS. The use of polystyrene sulfonate, widely prescribed, is often limited by patient acceptability. Recent data have cast doubt on its safety, particularly in terms of digestive tolerance. Two new potassium exchange molecules have appeared on the market: patiromer and zirconium sulfonate. Their value in clinical practice, and their acceptability in the event of prolonged prescription, remain to be demonstrated. The combination of a thiazide diuretic or an inhibitor of the sodium-glucose cotransporter type 2 (iSGLT2) with iRAAS therapy in CKD, may also improve control of kalemia. At present, there are no recommendations for the positioning of the various hypokalemic treatments. The choice of these treatments must be adapted to the patient's pathologies and consider the other expected effects of these molecules., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Hyperkalaemia is one of the common electrolyte imbalances dealt with in the emergency department and is caused by extracellular accumulation of potassium ions above normal limits usually greater than 5.0-5.5 mmol/L. It is found in a total of 1-10% of hospitalised patients usually associated with chronic kidney disease and heart failure. The presentation can range from being asymptomatic to deadly arrhythmias. The appearance of symptoms depends on the rate of change rather than just the numerical values. The rare presentation includes periodic paralysis characterised by the sudden onset of short-term muscle weakness, stiffness or paralysis. Management goals are directed towards reducing potassium levels in emergency settings and later on avoiding the triggers for future attacks. In this case, we present a man in his 50s with the generalised weakness later on diagnosed as hyperkalaemic periodic paralysis secondary to tumour lysis syndrome. Emergency physicians dealing with common electrolyte imbalances should keep a sharp eye on their rare presentation and their precipitating factors and should act accordingly., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose of Review: Hyperkalemia is a potentially fatal electrolyte abnormality with no standardized management. The purpose of this review is to provide the knowledge needed for timely and effective management of hyperkalemia in children. It describes the utility of existing and novel therapies., Recent Findings: Two newer oral potassium binding agents, patiromer sorbitex calcium and sodium zirconium cyclosilicate, have been FDA-approved for the management of hyperkalemia in adults. These newer agents offer hope for improved management, even though their use in pediatric patients requires further exploration., Summary: This review highlights the causes and life-threatening effects of hyperkalemia and provides a comprehensive overview of the management of hyperkalemia in both acute and chronic settings along with upcoming treatment strategies., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Heart failure is a major cause of morbidity and mortality among older adults. Sacubitril-Valsartan (Sac/Val) has been shown to improve patients' outcomes; however, its safety profile among older adults has not been adequately examined. We therefore aimed to examine its safety profile among this population., Methods: We conducted a retrospective pharmacovigilance study utilizing the FDA's database of safety reports (FAERS). We employed disproportionality analysis comparing Sac/Val to angiotensin receptor blockers (ARBs). We aim to evaluate the reporting of pre-defined adverse events associated with Sac/Val (hypotension, acute kidney injury (AKI), hyperkalemia and angioedema) in two age groups: adults (< 75 years) and older adults (≥ 75). For each subgroup, we calculated reporting odds ratio (ROR) and compared them by calculating P for interaction., Results: The FAERS database encompassed 18,432 unique reports of Sac/Val. Of them, 12,630 (68.5%) subjects were adults (< 75 years), and 5802 (31.5%) were older adults (≥ 75 years), with a median age (IQR) of 68 (59-77). When compared to ARBs, Sac/Val was associated with higher reporting of hypotension, lower reporting of acute kidney injury (AKI) and hyperkalemia, and similar reporting of angioedema. Notably, we did not observe a significant interaction between the age subgroups and the risk estimates (AKI: P interaction  = 0.72, hyperkalemia: P interaction  = 0.94, hypotension: P interaction  = 0.31, and angioedema: P interaction  = 0.61)., Conclusions: In this postmarking study, none of the prespecified adverse events was reported more frequently in older adults. These findings provide reassurance for safety use of Sac/Val in older adults., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Competing Interests: Declaration of Competing Interest The authors have no competing interest to declare.

