Electrophysiological and clinical consequences of hyperkalemia

Monitoring serum potassium concentration in patients with severe hyperkalemia: the role of bloodless artificial intelligence-enabled electrocardiography

Background

Severe hyperkalemia is a life-threatening emergency requiring prompt management and close surveillance. Although artificial intelligence-enabled electrocardiography (AI-ECG) has been developed to rapidly detect hyperkalemia, its application to monitor potassium (K+) levels remains unassessed. This study aimed to evaluate the effectiveness of AI-ECG for monitoring K+ levels in patients with severe hyperkalemia.

Methods

This retrospective study was performed at an emergency department of a single medical center over 2.5 years. Patients with severe hyperkalemia defined as Lab-K+ ≥6.5 mmol/l with matched ECG-K+ ≥5.5 mmol/l were included. ECG-K+ was quantified by ECG12Net analysis of the AI-ECG system. The following paired ECG-K+ and Lab-K+ were measured at least twice, almost simultaneously, during and after K+-lowering therapy in 1 day. Clinical characteristics, pertinent intervention, and laboratory data were analyzed.

Results

Seventy-six patients fulfilling the inclusion criteria exhibited initial Lab-K+ 7.4 ± 0.7 and ECG-K+ 6.8 ± 0.5 mmol/l. Most of them had chronic kidney disease (CKD) or were on chronic hemodialysis (HD). The followed Lab-K+ and ECG-K+ measured with a mean time difference of 11.4 ± 5.6 minutes significantly declined in parallel both in patients treated medically (n = 39) and with HD (n = 37). However, there was greater decrement in Lab-K⁺ (mean 7.3 to 4.1) than ECG-K⁺ (mean 6.6 to 5.0) shortly after HD. Three patients with persistent ECG-K+ hyperkalemia despite normalized Lab-K+ exhibited concomitant acute cardiovascular comorbidities.

Conclusions

AI-ECG for K+ prediction may help monitor K+ level for severe hyperkalemia and reveal more severe cardiac disorders in the patients with persistent AI-ECG hyperkalemia.

Mechanisms and Implications of Electrical Heterogeneity in Cardiac Function in Ischemic Heart Disease

A healthy heart shows intrinsic electrical heterogeneities that play a significant role in cardiac activation and repolarization. However, cardiac diseases may perturb the baseline electrical properties of the healthy cardiac tissue, leading to increased arrhythmic risk and compromised cardiac functions. Moreover, biological variability among patients produces a wide range of clinical symptoms, which complicates the treatment and diagnosis of cardiac diseases. Ischemic heart disease is usually caused by a partial or complete blockage of a coronary artery. The onset of the disease begins with myocardial ischemia, which can develop into myocardial infarction if it persists for an extended period. The progressive regional tissue remodeling leads to increased electrical heterogeneities, with adverse consequences on arrhythmic risk, cardiac mechanics, and mortality. This review aims to summarize the key role of electrical heterogeneities in the heart on cardiac function and diseases. Ischemic heart disease has been chosen as an example to show how adverse electrical remodeling at different stages may lead to variable manifestations in patients. For this, we have reviewed the dynamic electrophysiological and structural remodeling from the onset of acute myocardial ischemia and reperfusion to acute and chronic stages post-myocardial infarction. The arrhythmic mechanisms, patient phenotypes, risk stratification at different stages, and patient management strategies are also discussed. Finally, we provide a brief review on how computational approaches incorporate human electrophysiological heterogeneity to facilitate basic and translational research.

EMCREG-International Multidisciplinary Consensus Panel on Management of Hyperkalemia in Chronic Kidney Disease and Heart Failure

BACKGROUND

Hyperkalemia, generally defined as serum potassium levels greater than 5.0 mEq/L, poses significant clinical risks, including cardiac toxicity and muscle weakness. Its prevalence and severity increase in patients with chronic kidney disease (CKD), diabetes mellitus, and heart failure (HF), particularly when compounded by medications like angiotensin converting inhibitors, angiotensin receptor blockers, and potassium sparing diuretics. Hyperkalemia arises from disruptions in potassium regulation involving intake, excretion, and intracellular-extracellular distribution. In CKD and acute kidney injury, these regulatory mechanisms are impaired, leading to heightened risk. The management of chronic hyperkalemia presents a challenge due to the necessity of balancing effective cardiovascular and renal therapies against the risk of elevated potassium levels.

