Validation of Noninvasive Detection of Hyperkalemia by Artificial Intelligence-Enhanced Electrocardiography in High Acuity Settings.

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.

Balancing acute medical management of acute kidney injury and hyperkalaemia versus medicines optimisation for long-term Cardio-Renal-Metabolic (CaReMe) diseases: a narrative review.

Cardio-Renal-Metabolic (CaReMe) diseases, in the form of heart failure, chronic kidney disease and diabetes mellitus, justify prescription of multiple prognostically beneficial medications, specifically renin-angiotensin system inhibitors, mineralocorticoid receptor antagonists, and sodium-glucose co-transporter-2 inhibitors. Use of these medications is complicated by association with adverse effects, particularly acute kidney injury and hyperkalaemia. Balancing risk and benefit is a common dilemma in acute medicine, with increasingly frequent and complex treatment decisions. Physicians should contemplate adjustments to medications within the context of not just acute illness but also long-term benefit. In the setting of hyperkalaemia, potassium-binding medications can be utilised. At hospital discharge optimisation of therapy can be achieved through clear safety netting advice, scheduled biochemical follow-up, and planned clinical review.

The burden of hyperkalaemia on hospital healthcare resources.

Hyperkalaemia is associated with prolonged hospital admission and worse mortality. Hyperkalaemia may also necessitate clinical consults, therapies for hyperkalaemia and high-dependency bed utilisation. We evaluated the 'hidden' human and organisational resource utilisation for hyperkalaemia in hospitalised patients. This was a single-centre, observational cohort study (Jan 2017-Dec 2020) at a tertiary-care hospital. The CogStack system (data processing and analytics platform) was used to search unstructured and structured data from individual patient records. Association between potassium and death was modelled using cubic spline regression, adjusted for age, sex, and comorbidities. Cox proportional hazards estimated the hazard of death compared with normokalaemia (3.5-5.0 mmol/l). 129,172 patients had potassium measurements in the emergency department. Incidence of hyperkalaemia was 85.7 per 1000. There were 49,011 emergency admissions. Potassium > 6.5 mmol/L had 3.9-fold worse in-hospital mortality than normokalaemia. Chronic kidney disease was present in 21% with potassium 5-5.5 mmol/L and 54% with potassium > 6.5 mmol/L. For diabetes, it was 20% and 32%, respectively. Of those with potassium > 6.5 mmol/L, 29% had nephrology review, and 13% critical care review; in this group 22% transferred to renal wards and 8% to the critical care unit. Dialysis was used in 39% of those with peak potassium > 6.5 mmol/L. Admission hyperkalaemia and hypokalaemia were independently associated with reduced likelihood of hospital discharge. Hyperkalaemia is associated with greater in-hospital mortality and reduced likelihood of hospital discharge. It necessitated significant utilisation of nephrology and critical care consultations and greater likelihood of patient transfer to renal and critical care.

Stokes-Adams Syndrome as a Presenting Feature of Hypoadrenalism: A Rare Presentation.

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.

RésuméLa maladie d'Addison est connue pour provoquer une hyperkaliémie. Cependant, un bloc cardiaque résultant d'une telle hyperkaliémie est très rare. Nous rapportons un cas dans lequel la maladie d'Addison s'est accompagnée d'une hyperkaliémie et d'un bloc cardiaque et du syndrome de Stokes-Adam ainsi que d'autres caractéristiques d'hyposurrénalisme.

Extremely rare cause of hyperkalemia: ileostomy‒induced hyperkalemia in extremely low birth weight infants.

BACKGROUND: Hyperkalemia is one of the most serious electrolyte disturbances, and it can cause lethal cardiac arrhythmia. Although hyperkalemia associated with ileostomies has been reported in adults, to the best of our knowledge, it has not previously been reported in neonates. CASE: We report ileostomy‒induced hyperkalemia that persisted during the ileostomy and resolved promptly after the closure of the ileostomy in two extremely low birth weight (ELBW) infants, with birth weights of 850 g and 840 g and gestational ages of 27 weeks and 27 weeks 6 days. CONCLUSIONS: These cases highlight that disruption of intestinal integrity in ELBW infants may cause hyperkalemia. Ensuring the integrity of the gastrointestinal tract plays an important role in the treatment of electrolyte disorders such as hyperkalemia in ELBW infants with an ileostomy.

Development and Validation of an Interpretable Machine Learning Model for Early Prognosis Prediction in ICU Patients with Malignant Tumors and Hyperkalemia.

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.

