Controversies in Management of Hyperkalemia

Electrocardiographic Abnormalities in Patients with Hyperkalemia: A Retrospective Study in an Emergency Department in Colombia

Introduction

Hyperkalemia is a prevalent electrolyte disorder related to elevated serum potassium levels, resulting in diverse abnormal electrocardiographic findings and associated clinical signs and symptoms, often necessitating specific treatment. However, in some patients, these abnormal findings may not be present on the electrocardiogram even in elevated serum potassium levels. This study aims to identify electrocardiographic abnormalities related to the severity of hyperkalemia and the clinical outcomes in an emergency department in southwestern Colombia.

Methodology

This is a retrospective cross-sectional descriptive study. We described the electrocardiographic findings, clinical characteristics, treatment, and outcomes related to the degrees of hyperkalemia. The potential association between the severity of hyperkalemia and electrocardiographic findings was evaluated.

Results

A total of 494 patients were included. The median of the potassium level was 6.6 mEq/L. Abnormal electrocardiographic findings were reported in 61.5% of the cases. Mild and severe hyperkalemia groups reported abnormalities in 59.9% and 61.2%, respectively. The most common electrocardiography abnormalities were the peaked T wave 36.2%, followed by wide QRS 83 (16.8%). Only 1.4% of patients had adverse outcomes. The abnormal findings were registered in 61.5%. Mortality was 11.9%. The peaked T wave was the most common finding across different levels of hyperkalemia severity.

Conclusion

High serum potassium levels are related with abnormal ECG. However, patients with different degrees of hyperkalemia could not describe abnormal ECG findings. In a high proportion of patients with renal chronic disease and hyperkalemia, the abnormalities in the ECG could be minimal or absent.

Non-steroidal mineralocorticoid antagonists and hyperkalemia monitoring in chronic kidney disease patients associated with type II diabetes: a narrative review

Chronic kidney disease (CKD) is a prevalent complication of Type II diabetes (T2D). The coexistence of CKD with T2D is comparable to cardiovascular disease (CVD) when the estimated glomerular filtration rate declines below 60 ml/min/1.73 m2. Screening and early detection of people with high risk for CKD would be beneficial in managing CKD progress and the associated complications such as CV complications. Renin-angiotensin-aldosterone system inhibitors (RAASi) have demonstrated beneficial effects in delaying CKD progression, but they carry the risk of hyperkalemia. Nonsteroidal mineralocorticoid antagonists (nsMRA), such as finerenone, exhibit considerable efficacy in their anti-inflammatory, antifibrotic, and renal protective effects with demonstrable reductions in CV complications. In addition, nsMRAs do not cause significant changes in serum potassium levels compared to traditional steroidal MRA. Ongoing research explores the capacity of the sodium-glucose transport protein 2 inhibitors (SGLT-2i), combined with nsMRA, to produce synergistic renal protective effects and reduce the risk of hyperkalemia. Also, a dedicated renal outcomes study (FLOW study) involving a once-weekly injectable Glucagon-like peptide-1 receptor agonist, semaglutide, was halted early by the data monitoring committee due to having achieved the predefined efficacy endpoint and considerations related to renal disease. In CKD patients with T2D on nsMRA, hyperkalemia management requires a comprehensive approach involving lifestyle adjustments, dietary modifications, regular serum potassium level monitoring, and potassium binders, if necessary. Withholding or down-titration of nsMRAs with close monitoring of serum potassium levels may be required in patients with concerning potassium levels. In light of the current state of knowledge, this review article explores the perspectives and approaches that HCPs may consider when monitoring and managing hyperkalemia in CKD patients with T2D.

Sodium Bicarbonate and Calcium Chloride for the Treatment of Hyperkalemia-Induced Cardiac Arrest: A Randomized, Blinded, Placebo-Controlled Animal Study

OBJECTIVES

Current international guidelines recommend administrating calcium chloride and sodium bicarbonate to patients with hyperkalemia-induced cardiac arrest, despite limited evidence. The aim of this study was to evaluate the efficacy of calcium chloride and sodium bicarbonate on return of spontaneous circulation (ROSC) in a pig model of hyperkalemia-induced cardiac arrest.

DESIGN

A randomized, blinded, placebo-controlled experimental pig study. Hyperkalemia was induced by continuous infusion of potassium chloride over 45 minutes followed by a bolus. After a no flow period of 7 minutes, pigs first received 2 minutes of basic cardiopulmonary resuscitation and subsequently advanced life support. The first intervention dose was administered after the fifth rhythm analysis, followed by a defibrillation attempt at the sixth rhythm analysis. A second dose of the intervention was administered after the seventh rhythm analysis if ROSC was not achieved. In case of successful resuscitation, pigs received intensive care for 1 hour before termination of the study.

SETTING

University hospital laboratory.

SUBJECTS

Fifty-four female Landrace/Yorkshire/Duroc pigs (38-42 kg).

INTERVENTIONS

The study used a 2 × 2 factorial design, with calcium chloride (0.1 mmol/kg) and sodium bicarbonate (1 mmol/kg) as the interventions.

MEASUREMENTS AND MAIN RESULTS

Fifty-two pigs were included in the study. Sodium bicarbonate significantly increased the number of animals achieving ROSC (24/26 [92%] vs. 13/26 [50%]; odds ratio [OR], 12.0; 95% CI, 2.3-61.5; p = 0.003) and reduced time to ROSC (hazard ratio [HR] 3.6; 95% CI, 1.8-7.5; p < 0.001). There was no effect of calcium chloride on the number of animals achieving ROSC (19/26 [73%] vs. 18/26 [69%]; OR, 1.2; 95% CI, 0.4-4.0; p = 0.76) or time to ROSC (HR, 1.5; 95% CI, 0.8-2.9; p = 0.23).

CONCLUSIONS

Administration of sodium bicarbonate significantly increased the number of animals achieving ROSC and decreased time to ROSC. There was no effect of calcium chloride on the number of animals achieving ROSC or time to ROSC.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for treating hyperkalemia among Chinese patients

Objectives

Hyperkalemia most commonly develops in chronic kidney disease (CKD) or heart failure (HF) patients. Sodium zirconium cyclosilicate (SZC) is a new selective potassium (K+) binder for treating hyperkalemia. The aim of this study was to evaluate the cost-effectiveness of SZC vs. usual care for the treatment of hyperkalemia among CKD patients or HF patients in China.

