Sparing confirmatory testing in primary aldosteronism (SCIPA): a multicenter retrospective diagnostic accuracy study.

BACKGROUND: The diagnosis of primary aldosteronism (PA) is comprehensive, which includes case-detection testing, case confirmation followed by subtype classification. In certain instances, such as in the setting of spontaneous hypokalemia, suppressed renin activity (PRA) plus plasma aldosterone concentration (PAC) of > 15 ng/dL, one may not proceed with confirmatory tests. However, the quality of evidence behind this approach is very low. This study sought to evaluate the proposed "simplified confirmatory pathway" that can spare confirmatory testing for primary aldosteronism by evaluating the diagnostic performances of the various pre-specified PAC thresholds in combination with findings of suppressed renin and spontaneous hypokalemia. METHODS: This is a multi-center, retrospective diagnostic accuracy cohort-selected cross-sectional study. A total of 133 participants aged 18 years and above underwent saline infusion test between January 2010 to March 2024. The outcome measures comprise of the diagnostic performances of the different index test combinations (baseline PAC, baseline PRA and presence of spontaneous hypokalemia): sensitivity, specificity, negative predictive value, positive predictive value, positive likelihood ratio, negative likelihood ratio, and diagnostic accuracy. Data analysis was performed using SPSS 29.0.1.0 & MedCalc 20.218. RESULTS: Of the 133 patients who underwent saline infusion test, 88 (66.17%) were diagnosed with PA. A PAC of > 25 ng/dL plus PRA < 1.0 ng/dL/hr with spontaneous hypokalemia showed the highest specificity at 100% (95% CI 90.51%, 100.00%) and positive predictive value at 100% (85.18 - 100.00%). The minimum acceptable combination criteria were determined to be a PAC of > 20 ng/dL plus PRA < 0.6 ng/dL/hr, and presence of spontaneous hypokalemia. It has high specificity (94.59%; 95% CI 81.81%, 99.34%), positive predictive value (93.55%, 95% CI 78.49%, 98.29%), and moderate positive likelihood ratio (LR+) (6.39, 95% CI 1.61, 25.38) CONCLUSION: A hypertensive patient with spontaneous hypokalemia and screening findings of PAC > 20 ng/dL and suppressed PRA of < 0.6 ng/ml/hr, may be classified as "overt primary aldosteronism confirmed" and may not need to proceed with dynamic confirmatory testing. PROTOCOL REGISTRATION NUMBER: SRCTN34186253.

Pseudonormokalemia case report - What does it mean to have normal blood potassium?

This case report describes a case of pseudonormokalemia, true hypokalemia. Often, only laboratory values outside the normal range gain attention and false normal results are at risk of not being noticed. However, a disease state may be masked by another pathological process. Here, a 50-year old male was admitted to the Department of Internal Medicine due to sepsis from a dental infection. Initially, serum potassium measurement revealed a normal value of 4 mmol/L (reference interval 3.8-5.1 mmol/L). Thrombocyte number was above 500x109/L. Due to our policy to recommend a repeated measurement of potassium in whole blood or heparin plasma if a patient has thrombocytosis, pseudonormokalemia was identified because the heparin plasma potassium value was only 2.9 mmol/L (reference interval 3.5-4.8 mmol/L). The physiological difference between serum and plasma concentration is no more than 0.3 mmol/L. In this case, potassium concentration were falsely elevated in the serum sample, probably caused by the high number of platelets releasing potassium during clotting. Interpretative comments in patients with thrombocytosis over 500x109/L recommending plasma potassium measurement are helpful. The best way to eliminate pseudohyperkalemia and pseudonormokalemia phenomena caused by thrombocytosis is to completely change towards heparin plasma as the standard material.

Target organ damage in untreated hypertensive patients with primary aldosteronism.

