Potassium Disorders Research Articles

Disorders of potassium homeostasis after kidney transplantation.

Disturbances of potassium balance are often encountered when managing kidney transplant recipients (KTR). Both hyperkalemia and hypokalemia may present either as medical emergencies or chronic outpatient abnormalities. Despite the high incidence of hyperkalemia and its potential life-threatening implications, consensus on its management in KTR is lacking. Hypokalemia in KTR is also well-described, although it is given less attention by clinicians compared to hyperkalemia. This article discusses the etiology, pathophysiology and management of both types of potassium disorders in KTR. Once any emergent situation has been corrected, treatment approaches include correcting insulin deficiency if present, adjusting non-immunosuppressive and immunosuppressive medications, eliminating or supplementing potassium as needed, and dietary counselling. Although commonly of multifactorial etiology, ascertaining the specific cause in a particular patient will help guide successful management. Monitoring KTR through regular laboratory testing is essential to detect serious disturbances in potassium balance since patients are often asymptomatic.

Surface evolution of thermoelectric material KCu4Se3 explored by scanning tunneling microscopy

Abstract Novel two-dimensional thermoelectric materials have attracted significant attention in the field of thermoelectric due to their low lattice thermal conductivity. A comprehensive understanding of their microscopic structures is crucial for driving further the optimization of materials properties and developing novel functional materials. Here, by using in situ scanning tunneling microscopy, we report the atomic layer evolution and surface reconstruction on the cleaved thermoelectric material KCu4Se3 for the first time. We clearly revealed each atomic layer, including the naturally cleaved K atomic layer, the intermediate Se2− atomic layer, and the Se− atomic layer that emerges in the thermodynamic-stable state. Departing from the majority of studies that predominantly concentrate on macroscopic measurements of the charge transport, our results reveal the coexistence of potassium disorder and complex reconstructed patterns of selenium, which potentially influences charge carrier and lattice dynamics. These results provide direct insight into the surface microstructures and evolution of KCu4Se3, and shed useful light on designing functional materials with superior performance.

Protocolo diagnóstico y terapéutico de los trastornos del potasio

98% of the potassium in the body is inside the cells, fundamentally the musculoskeletal cells, while the remaining 2% is extracellular. The normal concentration of potassium in serum is 3.5–5.5mmol/l. Metabolic potassium disorders are some of the most common electrolytic disorders to be found in clinical practice, and they have a variable spectrum of severity. Hypopotassaemia and hyperpotassaemia cause alterations in the polarization of the cell membrane that leaves to a range of clinical manifestations, the most severe of which affect the cardiovascular system. Potassium regulation depends on intake, intra-extracellular exchange and elimination by the kidneys. After consumption potassium is absorbed in the small intestine and 90%-95% is eliminated in the urine and 5%-10% is excreted in the faeces. Knowledge of potassium regulation will be vital when establishing a suitable treatment for hypopotassaemia/hyperpotassaemia.

Acute stroke in patients with diabetes mellitus: clinical physiology, diagnosis and course features

Diabetes mellitus is one of the risk factors for the development of acute stroke. The effects of stress hormones during an acute stroke can exacerbate diabetic ketoacidosis (DKA). There is a significant overlap of symptoms, signs, and laboratory test results in stroke and DKA, which often complicates accurate diagnosis and differential diagnosis of these conditions. The article discusses the features of the clinic, diagnosis and course of an acute stroke in patients with diabetes mellitus, and the authors’ own experience is given. It has been shown that patients with acute stroke with concomitant diabetes mellitus develop disorders of electrolyte metabolism, potassium, magnesium and phosphate balance, which require timely detection and correction. In order to accurately and timely diagnose DKA in all acute stroke patients suffering from diabetes, serum pH, bicarbonate, blood gases, and anion difference should be measured upon admission.