Methods

Individual patient microsimulation models were constructed to simulate a CKD cohort until the initiation of renal replacement therapy (RRT) and a HF cohort across the lifetime horizon. K+ levels were based on two phase 3 clinical trials. Health state utility and event incidence rates were retrieved from literature. Drug costs and healthcare utilization costs were obtained from negotiated price, literature, and expert interviews. Costs and quality-adjusted life-years (QALYs) were both discounted at 5%. The main outcomes were overall costs, QALYs, and incremental cost-effectiveness ratio (ICER). The willingness-to-pay (WTP) threshold in China is CNY 80,976-242,928/QALY, which is one to three times the gross domestic product per capita. Sensitivity analyses were performed to characterize the models' uncertainty.

Results

In the HF cohort, the base case results revealed that SZC was associated with 2.86 QALYs and the total cost was CNY 92671.58; usual care was associated with 1.81 QALYs and CNY 54101.26. In the CKD cohort, SZC was associated with 3.23 QALYs and CNY 121416.82 total cost; usual care was associated with 2.91 QALYs and CNY 111464.57. SZC resulted in an ICER of CNY 36735.87/QALY for the HF cohort and CNY 31181.55/QALY for the CKD cohort, respectively. The one-way and probability sensitivity analyses found that the results were robust.

Conclusion

SZC is a cost-effective treatment compared to usual care in HF and CKD patients. SZC is an important novel treatment option for managing patients with hyperkalemia in China.

Consensus document on the management of hyperkalemia

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

High-Dose Insulin for Hyperkalemic Cardiac Arrest

ABSTRACT

Hyperkalemic cardiac arrest diagnosis can be elusive and management difficult as the cardiac rhythm restoration is often not achieved until the potassium level decreases to a relatively normal level for the patient who suffers the arrest. Current treatment modalities can take hours to achieve this goal. We describe two patients who survived a witnessed hyperkalemic cardiac arrest after being managed with conventional advanced cardiac life support and unconventionally high doses of intravenous insulin.

Lazarus Phenomenon or the Return from the Afterlife-What We Know about Auto Resuscitation

Autoresuscitation is a phenomenon of the heart during which it can resume its spontaneous activity and generate circulation. It was described for the first time by K. Linko in 1982 as a recovery after discontinued cardiopulmonary resuscitation (CPR). J.G. Bray named the recovery from death the Lazarus phenomenon in 1993. It is based on a biblical story of Jesus' resurrection of Lazarus four days after confirmation of his death. Up to the end of 2022, 76 cases (coming from 27 countries) of spontaneous recovery after death were reported; among them, 10 occurred in children. The youngest patient was 9 months old, and the oldest was 97 years old. The longest resuscitation lasted 90 min, but the shortest was 6 min. Cardiac arrest occurred in and out of the hospital. The majority of the patients suffered from many diseases. In most cases of the Lazarus phenomenon, the observed rhythms at cardiac arrest were non-shockable (Asystole, PEA). Survival time after death ranged from minutes to hours, days, and even months. Six patients with the Lazarus phenomenon reached full recovery without neurological impairment. Some of the causes leading to autoresuscitation presented here are hyperventilation and alkalosis, auto-PEEP, delayed drug action, hypothermia, intoxication, metabolic disorders (hyperkalemia), and unobserved minimal vital signs. To avoid Lazarus Syndrome, it is recommended that the patient be monitored for 10 min after discontinuing CPR. Knowledge about this phenomenon should be disseminated in the medical community in order to improve the reporting of such cases. The probability of autoresuscitation among older people is possible.

Crush injury and syndrome: A review for emergency clinicians

INTRODUCTION

Primary disasters may result in mass casualty events with serious injuries, including crush injury and crush syndrome.

OBJECTIVE

This narrative review provides a focused overview of crush injury and crush syndrome for emergency clinicians.

DISCUSSION

Millions of people worldwide annually face natural or human-made disasters, which may lead to mass casualty events and severe medical issues including crush injury and syndrome. Crush injury is due to direct physical trauma and compression of the human body, most commonly involving the lower extremities. It may result in asphyxia, severe orthopedic injury, compartment syndrome, hypotension, and organ injury (including acute kidney injury). Crush syndrome is the systemic manifestation of severe, traumatic muscle injury. Emergency clinicians are at the forefront of the evaluation and treatment of these patients. Care at the incident scene is essential and focuses on treating life-threatening injuries, extrication, triage, fluid resuscitation, and transport. Care at the healthcare facility includes initial stabilization and trauma evaluation as well as treatment of any complication (e.g., compartment syndrome, hyperkalemia, rhabdomyolysis, acute kidney injury).

CONCLUSIONS

Crush injury and crush syndrome are common in natural and human-made disasters. Emergency clinicians must understand the pathophysiology, evaluation, and management of these conditions to optimize patient care.

Hyperkalemia in the setting of severe leukocytosis: Should you treat?

BACKGROUND

Severe hyperkalemia is a common and life-threatening problem presenting to the emergency department. Rapid correction of the electrolyte abnormality is essential but doing so can be detrimental in circumstances under which delaying treatment for confirmation is required. Our case exemplifies one of those scenarios: pseudohyperkalemia in the setting of severe leukocytosis.

CASE

An elderly woman with long-standing but untreated chronic lymphocytic leukemia presented with a left hip fracture. She was found to have a potassium level of 8.4 mEq/L without symptoms of hyperkalemia, renal disease, or EKG findings. Her white blood cell count was 444 K/uL. Despite a potentially life-threatening hyperkalemia, correction was deferred pending confirmation by venous whole blood, which revealed a normal potassium level.

DISCUSSION

Pseudohyperkalemia can occur in the setting of severe leukocytosis. It is important for emergency physicians to recognize this phenomenon and avoid iatrogenic hypokalemia. The pathophysiology behind this phenomenon and the methods for correct analysis are presented here.

Calcium use during paediatric in-hospital cardiac arrest is associated with worse outcomes

AIM

To evaluate associations between calcium administration and outcomes among children with in-hospital cardiac arrest and among specific subgroups in which calcium use is hypothesized to provide clinical benefit.