Background: Sodium zirconium cyclosilicate, a non-absorbed non-polymer zirconium silicate, is a new potassium binder for hyperkalemia. A previous report showed that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows a higher continuation rate of renin-angiotensin-aldosterone system inhibitors. However, no studies have compared sodium zirconium cyclosilicate with existing potassium binders for renin-angiotensin-aldosterone system inhibitor continuity. The purpose of this study was to evaluate the effect of sodium zirconium cyclosilicate on angiotensin-converting enzyme inhibitor /angiotensin receptor blocker continuation in patients with hyperkalemia compared to that of calcium polystyrene sulfonate., Methods: Patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly prescribed sodium zirconium cyclosilicate or calcium polystyrene sulfonate to treat hyperkalemia at a tertiary referral hospital between August 2020 and April 2022 were enrolled in this single-center, retrospective observational study. The primary outcome measure was angiotensin-converting enzyme inhibitor/angiotensin receptor blocker prescription three months after initiating potassium binders., Results: In total, 174 patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly administered sodium zirconium cyclosilicate (n = 62) or calcium polystyrene sulfonate (n = 112) were analyzed. The prescription rate of angiotensin-converting enzyme inhibitors /angiotensin receptor blockers at 3 months was significantly higher in the sodium zirconium cyclosilicate group than in the calcium polystyrene sulfonate group (89 vs. 72%). Multivariate logistic regression models showed that sodium zirconium cyclosilicate was independently associated with the primary outcome (odds ratio 2.66, 95% confidence interval 1.05-7.43). The propensity score-matched comparison also showed a significant association between sodium zirconium cyclosilicate and the primary outcome., Conclusions: Our study suggests that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows for a higher continuation rate of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers than calcium polystyrene sulfonate. These findings suggest that sodium zirconium cyclosilicate has potential benefits for patients with chronic kidney disease receiving renin-angiotensin-aldosterone system inhibitors., (© 2023. The Author(s) under exclusive licence to Italian Society of Nephrology.)

Whereas the electrocardiogram (ECG) changes in hypokalemia are well known, they often receive less attention than the more striking features of hyperkalemia. Furthermore, there is a need for further discussion as to the subtleties of ECG changes that can aid in the differential diagnoses. This case study presents the ECG changes of a patient with severe hypokalemia due to diarrhea. It highlights how bifid T-waves in hypokalemia can be distinguished from other conditions such as coronary artery disease or pericarditis. Furthermore, it also shows the gradual reversal of ECG changes in the same patient when potassium is normalized., Competing Interests: Declaration of Competing Interest None of the authors have any disclosures related to this work., (Copyright © 2023. Published by Elsevier Inc.)

Background: Patients with end-stage renal disease (ESRD) especially those undergoing dialysis have a high prevalence of hyperkalemia, which must be detected and treated immediately. But the initial symptoms of hyperkalemia are insidious, and traditional laboratory serum potassium concentration testing takes time. Therefore, rapid and real-time measurement of serum potassium is urgently needed. In this study, different machine learning methods were used to make rapid predictions of different degrees of hyperkalemia by analyzing the ECG., Methods: A total of 1024 datasets of ECG and serum potassium concentrations were analyzed from December 2020 to December 2021. The data were scaled into training and test sets. Different machine learning models (LR, SVM, CNN, XGB, Adaboost) were built for dichotomous prediction of hyperkalemia by analyzing 48 features of chest leads V2-V5. The performance of the models was also evaluated and compared using sensitivity, specificity, accuracy, accuracy, F1 score and AUC., Results: We constructed different machine models to predict hyperkalemia using LR and four other common machine-learning methods. The AUCs of the different models ranged from 0.740 (0.661, 0.810) to 0.931 (0.912,0.953) when different serum potassium concentrations were used as the diagnostic threshold for hyperkalemia, respectively. As the diagnostic threshold of hyperkalemia was raised, the sensitivity, specificity, accuracy and precision of the model decreased to various degrees. And AUC also performed less well than when predicting mild hyperkalemia., Conclusion: Noninvasive and rapid prediction of hyperkalemia can be achieved by analyzing specific waveforms on the ECG by machine learning methods. But overall, XGB had a higher AUC in mild hyperkalemia, but SVM performed better in predicting more severe hyperkalemia.