Critically Ill Patient with Acute Exacerbation of Chronic Obstructive Pulmonary Disease Developing Sepsis and Potassium Disorder: a Case Report in Secondary Hospital Setting

Sepsis and electrolyte disturbances are frequently experienced among acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients. It is characterized by organ failure brought on by unbalanced host response to infection. A 63-year-old male presented to the hospital with the complaint of breathlessness with the oxygen saturation of 76%. The leukocyte level increased to 19.000 and the Potassium level decreased to 2.88. The combination of antibiotics, Potassium supplement, oxygen support through NRM of 15 liters per minute and symptomatic treatment were administered to the patient. The NRM was then changed to HFNC due to his worsening condition and successfully decreased oxygen demand. The patient’s condition has made a significant improvement after seven days of hospitalization. Patients with AECOPD are at higher risk of developing sepsis and electrolyte disturbances. Sepsis will change the biological system of the body due to different pathophysiology such as electrolyte imbalance and obviously engaged with the pathogenesis of ensuing regular intensifications. It is important for the clinicians to know the effective management for the patient, so that the critical phase can be passed even at the limited facilities.

Abstract 14194: Risk Factors of Hypokalemia and Hyperkalemia in Hypertensive Emergency

Introduction: Potassium disorders are common among hypertensive patients. There is a paucity of data on the prevalence and risk factors of dyskalemia in patients with hypertensive emergency. Hypothesis: We sought to investigate the prevalence and risk factors of potassium disorders in patients presenting with hypertensive emergency. Methods: A retrospective, cross-sectional study was employed by retrieving electronic medical records (EMR) of patients with a diagnosis of hypertensive emergency admitted from September 2016–December 2021 under Yale New Haven Health system. Hypertensive emergency patients were identified using the International Classification of Diseases, Tenth Edition (ICD-10) diagnosis. We selected patients who carried the diagnosis code of hypertensive emergency (I16.1) and at least 1 additional diagnosis for concurrent end organ damage (EOD). We manually examined all the electronic medical record (EMR) (n = 2664) to assure the correct establishment of diagnosis and removed 345 patients who are hypertensive urgency misclassified as hypertensive emergency. Hypokalemia is defined as serum potassium <3.5 mg/dL and hyperkalemia is defined as >5.5 mg/dL. Results: Among a total of 2,319 patients included in the study, 1,157(49.9%) were women and 1162(50.1%) were men. The mean age of the patients was 67.3 years. We have941(40.6%) African Americans, , 1048( 45.2%) Caucasian, and the rest of 240 (14.2%) are either Asians or unspecified. Average systolic blood pressure on presentation was 193 mmHg and average diastolic blood pressure was 106 mmHg. 143 (6.2%) patients had hyperkalemia and 260 (11.2%) patients had hypokalemia. After multivariable adjustment, older age, lower serum bicarbonate, elevated serum sodium and elevated serum creatinine were independently associated with hyperkalemia, and younger age, African American, higher serum bicarbonate, lower serum sodium, and lower serum creatinine were independently associated with hypokalemia. Conclusions: We identify a potential clinical phenotype of hypertensive emergency patients who present with potassium disorder. The risk for hypo- and hyperkalemia in hypertensive emergency can be stratified with common laboratory results and socio-demographic variable.

Hyperkalemia in Diabetes Mellitus Setting.

Diabetes mellitus is a global health problem that affects 9.3% of the worldwide population and is associated with a series of comorbidities such as heart failure (HF) and chronic kidney disease (CKD). Diabetic patients, especially those with associated CKD, are more susceptible to present potassium disorders, in particular hyperkalemia due to kidney disease progression or use of renin-angiotensin-aldosterone blockers. Hyperkalemia is a potentially life-threatening condition that increases the risk of cardiac arrhythmia episodes and sudden death, making the management of potassium levels a challenge to reduce the mortality rate in this population. This review aims to briefly present the potassium physiology and discuss the main conditions that lead to hyperkalemia in diabetic individuals, the main signs, symptoms, and exams for the diagnosis of hyperkalemia, and the steps that should be followed to manage patients with this potentially life-threatening condition.

Sodium and potassium disorders in patients with COPD exacerbation presenting to the emergency department