SUMMARY

The emergency department management of acute hyperkalemia focuses on preventing cardiac complications through strategies that stabilize cellular membranes and shift potassium intracellularly. Chronic management often involves dietary interventions and pharmacological treatments. Pharmacological management of acute hyperkalemia includes diuretics, which enhance kaliuresis, and potassium binders such as patiromer and sodium zirconium cyclosilicate, which facilitate fecal excretion of potassium. While diuretics are commonly used, they carry risks of volume contraction and renal function deterioration. The newer potassium binders have shown efficacy in lowering chronically elevated potassium levels in CKD and HF patients, offering an alternative to diuretics and other older agents such as sodium polystyrene sulfonate, which has significant adverse effects and limited evidence for chronic use.

KEY MESSAGES

We convened a consensus panel to describe the optimal management across multiple clinical settings when caring for patients with hyperkalemia. This consensus emphasizes a multidisciplinary approach to managing hyperkalemia, particularly in patients with cardiovascular kidney metabolic syndrome, to avoid fragmentation of care and ensure comprehensive treatment strategies. The primary goal of this manuscript is to describe strategies to maintain cardiovascular benefits of essential medications while effectively managing potassium levels.

Hyperkalemia During Prolonged Anesthesia in a Greyhound

Case Report: A 3-year-old female neutered greyhound presented for a dental procedure under general anesthesia. At the time of presentation, the dog was clinically well, with no health concerns from the client except for halitosis. The dog underwent general anesthesia with 13 teeth extracted and was stable until a severe, acute bradycardia was noticed at 2 h and 20 min postinduction. Venous blood analysis revealed a marked hyperkalemia. The dog was treated with calcium gluconate, an intravenous fluid bolus, glucose, and atropine. Serum potassium levels returned to within normal reference range at 60 min posttreatment. The dog developed ventricular tachycardia in recovery which responded to two lignocaine boluses. The dog was discharged from hospital in a stable condition. Conclusions: Unanticipated hyperkalemia during anesthesia was treated in an otherwise healthy greyhound undergoing a dental procedure.

Utilization of Potassium Binders for the Management of Hyperkalemia in Chronic Kidney Disease: A Position Statement by US Nephrologists

Two potassium (K+) binders-patiromer sorbitex calcium and sodium zirconium cyclosilicate-are recommended by international guidelines for the management of hyperkalemia. There is, however, no universally accepted best practice for how to appropriately utilize K+ binders in the long-term clinical management of CKD. A panel of eight US-based nephrologists convened in October 2022 to develop a consensus statement regarding utilizing K+ binders in clinical practice to help manage patients with nonemergent, persistent/recurrent hyperkalemia in CKD. Consensus was reached on the following topics: (1) identifying risk factors for hyperkalemia; (2) serum K+ monitoring before and during K+ binder use; (3) utilizing K+ binders in patients receiving renin-angiotensin-aldosterone system inhibitors and dialysis; and (4) when to initiate K+ binders and their duration of use. These consensus statements for the use of K+ binders may assist the nephrology community in optimizing management of hyperkalemia in patients across the spectrum of CKD.

Population Pharmacodynamic Dose-Response Analysis of Serum Potassium Following Dosing with Sodium Zirconium Cyclosilicate

BACKGROUND

Sodium zirconium cyclosilicate (SZC) is an approved oral treatment for hyperkalemia that selectively binds potassium (K+) in the gastrointestinal tract and removes K+ from the body through increased fecal excretion. Here, we describe the population pharmacodynamic (PopPD) response of serum K+ concentration in patients with hyperkalemia who are treated with SZC, estimate the impact of patients' intrinsic and extrinsic factors, and compare predicted serum K+ responses between 5 g alternate daily (QOD) and 2.5 g once daily (QD) maintenance doses.

