<h4>Background</h4>Hyponatremia is the most common electrolyte disorder and it is associated with increased morbidity and mortality. However, there is no clear demonstration that the improvement of serum sodium concentration ([Na(+)]) counteracts the increased risk of mortality associated with hyponatremia. Thus, we performed a meta-analysis that included the published studies that addressed the effect of hyponatremia improvement on mortality.<h4>Methods and findings</h4>A Medline, Embase and Cochrane search was performed to retrieve all English-language studies of human subjects published up to June 30th 2014, using the following words: "hyponatremia", "hyponatraemia", "mortality", "morbidity" and "sodium". Fifteen studies satisfied inclusion criteria encompassing a total of 13,816 patients. The identification of relevant abstracts, the selection of studies and the subsequent data extraction were performed independently by two of the authors, and conflicts resolved by a third investigator. Across all fifteen studies, any improvement of hyponatremia was associated with a reduced risk of overall mortality (OR=0.57[0.40-0.81]). The association was even stronger when only those studies (n=8) reporting a threshold for serum [Na(+)] improvement to >130 mmol/L were considered (OR=0.51[0.31-0.86]). The reduced mortality rate persisted at follow-up (OR=0.55[0.36-0.84] at 12 months). Meta-regression analyses showed that the reduced mortality associated with hyponatremia improvement was more evident in older subjects and in those with lower serum [Na(+)] at enrollment.<h4>Conclusions</h4>This meta-analysis documents for the first time that improvement in serum [Na(+)] in hyponatremic patients is associated with a reduction of overall mortality.

Exercise-associated hyponatremia (EAH) typically occurs during or up to 24 hours after prolonged physical activity, and is defined by a serum or plasma sodium concentration below the normal reference range of 135 mEq/L. It is also reported to occur in individual physical activities or during organized endurance events conducted in austere environments in which medical care is limited or often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to ensure a positive outcome. Failure in this regard is a recognized cause of event-related fatality. In an effort to produce best practice guidelines for EAH in the austere environment, the Wilderness Medical Society convened an expert panel. The panel was charged with the development of evidence-based guidelines for management of EAH. Recommendations are made regarding the situations when sodium concentration can be assessed in the field and when these values are not known. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.