Background: Hyperkalemia is a potentially fatal condition that mandates rapid identification in emergency departments (EDs). Although a 12-lead electrocardiogram (ECG) can indicate hyperkalemia, subtle changes in the ECG often pose detection challenges. An artificial intelligence application that accurately assesses hyperkalemia risk from ECGs could revolutionize patient screening and treatment. We aimed to evaluate the efficacy and reliability of a smartphone application, which utilizes camera-captured ECG images, in quantifying hyperkalemia risk compared to human experts., Methods: We performed a retrospective analysis of ED hyperkalemic patients (serum potassium ≥ 6 mmol/L) and their age- and sex-matched non-hyperkalemic controls. The application was tested by five users and its performance was compared to five board-certified emergency physicians (EPs)., Results: Our study included 125 patients. The area under the curve (AUC)-receiver operating characteristic of the application's output was nearly identical among the users, ranging from 0.898 to 0.904 (median: 0.902), indicating almost perfect interrater agreement (Fleiss' kappa 0.948). The application demonstrated high sensitivity (0.797), specificity (0.934), negative predictive value (NPV) (0.815), and positive predictive value (PPV) (0.927). In contrast, the EPs showed moderate interrater agreement (Fleiss' kappa 0.551), and their consensus score had a significantly lower AUC of 0.662. The physicians' consensus demonstrated a sensitivity of 0.203, specificity of 0.934, NPV of 0.527, and PPV of 0.765. Notably, this performance difference remained significant regardless of patients' sex and age ( P < 0.001 for both)., Conclusion: Our findings suggest that a smartphone application can accurately and reliably quantify hyperkalemia risk using initial ECGs in the ED., Competing Interests: Joonghee Kim, MD developed the algorithm and founded a start-up company ARPI Inc. He is the CEO of the company. Youngjin Cho works for the company as a research director. Eunkyoung Lee and Bumi Jeong work for the company as clinical researcher. Otherwise, there is no conflict of interest for the other authors., (© 2023 The Korean Academy of Medical Sciences.)

Abnormalities in serum potassium are commonly encountered in patients presenting to the emergency department. A variety of acute and chronic causes can lead to life-threatening illness in both hyperkalemia and hypokalemia. Here we summarize the relevant causes, risks, and treatment options for these frequently encountered disorders., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hyperkalaemia is a common electrolyte imbalance with potentially serious short-, medium- and long-term consequences on morbidity and mortality rates and the use of national health service resources. The fact that different medical specialities can manage hyperkalaemia makes it important to have a unified approach, and the recent availability of new specific drug treatments means that the approach needs to be updated. This consensus document from the scientific societies most directly involved in the management of hyperkalaemia (Sociedad Española de Cardiología [Spanish Society of Cardiology], Sociedad Española de Endocrinología y Nutrición [Spanish Society of Endocrinology and Nutrition], Sociedad Española de Medicina Interna [Spanish Society of Internal Medicine], Sociedad Española de Medicina de Urgencias y Emergencias [Spanish Society of Accident and Emergency Medicine] and Sociedad Española de Nefrología [Spanish Society of Nephrology]) first of all reviews basic aspects of potassium balance and blood potassium. Then it goes on to focus on the concept, epidemiology, pathophysiology and diagnostic and therapeutic approaches to hyperkalaemia. The available evidence and the main published studies have been reviewed with the aim of providing a useful tool in the multidisciplinary approach to patients with hyperkalaemia., (Copyright © 2023 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.)