METHODS

This is a secondary analysis of observational data collected prospectively as part of the ICU-RESUScitation project. Children 37 weeks post-conceptual age to 18 years who received chest compressions in one of 18 intensive care units from October 2016-March 2021 were eligible. Data included child and event characteristics, pre-arrest laboratory values, pre- and intra-arrest haemodynamics, and outcomes. Outcomes included sustained return of spontaneous circulation (ROSC), survival to hospital discharge, and survival to hospital discharge with favourable neurologic outcome. A propensity score weighted cohort was used to evaluate associations between calcium use and outcomes. Subgroups included neonates, and children with hyperkalaemia, sepsis, renal insufficiency, cardiac surgery with cardiopulmonary bypass, and calcium-avid cardiac diagnoses.

RESULTS

Of 1,100 in-hospital cardiac arrests, median age was 0.63 years (IQR 0.19, 3.81); 450 (41%) received calcium. Among the weighted cohort, calcium use was not associated with sustained ROSC (aOR, 0.87; CI95 0.61-1.24; p = 0.445), but was associated with lower rates of both survival to hospital discharge (aOR, 0.68; CI95 0.52-0.89; p = 0.005) and survival with favourable neurologic outcome at hospital discharge (aOR, 0.75; CI95 0.57-0.98; p = 0.038). Among subgroups, calcium use was associated with lower rates of survival to hospital discharge in children with sepsis and renal insufficiency.

CONCLUSIONS

Calcium use was common during paediatric in-hospital cardiac arrest and associated with worse outcomes at hospital discharge.

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.

Sodium polystyrene sulfonate versus sodium zirconium cyclosilicate for the treatment of hyperkalemia in the emergency department

BACKGROUND

Hyperkalemia accounts for over 800,000 emergency department (ED) visits in the United States each year, and has been associated with significant morbidity and mortality likely due to fatal cardiac dysrhythmias. Previous studies have demonstrated reductions in mortality when potassium levels are normalized in the ED. Cation exchange resins, such as sodium polystyrene sulfonate (SPS) and sodium zirconium cyclosilicate (SZC), may be administered as a means of definitively eliminating potassium from the body. This practice is based on physician preference and is not supported by high quality data. Two studies evaluating the use of cation exchange resins versus standard treatment in the ED demonstrated reductions in serum potassium levels within two hours of administration; however, there have been no published studies investigating these agents in a head-to-head comparison.

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of SPS versus SZC in lowering serum potassium in patients presenting to the ED with hyperkalemia.

METHODS

This was an institutional review board-approved, retrospective cohort study conducted at a single-site ED. All patients who received medications under the "ED Hyperkalemia Treatment" order set between August 26, 2019 and May 13, 2021 were eligible for inclusion. The primary outcome was the change in serum potassium from baseline to first repeat level following SPS or SZC administration in the ED.

RESULTS

A total of 885 patients were screened with 54 patients in the SPS group and 51 patients in the SZC group included in the final analyses. The mean change in serum potassium from baseline to first repeat level following administration of the cation exchange resin was -1.1 mEq/L for both groups.

CONCLUSION

Administration of SPS or SZC for the treatment of hyperkalemia in the ED resulted in similar reductions in serum potassium.

Acute hyperkalemia in adults

Hyperkalemia is a common, life-threatening medical situation in chronic renal disease patients in the emergency department (ED). Since hyperkalemia does not present with any specific symptom, it is difficult to diagnose clinically. Hyperkalemia causes broad and dramatic medical presentations including cardiac arrhythmia and sudden death. Hyperkalemia is generally determined through serum measurement in the laboratory. Treatment includes precautions to stabilize cardiac membranes, shift potassium from the extracellular to the intracellular, and increase potassium excretion. The present article discusses the management of hyperkalemia in the ED in the light of current evidence.

Effects of different potassium-lowering regimens on acute hyperkalemia in hemodialysis patients: a real-world, retrospective study

Background

Hyperkalemia is a common and potentially life-threatening electrolyte disorder in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the efficacy and safety of potassium-lowering regimens during treatment of acute hyperkalemia in MHD patients.

Methods

This retrospective real-world study (RWS) was conducted among 139 MHD patients. They were given different potassium-lowering regimens, viz. the insulin and glucose (IG) intravenous administration group (IG, 46 patients), the sodium polystyrene sulfonate group (SPS, 33 patients), the sodium zirconium cyclosilicate group (SZC, 38 patients), the IG + SZC group (22 patients). The primary efficacy end point was the rate of serum potassium decline at 2 h. The rates of adverse events were also compared.

Results

At 2 h, the mean ± SE change of serum potassium level was − 0.71 ± 0.32 mmol per liter (mmol/L) in IG group, − 0.43 ± 0.38 mmol/L in SPS group, − 0.64 ± 0.36 mmol/L in SZC group, − 1.43 ± 0.38 mmol/L in IG + SZC group (P < 0.01). The serum potassium level in IG + SZC group decreased more than that in the other three groups (P < 0.01), while the serum potassium level in SPS group decreased less than that in the other three groups (P < 0.05). There was no significant difference on the decrease of the serum potassium level between IG group and the SZC group (P = 0.374). The IG group and the IG + SZC group had higher rates of symptomatic hypoglycemia. The SPS group had significant decreases of serum calcium and serum magnesium after treatment.

Conclusions

Among MHD patients with acute hyperkalemia, SZC had similar potassium-lowering efficacy with IG intravenous administration at 2 h and superior on convenience and side-effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03530-4.

In-hospital mortality, length of stay, and hospitalization cost of COVID-19 patients with and without hyperkalemia

BACKGROUND

Hyperkalemia (HK) may be associated with poor clinical outcomes among COVID-19 patients. This study aimed to describe the prevalence of HK and evaluate the associations between HK and in-hospital mortality, intensive care unit (ICU) admission, length of hospital stay (LOS), and hospitalization cost among COVID-19 inpatients.

METHODS

A retrospective cohort study was conducted using a large hospital discharge database (PINC AI Healthcare Database) for COVID-19 inpatients discharged between April 1 and August 31, 2020. HK was defined with discharge diagnosis and potassium binder use.

RESULTS

Of 192,182 COVID-19 inpatients, 12% (n = 22,702) had HK. HK patients were more likely to be older (median age 67 vs 63 years), male (63% vs 50%), black (30% vs 22%), and have a history of chronic kidney disease (45% vs 16%) or diabetes mellitus (55% vs 35%) than non-HK patients (all p<.001). A significantly higher proportion of patients with HK had in-hospital mortality (42% vs 11%, p<.001) than those without HK; this was persistent after adjusting for confounders (adjusted odds ratio [_aOR] 1.69, 95% confidence interval [CI]1.62-1.77). Patients with HK were also more likely to be admitted to ICU (_aOR 1.05, 95% CI 1.01-1.09), incur higher cost of care (adjusted mean difference $5,389) and have longer LOS (adjusted mean difference 1.3 days) than non-HK patients.