Sodium-glucose cotransporter-2 inhibitors and abnormal serum potassium: a real-world, pharmacovigilance study.

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.

Cost analysis of patiromer vs sodium zirconium cyclosilicate for the treatment of hyperkalemia in Spain and the UK.

BACKGROUND: Hyperkalemia is an electrolyte abnormality with potentially life-threatening consequences. Published data have shown that potassium-binding polymer patiromer (Veltassa) is associated with reduced rates of severe edema and hospitalization for heart failure compared with sodium zirconium cyclosilicate (SZC, Lokelma) when treating hyperkalemia. The aim of this study was to evaluate the possible costs associated with these interventions in the Spanish and UK settings. METHODS: A cost-analysis model was developed in Microsoft Excel to compare the costs associated with patiromer and SZC for the management of hyperkalemia. Clinical event rates were taken from a published real-world comparative study, with the base case capturing the statistically significant reduction in severe edema with patiromer vs SZC and a sensitivity analysis also including the non-statistically significant reduction in hospitalization for heart failure. Country-specific costs, expressed in 2022 Euros (EUR) and British pounds sterling (GBP), were evaluated from a healthcare payer perspective and included pharmacy costs and costs of clinical events. RESULTS: Patiromer may be associated with cost savings of EUR 107 and GBP 630 per patient-year of treatment vs SZC in Spain and the UK, respectively. The majority of cost savings were due to the possible lower daily cost of patiromer compared with SZC. Including the difference in heart failure hospitalization rates in a sensitivity analysis led to greater cost savings with patiromer over SZC, increasing to EUR 460 and GBP 902 in Spain and the UK, respectively. Extrapolation of patient-level economic outcomes to a population level found that patiromer was associated with annual cost savings of EUR 30.6 million in Spain, and GBP 801.7 million in the UK vs SZC. CONCLUSIONS: Patiromer has the potential to be cost saving vs SZC for the treatment of hyperkalemia in Spain and the UK based on the results of a real-world evidence analysis.

Not only Van Gogh: a case of BRASH syndrome with concomitant digoxin toxicity.

BACKGROUND: Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a potentially life-threatening clinical condition characterized by bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia. It constitutes a vicious circle in which the accumulation of pharmacologically active compounds and hyperkalemia lead to hemodynamic instability and heart failure. CASE PRESENTATION: A 66-year-old Caucasian female patient was admitted to the emergency department presenting with fatigue and bradycardia. Upon examination, the patient was found to be anuric and hypotensive. Laboratory investigations revealed metabolic acidosis and hyperkalemia. Clinical evaluation suggested signs of digoxin toxicity, with serum digoxin concentrations persistently elevated over several days. Despite the implementation of antikalemic measures, the patient's condition remained refractory, necessitating renal dialysis and administration of digoxin immune fab. CONCLUSION: Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a life-threatening condition that requires prompt management. It is important to also consider potential coexisting clinical manifestations indicative of intoxication from other pharmacological agents. Specifically, symptoms associated with the accumulation of drugs eliminated via the kidneys, such as digoxin. These manifestations may warrant targeted therapeutic measures.

Sulfamethoxazole-Trimethoprim-Induced Hyperkalemia in Hospitalized Patients Using Potassium-Sparing Drugs: An Observational Study.

The objective of this analysis is to investigate the risk of hyperkalemia in hospitalized patients using sulfamethoxazole-trimethoprim (Co-trimoxazole) and a potassium-sparing drug (potassium-sparing diuretic or renin-angiotensin system [RAS]-inhibitor). Researchers conducted a nested case control study within a cohort of hospitalized patients using a potassium-sparing diuretic and/or a RAS-inhibitor from the PHARMO Database Network. Researchers estimated the odds ratios (ORs) and 95% confidence intervals (CI) for the risk of hyperkalemia in patients receiving both Co-trimoxazole and a potassium-sparing drug compared with patients only receiving a potassium-sparing drug. Among a cohort of 25,849 patients, researchers identified 2054 cases of hyperkalemia during hospitalization in patients also using a potassium-sparing drug. Using Co-trimoxazole in addition to a potassium-sparing drug was associated with an increased risk of hyperkalemia in hospitalized patients (ORadj = 1.65, 95% CI 1.26-2.16) compared with using only a potassium-sparing drug. There was a trend of a more pronounced association between hyperkalemia and the co-use of Co-trimoxazole and potassium-sparing drugs in patients with an estimated GFR of 15-29 mL/min (ORadj = 3.15, 95% CI 1.29-7.70). The number needed to harm for hyperkalemia induced by adding Co-trimoxazole to patients receiving a potassium-sparing drug is 19.5. Using the combination of Co-trimoxazole with a potassium-sparing drug in hospitalized patients increases the risk of hyperkalemia compared with using only a potassium-sparing drug. Physicians and other prescribers should be aware of hyperkalemia and routinely monitor serum potassium levels in hospitalized patients using this combination of drugs.