METHODS

PopPD analysis was based on pooled data from seven phase II and III clinical trials for SZC. A semi-mechanistic longitudinal mixed-effects (base) model was used to characterize serum K+ concentration after SZC dosing. Indirect-response, virtual pharmacokinetics-pharmacodynamics (PK-PD) modeling was used to mimic the drug exposure compartment. Full covariate modeling was used to assess covariate impact on the half-maximal effective concentration of drug (EC50), placebo response, and Kout. Models were evaluated using goodness-of-fit plots, relative standard errors, and visual predictive checks, and data were stratified to optimize model performance across subgroups. Covariate effects were evaluated based on the magnitude of change in serum K+ between baseline and end of correction phase dosing (48 h, SZC 10 g three times a day) and maintenance phase dosing (28 days, SZC 10 g QD) using a reference subject.

RESULTS

The analysis data set included 2369 patients and 25,764 serum K+ observations. The mean (standard deviation) patient age was 66.0 (12) years, 61% were male, 68% were White, 34% had congestive heart failure, and 62% had diabetes. Mean (standard deviation) serum K+ at baseline was 5.49 (0.43) mmol/L. Both the base and full covariance models adequately described observed data. In the final model, there was a sigmoid exposure response on Kin, with EC50 of 32.8 g and a Hill coefficient of 1.36. The predicted placebo-adjusted dose-responses of serum K+ change appeared nearly linear in the correction and maintenance phases. No clinically meaningful difference in placebo-adjusted serum K+ change from baseline at 28 days was observed between maintenance regimens of SZC 5 g QOD and 2.5 g QD. A greater SZC treatment response was associated with high serum K+ at baseline, advanced age, lower body weight, lower estimated glomerular filtration rate, and Black/African American and Asian race, compared with the reference patient. The impact of heart failure status and diabetes status was only minor.

CONCLUSIONS

The PopPD model of SZC adequately described changes in serum K+ concentration during correction and maintenance phase dosing. A greater treatment response was associated with various covariates, but the impact of each was modest. Overall, these findings suggest that no adjustment in SZC dose is needed for any of the covariates evaluated.

Machine learning models for early prediction of potassium lowering effectiveness and adverse events in patients with hyperkalemia

The aim of this study was to develop a model for early prediction of adverse events and treatment effectiveness in patients with hyperkalemia. We collected clinical data from patients with hyperkalemia in the First Hospital of Zhejiang University School of Medicine between 2015 and 2021. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to analyze the predictors on the full dataset. We randomly divided the data into a training group and a validation group, and used LASSO to filter variables in the training set. Six machine learning methods were used to develop the models. The best model was selected based on the area under the curve (AUC). Shapley additive exPlanations (SHAP) values were used to explain the best model. A total of 1074 patients with hyperkalemia were finally enrolled. Diastolic blood pressure (DBP), breathing, oxygen saturation (SPO2), Glasgow coma score (GCS), liver disease, oliguria, blood sodium, international standardized ratio (ISR), and initial blood potassium were the predictors of the occurrence of adverse events; peripheral edema, estimated glomerular filtration rate (eGFR), blood sodium, actual base residual, and initial blood potassium were the predictors of therapeutic effect. Extreme gradient boosting (XGBoost) model achieved the best performance (adverse events: AUC = 0.87; therapeutic effect: AUC = 0.75). A model based on clinical characteristics was developed and validated with good performance.

Hyperkalemia: Pharmacotherapies and Clinical Considerations

Hyperkalemia has been defined as a condition where a serum potassium level is >5.5 mmol/l. It is associated with fatal dysrhythmias and muscular dysfunction. Certain medical conditions, such as chronic kidney disease (CKD), diabetes mellitus, and others, can lead to hyperkalemia. Many of the signs of hyperkalemia are nonspecific. A history and physical examination can be beneficial in the diagnosis of the condition. In this regard, certain characteristic electrocardiogram findings are associated with hyperkalemia along with laboratory potassium levels. In acute and potentially lethal conditions, hyperkalemia treatments include glucose and insulin, bicarbonate, calcium gluconate, beta-2 agonists, hyperventilation, and dialysis. There are several drugs, both old and new, that can additionally aid in the reduction of serum potassium levels. The present investigation evaluated some of these different drugs, including sodium polystyrene sulfonate (SPS), sodium zirconium cyclosilicate (SZC), and patiromer. These drugs each have increased selectivity for potassium and work primarily in the gastrointestinal (GI) tract. Each of these medications has unique benefits and contraindications. Clinicians must be aware of these medications when managing patients with hyperkalemia.