Abstract Introduction Current guidelines recommend limiting the rate of correction in patients with severe hyponatremia to avoid severe neurologic complications such as osmotic demyelination syndrome (ODS). However, published data have been conflicting. We aimed to evaluate the association between rapid sodium correction and ODS in patients with severe hyponatremia. Materials and methods We searched PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials from inception to November 2023. The primary outcome was ODS and the secondary outcomes were in-hospital mortality and length of hospital stay. Results We identified 7 cohort studies involving 6,032 adult patients with severe hyponatremia. Twenty-nine patients developed ODS, resulting in an incidence rate of 0.48%. Seventeen patients (61%) had a rapid correction of serum sodium in the first or any 24-hour period of admission. Compared with a limited rate of sodium correction, a rapid rate of sodium correction was associated with an increased risk of ODS (RR, 3.91 [95% CI, 1.17 to 13.04]; I2 = 44.47%; p = 0.03). However, a rapid rate of sodium correction reduced the risk of in-hospital mortality by approximately 50% (RR, 0.51 [95% CI, 0.39 to 0.66]; I2 = 0.11%; p < 0.001) and the length of stay by 1.3 days (Mean difference, −1.32 [95% CI, −2.54 to −0.10]; I2 = 71.47%; p = 0.03). Conclusions Rapid correction of serum sodium may increase the risk of ODS among patients hospitalized with severe hyponatremia. However, ODS may occur in patients regardless of the rate of serum sodium correction. The primary outcome was ODS and the secondary outcomes were in-hospital mortality and length of hospital stay. Results We identified 7 cohort studies involving 6,032 adult patients with severe hyponatremia. Twenty-nine patients developed ODS, resulting in an incidence rate of 0.48%. Seventeen patients (61%) had a rapid correction of serum sodium in the first or any 24-hour period of admission. Compared with a limited rate of sodium correction, a rapid rate of sodium correction was associated with an increased risk of ODS (RR, 3.91 [95% CI, 1.17 to 13.04]; I 2 = 44.47%; p = 0.03). However, a rapid rate of sodium correction reduced the risk of in-hospital mortality by approximately 50% (RR, 0.51 [95% CI, 0.39 to 0.66]; I 2 = 0.11%; p < 0.001) and the length of stay by 1.3 days (Mean difference, −1.32 [95% CI, −2.54 to −0.10]; I 2 = 71.47%; p = 0.03). Conclusions Rapid correction of serum sodium may increase the risk of ODS among patients hospitalized with severe hyponatremia. However, ODS may occur in patients regardless of the rate of serum sodium correction. Keywords: hyponatremia, rapid correction, osmotic demyelination syndrome status released display-pdf yes is-olf no is-manuscript no is-preprint no is-journal-matter no is-scanned no is-retracted no Received 2024 Apr 29; Accepted 2024 Jul 2; Collection date 2024 Jul. Introduction Hyponatremia is one of the most common electrolyte disorders in hospitalized patients. Current guidelines, based on data reported by small retrospective case series, recommend limiting the rate of correction in patients with severe hyponatremia to avoid severe neurologic complications, most notably osmotic demyelination syndrome (ODS) [ 1 , 2 ]. However, in a recent large cohort study, rapid correction of sodium was not associated with an increased risk of ODS in patients with severe hyponatremia [ 3 ]. Given this conflicting data, we conducted a systematic review and We performed this study in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [ 4 ]. We included randomized controlled trials or observational studies that reported adult patients admitted with severe hyponatremia, defined as serum sodium of less than 120 mmol/L on admission. We excluded case series or case reports. The primary outcome was ODS diagnosed by brainstem auditory evoked response [ 5 ], neuroimaging (magnetic resonance imaging) [ 3 , 6 , 7 , 8 , 9 ], or pathology (postmortem examination) [ 5 ], and the secondary outcomes were in-hospital mortality and length of hospital stay. There was only one patient diagnosed with ODS in this study; c The study has different data available for different definitions of rapid correction; d One patient had ODS occurring before hospitalization with severe hyponatremia and was excluded from our table 1 . Fig. 1. Forest plot showing the association between rapid serum sodium correction and osmotic demyelination syndrome Discussion In this systematic review and meta-analysis, ODS occurred in less than 5 per 1000 patients with an initial serum sodium of less than 120 mmol/L. A sodium correction rate of more than 10 or 12 mmol/L within the first or any 24-hour period after admission appeared to increase the risk of ODS by nearly 4-fold though it also led to a reduction in in-hospital mortality and length of stay among patients hospitalized with severe hyponatremia. Importantly, ODS was observed in both rapid and limited correction of serum sodium. Furthermore, the majority (89%) of the ODS cases occurred in patients with a history of alcohol use disorder, associated hypokalemia, cirrhosis, or an initial serum sodium of less than 105 mmol/L, regardless of the rate of serum sodium correction. This study has several limitations. Current guidelines on limiting the rate of serum sodium correction apply to patients with chronic hyponatremia (defined as hyponatremia for more than 48 hours) in which the risk of ODS in rapid correction is postulated to be greater [ 1 , 2 ]. Finally, these results only apply to patients with an initial serum sodium of less than 120 mmol/L. In conclusion, rapid correction of serum sodium may increase the risk of ODS among patients hospitalized with severe hyponatremia. Nevertheless, ODS typically occurs in patients with predisposing risk factors regardless of the rate of serum sodium correction.