SGLT-2 inhibitors, GLP-1 receptor agonists, and DPP-4 inhibitors and risk of hyperkalemia among people with type 2 diabetes in clinical practice: population based cohort study.

OBJECTIVES: To evaluate the comparative effectiveness of sodium-glucose cotransporter-2 (SGLT-2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dipeptidyl peptidase-4 (DPP-4) inhibitors in preventing hyperkalemia in people with type 2 diabetes in routine clinical practice. DESIGN: Population based cohort study with active-comparator, new user design. SETTING: Claims data from Medicare and two large commercial insurance databases in the United States from April 2013 to April 2022. PARTICIPANTS: 1:1 propensity score matched adults with type 2 diabetes newly starting SGLT-2 inhibitors versus DPP-4 inhibitors (n=778 908), GLP-1 receptor agonists versus DPP-4 inhibitors (n=729 820), and SGLT-2 inhibitors versus GLP-1 receptor agonists (n=873 460). MAIN OUTCOME MEASURES: Hyperkalemia diagnosis in the inpatient or outpatient setting. Secondary outcomes were hyperkalemia defined as serum potassium levels ≥5.5 mmol/L and hyperkalemia diagnosis in the inpatient or emergency department setting. RESULTS: Starting SGLT-2 inhibitor treatment was associated with a lower rate of hyperkalemia than DPP-4 inhibitor treatment (hazard ratio 0.75, 95% confidence interval (CI) 0.73 to 0.78) and a slight reduction in rate compared with GLP-1 receptor agonists (0.92, 0.89 to 0.95). Use of GLP-1 receptor agonists was associated with a lower rate of hyperkalemia than DPP-4 inhibitors (0.79, 0.77 to 0.82). The three year absolute risk was 2.4% (95% CI 2.1% to 2.7%) lower for SGLT-2 inhibitors than DPP-4 inhibitors (4.6% v 7.0%), 1.8% (1.4% to 2.1%) lower for GLP-1 receptor agonists than DPP-4 inhibitors (5.7% v 7.5%), and 1.2% (0.9% to 1.5%) lower for SGLT-2 inhibitors than GLP-1 receptor agonists (4.7% v 6.0%). Findings were consistent for the secondary outcomes and among subgroups defined by age, sex, race, medical conditions, other drug use, and hemoglobin A1c levels on the relative scale. Benefits for SGLT-2 inhibitors and GLP-1 receptor agonists on the absolute scale were largest for those with heart failure, chronic kidney disease, or those using mineralocorticoid receptor antagonists. Compared with DPP-4 inhibitors, the lower rate of hyperkalemia was consistently observed across individual agents in the SGLT-2 inhibitor (canagliflozin, dapagliflozin, empagliflozin) and GLP-1 receptor agonist (dulaglutide, exenatide, liraglutide, semaglutide) classes. CONCLUSIONS: In people with type 2 diabetes, SGLT-2 inhibitors and GLP-1 receptor agonists were associated with a lower risk of hyperkalemia than DPP-4 inhibitors in the overall population and across relevant subgroups. The consistency of associations among individual agents in the SGLT-2 inhibitor and GLP-1 receptor agonist classes suggests a class effect. These ancillary benefits of SGLT-2 inhibitors and GLP-1 receptor agonists further support their use in people with type 2 diabetes, especially in those at risk of hyperkalemia.

An unusual case of Pseudohypoaldosteronism coexisting with cystic fibrosis.

Pseudohypoaldosteronism type 1 is a rare congenital autosomal recessive disorder, characterised by failure of receptor response to aldosterone. It is caused by mutation in SCNN1A gene with clinical features like failure to thrive in infancy, hyponatraemia, hyperkalaemia and metabolic acidosis. We present a male infant with seizures, hyperkalaemia and with failure to thrive, diagnosed at day 6 of life. The baby required repeated correction for hyperkalaemia; hence, after ruling out treatable causes for hyperkalaemia, exonerated sequencing was done which showed pathogenic mutation for cystic fibrosis and recessive mutation for pseudohypoaldosteronism. But the child was clinically in favour of pseudohypoaldosteronism. Hence, features of pseudohypoaldosteronism predominate cystic fibrosis; they both may coexist.