Safety and efficacy of new potassium binders on hyperkalemia management in patients with heart failure: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Hyperkalemia leads to suboptimal use of evidence-based therapies in patients with heart failure (HF). Therefore, we aimed to assess whether new potassium binders are effective and safe to promote medical optimization in patients with HF.

METHODS

MEDLINE, Cochrane, and Embase were searched for randomized controlled trials (RCTs) that reported outcomes after initiation of Patiromer or Sodium Zirconium Cyclosilicate (SZC) versus placebo in patients with HF at high risk of hyperkalemia development. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random effects model. Quality assessment and risk of bias were performed according to Cochrane recommendations.

RESULTS

A total of 1432 patients from 6 RCTs were included, of whom 737 (51.5%) patients received potassium binders. In patients with HF, potassium binders increased the use of renin-angiotensin-aldosterone inhibitors (RR 1.14; 95% CI 1.02-1.28; p = 0.021; I2 = 44%) and reduced the risk of hyperkalemia (RR 0.66; 95% CI 0.52-0.84; p < 0.001; I2 = 46%). The risk of hypokalemia was significantly increased in patients treated with potassium binders (RR 5.61; 95% CI 1.49-21.08; p = 0.011; I2 = 0%). There was no difference between groups in all-cause mortality rates (RR 1.13; 95% CI 0.59-2.16; p = 0.721; I2 = 0%) or in adverse events leading to drug discontinuation (RR 1.08; 95% CI 0.60-1.93; p = 0.801; I2 = 0%).

CONCLUSION

The use of new potassium binders Patiromer or SZC in patients with HF at risk for hyperkalemia increased the rates of medical therapy optimization with renin-angiotensin-aldosterone inhibitors and reduced the incidence of hyperkalemia, at the cost of an increased prevalence of hypokalemia.

Managing Hyperkalemia in the Modern Era: A Case-Based Approach

The last decade has seen tremendous advances in the prevention and treatment of recurrent hyperkalemia. In this narrative review, we aim to highlight contemporary data on key areas in the epidemiology and management of hyperkalemia. Focusing on drug-induced hyperkalemia (the implications of renin-angiotensin-aldosterone system inhibitors [RAASi] discontinuation and the role of mineralocorticoid receptor antagonists), newer concurrent therapies that modify potassium handling (sodium-glucose transporter 2 inhibitors [SGLT2i]), the introduction of new treatment agents (oral potassium binding agents), and the controversial role of dietary potassium restriction, we apply recent research findings and review the evidence in a case-based format.

Retrospective evaluation of acute hyperkalemia of unknown origin during general anesthesia in dogs

OBJECTIVE

To report and characterize cases of acute hyperkalemia of unknown origin in dogs under anesthesia.

STUDY DESIGN

Multicentric retrospective clinical study.

ANIMALS

Medical records of 19 client-owned dogs that developed acute hyperkalemia during anesthesia.

METHODS

Anesthetic records of dogs developing acute hyperkalemia from January 2015 to December 2022 were evaluated. Data collected included demographics, duration of anesthesia until the episode, electrolytes and blood gas measurements, electrocardiogram (ECG) abnormalities, drugs used as part of the anesthetic protocol, hyperkalemia treatment and outcome.

RESULTS

A total of 13 cases met the inclusion criteria with documented acute hyperkalemia with no apparent underlying cause during anesthesia. Dogs were [mean ± standard deviation (range)] 6.5 ± 5.0 (3-10) years old and weighed 18.0 ± 14.3 (5.1-40.0) kg. All dogs were administered dexmedetomidine and an opioid as part of the premedication. All dogs had inhalation anesthesia of >60 minutes' duration. The first clinical sign was bradycardia that was minimally responsive to anticholinergic administration and was often accompanied by moderate/severe hypotension. These signs were rapidly followed by ECG changes compatible with hyperkalemia and/or cardiac arrest. Rapid identification and treatment for hyperkalemia, with or without dexmedetomidine reversal, resulted in survival of 12 dogs and one fatality.

