Electrolitos

Hyponatraemia is the most common electrolyte abnormality encountered in clinical practice; despite this, the work-up and management of hyponatraemia remain suboptimal and varies among different specialist groups. The majority of data comparing hyponatraemia treatments have been observational, up until recently. The past two years have seen the publication of several randomised control trials investigating hyponatraemia treatments, both for chronic and acute hyponatraemia. In this article, we aim to provide a background to the physiology, cause and impact of hyponatraemia and summarise the most recent data on treatments for acute and chronic hyponatraemia, highlighting their efficacy, tolerability and adverse effects...

Familial hypocalciuric hypercalcemia (FHH) is a mostly benign condition of elevated calcium and PTH levels based on a hyposensitive calcium sensing receptor ( CaSR ) in FHH 1 or its downstream regulatory pathway in FHH2 and FHH3. In children, adolescents and young adults with FHH the main challenge is to distinguish the condition from primary hyperparathyroidism and thereby to avoid unnecessary treatments including parathyroidectomy. However, inheritance of FHH may result in neonatal hyperparathyroidism (NHPT) or neonatal severe hyperparathyroidism (NSHPT), conditions with high morbidity, and in the latter even high mortality...

Cardiovascular (CV) disease (CVD) accounts for >50% of deaths with known causes in patients on dialysis. Elevated serum phosphorus levels are an important nontraditional risk factor for bone mineral disease and CVD in patients with chronic kidney disease (CKD). Given that phosphorus concentrations drive other disorders associated with increased CV risk (e.g., endothelial dysfunction, vascular calcification, fibroblast growth factor-23, parathyroid hormone), phosphate is a logical target to improve CV health...

Phosphate is essential in living organisms and its blood levels are regulated by a complex network involving the kidneys, intestine, parathyroid glands, and the skeleton. The crosstalk between these organs is executed primarily by three hormones, calcitriol, parathyroid hormone, and fibroblast growth factor 23. Largely due to a higher intake of ultraprocessed foods, dietary phosphate intake has increased in the last decades. The average intake is now about twice the recommended dietary allowance. Studies investigating the side effect of chronic high dietary phosphate intake suffer from incomplete dietary phosphate assessment and, therefore, often make data interpretation difficult...

Hyponatremia is the most common electrolyte disturbance seen in clinical practice, affecting up to 30% of acute hospital admissions, and is associated with significant adverse clinical outcomes. Acute or severe symptomatic hyponatremia carries a high risk of neurological morbidity and mortality. In contrast, chronic hyponatremia is associated with significant morbidity including increased risk of falls, osteoporosis, fractures, gait instability, and cognitive decline; prolonged hospital admissions; and etiology-specific increase in mortality...

Hyperkalemia represents a widespread and potentially lethal condition that affects millions of people across their lives. Despite the prevalence and severity of the condition, there are no consensus guidelines on the treatment of hyperkalemia or even a standard definition. Herein, we provide a succinct review of what we believe to be the most significant misconceptions encountered in the emergency care of hyperkalemia, examine current available literature, and discuss practical points on several modalities of hyperkalemia treatment...

Because of their rarity, diseases characterized by chronic hypophosphatemia can be underrecognized and suboptimally managed, resulting in poor clinical outcomes. Moreover, serum phosphate may not be measured routinely in primary care practice. Authors participated in several working sessions to advance the understanding of phosphate homeostasis and the causes, consequences, and clinical implications of chronic hypophosphatemia. Phosphate levels are regulated from birth to adulthood. Dysregulation of phosphate homeostasis can result in hypophosphatemia, which becomes chronic if phosphate levels cannot be normalized...

Hypernatraemia is most commonly caused by excessive loss of solute-free water or decreased fluid intake; less often, the aetiology is salt intoxication. Especially infants, young children and individuals with a lack of access to water are at risk of developing hypernatraemia. Diagnosis is based on detailed history, physical examination and basic laboratory tests. Correction of hypernatraemia must be slow to prevent cerebral oedema and irreversible brain damage. This article reviews the aetiology, differential diagnosis and management of conditions associated with paediatric hypernatraemia...

Hyponatremia, especially if acute and severe, can be a life-threatening condition. Several conditions can trigger hyponatremia. In this review, we will discuss two conditions that can determine euvolemic hyponatremia: the cerebral/renal salt wasting (CRSW) syndrome and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), including the two subtypes: reset osmostat (RO) and nephrogenic syndrome of inappropriate antidiuresis (NSIAD) and their differential diagnoses. Despite the passage of over 70 years since its first description, to date, the true etiopathogenesis of CRSW syndrome, a rare cause of hypovolemic/euvolemic hyponatremia, is almost unknown...

The causes of hypercalcaemia in the neonate and infant are varied, and often distinct from those in older children and adults. Hypercalcaemia presents clinically with a range of symptoms including failure to thrive, poor feeding, constipation, polyuria, irritability, lethargy, seizures and hypotonia. When hypercalcaemia is suspected, an accurate diagnosis will require an evaluation of potential causes (e.g. family history) and assessment for physical features (such as dysmorphology, or subcutaneous fat deposits), as well as biochemical measurements, including total and ionised serum calcium, serum phosphate, creatinine and albumin, intact parathyroid hormone (PTH), vitamin D metabolites and urinary calcium, phosphate and creatinine...