We herein report two suspected cases of pseudohyperkalemia who presented with severe hyperkalemia examined at small primary care clinics; however, re-exams at a tertiary care hospital showed normal potassium levels. We reproduced the laboratory examination conditions of the clinics and found that hyperkalemia was due to sampling/storage condition of serum, which is strongly suggestive of familial pseudohyperkalemia (FP). FP is a possible but under-appreciated cause of hyperkalemia, which does not require treatment, so it is important to include FP in the differential diagnosis of hyperkalemia especially in cases with discrepant of serum potassium levels at different settings., (© 2023. The Author(s) under exclusive licence to The Japan Society of Nephrology.)

Background: Hyperkalaemia is managed in the emergency department (ED) following measurement of potassium results by blood gas analysers (BGA) or laboratory analysers (LAB)., Aims: To determine the prevalence of clinically significant differences between BGA and LAB potassium results and the impact on ED hyperkalaemia management., Methods: Retrospective analysis of time-matched ED BGA and LAB potassium samples from 2019 to 2020 (taken within 15 min, one or both results ≥6.0 mmol/L). Mean differences and 95% limits of agreement (LoA) were determined for pairs with one or both results ≥6.0 mmol/L and a separate 500 consecutive sample pairs., Results: Four hundred eighty-eight matched BGA and LAB samples met the inclusion criteria. Of these, 201 (41.2%) differed by ≤0.5 mmol/L, 169 (34.6%) included a haemolysed LAB sample, and 12 (2.5%) had an unreportable BGA sample. One hundred six (21.7%) pairs differed by >0.5 mmol/L, and 60/106 (57%) had normal LAB potassium results, but BGA indicated moderate/severe hyperkalaemia (two of these pairs received hyperkalaemia treatment). Of patients with a haemolysed LAB sample, or where pairs differed by >0.5 mmol, 48 were treated with insulin and five (10.4%) experienced hypoglycaemia. Mean differences and LoA for pairs with LAB results <6.0 mmol/L but BGA ≥6.0 mmol/L demonstrated unacceptable agreement, with 18 (25.7%) BGA results exceeding 8.0 mmol/L., Conclusions: Potentially significant discordance may occur between BGA and LAB potassium results. Clinicians need to be aware of factors impacting both analytical methods' accuracy (such as poor venepuncture or sample handling, (K) EDTA interference) and undetectable haemolysis with BGA measurements. We recommend BGA hyperkalaemia be confirmed with LAB results using a non-haemolysed sample where time permits., (© 2023 Royal Australasian College of Physicians.)