CONCLUSIONS AND CLINICAL RELEVANCE

Unknown origin hyperkalemia is a life-threatening complication that can occur during general anesthesia. In healthy dogs, preanesthetic administration of dexmedetomidine in association with an opioid and followed by inhalation anesthesia of more than 1 hour duration may predispose to this complication. A sudden decrease in heart rate >90 minutes after dexmedetomidine administration, or ECG changes, may warrant measurement of blood potassium concentrations.

First 24-Hour Potassium Concentration and Variability and Association with Mortality in Patients Requiring Continuous Renal Replacement Therapy in Intensive Care Units: A Hospital-Based Retrospective Cohort Study

Serum potassium (K+) levels between 3.5 and 5.0 mmol/L are considered safe for patients. The optimal serum K+ level for critically ill patients with acute kidney injury undergoing continuous renal replacement therapy (CRRT) remains unclear. This retrospective study investigated the association between ICU mortality and K+ levels and their variability. Patients aged >20 years with a minimum of two serum K+ levels recorded during CRRT who were admitted to the ICU in a tertiary hospital in central Taiwan between January 01, 2010, and April 30, 2021 were eligible for inclusion. Patients were categorized into different groups based on their mean K+ levels: <3.0, 3.0 to <3.5, 3.5 to <4.0, 4.0 to <4.5, 4.5 to <5.0, and ≥5.0 mmol/L; K+ variability was divided by the quartiles of the average real variation. We analyzed the association between the particular groups and in-hospital mortality by using Cox proportional hazard models. We studied 1991 CRRT patients with 9891 serum K+ values recorded within 24 h after the initiation of CRRT. A J-shaped association was observed between serum K+ levels and mortality, and the lowest mortality was observed in the patients with mean K+ levels between 3.0 and 4.0 mmol/L. The risk of in-hospital death was significantly increased in those with the highest variability (HR and 95% CI = 1.61 [1.13−2.29] for 72 h mortality; 1.39 [1.06−1.82] for 28-day mortality; 1.43 [1.11−1.83] for 90-day mortality, and 1.31 [1.03−1.65] for in-hospital mortality, respectively). Patients receiving CRRT may benefit from a lower serum K+ level and its tighter control. During CRRT, progressively increased mortality was noted in the patients with increasing K+ variability. Thus, the careful and timely correction of dyskalemia among these patients is crucial.

Development and outcomes of hyperkalemia in hospitalized patients: potential implications for care

INTRODUCTION

While severe hyperkalemia is commonly encountered, its manifestation in hospitalized patients and related outcomes are unclear. We aimed to examine development of hyperkalemia in hospitalized patients and associated outcomes.

METHODS

Data from a county hospital electronic health record were used to assess all inpatient admissions, 2012-2016, for non-dialysis-dependent patients with ≥1 K value for development of hyperkalemia. Unadjusted odds ratios (ORs) were calculated for associations of the maximum K value with in-hospital mortality and adjusted ORs were calculated for death associated with hyperkalemia.

RESULTS

In 47,018 individual patient hospitalizations, 1.3% had a maximum K ≥6.0 mEq/L and 4.2% <3.5 mEq/L. Fifth and 95th percentiles for maximum K values were 3.5 and 5.3 mEq/L. For high-K patients with a prior K value, the mean (SD) of the immediate pre-maximum K value was 5.0 ± 1.0 mEq/L, and the mean difference in K values (immediate pre-maximum to maximum) was 1.5 ± 1.1 mEq/L; mean duration between these two K tests was 10.7 ± 14.9 hours. Compared with maximum K values 3.5 to 4.0 mEq/L, ORs for death were 37.1 (95% confidence intervals, 25.8-53.3) for K 6.0 to <6.5, 88.6 (56.8-138.2) for K ≥7.0, and 18.9 (4.3-82.2) for K <3.0 mEq/L. In adjusted models, the OR for death for K ≥6.0 mEq/L was 4.9 (3.7-6.4).