BackgroundElectrolyte disorders are common in the emergency department. Hyponatremia is known to be associated with adverse outcome in community-acquired pneumonia (CAP) and acute exacerbation of chronic obstructive pulmonary disease (AECOPD). No studies investigating the prevalence and influence of hypernatremia or potassium disorders in patients with AECOPD exist.MethodsIn this retrospective cohort analysis, the prevalence of sodium and potassium disorders was investigated in patients with AECOPD presenting to an emergency department (ED) between January 1st 2017 and December 31st 2018 and compared to all ED patients with electrolyte measurements and patients presenting with CAP. Exclusion criteria were age younger than 18 years, written or verbal withdrawal of consent and outpatient treatment. Additionally, the influence of dysnatremias and dyskalemias on outcome measured by ICU admission, need for mechanical ventilation, length of hospital stay, 30-day re-admission, 180-day AECOPD recurrence and in-hospital mortality and their role as predictors of disease severity measured by Pneumonia Severity Index (PSI) were investigated in patients with AECOPD.ResultsNineteen point nine hundred forty-eight ED consultations with measurements of sodium and potassium were recognized between January 1st 2017 and December 31st 2018 of which 102 patients had AECOPD. Of these 23% had hyponatremia, 5% hypernatremia, 16% hypokalemia and 4% hyperkalemia on admission to the ED. Hypo- and hypernatremia were significantly more common in patients with AECOPD than in the overall ED population: 23 versus 11% (p = 0.001) for hypo- and 5% versus 0.6% (p < 0.001) for hypernatremia. In the logistic regression analysis, no association between the presence of either sodium or potassium disorders and adverse outcome were found.ConclusionDysnatremias and dyskalemias are common in patients with AECOPD with as many as 1 in 5 having hyponatremia and/or hypokalemia. Hypo- and hypernatremia were significantly more common in AECOPD than overall. No significant association was found for dysnatremias, dyskalemias and adverse outcomes in AECOPD.

Hypokalemia in Diabetes Mellitus Setting.

Diabetes mellitus is a public health problem that affects millions of people worldwide regardless of age, sex, and ethnicity. Electrolyte disturbances may occur as a consequence of disease progression or its treatment, in particular potassium disorders. The prevalence of hypokalemia in diabetic individuals over 55 years of age is up to 1.2%. In patients with acute complications of diabetes, such as diabetic ketoacidosis, this prevalence is even higher. Potassium disorders, either hypokalemia or hyperkalemia, have been associated with increased all-cause mortality in diabetic individuals, especially in those with associated comorbidities, such as heart failure and chronic kidney disease. In this article, we discuss the main conditions for the onset of hypokalemia in diabetic individuals, briefly review the pathophysiology of acute complications of diabetes mellitus and their association with hypokalemia, the main signs, symptoms, and laboratory parameters for the diagnosis of hypokalemia, and the management of one of the most common electrolyte disturbances in clinical practice.

Sodium and Potassium Dysregulation in the Patient With Cancer.

Sodium and potassium disorders are pervasive in patients with cancer. The causes of these abnormalities are wide-ranging, are often primary or second-order consequences of the underlying cancer, and have prognostic implications. The approach to hyponatremia should focus on cancer-related etiologies, such as syndrome of inappropriate antidiuretic hormone, to the exclusion of other causes. Hypernatremia in non-iatrogenic forms is generally due to water loss rather than excessive sodium intake. Debilitated or dependent patients with cancer are particularly vulnerable to hypernatremia. Hypokalemia can occur in patients with cancer due to gastrointestinal disturbances, resulting from decreased intake or increased losses. Renal losses can occur as a result of excessive mineralocorticoid secretion or therapy-related nephrotoxicity. The approach to hyperkalemia should be informed by historical and laboratory clues, and pseudohyperkalemia is particularly common in patients with hematological cancers. Hyperkalemia can be seen in primary or metastatic disease that interrupts the adrenal axis. It can also develop as a consequence of immunotherapy, which can cause adrenalitis or hypophysitis. Tumor lysis syndrome (TLS) is defined by the development of hyperkalemia and is a medical emergency. Awareness of the electrolyte abnormalities that can befall patients with cancer is vital for its prompt recognition and management.

Metabolic Emergencies in Newborns in a Subsaharian Neonatology Department: Evaluation of Glucose, Sodium and Potassium Disorders