CONCLUSIONS

Presence of HK was independently associated with higher in-hospital mortality, LOS, and cost of care among COVID-19 inpatients. Detecting and closely monitoring HK are recommended to improve clinical outcomes and reduce LOS and healthcare cost among COVID-19 patients.

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.

Estimating in vivo potassium distribution and fluxes with stable potassium isotopes

Extracellular potassium (K⁺) homeostasis is achieved by a concerted effort of multiple organs and tissues. A limitation in studies of K⁺ homeostasis is inadequate techniques to quantify K⁺ fluxes into and out of organs and tissues in vivo. The goal of the present study was to test the feasibility of a novel approach to estimate K⁺ distribution and fluxes in vivo using stable K⁺ isotopes. ⁴¹K was infused as KCl into rats consuming control or K⁺-deficient chow (n = 4 each), ⁴¹K-to-³⁹K ratios in plasma and red blood cells (RBCs) were measured by inductively coupled plasma mass spectrometry, and results were subjected to compartmental modeling. The plasma ⁴¹K/³⁹K increased during ⁴¹K infusion and decreased upon infusion cessation, without altering plasma total K⁺ concentration ([K⁺], i.e., ⁴¹K + ³⁹K). The time course of changes was analyzed with a two-compartmental model of K⁺ distribution and elimination. Model parameters, representing transport into and out of the intracellular pool and renal excretion, were identified in each rat, accurately predicting decreased renal K⁺ excretion in rats fed K⁺-deficient vs. control diet (P < 0.05). To estimate rate constants of K⁺ transport into and out of RBCs, ⁴¹K/³⁹K were subjected to a simple model, indicating no effects of the K⁺-deficient diet. The findings support the feasibility of the novel stable isotope approach to quantify K⁺ fluxes in vivo and sets a foundation for experimental protocols using more complex models to identify heterogeneous intracellular K⁺ pools and to answer questions pertaining to K⁺ homeostatic mechanisms in vivo.

Hypokalemic Cardiac Arrest: Narrative Review of Case Reports and Current State of Science

PURPOSE

Hypokalemic cardiac arrest is an uncommon occurrence in the emergency department. Electrocardiogram findings related to hypokalemic cardiac arrest include prolonged QT, U waves, and preventricular contractions leading to Torsades de Pointes and then arrest. Literature evaluating the prevalence of hypokalemic cardiac arrest is scarce, and its management is lacking. This review provides a summary of current literature, recommendations from current guidelines, and proposed management strategies of hypokalemic cardiac arrest.

SUMMARY

Intravenous potassium administration is the treatment for hypokalemic cardiac arrest. Although the treatment for hypokalemic cardiac arrest is known, there is limited evidence on the proper procedure for administering intravenous potassium appropriately and safely. Owing to the time-sensitive nature of treating hypokalemic cardiac arrest, rapid administration of intravenous potassium (10 mEq/100 mL of potassium chloride over 5 minutes) is warranted. Concerns regarding rapid potassium administration are not without merit; however, a risk-benefit analysis and potential mitigation strategies for unwanted side effects need to be considered if hypokalemic cardiac arrest is to remain a reversible cause. It is imperative to identify hypokalemia as the cause for arrest as soon as possible and administer potassium before systemic acidosis, ischemia, and irreversible cell death.

CONCLUSIONS

More evidence is necessary to support treatment recommendations for hypokalemic cardiac arrest; however, it is the authors' opinion that, if identified early during cardiac arrest, intravenous potassium should be administered to treat a reversible cause for cardiac arrest.

Suspected vagal reflex and hyperkalaemia inducing asystole in an anaesthetised horse

A 10‐year‐old 466 kg mustang gelding presented to an equine referral hospital for surgical repair of nasal, frontal and lacrimal bone fractures from an unknown trauma. Surgical repair was performed under general anaesthesia, including a right‐sided maxillary regional anaesthetic block with mepivacaine hydrochloride. Progressive hyperkalaemia was documented perianaesthetically (T‐3 mins; 134 mins after induction; potassium 6.4 mmol/L (ref 3.5‐5.1 mmol/L). Perianaesthetic bradycardia was attributed to alpha −2 agonist infusion administration, and other characteristic ECG changes (flattened P waves, narrow T waves of increased amplitude, prolonged QRS complex) were not documented. Asystole occurred 137 min after induction of anaesthesia; however, a review of the available literature suggests the degree of hyperkalaemia documented was unlikely to be the primary cause of asystole but may have been a contributing factor. It is hypothesised that a trigeminocardiac reflex was the primary contributory factor to asystole in the described case, and may represent a maxillomandibulocardiac reflex that has not been previously described in the horse.

Sodium bicarbonate administration and subsequent potassium concentration in hyperkalemia treatment

BACKGROUND

Hyperkalemia is an electrolyte disorder commonly encountered in the emergency department that can result in significant morbidity and mortality. While sodium bicarbonate is often used for acute lowering of serum potassium, its efficacy is not well established. The purpose of this study was to evaluate and quantify the amount of potassium reduction in emergency department patients who received intravenous sodium bicarbonate as part of treatment for hyperkalemia compared with those who did not.

METHODS

A retrospective electronic chart review was conducted on adult patients who presented to the emergency department with initial potassium concentration greater than or equal to 5.4 mMol/L and received intravenous insulin as part of hyperkalemia treatment. Patients who received intravenous sodium bicarbonate in addition to intravenous insulin were included in the sodium bicarbonate group. The control group included patients who did not receive intravenous sodium bicarbonate. The primary objective of this study was to compare the absolute reduction in serum potassium between initial and second concentrations in patients from the sodium bicarbonate group and those in the control group.

RESULTS

A total of 106 patients were included in this study with 38 patients in the sodium bicarbonate group and 68 patients in the control group. Median initial potassium concentration was 6.6 mMol/L in the sodium bicarbonate group and 6.1 mMol/L in the control group (P = 0.009). Absolute reduction of potassium at first repeat was 1 and 0.9 mMol/L in sodium bicarbonate group and control group respectively (P = 0.976).