An increased risk of target organ damage (TOD) has been reported in patients with primary aldosteronism (PA). However, there is relatively little related research on the correlation between the degree of TOD and those with and without PA in newly diagnosed hypertensive patients. The aim of this study was to assess the association between PA and TOD among patients with newly diagnosed hypertension. Newly diagnosed hypertensive patients were consecutively recruited from January 2015 to June 2020 at the University of Hong Kong-Shenzhen Hospital. Patients were stratified into those with and without PA. Data for left ventricular mass index (LVMI), carotid intima-media thickness (CIMT) and plaque, and microalbuminuria were systematically collected. A total of 1044 patients with newly diagnosed hypertension were recruited, 57 (5.5%) of whom were diagnosed with PA. Patients with PA had lower blood pressure, serum lipids, body mass index, and plasma renin activity and a higher incidence of hypokalemia than those without PA. In contrast, the prevalence of left ventricular hypertrophy, increased CIMT, and microalbuminuria was higher in patients with PA than in those without PA. Multivariable regression analysis demonstrated that PA was independently associated with increased LVMI, CIMT and microalbuminuria. Among patients with newly diagnosed hypertension, those with PA had more severe TOD, including a higher LVMI, CIMT and microalbuminuria, than those without PA. These findings emphasize the need for screening TOD in newly diagnosed hypertension due to underlying PA.

Update on Primary Aldosteronism: Time to Screen All Hypertensives.

Primary aldosteronism (PA), characterized by autonomous renin-independent aldosterone production, is the most common endocrine cause of hypertension.1 PA was initially considered a rare cause of secondary hypertension, as experts described 0.451% prevalence in mild to moderate hypertension when hypokalemia was an essential reason for screening.1 However, recent data suggests that PA may be present even in patients with normokalemia, and 515% of patients in the hypertensive cohort have underlying overt PA.2.

Renal Hypokalemia: An Endocrine Perspective.

The majority of disorders that cause renal potassium wasting present with abnormalities in adrenal hormone secretion. While these findings frequently lead patients to seek endocrine evaluation, clinicians often struggle to accurately diagnose these conditions, delaying treatment and adversely impacting patient care. At the same time, growing insight into the genetic and molecular basis of these disorders continues to improve their diagnosis and management. In this review, we outline a practical integrated approach to the evaluation of renal hypokalemia syndromes that are seen in endocrine practice while highlighting recent advances in understanding of the genetics and pathophysiology behind them.

Risk of hyperkalaemia in patients with type 2 diabetes mellitus prescribed with SGLT2 versus DPP-4 inhibitors.

AIMS: To investigate the risk of hyperkalaemia in new users of sodium-glucose cotransporter 2 (SGLT2) inhibitors vs. dipeptidyl peptidase-4 (DPP-4) inhibitors among patients with type 2 diabetes mellitus (T2DM). METHODS AND RESULTS: Patients with T2DM who commenced treatment with an SGLT2 or a DPP-4 inhibitor between 2015 and 2019 were collected. A multivariable Cox proportional hazards analysis was applied to compare the risk of central laboratory-determined severe hyperkalaemia, hyperkalaemia, hypokalaemia (serum potassium ≥6.0, ≥5.5, and <3.5 mmol/L, respectively), and initiation of a potassium binder in patients newly prescribed an SGLT2 or a DPP-4 inhibitor. A total of 28 599 patients (mean age 60 ± 11 years, 60.9% male) were included after 1:2 propensity score matching, of whom 10 586 were new users of SGLT2 inhibitors and 18 013 of DPP-4 inhibitors. During a 2-year follow-up, severe hyperkalaemia developed in 122 SGLT2 inhibitor users and 325 DPP-4 inhibitor users. Use of SGLT2 inhibitors was associated with a 29% reduction in incident severe hyperkalaemia [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58-0.88] compared with DPP-4 inhibitors. Risk of hyperkalaemia (HR 0.81, 95% CI 0.71-0.92) and prescription of a potassium binder (HR 0.74, 95% CI 0.67-0.82) were likewise decreased with SGLT2 inhibitors compared with DPP-4 inhibitors. Occurrence of incident hypokalaemia was nonetheless similar between those prescribed an SGLT2 inhibitor and those prescribed a DPP-4 inhibitor (HR 0.90, 95% CI 0.81-1.01). CONCLUSION: Our study provides real-world evidence that compared with DPP-4 inhibitors, SGLT2 inhibitors were associated with lower risk of hyperkalaemia and did not increase the incidence of hypokalaemia in patients with T2DM.

