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.

Evaluation of the effect of sodium zirconium cyclosilicate on arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with hyperkalaemia: protocol for the multicentre, randomised, controlled DIALIZE-Outcomes study.

INTRODUCTION: Patients with kidney failure receiving chronic haemodialysis have elevated risk of arrhythmias potentially increasing the likelihood of sudden cardiac death, stroke and hospitalisation. The DIALIZE study (NCT03303521) demonstrated that sodium zirconium cyclosilicate (SZC) was an efficacious and well-tolerated treatment for predialysis hyperkalaemia in patients undergoing haemodialysis. The DIALIZE-Outcomes study evaluates the effect of SZC on sudden cardiac death and arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with recurrent hyperkalaemia. METHODS AND ANALYSIS: International, multicentre, randomised, double-blind, placebo-controlled study conducted at 357 study sites across 25 countries. Adults (≥18 years) receiving chronic haemodialysis three times per week with recurrent predialysis serum potassium (K+) ≥5.5 mmol/L post long interdialytic interval (LIDI) are eligible. Patients (~2800) will be randomised 1:1 to SZC or placebo, starting at 5 g orally once daily on non-dialysis days and titrated weekly in 5 g increments (maximum 15 g) to target predialysis serum K+ 4.0-5.0 mmol/L post LIDI. The primary objective is to evaluate efficacy of SZC versus placebo in reducing occurrence of the primary composite endpoint of sudden cardiac death, stroke or arrhythmia-related hospitalisation, intervention or emergency department visit. Secondary endpoints include efficacy of SZC versus placebo in maintaining normokalaemia (serum K+ 4.0-5.5 mmol/L post LIDI) at the 12-month visit, preventing severe hyperkalaemia (serum K+ ≥6.5 mmol/L post LIDI) at the 12-month visit and reducing the incidence of individual cardiovascular outcomes. Safety of SZC will be evaluated. The study is event driven, with participants remaining in the study until 770 primary endpoint events have occurred. Average time in the study is expected to be ~25 months. ETHICS AND DISSEMINATION: Approval was obtained from the relevant institutional review board/independent ethics committee from each participating site (approving bodies in supplementary information). The results will be submitted to a peer-reviewed journal. TRIAL REGISTRATION NUMBERS: EudraCT 2020-005561-14 and clinicaltrials.gov identifier NCT04847232.

Efficacy and safety of calcium polystyrene sulfonate in patients with hyperkalemia and stage 3-5 non-dialysis chronic kidney disease: a single-center randomized controlled trial.

OBJECTIVE: To observe the clinical efficacy and safety of the short-term administration of different doses of calcium polystyrene sulfonate in the treatment of hyperkalemia in patients with stage 3-5 non-dialysis chronic kidney disease. METHODS: A prospective, open, randomized, controlled, single-center clinical observation was conducted. In total, 107 patients were randomly assigned to receive calcium polystyrene sulfonate at 15 (group A) or 30 mg/day (group B) for 1 week. Patients were assessed on days 0, 3, and 7. RESULTS: After 3 days of treatment, the serum potassium levels in groups A and B had decreased by 0.68 ± 0.46 and 0.75 ± 0.43 mmol/L, respectively. After 7 days, the serum potassium levels in groups A and B had decreased by 0.64 ± 0.37 and 0.94 ± 0.49 mmol/L, respectively. Conversely, serum sodium, phosphorus, and calcium levels did not significantly change during the treatment period. Constipation was the most common adverse drug reaction, and no treatment-related serious adverse events were observed. CONCLUSION: Calcium polystyrene sulfonate administered at a dose of 15 or 30 g/day can rapidly reduce potassium levels in patients with stage 3-5 non-dialysis chronic kidney disease without adverse effects on sodium, phosphorus, or calcium levels.