CONCLUSIONS

The addition of sodium bicarbonate therapy to intravenous insulin in the treatment of hyperkalemia did not offer statistically significant added efficacy in potassium lowering. Larger studies are needed to further validate the result findings.

Treatment of Mild Hyperkalemia in Hospitalized Patients: An Unnecessary Practice?

Background

Sodium polystyrene sulfonate (SPS) is one of the most commonly used treatments for mild hyperkalemia. Other treatments include insulin, sodium bicarbonate, and salbutamol, which may be given alone or in combination. The results of research examining treatment effectiveness for mild hyperkalemia (e.g., the ability of SPS to achieve normokalemia) thus far have been inconsistent. Given that the effectiveness of treatment for mild hyperkalemia is debatable, new research is needed.

Objective

To determine whether treatment of hospitalized patients with mild hyperkalemia (using SPS or another approach, relative to no treatment) was associated with achievement of normokalemia (serum potassium < 5.1 mmol/L).

Methods

For this retrospective, quasi-experimental study, hospitalized patients with index serum potassium level between 5.1 and 6.4 mmol/L were identified. Post-index serum potassium level within 24 hours was dichotomized (< 5.1 or ≥ 5.1 mmol/L). Pre-index serum creatinine and serum potassium levels were recorded as the average of the first 5 values immediately before the index potassium value. For each patient, treatment was categorized as no treatment, SPS treatment, or other treatment strategy.

Results

Among the 1944 patients included in the analysis, the average age was 66.8 (standard deviation 13.5) years; 605 (31.1%) of the patients were women and 1339 (68.9%) were men. Logistic regression results indicated that patients who were female and/or had higher pre-index serum potassium were less likely to return to normokalemia within 24 hours after the time of the index serum potassium value. Treatment category was not a statistically significant predictor of the achievement of normokalemia. Most patients with mild hyperkalemia (> 74.5% in each treatment category) achieved normokalemia, whether or not they received treatment.

Conclusions

The findings of this study suggest that although follow-up is required for mild hyperkalemia in hospitalized patients, active treatment may be unnecessary.

Hyperkalemia excursions are associated with an increased risk of mortality and hospitalizations in hemodialysis patients

BACKGROUND

Hyperkalemia is common among hemodialysis (HD) patients and has been associated with adverse clinical outcomes. Previous studies considered a single serum potassium (K) measurement or time-averaged values, but serum K excursions out of the target range may be more reflective of true hyperkalemia events. We assessed whether hyperkalemia excursions lead to an elevated risk of adverse clinical outcomes.

METHODS

Using data from 21 countries in Phases 4-6 (2009-18) of the Dialysis Outcomes and Practice Patterns Study (DOPPS), we investigated the associations between peak serum K level, measured monthly predialysis, over a 4-month period ('peak K') and clinical outcomes over the subsequent 4 months using Cox regression, adjusted for potential confounders.

RESULTS

The analysis included 62 070 patients contributing a median of 3 (interquartile range 2-6) 4-month periods. The prevalence of hyperkalemia based on peak K was 58% for >5.0, 30% for >5.5 and 12% for >6.0 mEq/L. The all-cause mortality hazard ratio for peak K (reference ≤5.0 mEq/L) was 1.15 [95% confidence interval (CI) 1.09, 1.21] for 5.1-5.5 mEq/L, 1.19 (1.12, 1.26) for 5.6-6.0 mEq/L and 1.33 (1.23, 1.43) for >6.0 mEq/L. Results were qualitatively consistent when analyzing hospitalizations and a cardiovascular composite outcome.

CONCLUSIONS

Among HD patients, we identified a lower K threshold (peak K 5.1-5.5 mEq/L) than previously reported for increased risk of hospitalization and mortality, with the implication that a greater proportion (>50%) of the HD population may be at risk. A reassessment of hyperkalemia severity ranges is needed, as well as an exploration of new strategies for effective management of chronic hyperkalemia.

Reduced alternative insulin dosing in hyperkalemia: A meta-analysis of effects on hypoglycemia and potassium reduction

STUDY OBJECTIVE

Recent studies have identified that reduced alternative intravenous insulin doses, such as 5 units or 0.1 units/kg, may reduce the risk of hypoglycemia compared to standard doses of 10 units in patients treated for hyperkalemia. However, some studies suggest that these alternative doses may reduce the ability to lower serum potassium. This study was performed to determine the impact of alternative insulin dosing on hypoglycemia and potassium reduction in patients with hyperkalemia.

DESIGN

Meta-analysis.

DATA SOURCE

PubMed/MEDLINE, CENTRAL, Ovid, and ClinicalTrials.gov were searched from inception through November 2020.

PATIENTS

Patients treated with standard (10 units) or alternative (<10 units) insulin dosing strategies for hyperkalemia. Only studies that evaluated hypoglycemia (serum glucose <70 mg/dl), severe hypoglycemia (serum glucose <50 mg/dl), and potassium reduction post-treatment were included in the meta-analysis. All articles were assessed for bias using the Cochrane Risk of Bias Assessment Tool and Newcastle-Ottawa scales for randomized prospective trials and retrospective trials, respectively.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Ten retrospective cohort studies (n = 3437) were included and had low- or moderate-risk of bias. Alternative insulin dosing strategies included 5 units, 0.1 units/kg, and <10 units. Alternative dosing had lower pooled odds of hypoglycemia (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.43-0.69, I²  = 8%) and severe hypoglycemia (OR 0.41, 95% CI 0.27-0.64, I²  = 0%). No difference in potassium reduction was detected (mean difference -0.02 mmol/L, 95% CI -0.11-0.07, I²  = 53%).

CONCLUSIONS

Alternative insulin dosing strategies for hyperkalemia management resulted in less hypoglycemia and severe hypoglycemia without compromising potassium reduction compared to standard dose. Prospective studies are needed to confirm these findings.

Effects of estimated glomerular filtration rate and diabetes mellitus on the effect of insulin for treating hyperkalemia during anesthesia

PURPOSE

We analyzed the effectiveness of insulin for treating hyperkalemia (≥ 5 mEq/L) during anesthesia and the effects of the estimated glomerular filtration rate (eGFR) and diabetes mellitus (DM) on the insulin treatment.

METHODS

Patients 18 years of age and older who received intravenous insulin lispro for hyperkalemia under general anesthesia between January 2010 and March 2020 were enrolled. We performed three propensity score matching analyses according to eGFR stages (eGFR ≥ 60 vs. 30 ≤ eGFR < 60 and eGFR ≥ 60 vs. eGFR < 30 mL/min/1.73 m²) and DM status.