Kidney manifestations of pediatric Sjögren's syndrome.

Approximately 1% of all patients with Sjögren's syndrome (SS) are children. Unlike the adult form, in which sicca syndrome is the main presentation, in children, the most common clinical finding is recurrent enlargement of the salivary glands. In pediatric SS, extraglandular manifestations represent a significant feature and, among these, kidney manifestations are relevant. Kidney involvement is observed in 5-20.5% of children with SS, most frequently tubulointerstitial nephritis. This injury can lead to serious phenotypes, including distal kidney tubular acidosis with the development of severe hypokalemia, which can lead to ECG abnormalities, weakness, and hypokalemic periodic paralysis. Kidney implications in pediatric SS also include nephrolithiasis, nephrocalcinosis, and various types of glomerular damage, which often require immunosuppressive therapies. Laboratory findings are usually comparable to adults, including hyperglobulinemia and high rates of antinuclear antibodies (ANA, 63.6-96.2%), and anti-Ro/SSA (36.4-84.6%). The current classification criteria for SS are inaccurate for the pediatric population, and more specific criteria are needed to improve the diagnostic rate. Due to the rarity of the disease, strong recommendations for treatment are lacking, and several therapeutic strategies have been reported, mostly based on glucocorticoids and disease-modifying antirheumatic drugs, with different outcomes. The aim of this paper is to provide an overview of the kidney implications of pediatric SS based on the latest evidence of the medical literature.

Prolonged Hypokalemia and Delayed Diagnosis of Primary Aldosteronism: Clinical Course and Risk Factors.

CONTEXT: Primary aldosteronism (PA) is a common cause of hypertension (HT). However, diagnosis is often delayed, leading to poorer clinical outcomes. Hypokalemia with HT is characteristic of PA, and is an indication for screening. OBJECTIVE: We evaluated if patients with PA had prolonged hypokalemia before diagnosis, the subsequent biochemical/clinical control, and factors associated with delayed diagnosis. METHODS: Our study included all PA patients with hypokalemia diagnosed between 2001 and 2022. Delayed diagnosis was defined as duration of hypokalemia of more than 1 year from first occurrence to first evaluation by a PA specialist. Patients were reassessed post adrenalectomy using the Primary Aldosteronism Surgery Outcomes criteria. We performed multivariable analysis to assess for factors associated with delayed diagnosis. RESULTS: Among 240 patients with PA who presented with hypokalemia, 122 (51%) patients had delayed diagnosis, with prolonged hypokalemia of median duration 4.5 years (range, 2.4-7.5 years). Patients with delayed diagnosis were older, had longer duration of HT, higher pill burden, lower renal function, and more prevalent cardiovascular disease. Factors associated with delayed diagnosis included older age, presence of hyperlipidemia, and less severe hypokalemia (serum potassium >3.0 mmol/L). Compared to patients with early diagnosis, a lower proportion of those with delayed diagnosis underwent adrenal vein sampling (73% vs 58%) (P < .05). Sixty of 118 (50.8%) nondelayed, and 39 of 122 (32.0%) patients with delayed diagnosis, underwent surgery. CONCLUSION: Despite manifestation of hypokalemia, many patients with PA fail to be promptly screened. Greater emphasis in HT guidelines, and efforts to improve awareness of PA among primary care physicians, are urgently needed.

"Ion-Flux": The natural course of ECG changes in severe hypokalemia.

Whereas the electrocardiogram (ECG) changes in hypokalemia are well known, they often receive less attention than the more striking features of hyperkalemia. Furthermore, there is a need for further discussion as to the subtleties of ECG changes that can aid in the differential diagnoses. This case study presents the ECG changes of a patient with severe hypokalemia due to diarrhea. It highlights how bifid T-waves in hypokalemia can be distinguished from other conditions such as coronary artery disease or pericarditis. Furthermore, it also shows the gradual reversal of ECG changes in the same patient when potassium is normalized.