Patiromer Treatment in Patients With CKD, Hyperkalemia, and Hyperphosphatemia: A Post Hoc Analysis of 3 Clinical Trials.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD), hyperkalemia (serum potassium [sK+]>5.0 mEq/L), and hyperphosphatemia experience poor clinical outcomes. Patiromer, a potassium binder that uses calcium as the exchange ion, may also reduce serum phosphorus (sP). We characterized the effect of patiromer on sP in patients with CKD, hyperkalemia, and hyperphosphatemia. STUDY DESIGN: A post hoc pooled analysis of individual-level data from the AMETHYST-DN, OPAL-HK, and TOURMALINE trials of patiromer. SETTING & PARTICIPANTS: Patients with CKD and hyperkalemia. EXPOSURE: Patients treated with patiromer (8.4-33.6 g/day). OUTCOME: Mean changes from baseline in sP, sK+, serum calcium (sCa2+), and serum magnesium (sMg2+) after 2 and 4 weeks of treatment. ANALYTICAL APPROACH: Descriptive statistics to summarize pooled data on the study outcomes from the 3 studies. RESULTS: We included 578 patients in the analysis. Of these participants, 86 patients (14.9%) had baseline hyperphosphatemia of whom 75.6% (65 of 86) had CKD stage 4/5 and 31.1% (153 of 492) with sP≤4.5mg/dL had CKD stage 4/5. Among the patients with elevated sP and sK+at baseline, the mean±SD reduction in sP and sK+after 4 weeks of patiromer treatment was-0.62±1.09mg/dL and-0.71± 0.51 mEq/L, respectively. Additionally, the mean±SD reduction in sMg2+in these patients was -0.25±0.23mg/dL while sCa2+remained unchanged. Both sMg2+and sCa2+remained within the normal range. Patiromer was generally well tolerated, and no serious adverse events were considered related to patiromer. LIMITATIONS: These were post hoc analyses, no placebo comparison was performed due to the design of the original studies, and the follow-up period was limited to 4 weeks. CONCLUSIONS: Reductions in sP and sK+to the normal range were observed after 2 weeks of patiromer treatment, and the reduction was sustained during 4 weeks of treatment among patients with non-dialysis-dependent CKD, hyperkalemia, and hyperphosphatemia. Future controlled trials are needed to establish if patiromer is useful to reduce both sK+and sP in hyperkalemic patients with CKD and hyperphosphatemia.

Hyponatremia Associated With Standard-Dose Trimethoprim-Sulfamethoxazole Use in an Immunocompetent Patient.

INTRODUCTION: Trimethoprim-sulfamethoxazole (TMP-SMX) use in immunocompromised patients can cause dose-dependent electrolyte irregularities including hyponatremia, hyperkalemia, and metabolic acidosis. We report a case of isolated hyponatremia caused by low-dose TMP-SMX use in an immunocompetent patient that mimicked the syndrome of inappropriate antidiuretic hormone secretion (SIADH). CASE PRESENTATION: A 72-year-old woman was admitted to the hospital for acute onset of weakness and ambulatory dysfunction after starting TMP-SMX (160 mg/800 mg). She was found hyponatremic (sodium level, 125 mmol/L, down from 141 mmol/L prior to medication initiation). After ruling out diuretics use, and adrenal and thyroid dysfunction, we started her on intravenous saline infusion to manage her TMP-SMX-induced hyponatremia, and her symptoms resolved. DISCUSSION: Electrolyte problems in immunocompromised patients treated for opportunistic infections with high-dose TMP-SMX (≥ 8 mg/kg/d TMP) are well-documented. However, the effects in immunocompetent patients are uncommon when standard dose (< 8 mg/kg/d TMP) is used. CONCLUSIONS: TMP-SMX blocks the aldosterone-mediated sodium reabsorption in the collecting ducts, and the trimethoprim component itself is structurally similar to potassium-sparing diuretics, which block sodium uptake at the distal nephron-both of which can cause hyponatremia.

Effect of inhaled albuterol on whole blood potassium concentrations in dogs.

BACKGROUND: Albuterol by inhalation (IH) is a common treatment for hyperkalemia in humans but its effect on blood potassium concentrations in dogs is unknown. OBJECTIVE: Determine whether albuterol (IH) decreases blood potassium concentrations in healthy normokalemic dogs and if effects are dose-dependent. ANIMALS: Ten healthy dogs. METHODS: Prospective, crossover experimental study. Albuterol sulfate was administered at a low-dose (90 µg) in phase I and, 7 days later, high-dose (450 µg) in phase II. Blood potassium and glucose concentrations (measured via blood gas analyzer) and heart rates were obtained at baseline and then 3, 5, 10, 15, 30, 60, 90, 120, 180, and 360 minutes after inhaler actuation. RESULTS: Blood potassium concentrations decreased rapidly after albuterol delivery with a significant reduction compared to baseline within 30 minutes in both phases (P = .05). The potassium nadir concentration of phase I occurred at 60 minutes (mean, SD; 4.07 mmol/L, 0.4) and was significantly decreased from baseline, (4.30 mmol/L, 0.3; t(9) = 2.40, P = .04). The potassium nadir concentration of phase II occurred at 30 minutes (mean, SD; 3.96 mmol/L, 0.39) and was also significantly decreased from baseline, (4.33 mmol/L, 0.4; t(9) = 2.22, P = .05). The potassium nadir concentration decreased by 0.1 mmol/L for each 10 µg/kg increase in dose of albuterol (P = .01). Five dogs had ≥1 hyperglycemic measurement (ie, >112 mg/dL). No median heart rate was tachycardic nor was any mean blood glucose concentration hyperglycemic at any time point. CONCLUSION AND CLINICAL IMPORTANCE: Albuterol IH decreases blood potassium concentrations in a dose-dependent manner without clinically meaningful alterations to heart rate or blood glucose concentrations in healthy dogs. The mean decrease in potassium concentration at the high-dose of albuterol was modest (0.38 mmol/L).