DISCUSSION/CONCLUSIONS

Peak K values ≥6.0 mEq/L were associated with mortality. Values tended to increase rapidly, limiting opportunities for detection and treatment. Systems-based approaches to detect life-threatening hyperkalemia should be studied.

Hyperkalemia mimicking brugada pattern in electrocardiogram: A rare case report from Nepal

Hyperkalemia is one of the dangerous complications of renal impairment (acute kidney injury or chronic kidney disease). Hyperkalemia may present with the electrocardiogram (ECG) changes as nonspecific repolarization abnormalities. Here, we report a case of AKI with hyperkalemia and the Brugada pattern of ECG, which reverted to normal after effective management of hyperkalemia. A 55-year-old male reported to the Emergency Department of National Academy of Medical Sciences (Bir Hospital) with injuries in his lower limbs and spine after he had met an accident two days back. He also had decreased urine output for the last one day. On physical examination, he had injuries in the spine and lower limbs. His laboratory investigations showed impaired renal function parameters with serum sodium 130 mEq/L and serum potassium of 7.3 mEq/L. His ECG was consistent with Brugada pattern. Patient was treated with 10% calcium gluconate, insulin and dextrose, salbutamol nebulization, and sodium polystyrene sulfonate till hemodialysis was initiated. Hyperkalemia and acidosis can manifest with the Brugada pattern in ECG. Thus, a careful evaluation of hyperkalemia and its treatment must be instituted in such an ECG pattern.

Management of hyperkalemia during treatment with mineralocorticoid receptor blockers: findings from esaxerenone

The nonsteroidal mineralocorticoid receptor (MR) blocker esaxerenone has demonstrated good antihypertensive activity in a variety of patients, including those with uncomplicated grade I-III hypertension, hypertension with moderate renal dysfunction, hypertension with type 2 diabetes mellitus with albuminuria, and hypertension associated with primary aldosteronism. Hyperkalemia has long been recognized as a potential side effect occurring during treatment with MR blockers, but there is a lack of understanding and guidance about the appropriate management of hyperkalemia during antihypertensive therapy with MR blockers, especially in regard to the newer agent esaxerenone. In this article, we first highlight risk factors for hyperkalemia, including advanced chronic kidney disease, diabetes mellitus, cardiovascular disease, age, and use of renin-angiotensin-aldosterone system inhibitors. Next, we examine approaches to prevention and management, including potassium monitoring, diet, and the use of appropriate therapeutic techniques. Finally, we summarize the currently available data for esaxerenone and hyperkalemia. Proper management of serum potassium is required to ensure safe clinical use of MR blockers, including awareness of at-risk patient groups, choosing appropriate dosages for therapy initiation and dosage titration, and monitoring of serum potassium during therapy. It is critical that physicians take such factors into consideration to optimize MR blocker therapy in patients with hypertension.

Cardiac Manifestations in a Case of Severe Hyperkalemia

Severe hyperkalemia is a life-threatening electrolyte imbalance that may lead to fatal arrhythmias. ECG (electrocardiogram) and serum potassium levels are vital for diagnosing and stratifying the risk. Management involves shifting potassium intracellularly and eliminating it through renal and gastrointestinal routes. Failure to diagnose early and manage severe hyperkalemia requires emergent hemodialysis.