Ramen noodle neuropathy: an atypical case of partial paralysis from malnutrition.

INTRODUCTION: Due to a COVID-related job loss resulting in financial and food insecurity, a 28-year-old woman initiated a diet consisting solely of one cup of ramen noodles daily for twenty-two months, leading to 27 kg of weight loss. Ramen noodles are low in calories and lack key nutrients, including potassium, chloride, and vitamin B12. CASE DESCRIPTION: The patient presented to the emergency department with acute, worsening weakness and paresthesias in her left wrist and hand. Exam revealed no other abnormalities aside from a cachectic appearance. Labs revealed marked hypokalemia, hypochloremia, lactic acidosis, a mixed metabolic alkalosis with respiratory acidosis, and low levels of zinc and copper. An EKG revealed a prolonged QT interval. After a neurology and psychiatry consult, the patient was admitted for failure to thrive with malnutrition, peripheral neuropathy, hypokalemia, and an acid-base disorder. An MRI of the brain was unremarkable. Studies of other nutritional deficiencies, autoimmune conditions, and sexually transmitted infections were unremarkable. The patient received food and vitamin supplementation, was monitored for re-feeding syndrome, and had a significant recovery. DISCUSSION: After stroke, spinal injury, multiple sclerosis, and the most common focal mononeuropathies were ruled out, the clinical focus turned to nutritional deficiencies, the most significant of which was hypokalemia. Prior research has shown that severe hypokalemia can lead to weakness. It has also shown that chronically insufficient dietary intake is a common cause of hypokalemia. This case, with its partial paralysis of a unilateral upper extremity, may add to the known clinical manifestations of hypokalemia. We review the role of hypokalemia and hypochloremia in acid-base dynamics. Etiologies and clinical manifestations of cobalamin, thiamine, pyridoxine, and copper deficiencies, along with lead toxicity, are also discussed. Diagnostic clarity of mononeuropathies in the context of malnutrition and hypokalemia can be aided by urine potassium levels prior to repletion, neuroimaging that includes the cervical spine, and follow-up electromyography.

Concomitant hypokalemia and hypocalcemia: a very rare but life-threating combination of reversible causes of cardiac arrest - an unusual first manifestation of coeliac disease.

The causes of cardiac arrest are extremely heterogeneous. Among these, both hypokalemia and hypocalcemia are known reversible factors that can lead to cardiac arrest. In this report, we present a unique case report of a patient with previously undiagnosed coeliac disease who experienced cardiac arrest due a combination of hypokalemia and hypocalcemia resulting from malabsorption. A 66-year-old male presented to the emergency department with symptoms of malaise, weakness, weight loss, and persistent diarrhea. The patient exhibited characteristic signs of hypokalemia and hypocalcemia, including fasciculations, weakness, and swelling. An electrocardiogram showed a normal rhythm, and blood tests confirmed the electrolyte imbalances. Despite initial treatment, the patient experienced sudden cardiac arrest. Prompt resuscitation efforts were successful in restoring spontaneous circulation. However, recurrent episodes of ventricular arrhythmias and cardiac arrest occurred. Large doses of intravenous potassium chloride, in conjunction with magnesium, were needed prior to restore electrolyte balance. The concomitant severe hypocalcemia required caution calcium supplementation, to avoid further decreases in serum potassium levels. Appropriate ion replacements ultimately led to successful resuscitation with good functional recovery. During the hospital stay, the patient was diagnosed with coeliac disease. This case is noteworthy for its uniqueness, as there are no documented instances in the scientific literature linking cardiac arrest directly to coeliac disease. It is important to emphasize the need for investigating potential reversible causes of cardiac arrest, such as hypokalemia and hypocalcemia, and implementing appropriate interventions to address these factors.