Experience of a Bespoke Hyperkalaemia Clinic to Facilitate Prescribing of Renin-Angiotensin-Aldosterone System Inhibitors in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Renin-angiotensin-aldosterone system inhibitors (RAASi) improve prognosis in patients with heart failure with reduced ejection fraction (HFrEF), but suboptimal dosing or discontinuation of these medications often occurs due to RAASi-associated hyperkalaemia. We established a nephrology-led hyperkalaemia clinic to oversee prescribing of patiromer, an oral potassium binder, to facilitate RAASi optimization. METHODS: The clinic was established in July 2019 at a nephrology tertiary centre in the UK. Patients with HFrEF who were unable to increase RAASi dosage due to hyperkalaemia were referred to the clinic, where all patients commenced patiromer 8.4 g daily. RAASi adjustments were deferred to the referring teams. Study outcomes included the percentage of patients who achieved a RAASi dose increase and the proportion of patients with normokalaemia at follow-up. Outcomes were evaluated until 1 May 2021. RESULTS: A total of 34 patients were reviewed in the clinic between July 2019 and December 2020. Mean age was 71.6 years (±10.6 years), 56% had diabetes, and 71% had chronic kidney disease stages 3a-5; mean estimated glomerular filtration rate was 56 mL/min/1.73 m2 (±21 mL/min/1.73 m2). During follow-up, 13 patients discontinued patiromer (6 of whom did so due to gastrointestinal side effects) and were discharged; 2 patients died from non-hyperkalaemia-related illness; one switched to an alternative potassium binder. Over a mean follow-up of 13.4 months (±5.8 months), 17 of the 20 patients (85%) who continued with a potassium binder achieved a RAASi dose increase, with 4 patients (20%) receiving maximal dosages. This was attained by achieving normokalaemia during follow-up. No patients required magnesium supplementation. Of the 19 patients on patiromer, 12 continued this therapy for more than 12 months and 4 received it safely for 20 months. DISCUSSION/CONCLUSION: Patiromer prescribing in a nephrology-led hyperkalaemia clinic facilitated RAASi up-titration in patients with HFrEF by controlling potassium levels.

A 77-Year-Old Man with Heparin-Induced Aldosterone Suppression Causing Hyperkalemia.

BACKGROUND Anticoagulation with heparin infrequently causes elevated serum potassium via a reduction in the number and affinity of adrenal angiotensin II receptors, causing reversible aldosterone suppression, thereby leading to enhanced sodium excretion and hyperkalemia. CASE REPORT A 77 year-old man presented with productive cough and shortness of breath and was subsequently found to have non-ST-elevation myocardial infarction and concomitant symptomatic COVID-19 infection, for which he was started on a high-dose unfractionated heparin infusion. A gradual increase in serum potassium followed, with a subsequent return to a normal potassium level after stopping treatment with heparin. An evaluation for hemolysis was unrevealing, and the patient was not on any other medications known to cause hyperkalemia. On day 6, heparin was restarted owing to a high suspicion of pulmonary embolism. There was a subsequent increase in serum potassium level, which was followed by a return to baseline after discontinuation of heparin, thereby confirming the suspected diagnosis. CONCLUSIONS Acute increases in serum potassium levels in hospitalized patients can result in weakness, paralysis, conduction abnormalities, and cardiac arrhythmias that, if left untreated, can result in serious morbidity and potentially death in a short period of time. As this clinical entity is infrequently encountered in clinical practice, it can easily be overlooked by clinicians. The prompt exclusion of alternative causes of acutely elevated serum potassium levels and the identification of heparin administration as an easily reversible trigger is imperative and can potentially be life-saving.