Hyperkaliemia is a relatively common electrolyte disorder whose manifestations and consequences can be serious if severe hyperkalemia is not treated. In the context of hypertension, it is important to look for co-morbidities and conditions favoring hyperkaliemia, to review the drugs prescribed that could contribute to potassium elevation and to bear in mind that when the common causes have been excluded, a genetic origin may be present. In this article, the focus is on the association of hypertension and hyperkaliemia, in the context of the marketing of new cardiovascular and renal drugs that may induce this electrolyte disorder., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Purpose: Potassium binders are frequently utilized for the treatment of hyperkalemia in hospitalized patients; however, there is limited data directly comparing individual agents. The purpose of this study was to compare the effectiveness and safety of sodium polystyrene sulfonate (SPS) and sodium zirconium cyclosilicate (SZC) for hyperkalemia treatment in hospitalized patients., Methods: This retrospective cohort study evaluated adult patients who were admitted within a 7-hospital health system and received SPS or SZC for a serum potassium level greater than 5.0 mEq/L. Patients receiving dialysis prior to SPS/SZC administration, those receiving other potassium-lowering medications within 6 hours prior to blood sampling for a repeat potassium level, and those started on kidney replacement therapy prior to sampling for a repeat potassium level were excluded., Results: Following evaluation of 3,903 patients, the mean reduction in serum potassium 4 to 24 hours after binder administration was 0.96 mEq/L with SPS and 0.78 mEq/L with SZC (P < 0.0001). The median dose of SPS was 30 g (interquartile range [IQR], 15-30 g) while the median (IQR) dose of SZC was 10 g (10-10 g). Resolution of hyperkalemia within 24 hours was achieved in a higher percentage of patients with use of SPS (74.9%) versus SZC (68.8%) (P < 0.001)., Conclusion: One of the largest comparisons of SPS and SZC conducted to date, this study demonstrated the effectiveness and safety of both agents. While a statistically greater reduction in serum potassium was observed with use of SPS, there was significant dosing variability among agents that limited the ability to directly compare specific doses. Further investigation is needed to determine the optimal dose of each agent for acute hyperkalemia management. This data will inform clinical decisions about the choice of potassium binder for acute hyperkalemia., (© American Society of Health-System Pharmacists 2023. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Abstract: Hyperkalemic cardiac arrest diagnosis can be elusive and management difficult as the cardiac rhythm restoration is often not achieved until the potassium level decreases to a relatively normal level for the patient who suffers the arrest. Current treatment modalities can take hours to achieve this goal. We describe two patients who survived a witnessed hyperkalemic cardiac arrest after being managed with conventional advanced cardiac life support and unconventionally high doses of intravenous insulin., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: As hyperkalemia may be life-threatening, it is critical to recognize artifactually increased potassium concentrations. Pseudohyperkalemia may occur in myopathies when using the VetScan2 analyzer (VS2), but the degree of pseudohyperkalemia and relationships relative to creatine kinase activity (CK) are unknown., Objectives: We aimed to determine what degree of muscle enzyme leakage, as reflected by increased serum CK activity, results in cases with falsely elevated potassium concentrations when measured by the VS2. We also sought to establish if a linear relationship exists between potassium concentrations measured by the VS2 and CK activity., Methods: Serum samples from dogs with increased CK activity and with CK activity within the reference interval and without clinically relevant biochemical alterations were used to create diluted samples having various CK activities. Potassium concentrations and CK activities were determined on VS2 and Cobas c501 (Cobas) analyzers. Wilcoxon signed rank, Bland-Altman, and Passing-Bablok analyses were used to compare potassium concentrations generated by the VS2 and Cobas analyzers. Least squares regression analysis was performed to evaluate if a linear relationship exists between VS2 potassium concentrations and Cobas CK activities., Results: Potassium concentrations from the VS2 were higher (median and standard deviation (SD) = 5.2 +/- 0.46 mmol/L) than those from the Cobas analyzer (4.4 +/- 0.35 mmol/L; P < 0.000), and a positive mean bias was found (mean difference = 0.774 mmol/L; 95% Confidence Interval (CI) = 0.706-0.842; limits of agreement = 0.21-1.34). Passing-Bablok regression showed a positive proportional bias for potassium concentrations on the VS2 compared with paired Cobas results (Slope = 1.328; 95% CI = 1.100-1.500) but did not reveal systematic bias (Intercept = -0.714; 95% CI = -1.46-0.265). Least squares regression analysis showed a poor non-significant relationship (R 2  = 0.19) between potassium measured by the VS2 and CK measured by the Cobas analyzer., Conclusions: A defined threshold value of CK activity at which potassium concentration begins to falsely increase when measured on the VS2 was not established as data widely varied. A poor non-significant relationship between potassium concentrations and CK activities did not allow prediction of the threshold at which falsely increased potassium concentrations would be expected on the VS2., (© 2023 The Authors. Veterinary Clinical Pathology published by Wiley Periodicals LLC on behalf of American Society for Veterinary Clinical Pathology.)