SARS-COV2 infection has swiftly become a pandemic disease of historic relevance and widely variable outcomes. This variable prognosis is related both to uneven damage, among others, to lungs, heart and kidneys, and to a multisystemic inflammatory reaction. All these factors are known to disrupt water balance and potentially induce hyponatraemia or hypernatraemia. Water balance disorders are known mortality and morbidity risk factors in several clinical scenarios and their proper management, though often complex and hazardous, can reduce mortality and length of hospitalization...

The calcium-sensing receptor (CaSR) provides the major mechanism for the detection of extracellular calcium concentration in several cell types, via the induction of G-protein-coupled signalling. Accordingly, CaSR plays a pivotal role in calcium homeostasis, and the CaSR gene defects are related to diseases characterized by serum calcium level changes. Activating mutations of the CaSR gene cause enhanced sensitivity to extracellular calcium concentration resulting in autosomal dominant hypocalcemia or Bartter-syndrome type V...

Hyperkalemia is an electrolyte abnormality with potentially life-threatening consequences. Despite various guidelines, no universally accepted consensus exists on best practices for hyperkalemia monitoring, with variations in precise potassium (K+ ) concentration thresholds or for the management of acute or chronic hyperkalemia. Based on the available evidence, this review identifies several critical issues and unmet needs with regard to the management of hyperkalemia. Real-world studies are needed for a better understanding of the prevalence of hyperkalemia outside the clinical trial setting...

COVID-19 has changed the nature of medical consultations, emphasizing virtual patient counseling, with relevance for patients with diabetes insipidus (DI) or hyponatraemia. The main complication of desmopressin treatment in DI is dilutional hyponatraemia. Since plasma sodium monitoring is not always possible in times of COVID-19, we recommend to delay the desmopressin dose once a week until aquaresis occurs allowing excess retained water to be excreted. Patients should measure their body weight daily. Patients with DI admitted to the hospital with COVID-19 have a high risk for mortality due to volume depletion...

Hyponatremia is frequent in cancer patients and potentially deleterious. Cancer patients have specific requirements due to the nature and treatment of their disease, which can directly impact the occurrence and severity of hyponatremia, and limit treatment choices. Although essential for successful hyponatremia management, appropriate diagnostic testing is not routinely performed in the current practice. Despite clear evidence that hyponatremia is associated with poor outcome in oncology patients, most patients are still hyponatremic while under observation...

Euvolemic hyponatremia is the most common cause of hyponatremia in both hospitalized patients and outpatients. The most common etiology of euvolemic hyponatremia is the syndrome of inappropriate antidiuresis (SIAD). Diagnosis of SIAD involves evaluation of a set of long-standing clinical and laboratory criteria for this diagnosis. Many treatment options for SIAD exist, and choosing among them should be based on the chronicity of the hyponatremia and neurological symptomatology. Importantly, clinical judgment and risk/benefit analysis that is individualized for specific patients should drive therapeutic decisions, because there is no single treatment that represents the "best" therapy for all patients with SIAD...

Hyponatremia is a frequently encountered clinical finding, and by far the most common disorder of electrolyte and water homeostasis throughout the world. Given the complex pathophysiology of hyponatremia as well as its clinical implications, which range from apparently asymptomatic presentations to life-threatening conditions, a comprehensive understanding of its possible causes and of the frequencies of occurrence of the various types of hyponatremia in distinct clinical settings is essential for successful disease management...

Chronic hyponatremia may not cause overt symptoms, and therefore frequently remains untreated. More recently, growing evidence indicate that this condition is not benign, and can lead to unsteady gait, deterioration of bone mass and strength, increased fragility, and increased all-cause mortality. We provided the first evidence for hyponatremia-induced osteoporosis based on markedly reduced bone mineral density and bone structural changes in hyponatremic rats, which is an experimental model of the syndrome of inappropriate antidiuresis (SIAD)...

Hyponatremia is a frequent complication in patients with advanced cirrhosis. Patients with cirrhosis can develop two types of hyponatremia, hypovolemic or hypervolemic (dilutional) hyponatremia. Hypervolemic hyponatremia is the most common type and it develops as a consequence of an impairment in the renal capacity to eliminate solute-free water. The key mechanism leading to solute-free water retention is a non-osmotic hypersecretion of vasopressin (AVP), secondary to a reduction in effective arterial blood pressure existing in patients with advanced cirrhosis...

Numerous observational studies have confirmed that inadequate investigation of hyponatremia leads to diagnostic errors and incorrect treatment. In fact, only one out of five patients diagnosed as having syndrome of inappropriate antidiuresis (SIAD) have had all the tests necessary to meet the diagnostic criteria. Diagnostic errors could help explain why a majority of patients presenting hyponatremia during hospitalization are discharged while still hyponatremic. The correct differentiation of hypovolemic from euvolemic patients is a clinical diagnostic challenge...