Patiromer for the management of hyperkalemia in heart failure with reduced ejection fraction: the DIAMOND trial.

AIMS: To investigate the impact of patiromer on the serum potassium level and its ability to enable specified target doses of renin-angiotensin-aldosterone system inhibitor (RAASi) use in patients with heart failure and reduced ejection fraction (HFrEF). METHODS AND RESULTS: A total of 1642 patients with HFrEF and current or a history of RAASi-related hyperkalemia were screened and 1195 were enrolled in the run-in phase with patiromer and optimization of the RAASi therapy [≥50% recommended dose of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, and 50 mg of mineralocorticoid receptor antagonist (MRA) spironolactone or eplerenone]. Specified target doses of the RAASi therapy were achieved in 878 (84.6%) patients; 439 were randomized to patiromer and 439 to placebo. All patients, physicians, and outcome assessors were blinded to treatment assignment. The primary endpoint was between-group difference in the adjusted mean change in serum potassium. Five hierarchical secondary endpoints were assessed. At the end of treatment, the median (interquartile range) duration of follow-up was 27 (13-43) weeks, the adjusted mean change in potassium was +0.03 mmol/l in the patiromer group and +0.13 mmol/l in the placebo group [difference in the adjusted mean change between patiromer and placebo: -0.10 mmol/l (95% confidence interval, CI -0.13, 0.07); P < 0.001]. Risk of hyperkalemia >5.5 mmol/l [hazard ratio (HR) 0.63; 95% CI 0.45, 0.87; P = 0.006), reduction of MRA dose (HR 0.62; 95% CI 0.45, 0.87; P = 0.006), and total adjusted hyperkalemia events/100 person-years (77.7 vs. 118.2; HR 0.66; 95% CI 0.53, 0.81; P < 0.001) were lower with patiromer. Hyperkalemia-related morbidity-adjusted events (win ratio 1.53, P < 0.001) and total RAASi use score (win ratio 1.25, P = 0.048) favored the patiromer arm. Adverse events were similar between groups. CONCLUSION: Concurrent use of patiromer and high-dose MRAs reduces the risk of recurrent hyperkalemia (ClinicalTrials.gov: NCT03888066).

An Overview of Clinically Imperative and Pharmacodynamically Significant Drug Interactions of Renin-Angiotensin-Aldosterone System (RAAS) Blockers.

INTRODUCTION: Hypertension is a leading cause of cardiovascular disease and chronic kidney disease, resulting in premature death and disability. The Renin-Angiotensin-Aldosterone System (RAAS) blockers, including Angiotensin-Converting Enzyme (ACE) inhibitors or Angiotensin Receptor Blockers (ARBs), are used as first-line antihypertensive therapy to treat hypertensive patients with comorbidities, including diabetes, ischemic heart disease, heart failure, and chronic kidney disease. The use of RAS blockers is associated with the risks, such as hyperkalemia, angioedema, etc. The drugs potentiating them interact pharmacodynamically, resulting in adverse consequences. This review article focuses on the clinically important drug interactions of RAAS blockers. MATERIALS AND METHODS: The electronic databases, such as Medline/PubMed Central/PubMed, Google Scholar, ScienceDirect, Cochrane Library, Directory of Open Access Journals (DOAJ), Embase, and reference lists were searched to identify relevant articles. RESULTS: The risk of hyperkalemia may be enhanced potentially in patients receiving a RAS blocker and potassium-sparing diuretics, potassium supplements, trimethoprim, adrenergic betablockers, antifungal agents, calcineurin inhibitors, pentamidine, heparins or an NSAID, concomitantly. The patients taking ACE inhibitors and mTOR inhibitors, DPP4 inhibitors, alteplase, or sacubitril/valsartan concurrently may be at increased risk of developing angioedema. CONCLUSION: Clinicians, pharmacists, and other healthcare practitioners should be accountable for medication safety. To avoid adverse implications, prescribers and pharmacists must be aware of the drugs that interact with RAAS blockers.

Current Management of Hyperkalemia in Non-Dialysis CKD: Longitudinal Study of Patients Receiving Stable Nephrology Care.