The impact of hyperkalemia on ICU admission and mortality: a retrospective study of Chinese emergency department data.

OBJECTIVE: This study assesses the influence of hyperkalemia on both disease severity and the risk of mortality among patients admitted to the emergency room. METHODS: This retrospective observational study utilized data from the Chinese Emergency Triage Assessment and Treatment database (CETAT, version 2.0), which was designed to evaluate and optimize management strategies for emergency room (ER) patients. Patients were systematically categorized based on serum potassium levels. Relationships between serum potassium levels, risk of mortality, and the severity of illness were then analyzed using multifactorial logistic regression and through Receiver Operating Characteristic (ROC) analysis. The effectiveness of various treatments at lowering potassium levels was also investigated. RESULTS: 12,799 emergency patients were enrolled, of whom 20.1% (n = 2,577) were hypokalemic and 2.98% (n = 381) were hyperkalemic. Among hyperkalemic patients, the leading reasons for visiting the ER were altered consciousness 23.88% (n = 91), cardiovascular symptoms 22.31% (n = 85), and gastrointestinal symptoms 20.47% (n = 78). Comparative analysis with patients exhibiting normal potassium levels revealed hyperkalemia as an independent factor associated with mortality in the ER. Mortality risk appears to positively correlate with increasing potassium levels, reaching peaks when blood potassium levels ranged between 6.5 and 7.0. Hyperkalemia emerged as a strong predictor of death in the ER, with an Area Under the Curve (AUC) of 0.89. The most frequently prescribed treatment for hyperkalemia patients was diuretics (57.32%, n = 188), followed by intravenous sodium bicarbonate (50.91%, n = 167), IV calcium (37.2%, n = 122), insulin combined with high glucose (27.74%, n = 91), and Continuous Renal Replacement Therapy (CRRT) for 19.82% (n = 65). Among these, CRRT appeared to be the most efficacious at reducing potassium levels. Diuretics appeared relatively ineffective, while high-glucose insulin, sodium bicarbonate, and calcium preparations having no significant effect on the rate of potassium decline. CONCLUSION: Hyperkalemia is common in emergency situations, especially among patients with altered consciousness. There is a strong positive correlation between the severity of hyperkalemia and mortality risk. CRRT appears to be the most effective potassium reducting strategy, while the use of diuretics should be approached with caution.

Role of calcineurin in regulating renal potassium (K+) excretion: Mechanisms of calcineurin inhibitor-induced hyperkalemia.

Calcineurin, protein phosphatase 2B (PP2B) or protein phosphatase 3 (PP3), is a calcium-dependent serine/threonine protein phosphatase. Calcineurin is widely expressed in the kidney and regulates renal Na+ and K+ transport. In the thick ascending limb, calcineurin plays a role in inhibiting NKCC2 function by promoting the dephosphorylation of the cotransporter and an intracellular sorting receptor, called sorting-related-receptor-with-A-type repeats (SORLA), is involved in modulating the effect of calcineurin on NKCC2. Calcineurin also participates in regulating thiazide-sensitive NaCl-cotransporter (NCC) in the distal convoluted tubule. The mechanisms by which calcineurin regulates NCC include directly dephosphorylation of NCC, regulating Kelch-like-3/CUL3 E3 ubiquitin-ligase complex, which is responsible for WNK (with-no-lysin-kinases) ubiquitination, and inhibiting Kir4.1/Kir5.1, which determines NCC expression/activity. Finally, calcineurin is also involved in regulating ROMK (Kir1.1) channels in the cortical collecting duct and Cyp11 2 expression in adrenal zona glomerulosa. In summary, calcineurin is involved in the regulation of NKCC2, NCC, and inwardly rectifying K+ channels in the kidney, and it also plays a role in modulating aldosterone synthesis in adrenal gland, which regulates epithelial-Na+-channel expression/activity. Thus, application of calcineurin inhibitors (CNIs) is expected to abrupt calcineurin-mediated regulation of transepithelial Na+ and K+ transport in the kidney. Consequently, CNIs cause hypertension, compromise renal K+ excretion, and induce hyperkalemia.

A Chinese Multi-Specialty Delphi Consensus to Optimize RAASi Usage and Hyperkalaemia Management in Patients with Chronic Kidney Disease and Heart Failure.