The term pseudohyperkalemia refers to a false elevation in serum potassium levels due to potassium release from cells in vitro. Falsely elevated potassium levels have been reported in patients with thrombocytosis, leukocytosis, and hematologic malignancies. This phenomenon has been particularly described in chronic lymphocytic leukemia (CLL). Leukocyte fragility, extremely high leukocyte counts, mechanical stress, higher cell membrane permeability related to an interaction with lithium heparin in plasma blood samples, and metabolite depletion due to a high leukocyte burden have been reported to contribute to pseudohyperkalemia in CLL. The prevalence of pseudohyperkalemia is up to 40%, particularly in the presence of a high leukocyte count (>50 × 10 9 /L). The diagnosis of pseudohyperkalemia is often overlooked, which may result in unnecessary and potentially harmful treatment. The use of whole blood testing and point-of-care blood gas analysis, along with thorough clinical evaluation, may help differentiate between true and pseudohyperkalemic episodes., Competing Interests: Declaration of Competing Interest The author has no financial or other conflicts of interest to disclose., (Copyright © 2023 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Objectives: Serum potassium (K) exhibits a positive shift relative to plasma K due to a variable amount of K release associated with clotting. Because of this variation, plasma K results outside of the reference interval (RI) for plasma (hypokalemia or hyperkalemia) in individual samples may not produce classification-concordant results in serum according to the serum RI. We examined this premise from a theoretical standpoint by simulation., Design & Methods: We used textbook K reference intervals for plasma (PRI = 3.4-4.5 mmol/L) and serum (SRI = 3.5-5.1 mmol/L). The difference between PRI and SRI is characterized by a normal distribution: serum K = plasma K + 0.35 ± 0.308 mmol/L. This transformation was applied by simulation to an observed patient data distribution for plasma K to generate a corresponding theoretical serum K distribution. Individual samples were tracked for comparison with respect to classification (below, within, above RI) for plasma and serum., Results: Primary data were an all-comers plasma K patient distribution (n = 41,768; median = 4.1 mmol/L; 7.1% below PRI (hypokalemia); 15.5% above PRI (hyperkalemia)). Simulation to obtain the associated serum K yielded a right-shifted distribution (median = 4.4 mmol/L; 4.8% below SRI; 10.8% above SRI). Sensitivity for detection in serum (flagged below SRI) for samples originating as hypokalemic in plasma was 45.7% (specificity = 98.3%). Sensitivity for detection in serum (flagged above SRI) for samples originating as hyperkalemic in plasma was 56.6% (specificity = 97.6%)., Conclusions: Simulation results indicate that serum K should best be thought of as an inferior substitute marker for plasma K. These results follow simply from the variable component of serum K compared to plasma K. Plasma should be the preferred specimen type for K assessment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

An 18-day-old male infant was admitted to the hospital due to recurrent hyperkalemia for more than 10 days. The neonate had milk refusal and dyspnea. The blood gas analysis revealed recurrent hyperkalemia, hyponatremia and metabolic acidosis. Adrenocortical hormone replacement therapy was ineffective. Additional tests showed a significant increase in aldosterone levels. Family whole exome sequencing revealed that the infant had compound heterozygous in the SCNNIA gene, inherited from both parents. The infant was diagnosed with neonatal systemic pseudohypoaldosteronism type I. The infant's electrolyte levels were stabilized through treatment with sodium polystyrene sulfonate and sodium supplement. The infant was discharged upon clinical recovery. This study provides a focused description of differential diagnosis of salt-losing syndrome in infants and introduces the multidisciplinary management of neonatal systemic pseudohypoaldosteronism type I.

Potassium ions (K + ) play crucial roles in many biological processes. Abnormal K + levels in the body are usually associated with physiological disorders or diseases, and thus, developing K + -sensitive sensors/devices is of great importance for disease diagnosis and health monitoring. Herein, we report a K + -sensitive photonic crystal hydrogel (PCH) sensor with bright structural colors for efficient monitoring of serum potassium. This PCH sensor consists of a poly(acrylamide- co-N -isopropylacrylamide- co -benzo-15-crown-5-acrylamide) (PANBC) smart hydrogel with embedded Fe 3 O 4 colloidal photonic crystals (CPCs), which could strongly diffract visible light and endow the hydrogel with brilliant structural colors. The rich 15-crown-5 (15C5) units appended on the polymer backbone could selectively bind K + ions to form stable 2 : 1 [15C5] 2 /K + supramolecular complexes. These bis-bidentate complexes served as physical crosslinkers to crosslink the hydrogel and contracted its volume, and thus reduced the lattice spacing of Fe 3 O 4 CPCs and blue-shifted the light diffraction, and finally reported on the K + concentrations by a color change of the PCH. Our fabricated PCH sensor possessed high K + selectivity and pH- and thermo-sensitive response performances to K + . Most interestingly, the K + -responding PANBC PCH sensor could be conveniently regenerated via simple alternate flushing with hot/cold water due to the excellent thermosensitivity of the introduced PNIPAM moieties into the hydrogel. Such a PCH sensor provides a simple, low-cost and efficient strategy for visualized monitoring of hyperkalemia/hypokalemia, which will significantly promote the development of biosensors.