BACKGROUND: No study has explored the limitations of current long-term management of hyperkalemia (HK) in outpatient CKD clinics. METHODS: We evaluated the association between current therapeutic options and control of serum K (sK) during 12-month follow up in ND-CKD patients stratified in four groups by HK (sK ≥ 5.0 mEq/L) at baseline and month 12: Absent (no-no), Resolving (yes-no), New Onset (no-yes), Persistent (yes-yes). RESULTS: We studied 562 patients (age 66.2 ± 14.5 y; 61% males; eGFR 39.8 ± 21.8 mL/min/1.73 m2, RAASI 76.2%). HK was "absent" in 50.7%, "resolving" in 15.6%, "new onset" in 16.6%, and "persistent" in 17.1%. Twenty-four hour urinary measurements testified adherence to nutritional recommendations in the four groups at either visit. We detected increased prescription from baseline to month 12 of bicarbonate supplements (from 5.0 to 14.1%, p < 0.0001), K-binders (from 2.0 to 7.7%, p < 0.0001), and non-K sparing diuretics (from 34.3 to 41.5%, p < 0.001); these changes were consistent across groups. Similar results were obtained when using higher sK level (≥5.5 mEq/L) to stratify patients. Mixed-effects regression analysis showed that higher sK over time was associated with eGFR < 60, diabetes, lower serum bicarbonate, lower use of non-K sparing diuretics, bicarbonate supplementation, and K-binder use. Treatment-by-time interaction showed that sK decreased in HK patients given bicarbonate (p = 0.003) and K-binders (p = 0.005). CONCLUSIONS: This observational study discloses that one-third of ND-CKD patients under nephrology care remain with or develop HK during a 12-month period despite low K intake and increased use of sK-lowering drugs.

Transient complete atrioventricular block and ST-segment elevation induced by coronary vasospasm due to iatrogenic hyperkalemia: a case report.

BACKGROUND: Hyperkalemia and acute coronary syndrome are not only all responsible for syncope related to complete atrioventricular block, but also share parts of electrocardiogram manifestations. Additionally, they influence each other. CASE PRESENTATION: A 32-year-old Chinese man presented with severe hypokalemia (1.63 mmol/l) at midnight in the emergency room. He developed unexpected rebound hyperkalemia (7.76 mmol/l) after 18 hours of oral and intravenous potassium chloride supplementation at a concentration of about 10 g/day and a rate of 10 mmol/hour. Subsequently, the patient complained of chest discomfort and dyspnea, followed by syncope for several minutes, approximately 2 hours after potassium reduction treatment had been started. The instant electrocardiogram showed complete atrioventricular block and elevated ST segment in the inferolateral leads, which resolved 15 minutes later, before hyperkalemia was corrected. Combined with mild coronary stenosis and negative myocardial injury markers, transient complete atrioventricular block induced by coronary vasospasm due to iatrogenic hyperkalemia was diagnosed. Normal urine potassium excretion, acid-base state, and other examinations made the diagnosis of hypokalemic periodic paralysis possible. CONCLUSIONS: Hyperkalemia may provoke acute coronary syndrome, and early coronary angiography is an effective strategy for identifying the direct cause of acute complete atrioventricular block.

Pharmacodynamic effects of the K+ binder patiromer in a novel chronic hyperkalemia model in spontaneously hypertensive rats.

Currently described hyperkalemia (HK) animal models are typically acute and cause significant distress and mortality to the animals, warranting new approaches for studying chronic HK in a more appropriate clinical setting. Using the spontaneously hypertensive rat (SHR) model as a more relevant disease template, as well as surgical (unilateral nephrectomy), dietary (3% potassium [K+ ] supplementation), and pharmacological (amiloride) interventions, we were able to stably induce HK on a chronic basis for up to 12 weeks to serum K+ elevations between 8 and 9 mmol/L, with minimal clinical stress to the animals. Short-term proof-of-concept and long-term chronic studies in hyperkalemic SHRs showed concomitant increases in serum aldosterone, consistent with the previously reported relationship between serum K+ and aldosterone. Treatment with the K+ binder patiromer demonstrated that the disease model was responsive to pharmacological intervention, with significant abrogation in serum K+ , as well as serum aldosterone to levels near baseline, and this was consistent in both short-term and long-term 12-week chronic studies. Our results demonstrate the feasibility of establishing a chronic HK disease state, and this novel HK animal model may be suitable for further evaluating the effects of long-term, K+ -lowering therapies on effects such as renal fibrosis and end-organ damage.

Potassium binders for chronic hyperkalaemia in people with chronic kidney disease.