Acute hyperkalemia in the emergency department: a summary from a Kidney Disease: Improving Global Outcomes conference

Hyperkalemia is a common electrolyte disorder observed in the emergency department. It is often associated with underlying predisposing conditions, such as moderate or severe kidney disease, heart failure, diabetes mellitus, or significant tissue trauma. Additionally, medications, such as inhibitors of the renin-angiotensin-aldosterone system, potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs, succinylcholine, and digitalis, are associated with hyperkalemia. To this end, Kidney Disease: Improving Global Outcomes (KDIGO) convened a conference in 2018 to identify evidence and address controversies on potassium management in kidney disease. This review summarizes the deliberations and clinical guidance for the evaluation and management of acute hyperkalemia in this setting. The toxic effects of hyperkalemia on the cardiac conduction system are potentially lethal. The ECG is a mainstay in managing hyperkalemia. Membrane stabilization by calcium salts and potassium-shifting agents, such as insulin and salbutamol, is the cornerstone in the acute management of hyperkalemia. However, only dialysis, potassium-binding agents, and loop diuretics remove potassium from the body. Frequent reevaluation of potassium concentrations is recommended to assess treatment success and to monitor for recurrence of hyperkalemia.

Ranolazine Induced Bradycardia, Renal Failure, and Hyperkalemia: A BRASH Syndrome Variant

Ranolazine is a well-known antianginal drug, that was first licensed for use in the United States in 2006. It was objectively shown to improve exercise capacity and to lengthen the time to symptom onset in patients with coronary artery disease. The most commonly reported side effects of ranolazine include dizziness, headache, constipation, and nausea. Here, we describe a case of bradycardia, hyperkalemia, and acute renal injury in the setting of ranolazine use. Our patient is an 88-year-old female who presented with abdominal pain, nausea, and vomiting. Her medical comorbidities included hypertension, diabetes, CAD, heart failure with preserved ejection fraction, paroxysmal atrial fibrillation, hypothyroidism, and a history of cerebrovascular accident without any residual deficits. Her prescription regimen included amlodipine, furosemide, isosorbide mononitrate, levothyroxine, metformin, omeprazole, and ranolazine. Physical examination was remarkable for bradycardia and decreased breath sounds in the left lower lung field. Laboratory studies were significant for a serum potassium level of 6.8 mEq/L and a serum creatinine level of 1.6 mg/dL. She was given insulin with dextrose, sodium polystyrene, and calcium gluconate in addition to fluids. Her bradycardia and renal function worsened over the next 24 hours. Ranolazine was discontinued. Metabolic derangements were treated appropriately. After 48 hours from presentation, potassium and renal function returned to baseline and her heart rate improved to a range of 60-100 bpm. She was discharged with an outpatient cardiology follow-up. Ranolazine treatment was not continued upon discharge. In summary, our case illustrates an association between ranolazine and renal failure induced hyperkalemia, leading to conduction delays in the myocardium. Though further studies are warranted, we suspect that this is a variant of the recently described BRASH syndrome. We propose that in cases such as ours, along with treatment of the hyperkalemia, medication review and removal of any offending agent should be considered.

Pivotal clinical trials, meta-analyses and current guidelines in the treatment of hyperkalemia

Hyperkalemia (HK) is the most common electrolyte disturbance observed in patients with advanced stages of chronic kidney disease (CKD), is a potentially life-threatening clinical condition due to an increased risk of fatal arrhythmias, and strongly impacts the quality of life and prognosis of CKD patients. Moreover, while renin–angiotensin–aldosterone system inhibitors (RAASIs) represent the most cardio-nephro-protective drugs used in clinical practice, the treatment with these drugs per se increases serum potassium (sK) values, particularly when heart failure and diabetes mellitus coexist. In fact, the onset or recurrence of HK is frequently associated with not starting, down-titrating or withdrawing RAASIs, and is an indication to begin renal replacement treatment in end-stage renal disease. Current strategies aimed at preventing and treating chronic HK are still unsatisfactory, as evidenced by the relatively high prevalence of HK also in patients under stable nephrology care, and even in the ideal setting of randomized clinical trials. Indeed, dietary potassium restriction, the use of sodium bicarbonate or diuretics, the withdrawal or down-titration of RAASIs, or the administration of old potassium binders, namely sodium polystyrene sulphonate and calcium polystyrene sulphonate, have limited efficacy and are poorly tolerated; therefore, these strategies are not suitable for long-term control of sK. As such, there is an important unmet need for novel therapeutic options for the chronic management of patients at risk for HK. The development of new potassium binders may change the treatment landscape in the near future. This review summarizes the current evidence on the treatment of chronic HK in cardio-renal patients.