Objective Variations are present in common clinical practices regarding best practice in managing hyperkalaemia (HK), there is therefore a need to establish a multi-specialty approach to optimal renin-angiotension-aldosterone system inhibitors (RAASi) usage and HK management in patients with chronic kidney disease (CKD) & heart failure (HF).This study aimed to establish a multi-speciality approach to the optimal use of RAASi and the management of HK in patients with CKD and HF. Methods A steering expert group of cardiology and nephrology experts across China were convened to discuss challenges to HK management through a nominal group technique. The group then created a list of 41 statements for a consensus questionnaire, which was distributed for a further survey in extended panel group of cardiologists and nephrologists across China. Consensus was assessed using a modified Delphi technique, with agreement defined as "strong" (≥75% and <90%) and "very strong" (≥90%). The steering group, data collection, and analysis were aided by an independent facilitator. Results A total of 150 responses from 21 provinces across China were recruited in the survey. Respondents were comprised of an even split (n=75, 50%) between cardiologists and nephrologists. All 41 statements achieved the 75% consensus agreement threshold, of which 27 statements attained very strong consensus (≥90% agreement) and 14 attained strong consensus (agreement between 75% and 90%). Conclusion Based on the agreement levels from respondents, the steering group agreed a set of recommendations intended to improve patient outcomes in the use of RAASi therapy and HK management in China.

Acquired hyperkalaemia leading to periodic paralysis: an emergency department perspective.

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.

Pseudohypoaldosteronism and acquired renal aldosterone resistance with hyperkalemic type IV renal tubular acidosis in 2 cats.

This report describes the diagnosis and treatment of aldosterone resistance (AR) and acquired hyperkalemic type IV renal tubular acidosis (RTA) in 2 cats comparable to acquired pseudohypoaldosteronism in people. One cat developed AR from chronic kidney disease after an acute kidney injury and was treated with furosemide per os, which resolved the hyperkalemic RTA. The second cat developed transient AR secondary to a bacterial urinary tract infection associated with urethral catheterization, and treatment with antibiotics resolved the hyperkalemic RTA.

Calcineurin inhibitor-related hyperkalemia is caused by hyporeninemic hypoaldosteronism and fludrocortisone is an effective treatment: Report of a case series and review of the literature.

INTRODUCTION: Calcineurin inhibitors (CNIs) are widely used in transplantation. Although CNI-related hyperkalemia is common (10%-60.6%), the underlying pathogenetic mechanism is not well-elucidated and may lead to dose adjustment or treatment withdrawal. OBJECTIVE: The aim of this study is to describe CNI-related hyperkalemia due to hyporeninemic hypoaldosteronism in pediatric transplant recipients who were successfully treated with fludrocortisone. METHOD: In a total of 55 hematopoietic stem cell (HSCT) and 35 kidney transplant recipients followed according to institutional immunosuppression protocols, recipients diagnosed with CNI-related hyperkalemia were reviewed. Recipients who were receiving intravenous fluid, potassium, or were diagnosed with hemolysis, acute graft rejection, or had an eGFR < 30 mL/min/1.73m2, were excluded. A detailed analysis of clinical history as well as biochemical studies was carried out to reveal possible pathophysiology. RESULTS: Three pediatric transplant recipients (one HSCT, two kidney transplantation) with findings of hyperkalemia, hyponatremia, and a mild elevation in blood urea nitrogen while on CNIs were recruited. Urinary potassium excretion was diminished while sodium excretion was increased. Plasma aldosterone levels were low, and renin was not increased in response. Primary adrenal insufficiency was ruled out, and hyporeninemic hypoaldosteronism was diagnosed. CNI-related hyperkalemia was detected earlier in case 1, who had HSCT (22 days), than in the second and third cases, who had kidney transplantation (24 and 30 months post-transplantation, respectively). The discrepancy was hypothesized to be explained by higher overall CNI dose due to higher serum target CNI used in HSCT than kidney transplantation. Electrolyte imbalance was reversed upon administration of physiologic dose fludrocortisone (0.05 mg, daily), while fludrocortisone was ceased after CNI withdrawal in case 1, which is additional evidence for the etiological association of CNIs and hyporeninemic hypoaldosteronism. CONCLUSION: Our three cases strengthen the premise that CNI-related hyperkalemia may be due to hyporeninemic hypoaldosteronism, and the timing and severity may be related to CNI dose. Fludrocortisone is a safe and effective treatment in CNI-related hyperkalemia, providing maintenance of CNIs, which are one of the essential therapeutic agents for pediatric transplantation.