BACKGROUND: Hyperkalaemia is a common electrolyte abnormality caused by reduced renal potassium excretion in patients with chronic kidney diseases (CKD). Potassium binders, such as sodium polystyrene sulfonate and calcium polystyrene sulfonate, are widely used but may lead to constipation and other adverse gastrointestinal (GI) symptoms, reducing their tolerability. Patiromer and sodium zirconium cyclosilicate are newer ion exchange resins for treatment of hyperkalaemia which may cause fewer GI side-effects. Although more recent studies are focusing on clinically-relevant endpoints such as cardiac complications or death, the evidence on safety is still limited. Given the recent expansion in the available treatment options, it is appropriate to review the evidence of effectiveness and tolerability of all potassium exchange resins among people with CKD, with the aim to provide guidance to consumers, practitioners, and policy-makers. OBJECTIVES: To assess the benefits and harms of potassium binders for treating chronic hyperkalaemia among adults and children with CKD. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 10 March 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-randomised controlled studies (quasi-RCTs) evaluating potassium binders for chronic hyperkalaemia administered in adults and children with CKD. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risks of bias and extracted data. Treatment estimates were summarised by random effects meta-analysis and expressed as relative risk (RR) or mean difference (MD), with 95% confidence interval (CI). Evidence certainty was assessed using GRADE processes. MAIN RESULTS: Fifteen studies, randomising 1849 adult participants were eligible for inclusion. Twelve studies involved participants with CKD (stages 1 to 5) not requiring dialysis and three studies were among participants treated with haemodialysis. Potassium binders included calcium polystyrene sulfonate, sodium polystyrene sulfonate, patiromer, and sodium zirconium cyclosilicate. A range of routes, doses, and timing of drug administration were used. Study duration varied from 12 hours to 52 weeks (median 4 weeks). Three were cross-over studies. The mean study age ranged from 53.1 years to 73 years. No studies evaluated treatment in children. Some studies had methodological domains that were at high or unclear risks of bias, leading to low certainty in the results. Studies were not designed to measure treatment effects on cardiac arrhythmias or major GI symptoms. Ten studies (1367 randomised participants) compared a potassium binder to placebo. The certainty of the evidence was low for all outcomes. We categorised treatments in newer agents (patiromer or sodium zirconium cyclosilicate) and older agents (calcium polystyrene sulfonate and sodium polystyrene sulfonate). Patiromer or sodium zirconium cyclosilicate may make little or no difference to death (any cause) (4 studies, 688 participants: RR 0.69, 95% CI 0.11, 4.32; I2 = 0%; low certainty evidence) in CKD. The treatment effect of older potassium binders on death (any cause) was unknown. One cardiovascular death was reported with potassium binder in one study, showing that there was no difference between patiromer or sodium zirconium cyclosilicate and placebo for cardiovascular death in CKD and HD. There was no evidence of a difference between patiromer or sodium zirconium cyclosilicate and placebo for health-related quality of life (HRQoL) at the end of treatment (one study) in CKD or HD. Potassium binders had uncertain effects on nausea (3 studies, 229 participants: RR 2.10, 95% CI 0.65, 6.78; I2 = 0%; low certainty evidence), diarrhoea (5 studies, 720 participants: RR 0.84, 95% CI 0.47, 1.48; I2 = 0%; low certainty evidence), and vomiting (2 studies, 122 participants: RR 1.72, 95% CI 0.35 to 8.51; I2 = 0%; low certainty evidence) in CKD. Potassium binders may lower serum potassium levels (at the end of treatment) (3 studies, 277 participants: MD -0.62 mEq/L, 95% CI -0.97, -0.27; I2 = 92%; low certainty evidence) in CKD and HD. Potassium binders had uncertain effects on constipation (4 studies, 425 participants: RR 1.58, 95% CI 0.71, 3.52; I2 = 0%; low certainty evidence) in CKD. Potassium binders may decrease systolic blood pressure (BP) (2 studies, 369 participants: MD -3.73 mmHg, 95%CI -6.64 to -0.83; I2 = 79%; low certainty evidence) and diastolic BP (one study) at the end of the treatment. No study reported outcome data for cardiac arrhythmias or major GI events. Calcium polystyrene sulfonate may make little or no difference to serum potassium levels at end of treatment, compared to sodium polystyrene sulfonate (2 studies, 117 participants: MD 0.38 mEq/L, 95% CI -0.03 to 0.79; I2 = 42%, low certainty evidence). There was no evidence of a difference in systolic BP (one study), diastolic BP (one study), or constipation (one study) between calcium polystyrene sulfonate and sodium polystyrene sulfonate. There was no difference between high-dose and low-dose patiromer for death (sudden death) (one study), stroke (one study), myocardial infarction (one study), or constipation (one study). The comparative effects whether potassium binders were administered with or without food, laxatives, or sorbitol, were very uncertain with insufficient data to perform meta-analysis. AUTHORS' CONCLUSIONS: Evidence supporting clinical decision-making for different potassium binders to treat chronic hyperkalaemia in adults with CKD is of low certainty; no studies were identified in children. Available studies have not been designed to measure treatment effects on clinical outcomes such as cardiac arrhythmias or major GI symptoms. This review suggests the need for a large, adequately powered study of potassium binders versus placebo that assesses clinical outcomes of relevance to patients, clinicians and policy-makers. This data could be used to assess cost-effectiveness, given the lack of definitive studies and the clinical importance of potassium binders for chronic hyperkalaemia in people with CKD.