RESULTS

The study included 475 patients. For patients with hyperkalemia during surgery, the odds ratios [ORs] of failure to decrease potassium (K⁺) after insulin treatment were higher in patients with eGFR < 30 mL/min/1.73 m² (adjusted OR 3.24; 95% confidence interval 1.38-7.64; P = 0.007) than in patients with eGFR ≥ 60 mL/min/1.73 m². There was no significant difference in the ORs of patients with 30 ≤ eGFR < 60 mL/min/1.73 m² and DM.

CONCLUSION

The patients with a low eGFR had a higher incidence of K⁺ not decreasing after insulin treatment. Periodic assessment of K⁺ may be required during anesthesia.

Regulation of muscle potassium: exercise performance, fatigue and health implications

This review integrates from the single muscle fibre to exercising human the current understanding of the role of skeletal muscle for whole-body potassium (K⁺) regulation, and specifically the regulation of skeletal muscle [K⁺]. We describe the K⁺ transport proteins in skeletal muscle and how they contribute to, or modulate, K⁺ disturbances during exercise. Muscle and plasma K⁺ balance are markedly altered during and after high-intensity dynamic exercise (including sports), static contractions and ischaemia, which have implications for skeletal and cardiac muscle contractile performance. Moderate elevations of plasma and interstitial [K⁺] during exercise have beneficial effects on multiple physiological systems. Severe reductions of the trans-sarcolemmal K⁺ gradient likely contributes to muscle and whole-body fatigue, i.e. impaired exercise performance. Chronic or acute changes of arterial plasma [K⁺] (hyperkalaemia or hypokalaemia) have dangerous health implications for cardiac function. The current mechanisms to explain how raised extracellular [K⁺] impairs cardiac and skeletal muscle function are discussed, along with the latest cell physiology research explaining how calcium, β-adrenergic agonists, insulin or glucose act as clinical treatments for hyperkalaemia to protect the heart and skeletal muscle in vivo. Finally, whether these agents can also modulate K⁺-induced muscle fatigue are evaluated.

ENaC expression correlates with the acute furosemide-induced K+ excretion

BACKGROUND

In the aldosterone-sensitive distal nephron (ASDN), epithelial sodium channel (ENaC)-mediated Na+ absorption drives K+ excretion. K+ excretion depends on the delivery of Na+ to the ASDN and molecularly activated ENaC. Furosemide is known as a K+ wasting diuretic as it greatly enhances Na+ delivery to the ASDN. Here, we studied the magnitude of acute furosemide-induced kaliuresis under various states of basal molecular ENaC activity.

METHODS

C57/Bl6J mice were subjected to different dietary regimens that regulate molecular ENaC expression and activity levels. The animals were anesthetized and bladder-catheterized. Diuresis was continuously measured before and after administration of furosemide (2 µg/g BW) or benzamil (0.2 µg/g BW). Flame photometry was used to measure urinary [Na+ ] and [K+ ]. The kidneys were harvested and, subsequently, ENaC expression and cleavage activation were determined by semiquantitative western blotting.

RESULTS

A low K+ and a high Na+ diet markedly suppressed ENaC protein expression, cleavage activation, and furosemide-induced kaliuresis. In contrast, furosemide-induced kaliuresis was greatly enhanced in animals fed a high K+ or low Na+ diet, conditions with increased ENaC expression. The furosemide-induced diuresis was similar in all dietary groups.

CONCLUSION

Acute furosemide-induced kaliuresis differs greatly and depends on the a priori molecular expression level of ENaC. Remarkably, it can be even absent in animals fed a high Na+ diet, despite a marked increase of tubular flow and urinary Na+ excretion. This study provides auxiliary evidence that acute ENaC-dependent K+ excretion requires both Na+ as substrate and molecular activation of ENaC.

Polysulfonate Resins in Hyperkalemia: A Systematic Review

BACKGROUND

Hyperkalemia is a potentially life-threatening electrolyte abnormality defined as a serum potassium above the lab reference range (usually >5.0-5.5 mEq/L). Polystyrene resins, including sodium polystyrene sulfonate (SPS) and calcium polystyrene sulfonate (CPS), have long been used to treat hyperkalemia. Sodium polystyrene sulfonate/calcium polystyrene sulfonate act by exchanging a cation for potassium within the intestinal lumen. While SPS and CPS have been available since the 1960s, there are rising concerns about the validity of the data supporting its use and about serious adverse gastrointestinal effects.

OBJECTIVE

The objective of this systematic review was to quantify the efficacy and safety of polystyrene sulfonate resins (SPS/CPS) in the treatment of adults with hyperkalemia. This review focuses on the randomized control trial (RCT), interventional non-RCT, and observational data available on SPS/CPS use.

DESIGN

Systematic review.

SETTING

Any country of origin. Both inpatient and outpatient settings.

PATIENTS

Adults with hyperkalemia treated with polystyrene sulfonate resins.

MEASUREMENTS

The primary outcome was change in serum potassium. The secondary outcomes included adverse effects of SPS/CPS and prevention of recurrent hyperkalemia.

METHODS

We conducted a systematic review using Cochrane Library, EMBASE (1947-2019), and Medline (1946-2019) databases. Literature reviews, systematic reviews, case studies, case series, and editorial pieces were excluded. Included studies were assessed for risk of bias.

RESULTS

Four RCTs, 21 observational studies, and 5 quasi-experimental trials were included. A total of 212 351 patients were included. Two thousand and fifty-eight patients were studied for the primary outcome and 210 293 patients were studied for the secondary outcomes. Study designs were heterogeneous and not amenable to meta-analysis. Most studies included nonhemodialysis outpatients older than 65 years. Of the included studies, 22/25 (88%) demonstrated a reduction of serum potassium >0.5 mEq/L over the study period. The magnitude of reduction in serum potassium of potassium resin compared with placebo or matched controls in the 3 low-risk studies identified was 0.14 to 1.04 mEq/L. However, each study used different dosing regimens. Ten of 22 studies reported the effects of polystyrene resins on serum potassium within 24 hours. A few high-quality observational studies suggest an increased risk of serious adverse gastrointestinal events with a relative risk of 2.10 and a hazard ratio of 1.25 to 1.94; however, the absolute risk remains low. The incidence of adverse gastrointestinal events is 16 to 23 events per 1000 person-years.