Objective: To examine the effect of angiotensin II receptor blocker (ARB) treatment on serum potassium level and hyperkalaemia risk in a clinical setting with inpatients and outpatients using calcium channel blockers (CCBs) as a reference standard., Methods: The increased risk of hyperkalaemia associated with ARB treatment is known, however only a few studies have used an active comparator to examine this risk. In this retrospective study at a 320-bed general hospital in Japan, the hospital information system was used to identify patients with at least one prescription for an ARB (819 patients) or a CCB (1015 patients) who were naive to these drugs before study initiation. Serum potassium levels before and after ARB treatment were compared. Additionally, the unadjusted and adjusted hazard ratios for the risk of hyperkalaemia in the ARB and CCB users were estimated., Results: The serum potassium level was higher in patients receiving ARB treatment (0.05 mEq/L, p=0.02) compared with those on CCB treatment. However, there was no significant association between ARB use and hyperkalaemia (adjusted HR 0.91, 95% CI 0.42 to 1.99, p=0.82)., Conclusion: The increase in serum potassium level after ARB initiation makes it necessary to monitor serum potassium levels continuously during ARB treatment; however, the risk of hyperkalaemia appeared to be similar for ARB and CCB treatments., Competing Interests: Competing interests: None declared., (© European Association of Hospital Pharmacists 2023. Re-use permitted under CC BY-NC. No commercial re-use. Published by BMJ.)

Objectives: Transtubular potassium gradient has never been evaluated in the diagnosis of primary hypoadrenocorticism in dogs. The objective of this study is to evaluate the diagnostic utility of transtubular potassium gradient for the diagnosis of primary hypoadrenocorticism in dogs with serum K +  > 5.5 mol/L., Materials and Methods: Cross-sectional study including dogs with primary hypoadrenocorticism and dogs with other disease. Differences in signalment and laboratory parameters between groups were assessed by binary logistic regression modelling. Variables significantly associated with primary hypoadrenocorticism were evaluated for their diagnostic accuracy of this condition by receiver operator characteristic curve analysis and by multivariable logistic regression analysis, respectively., Results: Dogs with primary hypoadrenocorticism (n=39) were significantly younger than hyperkalemic dogs without primary hypoadrenocorticism (n=41). Moreover they had higher serum and urinary concentrations of Na + and Na + :K + , but lower transtubular potassium gradient than hyperkalemic dogs without hypoadrenocorticism. Serum Na + (sNa + ) had the highest diagnostic accuracy (area under the curve [AUC]: 0.87, 95% confidence interval, 0.78 to 0.96), followed by the transtubular potassium gradient (AUC: 0.81, 0.72 to 0.91), however the accuracy of the two AUCs was not statistically different. The transtubular potassium gradient-sNa + additive index (i.e. transtubular potassium gradient+sNa + /10) had a greater accuracy (AUC: 0.88, 0.79 to 0.94) than transtubular potassium gradient or sNa + , although it was not statistically superior to the latter. The multivariable logistic regression model showed that transtubular potassium gradient (adjusted odds ratio [aOR]: 0.51, 0.3 to 0.84), sNa + (aOR: 0.86, 0.78 to 0.95) and spayed female (aOR: 24.96, 2.32 to 267.66) were associated with primary hypoadrenocorticism., Clinical Significance: Transtubular potassium gradient-sNa + additive index can contribute to decision-making on diagnosis of primary hypoadrenocorticism in dogs presenting with hyperkalaemia., (© 2023 British Small Animal Veterinary Association.)