Treatment of hypokalemia with amiloride unmasked hypercalcemia and hyperparathyroidism: A case report.

Colonic pseudo-obstruction, also called Ogilvie's syndrome, occurs due to impaired intestinal propulsion, and may be caused by electrolyte imbalances such as hypokalemia and some endocrine disorders such as hyperparathyroidism. Secretory diarrhea due to intestinal pseudo-obstruction can cause hypokalemia. Diuretics such as amiloride can be used to treat hypokalemia, however in this case, treatment with amiloride induced hypercalcemia and unmasked hyperparathyroidism. A 73-year-old female with a history of hypertension and parathyroid adenoma presented with recurrent colonic pseudo-obstruction and chronic hypokalemia. Her hypokalemia was treated with amiloride, causing hypercalcemia of 14.4 mg/dL, elevated PTH, and altered mental status. Amiloride was subsequently discontinued with improvement in her symptoms, and her hyperparathyroidism was treated with cinacalcet. To our knowledge, this is the first report of amiloride unmasking hyperparathyroidism and inducing hypercalcemia.

Should we suspect primary aldosteronism in patients with hypokalaemic rhabdomyolysis? A systematic review.

Severe hypokalaemia causing rhabdomyolysis (RML) in primary aldosteronism (PA) is a rare entity, and only a few cases have been reported over the last four decades. This systematic review and case report aims to gather all published data regarding a hypokalaemic RML as presentation of PA in order to contribute to the early diagnosis of this extremely rare presentation. With the use of PubMed Central, EMBASE, and Google Scholar, a thorough internet-based search of the literature was conducted to identify articles and cases with RML secondary to hypokalaemia due to PA between June 1976 and July 2023. The case study concerns a 68-year-old male patient with hypokalaemic RML at presentation of PA. In the systematic review of the literature, 37 cases of RML secondary to hypokalaemia due to PA have been reported to date. In summary, the median age was 47.5 years, the male/female ratio was 17/21, all patients presented symptoms (weakness and/or myalgia), all the patients were hypertensive, and only four patients had complications with acute kidney injury (AKI). Although PA rarely presents with RML, it should be suspected when marked hypokalaemia and hypertension are also present. Early detection and management are essential to reduce the frequency of manifestations such as AKI.

Disorders of Potassium.

Abnormalities in serum potassium are commonly encountered in patients presenting to the emergency department. A variety of acute and chronic causes can lead to life-threatening illness in both hyperkalemia and hypokalemia. Here we summarize the relevant causes, risks, and treatment options for these frequently encountered disorders.

Hypokalemic paralysis due to renal tubular acidosis: uncommon initial manifestation of primary Sjögren´s syndrome.

Primary Sjögren´s Syndrome is an immune-mediated disease characterized by exocrine glands dysfunction due to lymphoplasmacytic infiltration with sicca symptoms being one of its main features. The disease may, however, present as distal renal tubular acidosis due to renal involvement, which can range from asymptomatic to life-threatening. We describe the case of a 33-year-old woman with hypokalemic paralysis and metabolic acidosis secondary to distal renal tubular acidosis, leading to the diagnosis of primary Sjögren´s Syndrome. Although rare, recognizing primary Sjögren´s Syndrome as a possible cause of distal renal tubular acidosis may elicit an earlier diagnosis and treatment, improving the patient´s prognosis.

Hypokalemia/Hyperkalemia and Hyponatremia/Hypernatremia.

Electrolyte disorders are very common in the pediatric population. Derangements in serum sodium and potassium concentrations are among the most frequently seen given the risk factors and comorbidities unique to children. Pediatricians, in both outpatient and inpatient settings, should be comfortable with the evaluation and initial treatment of disturbances in these electrolyte concentrations. However, to evaluate and treat a child with abnormal serum concentrations of sodium or potassium, it is critical to understand the regulatory physiology that governs osmotic homeostasis and potassium regulation in the body. Comprehension of these basic physiologic processes will allow the provider to uncover the underlying pathology of these electrolyte disturbances and devise an appropriate and safe treatment plan.