LIMITATIONS

We acknowledge several limitations in this study. Case studies and case series were excluded from the search results. Large case series may have been excluded despite having comparable sample sizes to studies included due to lack of a comparator and calculated estimates. Due to the heterogeneity of the studies, the data were unable to be meta-analyzed and as such the potassium-lowering effect of polystyrene sulfonate resins remains founded on small studies with potential confounders.

CONCLUSIONS

This systematic review demonstrates a continued lack of high-quality evidence for the use of SPS/CPS in hyperkalemia. Studies investigated highly variable timelines and the most robust evidence for SPS/CPS use is in chronic hyperkalemia. While the absence of high-quality evidence does not exclude the possibility of benefit, prescribers must understand that the use of SPS/CPS in acute hyperkalemia is not supported by high-quality evidence.

TRIAL REGISTRATION

The protocol for this systematic review was not registered.

Hyperkalemia: A persisting risk. A case report and update on current management

We report a case of hemodynamic instability due to bradycardia on the basis of severe hyperkalemia. Diabetic ketoacidosis and acute kidney injury together with polypharmacy triggered the acute onset. Potentially life-threatening hyperkalemia is often induced by drug interactions. ECG features may be crucial for diagnosis, and treatment depends on setting and resources.

BRASH Syndrome: Bradycardia, Renal Failure, AV Blockade, Shock, and Hyperkalemia

BACKGROUND

BRASH syndrome, or Bradycardia, Renal Failure, AV blockade, Shock, and Hyperkalemia, has recently become recognized as a collection of objective findings in a specific clinical context pertaining to emergency medicine and critical care. However, there is little emergency medicine and critical care literature specifically evaluating this condition.

OBJECTIVE

We sought to define and review BRASH syndrome and identify specific management techniques that differ from the syndromes as they present individually.

DISCUSSION

BRASH syndrome is initiated by synergistic bradycardia due to the combination of hyperkalemia and medications that block the atrioventricular (AV) node. The most common precipitant is hypovolemia or medications promoting hyperkalemia or renal injury. Left untreated, this may result in deteriorating renal function, worsening hyperkalemia, and hemodynamic instability. Patients can present with a variety of symptoms ranging from asymptomatic bradycardia to multiorgan failure. BRASH syndrome should be differentiated from isolated hyperkalemia and overdose of AV-nodal blocking medications. Treatment includes fluid resuscitation, hyperkalemia therapies (intravenous calcium, insulin/glucose, beta agonists, diuresis), management of bradycardia (which may necessitate epinephrine infusion), and more advanced therapies if needed (lipid emulsion, glucagon, or high-dose insulin infusion). Understanding and recognizing the pathophysiology of BRASH syndrome as a distinct entity may improve patient outcomes.

CONCLUSIONS

BRASH syndrome can be a difficult diagnosis and is due to a combination of hyperkalemia and medications that block the AV node. Knowledge of this condition may assist emergency and critical care providers.

Abnormal Basic Metabolic Panel Findings: Implications for Nursing

In this article, the second in a new series designed to improve acute care nurses' understanding of laboratory abnormalities, the author continues her discussion of important values in the basic metabolic panel (see Back to Basics, January, for a discussion of sodium and fluid balance). Here she addresses the electrolytes potassium and chloride as well as blood urea nitrogen and creatinine, four values that are best considered together because they both reflect and impact renal function as well as acid-base homeostasis. Important etiology, clinical manifestations, and treatment concerns are also presented. Three case studies are used to integrate select laboratory diagnostic tests with history and physical examination findings, allowing nurses to develop a thorough, focused plan of care for electrolyte abnormalities and kidney disorders commonly encountered in the medical-surgical setting.

Electrocardiographic T wave alterations and prediction of hyperkalemia in patients with acute kidney injury

Electrocardiographic (ECG) alterations are common in hyperkalemic patients. While the presence of peaked T waves is the most frequent ECG alteration, reported findings on ECG sensitivity in detecting hyperkalemia are conflicting. Moreover, no studies have been conducted specifically in patients with acute kidney injury (AKI). We used the best subset selection and cross-validation methods [via linear and logistic regression and leave-one-out cross-validation (LOOCV)] to assess the ability of T waves to predict serum potassium levels or hyperkalemia (defined as serum potassium ≥ 5.5 mEq/L). We included the following clinical variables as a candidate for the predictive models: peaked T waves, T wave maximum amplitude, T wave/R wave maximum amplitude ratio, age, and indicator variates for oliguria, use of ACE-inhibitors, sartans, mineralocorticoid receptor antagonists, and loop diuretics. Peaked T waves poorly predicted the serum potassium levels in both full and test sample (R² = 0.03 and R² = 0.01, respectively), and also poorly predicted hyperkalemia. The selection algorithm based on Bayesian information criterion identified T wave amplitude and use of loop diuretics as the best subset of variables predicting serum potassium. Nonetheless, the model accuracy was poor in both full and test sample [root mean square error (RMSE) = 0.96 mEq/L and adjR² = 0.08 and RMSE = 0.97 mEq/L, adjR² = 0.06, respectively]. T wave amplitude and the use of loop diuretics had also poor accuracy in predicting hyperkalemia in both full and test sample [area-under-curve (AUC) at receiver-operator curve (ROC) analysis 0.74 and AUC 0.72, respectively]. Our findings show that, in patients with AKI, electrocardiographic changes in T waves are poor predictors of serum potassium levels and of the presence of hyperkalemia.

Comparison of IV Insulin Dosing Strategies for Hyperkalemia in the Emergency Department

The objectives of this study were to evaluate the safety and efficacy of insulin dosing of less than 10 units versus 10 units in patients receiving hyperkalemia treatment.

DESIGN

Retrospective single-center study.

SETTING

Emergency department at a large academic medical center in the United States.

PATIENTS

Seven hundred adults treated for hyperkalemia with IV regular insulin between April 1, 2013, and September 27, 2018.

INTERVENTIONS

Patients that received less than 10 units of insulin were compared to those that received 10 units of insulin.