Introduction: Metabolic neonatal adaptation is a complex phenomenon and metabolic disorders can be frequent in immature newborns or in life-threatening situations. In Low and Middle income countries (LMIC) the difficult access to some diagnostic tests makes the management of the metabolic emergencies challenging. The main objectives of this study were to assess the frequency and circumstances of occurrence and to describe the clinical picture associated with glucose, sodium and potassium disorders in neonates. Patients and Methods: Our study was a retrospective and descriptive study conducted in the neonatology unit of National Children Hospital Albert Royer in Dakar (Senegal) from January 1 to December 31, 2014. Results: The prevalence of the studied metabolic disorders was 46.7%. The most common metabolic disorder noted was Hyperglycemia followed by Hyponatremia. Thermoregulation disturbances were found particularly in newborns with serum sodium disorders (hyponatremia 33.5% and hypernatremia 59.7%). Neurological signs were noted in case of blood sugar abnormalities (hypoglycemia 26.1% and hyperglycemia 29.8%). Half of the newborns with hyperglycemia (82 cases/50%) had blood sugar levels greater than or equal to 2 g/l. Hypernatremia was severe (Serum sodium> 180 mmol/l) in 12 neonates (16.7%). The main diagnoses retained were sepsis (159 cases/45.4%), prematurity (96 cases/27.4%), intrauterine growth retardation (66 cases/18.9%), malformations (63 cases/18%), perinatal asphyxia (44 cases/12.6%) and malnutrition (36 cases/10.3%). For most metabolic disorders, the correction was late and was done beyond 48 hours. On average, the correction time varied between 3 hours and 6 days. The most frequent complications were cerebral edema (12 cases), brain death (8 cases) and increased intracranial pressure (3 cases). The most lethal disorders were Hyperkalemia followed by Hyperglycemia. Conclusion: Metabolic disorders especially glucose, sodium and potassium disorders are common in newborns. They are medical emergencies that can lead to vital instability and death. Their management is challenging in low-income countries due to the lack of adapted facilities and means to diagnose them. It is therefore important to improve the availability of technical methods and means of biological analysis in hospital laboratories and to monitor closely all newborns for early diagnosis of these disorders.

Serum Potassium Disorders Predict Subsequent Kidney Injury: A Retrospective Observational Cohort Study of Hospitalized Patients

Introduction: Electrolyte disorders are common findings in kidney diseases and might represent a useful biomarker preceding kidney injury. Serum potassium [K⁺] imbalance is still poorly investigated for association with acute kidney injury (AKI), and most evidence came from intensive care units. The aim of our study was to comprehensively investigate this association in a large, unselected cohort of hospitalized patients. Methods: We performed a retrospective observational cohort study on the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 1, 2010 and December 31, 2014, with inclusion of adult patients with at least 2 [K⁺] and 3 serum creatinine measurements who did not develop AKI during an initial 10-day window. The outcome of interest was in-hospital AKI. The exposures of interest were [K⁺] fluctuations and hypo (HoK) and hyperkalemia (HerK). [K⁺] variability was evaluated using the coefficient of variation. Cox proportional hazards regression models were used to obtain hazard ratios and 95% confidence intervals of the association between the exposures of interest and development of AKI. Results: About 21,830 hospital admissions from 18,836 patients were included in our study. During a median follow-up of 5 (interquartile range [IQR] 7) days, AKI was observed in 555 hospital admissions (2.9%); median time for AKI development was 5 (IQR 7) days. Higher [K⁺] variability was independently associated with increased risk of AKI with a statistically significant linear trend across groups (p value = 0.012). A significantly higher incidence of AKI was documented in patients with HerK compared with normokalemia. No statistically significant difference was observed between HoK and HerK (p value = 0.92). Conclusion: [K⁺] abnormalities including fluctuations even within the normal range are associated with development of AKI.

Serum potassium abnormalities in chronic kidney disease: prevalence, patient characteristics and clinical outcomes.

Abnormalities in serum potassium are a well known complication of chronic kidney disease (CKD), but little is known about their impact on inpatient outcomes. To better understand the role of dyskalaemia in hospital in-patients, we assessed the epidemiology of potassium disorders among CKD patients, and the association between admission potassium and inpatient mortality or intensive care unit (ICU) requirement. This retrospective hospital-based cohort study (n = 11 156) included patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 admitted to Austin Health between 2014 and 2018 and who had an admission potassium value. Dialysis patients or those with a renal transplant were excluded. Multivariate logistic analysis was conducted to identify factors associated with hyperkalaemia (≥5.5 mmol/L) and hypokalaemia (<3.5 mmol/L). Odds ratios for inpatient mortality and ICU admission between potassium categories were obtained by multivariate regression with adjustments for demographics, renal function and comorbidities. Hyperkalaemia and hypokalaemia were present in 6.86% and 2.94% of hospital admissions respectively. In multivariate regression male sex, lower eGFR, diabetes and cardiac failure were associated with higher odds of hyperkalaemia. Thiazide diuretics, loop diuretics, infectious disease and endocrine pathology were associated with higher odds of hypokalaemia. A U-shaped association was noted between potassium and inpatient mortality. Potassium <4.0 mmol/L and ≥5.0 mmol/L was associated with increased mortality. Only patients with potassium ≥5.5 mmol/L had increased ICU admission risk. Derangements in potassium frequently occur in CKD inpatients and are independently associated with higher mortality and ICU requirement. Further studies are required to determine whether interventions to maintain normokalaemia improve outcomes in this population.