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.

A Case Involving Massive Insulin Overdose: Direct and Indirect Conditions Requiring Extended Management of Serum Potassium.

BACKGROUND Insulin lowers not only blood glucose levels but also serum potassium levels by driving potassium into the cells. Hypokalemia can occur during aggressive treatment of hypoglycemia in patients with insulin overdose and is a well-documented clinical phenomenon; however, there are no studies describing delayed hyperkalemia occurring after initial treatment in patients with insulin overdose. CASE REPORT A 23-year-old male with a history of type 2 diabetes mellitus and self-medicating with insulin, attempted suicide by subcutaneously injecting 2100 units of insulin. He was admitted to our emergency department due to recurrent hypoglycemia. Continuous administration of 50% glucose and potassium via a central venous catheter was performed to maintain his glucose levels above 80 mg/dL and serum potassium level between 3.5 and 4.0 mEq/L. Because his serum potassium level exceeded 4.5 mEq/L at day 3 after admission, the dosage was adjusted accordingly. After his serum potassium level declined to 3.0 mEq/L, his potassium level abruptly increased to 6.0 mEq/L at day 5 after admission. The patient was placed on a potassium-restricted diet and administered furosemide. Potassium infusion was also discontinued. After serum potassium levels returned to the normal range without interventional therapies, the patient was discharged to home on day 14. CONCLUSIONS In cases of high-dose insulin overdose, management of hyperkalemia following recovery from hypoglycemia is a critical aspect of patient management. Conservative administration of potassium to correct initial hypokalemia may be considered in patients with high-dose insulin overdose.

Decreasing Hypoglycemia following Insulin Administration for Inpatient Hyperkalemia.

BACKGROUND: Acute hyperkalemia (serum potassium ≥ 5.1 mEq/L) is often treated with a bolus of IV insulin. This treatment may result in iatrogenic hypoglycemia (glucose < 70 mg/dl). OBJECTIVES: The aims of this study were to accurately determine the frequency of iatrogenic hypoglycemia following insulin treatment for hyperkalemia, and to develop an electronic health record (EHR) orderset to decrease the risk for iatrogenic hypoglycemia. DESIGN: This study was an observational, prospective study. SETTING: The setting for this study was a university hospital. PATIENTS: All nonobstetric adult inpatients in all acute and intensive care units were eligible. INTERVENTION: Implementation of a hyperkalemia orderset (Orderset 1.1) with glucose checks before and then one, two, four, and six hours after regular intravenous insulin administration. Based on the results from Orderset 1.1, Orderset 1.2 was developed and introduced to include weight-based dosing of insulin options, alerts identifying patients at higher risk of hypoglycemia, and tools to guide decision-making based on the preinsulin blood glucose level. MEASUREMENTS: Patient demographics, weight, diabetes history, potassium level, renal function, and glucose levels were recorded before, and then glucose levels were measured again at one, two, four, and six hours after insulin was administered. RESULTS: The iatrogenic hypoglycemia rate identified with mandatory glucose checks in Orderset 1.1 was 21%; 92% of these occurred within three hours posttreatment. Risk factors for hypoglycemia included decreased renal function (serum creatinine >2.5 mg/dl), a high dose of insulin (>0.14 units/kg), and re-treatment with blood glucose < 140 mg/dl. After the introduction of Orderset 1.2, the rate of iatrogenic hypoglycemia decreased to 10%. CONCLUSIONS: The use of an EHR orderset for treating hyperkalemia may reduce the risk of iatrogenic hypoglycemia in patients receiving insulin while still adequately lowering their potassium.

Serial measurement of glyphosate blood concentration in a glyphosate potassium herbicide-intoxicated patient: A case report.