MEASUREMENTS AND MAIN RESULTS

Patients treated with less than 10 units had significantly lower frequency of hypoglycemia (11.2% vs 17.6%; p = 0.008). Reduction in serum potassium was significantly more modest in size in patients treated with less than 10 units (mean reduction 0.94 ± 0.71 mMol/L) compared with patients treated with 10 units (mean reduction 1.11 ± 0.8 mMol/L; p = 0.008). There were no statistically significant differences between groups in time to hypoglycemia, nadir serum glucose, severe hypoglycemia (<40 mg/dL), dextrose requirements, use of concurrent agents for hyperkalemia, need for repeat insulin dosing, length of stay, or mortality.

CONCLUSIONS

Patients treated for hyperkalemia with insulin doses less than 10 units had reduced frequency of hypoglycemia; however, potassium reduction post treatment was more modest in these patients. These findings suggest providers choosing to administer 10 units IV insulin should ensure patients have adequate monitoring for hypoglycemia.

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.

Ovarian hyperstimulation syndrome: A review for emergency clinicians

INTRODUCTION

A great deal of literature has recently evaluated the prevention and management of ovarian hyperstimulation syndrome (OHSS) in the outpatient setting, but there remains a dearth of research evaluating OHSS in the emergency department (ED) and its management.

OBJECTIVE

This narrative review evaluates the underlying pathophysiology and clinical manifestations of OHSS and discusses approaches to patient care in the ED based on current literature.

DISCUSSION

OHSS is an iatrogenic complication caused by an excessive response to controlled ovarian stimulation during assisted reproductive cycles (ART). OHSS complicates up to 30% of ART cycles, and many of these patients seek initial care in the ED. Risk factors for the development of OHSS include age < 35, history of polycystic ovarian syndrome or previous OHSS, and pregnancy. Emergency physicians will be faced with several complications including ascites, abdominal compartment syndrome, renal dysfunction, acute respiratory distress syndrome, thromboembolic disease, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the primary obstetrics/gynecology team is needed, which improves patient outcomes. This review provides several guiding principles for management of OHSS and associated complications.

CONCLUSIONS

OHSS occurs in up to 30% of IVF cycles and carries a high morbidity. Effective care of the OHSS patient begins with early diagnosis while evaluating for other diseases and complications. Understanding these complications and an approach to the management of OHSS is essential to optimizing patient care.

Efficacy and safety of the pharmacotherapy used in the management of hyperkalemia: a systematic review

BACKGROUND

Although the management of hyperkalemia follows expert guidelines, treatment approaches are based on traditionally accepted practice standards. New drugs have been assessed such as sodium zirconium cyclosilicate and patiromer; however, their safety and efficacy or effectiveness have not yet been compared to traditional pharmacotherapy.

OBJECTIVE

The present systematic review had the purpose to evaluate the efficacy, effectiveness, and safety of hyperkalemia pharmacotherapies.

METHODS

PubMed, LILACS, Cochrane Library, and ClinicalTrials were searched through November 2018. Clinical trial, cohort and case-control were searched. The risk of bias (RoB v2.0 and ROBINS-I) and quality of evidence (GRADE) at the level of outcomes were assessed.

RESULTS

Sixteen clinical trials and one retrospective cohort were identified regarding efficacy and safety of 24 different alternatives. The management of hyperkalemia remains empirical and off-label, since sodium zirconium cyclosilicate and patiromer are not available in several countries and further studies are required to assess efficacy, effectiveness and safety. Sodium or calcium polystyrene sulfonate (moderate confidence), sodium zirconium cyclosilicate (moderate confidence), and insulin plus dextrose (moderate confidence) showed superior efficacy to, respectively, placebo, no treatment, placebo, and dextrose. Other therapies (low confidence) showed similar efficacy compared to active or inactive alternatives. Most of the adverse events reported were nonspecific, so it was not possible to assign the cause and to classify as defined or probable.

CONCLUSIONS

Comparative cohort and case-control studies are need to evaluate the safety and effectiveness of new and traditional pharmacotherapies to support the development of guidelines about acute and chronic hyperkalemia, with high-quality evidence.

Patiromer: A Review in Hyperkalaemia

Patiromer (Veltassa^®) for oral suspension is a non-absorbed, sodium-free potassium binding polymer that exchanges calcium for potassium in the gastrointestinal (GI) tract, thereby increasing faecal potassium excretion and reducing serum potassium levels. Patiromer was approved in the USA in 2015 and is now approved in several other countries, including those of the EU, for the treatment of hyperkalaemia in adults. In clinical trials, patiromer reduced serum potassium levels and the risk of recurrent hyperkalaemia in patients with chronic kidney disease (CKD) and/or diabetic nephropathy with or without heart failure (HF), allowing the majority of patients to continue receiving renin-angiotensin-aldosterone system (RAAS) inhibitors (drugs that inhibit the renal excretion of potassium) for up to 52 weeks. Patiromer also maintained normokalaemia in patients with HF and a propensity for hyperkalaemia, enabling concomitant administration and up-titration of spironolactone. Patiromer was generally well tolerated, with a low risk of hypokalaemia. GI disorders and hypomagnesaemia were the most common adverse events; these were generally of mild or moderate severity. Therefore, oral patiromer is a valuable treatment option for the long-term management of hyperkalaemia.

Sodium Zirconium Cyclosilicate: A Review in Hyperkalaemia

Sodium zirconium cyclosilicate (Lokelma™) [hereafter referred to as SZC] is a non-absorbed, non-polymer zirconium silicate compound that preferentially exchanges hydrogen and sodium for potassium and ammonium ions in the gastrointestinal tract (GIT), thereby increasing faecal potassium excretion and lowering serum potassium levels. It is available as a powder for oral suspension (in water) and is approved in the EU and the USA for the treatment of hyperkalaemia in adults. In two multinational, phase III studies in adults with hyperkalaemia, SZC 10 g three times daily lowered serum potassium levels to within the normal range (3.5-5.0 mmol/L) during the first 48 h of treatment, and SZC 5 and 10 g once daily maintained normokalaemia over ≤ 28 days' therapy. These beneficial effects were consistent across all patient subgroups (e.g. chronic kidney disease, diabetes, heart failure, concomitant use of RAAS inhibitor therapy), and appeared to be maintained over the longer term (≤ 12 months). SZC was generally well tolerated in adults with hyperkalaemia. Its tolerability profile was generally similar to that seen with placebo over ≤ 28 day, and its safety profile appeared to remain consistent over the longer term (≤ 12 months). Moreover, the incidence of hypokalemia was low. Current evidence indicates that SZC is a promising therapy for the management of hyperkalaemia in adults.