Systematic online academic resource (SOAR) review: Endocrine, metabolic, and nutritional disorders.

Free open-access medical education (FOAM) has become an integral resource for medical school and residency education. However, questions of quality and inconsistent coverage of core topics remain. In this second entry of the SAEM Systematic Online Academic Resource (SOAR) series, we describe the application of a systematic methodology to identify, curate, and describe FOAM topics specific to endocrine, metabolic, and nutritional disorders as defined by the 2016Model of the Clinical Practice of Emergency Medicine (MCPEM). We developed an automated algorithm to search 264keywords derived from ninesubtopics within the MCPEM category in the FOAM Search (a customized FOAM search tool) and the Social Media index. The top 100 results were extracted for each keyword. Resources underwent a manual iterative screening process, and those relevant to endocrine, metabolic, or nutritional disorders and EM were evaluated with the revised Medical Education Translational Resources: Impact and Quality (rMETRIQ) tool. The search yielded 36,346 resources, of which 756met the criteria for quality assessment. After rMETRIQ tool training, four raters demonstrated an average measured intraclass correlation coefficient of 0.94 (95% confidence interval= 0.88 to 0.97, p<0.001). A total of 121 posts (16% of posts) covering 25subtopics were identified as high quality (rMETRIQ ≥16). The most covered subtopic was potassium disorders, representing 15% of all posts. Subtopics that did not have a high-quality resource identified include metabolic alkalosis, respiratory alkalosis, fluid overload, phosphorus metabolism, hyperglycemia, malabsorption, malnutrition, and thyroiditis. From most to least common, the overall target audience was junior resident (91%), PGY-1 resident (88%), senior resident (81%), clerk (64%), attending (50%), and preclerkship (9%). We systematically identified, described, and curated FOAM resources for EM learners on the topic of endocrine, metabolic, and nutritional disorders. A final list of high-quality resources can guide trainees, educator recommendations, and FOAM authors.

High performance implementation of the hierarchical likelihood for generalized linear mixed models: an application to estimate the potassium reference range in massive electronic health records datasets

BackgroundConverting electronic health record (EHR) entries to useful clinical inferences requires one to address the poor scalability of existing implementations of Generalized Linear Mixed Models (GLMM) for repeated measures. The major computational bottleneck concerns the numerical evaluation of multivariable integrals, which even for the simplest EHR analyses may involve millions of dimensions (one for each patient). The hierarchical likelihood (h-lik) approach to GLMMs is a methodologically rigorous framework for the estimation of GLMMs that is based on the Laplace Approximation (LA), which replaces integration with numerical optimization, and thus scales very well with dimensionality.MethodsWe present a high-performance, direct implementation of the h-lik for GLMMs in the R package TMB. Using this approach, we examined the relation of repeated serum potassium measurements and survival in the Cerner Real World Data (CRWD) EHR database. Analyzing this data requires the evaluation of an integral in over 3 million dimensions, putting this problem beyond the reach of conventional approaches. We also assessed the scalability and accuracy of LA in smaller samples of 1 and 10% size of the full dataset that were analyzed via the a) original, interconnected Generalized Linear Models (iGLM), approach to h-lik, b) Adaptive Gaussian Hermite (AGH) and c) the gold standard for multivariate integration Markov Chain Monte Carlo (MCMC).ResultsRandom effects estimates generated by the LA were within 10% of the values obtained by the iGLMs, AGH and MCMC techniques. The H-lik approach was 4–30 times faster than AGH and nearly 800 times faster than MCMC. The major clinical inferences in this problem are the establishment of the non-linear relationship between the potassium level and the risk of mortality, as well as estimates of the individual and health care facility sources of variations for mortality risk in CRWD.ConclusionsWe found that the direct implementation of the h-lik offers a computationally efficient, numerically accurate approach for the analysis of extremely large, real world repeated measures data via the h-lik approach to GLMMs. The clinical inference from our analysis may guide choices of treatment thresholds for treating potassium disorders in the clinic.