INTRODUCTION: This report describes changes in blood and urine concentrations of glyphosate potassium over time and their correlations with clinical symptoms in a patient with acute glyphosate potassium poisoning. CASE REPORT: A 67-year-old man visited the emergency center after ingesting 250 mL of a glyphosate potassium-based herbicide 5 h before. He was alert but presented with nausea, vomiting, and bradyarrhythmia with atrial fibrillation (tall T waves). Laboratory findings revealed a serum potassium level of 6.52 mEq/L. After treatment with an injection of calcium gluconate, insulin with glucose, bicarbonate, and an enema with polystyrene sulfonate, the patient's serum potassium level normalized and the bradyarrhythmia converted to a normal sinus rhythm. During admission, the blood and urine concentration of glyphosate and urine aminomethylphosphonic acid (AMPA, a glyphosate metabolite) was measured at regular time intervals. The patient's glyphosate blood concentration on admission was 11.48 mg/L, and it had decreased rapidly by 16 h and maintained about 1mgl/L by 70 h after admission. Urine glyphosate and AMPA levels had also decreased rapidly by 6 h after admission. DISCUSSION: Glyphosate potassium poisoning causes hyperkalemia. Blood concentrations of glyphosate were decreased rapidly by 16 h after admission, and urine concentrations were also decreased by 6 h after admission.

Plasma Potassium Determines NCC Abundance in Adult Kidney-Specific γENaC Knockout.

The amiloride-sensitive epithelial sodium channel (ENaC) and the thiazide-sensitive sodium chloride cotransporter (NCC) are key regulators of sodium and potassium and colocalize in the late distal convoluted tubule of the kidney. Loss of the αENaC subunit leads to a perinatal lethal phenotype characterized by sodium loss and hyperkalemia resembling the human syndrome pseudohypoaldosteronism type 1 (PHA-I). In adulthood, inducible nephron-specific deletion of αENaC in mice mimics the lethal phenotype observed in neonates, and as in humans, this phenotype is prevented by a high sodium (HNa+)/low potassium (LK+) rescue diet. Rescue reflects activation of NCC, which is suppressed at baseline by elevated plasma potassium concentration. In this study, we investigated the role of the γENaC subunit in the PHA-I phenotype. Nephron-specific γENaC knockout mice also presented with salt-wasting syndrome and severe hyperkalemia. Unlike mice lacking αENaC or ßΕΝaC, an HNa+/LK+ diet did not normalize plasma potassium (K+) concentration or increase NCC activation. However, when K+ was eliminated from the diet at the time that γENaC was deleted, plasma K+ concentration and NCC activity remained normal, and progressive weight loss was prevented. Loss of the late distal convoluted tubule, as well as overall reduced ßENaC subunit expression, may be responsible for the more severe hyperkalemia. We conclude that plasma K+ concentration becomes the determining and limiting factor in regulating NCC activity, regardless of Na+ balance in γENaC-deficient mice.

Efficacy and Safety of Patiromer in Hyperkalemia: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients at the highest risk of hyperkalemia are those with chronic kidney disease (CKD) stages 3 and 4. OBJECTIVE: To evaluate the efficacy and safety of patiromer in hyperkalemia in patients with heart failure or CKD. METHODS: The Cochrane Renal Group's Specialized Register was searched through contact with the Trials' Search Coordinator. We aimed at including randomized controlled trials with patiromer in patients with developed or risks of developing hyperkalemia, comparing against an active comparator or placebo. Three studies matched our inclusion and exclusion criteria, which we included in the meta-analysis. All-cause mortality, reduction in hospitalization, episodes of hypokalemia or hyperkalemia, and cardiovascular and gastrointestinal adverse events during the treatment period were our primary outcomes. Serial change in serum potassium (K+) until end of treatment or follow-up during the trial period and all other reported adverse reactions during the treatment period were our secondary outcomes. Meta-analysis (RevMan version 5.3.5) and descriptive statistics were used. RESULTS: There was a non-significant improvement in all-cause mortality and serious cardiovascular events with patiromer than placebo. Hospitalization data were unavailable. Although serious gastrointestinal events were more common with placebo, there was a significant reduction ( P = .02) in the risk of non-serious gastrointestinal events with placebo. Patiromer lowered serum K+ more than placebo, and there were more patients developing hyperkalemia with placebo. High-dose patiromer was associated with better efficacy in some parameters but with more adverse events. CONCLUSION: Although patiromer seems promising, more trials with active comparator are essential to finalize its indication and use in hyperkalemia.