Management of hyperkalemia in patients with kidney disease: a position paper endorsed by the Italian Society of Nephrology

Hyperkalemia (HK) is the most common electrolyte disturbance observed in patients with kidney disease, particularly in those in whom diabetes and heart failure are present or are on treatment with renin-angiotensin-aldosterone system inhibitors (RAASIs). HK is recognised as a major risk of potentially life threatening cardiac arrhythmic complications. When an acute reduction of renal function manifests, both in patients with chronic kidney disease (CKD) and in those with previously normal renal function, HK is the main indication for the execution of urgent medical treatment and the recourse to extracorporeal replacement therapies. In patients with end-stage renal disease, the presence of HK not responsive to medical therapy is an indication at the beginning of chronic renal replacement therapy. HK can also be associated indirectly with the progression of CKD, because the finding of high potassium values leads to withdrawal of treatment with RAASIs, which constitute the first choice nephro-protective treatment. It is therefore essential to identify patients at risk of developing HK, and to implement therapeutic interventions aimed at preventing and treating this dangerous complication of kidney disease. Current strategies aimed at the prevention and treatment of HK are still unsatisfactory, as evidenced by the relatively high prevalence of HK also in patients under stable nephrology care, and even in the ideal setting of randomized clinical trials where optimal treatment and monitoring are mandatory. This position paper will review the main therapeutic interventions to be implemented for the prevention, detection and treatment of HK in patients with CKD on conservative care, in those on dialysis, in patients in whom renal disease is associated with diabetes, heart failure, resistant hypertension and who are on treatment with RAASIs, and finally in those presenting with severe acute HK.

Renal Failure Patients in Disasters

Disasters occur regularly, and frequently large numbers of patients treated with maintenance dialysis or with the recent onset of acute kidney injury are put at risk owing to the lack of access to dialysis care precipitating also a kidney failure disaster. The absence of necessary dialysis treatments can result in excessive emergency department visits, hospitalizations, morbidity, or an early death. Those with kidney failure are often evaluated in disaster medical locations or hospitals without nephrologists in attendance. Here we offer guidance for medical personnel evaluating such patients so that dialysis-dependent individuals can be properly assessed and managed with the need for urgent dialysis recognized. A disaster dialysis triage system is proposed. (Disaster Med Public Health Preparedness. 2019;13:782-790).

Hyperkalemia constitutes a constraint for implementing renin-angiotensin-aldosterone inhibition: the widening gap between mandated treatment guidelines and the real-world clinical arena

Recent studies have reported a large gap between the forceful and assertive recommendations in the guidelines and real-world practice in the use of renin-angiotensin-aldosterone inhibitors (RAASi) therapies. A comprehensive, retrospective analysis of a large database of electronic medical records (>7 million patients) was undertaken to evaluate 3 pivotal concerns: (i) whether RAASi are being prescribed according to treatment guidelines, (ii) what happens to RAASi prescriptions after hyperkalemia events, and (iii) what the clinical outcomes are in patients whose RAASi are discontinued or who are prescribed at doses lower than the guidelines recommend. The results indicate that a substantial gap exists between guideline recommendations and real-world prescribing patterns for RAASi. Among patients with cardiorenal comorbidities for which RAASi are recommended by the guidelines, more than one-half were prescribed lower-than-recommended doses, and approximately 14% to 16% discontinued RAASi therapy. RAASi prescribing patterns may be altered by the development of hyperkalemia. Moderate-to-severe hyperkalemia events were followed by down-titration or discontinuation of RAASi therapy in nearly one-half of all patients on maximal dose and by discontinuation in nearly one-third of patients on submaximal dose. This analysis highlights the challenge behind RAASi prescribing decisions, balancing the risk of provoking hyperkalemia with the benefits to reducing cardiorenal morbidity and mortality. Patients who are known to derive the greatest benefit from these drugs (chronic kidney disease patients with concomitant diabetes mellitus or heart failure) are the same patients who are at highest risk of developing hyperkalemia. These observations constitute a "call to action" to develop newer treatment modalities to lower serum potassium and to achieve and sustain normokalemia long-term.