Investigation of acute kidney injury and related risk factors in patients with COVID-19

Introduction: The 2019 recent coronavirus disease (COVID- 19) is a novel pandemic disease in the world. The main organ involved in this viral sepsis is the respiratory system. Objectives: Regarding the expression of angiotensin-converting enzyme (ACE) receptors as entering route for virus’ particles into cells, the kidney organ is another important target in this catastrophic sepsis. There is little data about renal complications and related risk factors in victims. Patients and Methods: All patients with COVID-19 admitted to a referral and tertiary center (Shohada hospital, Khorramabad, Iran) were included in the study. The research was performed from February 20 to April 19, 2020. Diagnosis of patients was confirmed by COVID-19 upper respiratory sampling using real-time PCR. Patients’ demographic data, clinical and laboratory variables were included in pre-designed questionnaires according to the considered factors; then all collected data was entered into SPSS-26 software and statistical analysis was performed. Results: All COVID-19 patients included in the study were 232 cases. Out of them, 99 cases were female (42.7%) and 133 males (57.3%). Among patients, 19 cases had AKI (acute kidney injury); of these cases. Out of AKI patients, 12 (63.2%) were admitted to the ICU, whereas the mortality rate in patients with AKI was 63.2%. AKI was significantly associated with older age, ICU admission, and lower lymphocyte count. AKI occurrence was associated with the history of hypertension, or underlying kidney disease but hadn’t a significant relationship with diabetes. Conclusion: According to this study, age is an important risk factor for renal disease and poor outcomes in COVID-19 patients. Hence, old age patients should be given more attention. Concerning more prevalence of potassium disorders, further monitoring of hypokalemia or hyperkalemia is recommended. Considering, poor outcomes in patients with COVID-19 and AKI, nephrologist’s consultation is necessary.

Epidemiology, prognosis and management of potassium disorders in Covid-19.

Coronavirus disease (Covid‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), is currently the largest health crisis facing most countries. Several factors have been linked with a poor prognosis for this disease, including demographic factors, pre‐existing comorbidities and laboratory parameters such as white blood cell count, D‐dimer, C‐reactive protein, albumin, lactate dehydrogenase, creatinine and electrolytes. Electrolyte abnormalities particularly potassium disorders are common among Covid‐19 patients. Based on our pooled analysis, hypokalemia and hyperkalemia occur in 24.3% and 4.15% of Covid‐19 patients, respectively. Potassium level deviation from the normal range may increase the chances of unfavorable outcomes and even death. Therefore, this article reviewed the epidemiology of potassium disorders and explained how hypokalemia and hyperkalemia are capable of deteriorating cardiac outcomes and the prognosis of Covid‐19 for infected patients. The article finishes by highlighting some important considerations in the management of hypokalemia and hyperkalemia in these patients.

Serum potassium levels and prognosis in HBV-associated decompensated cirrhosis.

BackgroundSerum potassium disorders are commonly seen in patients with advanced cirrhosis and have a detrimental effect on clinical outcome, but its role in HBV‐related decompensated cirrhosis (DeCi) is remained to be illustrated. We aim to assess the effects of serum potassium on outcomes in HBV‐DeCi patients.MethodsRetrospective study included 155 subjects. Multivariate analysis was used to determine the independent prognostic factor. Predictive ability of mortality for variables was determined using the receiver operating characteristics curves.ResultsThe 30‐day in‐hospital mortality was 12.9%. Serum potassium levels differed markedly between survivors and non‐survivors. On multivariate analysis, Model for End‐Stage Liver Disease (MELD) score and serum potassium level were identified as independent predictors of outcomes in HBV‐DeCi patients. The combination of serum potassium and MELD score could improve prognostic accuracy in these patients.ConclusionsOur findings suggest that serum potassium is an effective predictor for poor outcomes in HBV‐DeCi patients.

Serum potassium levels provide prognostic information in symptomatic heart failure beyond traditional clinical variables

AimsDespite of recent advances in the pharmacological treatment, heart failure (HF) maintains significant morbidity and mortality rates. While serum potassium disorders are common and associated with adverse outcomes, the exact recommended potassium level for patients with HF are not entirely established. We aimed to investigate the prognostic role of potassium levels on a cohort of patients with symptomatic chronic HF.Methods and resultsPatients with symptomatic chronic HF were identified at the referral to 6 min walking test (6MWT) and were prospectively followed up for cardiovascular events. Clinical and laboratorial data were retrospectively obtained. The primary endpoint was the composite of cardiovascular death, hospitalization due to HF, and heart transplantation. The cohort included 178 patients with HF with the mean age of 51 ± 12.76 years, 39% were female, 85% of non‐ischaemic cardiomyopathy, and 38% had New York Heart Association Class III with a relatively high Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) score (12.91 ± 6.6). The mean left ventricular ejection fraction was 39.98 ± 15.79%, and the mean 6MWT distance was 353 ± 136 m. After a median follow‐up of 516 days, there were 22 major cardiovascular events (4 cardiovascular deaths, 13 HF admissions, and 5 heart transplants). Patients were stratified according to cut‐point level of serum potassium of 4.7 mmol/L to predict combined cardiac events based on receiver operating characteristic analysis. Individuals with higher potassium levels had worse renal function (glomerular filtration rate, K ≤ 4.7: 102.8 ± 32.2 mL/min/1.73 m2 vs. K > 4.7: 85.42 ± 36.2 mL/min/1.73 m2, P = 0.004), higher proportion of New York Heart Association Class III patients (K ≤ 4.7: 28% vs. K > 4.7: 48%, P = 0.0029), and also higher MAGGIC score (K ≤ 4.7: 12.08 ± 5.7 vs. K > 4.7: 14.9 ± 7.9, P = 0.0089), without significant differences on the baseline pharmacological HF treatment. Both potassium levels [hazard ratio (HR) 4.26, 95% confidence interval (CI) 1.59–11.421, P = 0.003] and 6MWT distance (HR 0.99, 95% CI 0.993–0.999, P = 0.01) were independently associated with the primary outcome. After adjustments for MAGGIC score and 6MWT distance, potassium levels > 4.7 mmol/L maintained a significant association with outcomes (HR 3.57, 95% CI 1.305–9.807, P = 0.013). Patients with K > 4.7 mmol/L were more likely to present clinical events during the follow‐up (log rank = 0.005). Adding potassium levels to the model including 6MWT and MAGGIC significantly improved the prediction of events over 2 years (integrated discrimination index 0.105, 95% CI 0.018–0.281, P = 0.012 and net reclassification index 0.447, 95% CI 0.077–0.703, P = 0.028).ConclusionsPotassium levels were independently associated with worse outcomes in patients with chronic symptomatic HF, also improving the accuracy model for prognostic prediction when added to MAGGIC score and 6MWT distance. The potassium levels above 4.7 mmol/L might identify those patients at an increased risk of cardiovascular events.

Arrhythmogenic Mechanisms in Hypokalaemia: Insights From Pre-clinical Models.

Potassium is the predominant intracellular cation, with its extracellular concentrations maintained between 3. 5 and 5 mM. Among the different potassium disorders, hypokalaemia is a common clinical condition that increases the risk of life-threatening ventricular arrhythmias. This review aims to consolidate pre-clinical findings on the electrophysiological mechanisms underlying hypokalaemia-induced arrhythmogenicity. Both triggers and substrates are required for the induction and maintenance of ventricular arrhythmias. Triggered activity can arise from either early afterdepolarizations (EADs) or delayed afterdepolarizations (DADs). Action potential duration (APD) prolongation can predispose to EADs, whereas intracellular Ca2+ overload can cause both EADs and DADs. Substrates on the other hand can either be static or dynamic. Static substrates include action potential triangulation, non-uniform APD prolongation, abnormal transmural repolarization gradients, reduced conduction velocity (CV), shortened effective refractory period (ERP), reduced excitation wavelength (CV × ERP) and increased critical intervals for re-excitation (APD–ERP). In contrast, dynamic substrates comprise increased amplitude of APD alternans, steeper APD restitution gradients, transient reversal of transmural repolarization gradients and impaired depolarization-repolarization coupling. The following review article will summarize the molecular mechanisms that generate these electrophysiological abnormalities and subsequent arrhythmogenesis.