Background: Adrenal crisis is a life-threatening endocrine emergency caused by a severe deficiency of cortisol, often triggered by physiologic stress in individuals with underlying adrenal insufficiency. Despite being treatable, it carries a significant mortality rate, estimated at 0.5 deaths per 100 patient-years, primarily due to delays in recognition and intervention. Aim: This article aims to outline the integrated, multidisciplinary approach required for the prompt recognition, emergency management, and long-term prevention of adrenal crisis, emphasizing roles across emergency medicine, nursing, and family medicine. Methods: Management is centered on immediate parenteral glucocorticoid administration (100mg hydrocortisone IV/IM) and aggressive fluid resuscitation with isotonic saline. This is coupled with correction of hypoglycemia and electrolyte imbalances. Diagnosis relies on clinical suspicion based on a history of adrenal insufficiency, chronic steroid use, or presentation with refractory hypotension, and is supported by laboratory findings (e.g., hyponatremia, hyperkalemia, hypoglycemia). Results: Prompt treatment leads to rapid clinical improvement, but delayed intervention results in high mortality and complications such as seizures, arrhythmias, and multi-organ failure. Patient education on "sick day rules" (stress-dose steroids) and access to emergency hydrocortisone injection kits are critical for preventing recurrent crises. Conclusion: Adrenal crisis remains a preventable cause of death. Optimal outcomes depend on a high index of suspicion, immediate empiric therapy, and a coordinated interprofessional team strategy to ensure seamless care from emergency response to long-term community management.

Hyponatremia treatment guidelines recommend limiting the correction of severe hyponatremia during the first 24 hours to prevent osmotic demyelination syndrome (ODS). Recent evidence suggests that slower rates of correction are associated with increased mortality. To evaluate the association of sodium correction rates with mortality among hospitalized adults with severe hyponatremia. We searched MEDLINE, Embase, the Cochrane Library, LILACS, Web of Science, CINAHL, and international congress proceedings for studies published between January 2013 and October 2023. Comparative studies assessing rapid (≥8-10 mEq/L per 24 hours) vs slow (<8 or 6-10 mEq/L per 24 hours) and very slow (<4-6 mEq/L per 24 hours) correction of severe hyponatremia (serum sodium <120 mEq/L or <125 mEq/L plus severe symptoms) in hospitalized patients. Pairs of reviewers (N.A.F., J.R.M., J.M.A., A.C.) independently reviewed studies, extracted data, and assessed each included study's risk of bias using ROBINS-I. Cochrane methods, PRISMA reporting guidelines, and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to rate the certainty of evidence were followed. Data were pooled using a random-effects model. Primary outcomes were in-hospital and 30-day mortality, and secondary outcomes were hospital length of stay (LOS) and ODS. Sixteen cohort studies involving a total of 11 811 patients with severe hyponatremia were included (mean [SD] age, 68.22 [6.88] years; 56.7% female across 15 studies reporting sex). Moderate-certainty evidence showed that rapid correction was associated with 32 (odds ratio, 0.67; 95% CI, 0.55-0.82) and 221 (odds ratio, 0.29; 95% CI, 0.11-0.79) fewer in-hospital deaths per 1000 treated patients compared with slow and very slow correction, respectively. Low-certainty evidence suggested that rapid correction was associated with 61 (risk ratio, 0.55; 95% CI, 0.45-0.67) and 134 (risk ratio, 0.35; 95% CI, 0.28-0.44) fewer deaths per 1000 treated patients at 30 days and with a reduction in LOS of 1.20 (95% CI, 0.51-1.89) and 3.09 (95% CI, 1.21-4.94) days, compared with slow and very slow correction, respectively. Rapid correction was not associated with a statistically significant increased risk of ODS. In this systematic review and meta-analysis, slow correction and very slow correction of severe hyponatremia were associated with an increased risk of mortality and hospital LOS compared to rapid correction.

Hyponatremia is the most common electrolyte disorder and it affects approximately 5% of adults and 35% of hospitalized patients. Hyponatremia is defined by a serum sodium level of less than 135 mEq/L and most commonly results from water retention. Even mild hyponatremia is associated with increased hospital stay and mortality. Symptoms and signs of hyponatremia range from mild and nonspecific (such as weakness or nausea) to severe and life-threatening (such as seizures or coma). Symptom severity depends on the rapidity of development, duration, and severity of hyponatremia. Mild chronic hyponatremia is associated with cognitive impairment, gait disturbances, and increased rates of falls and fractures. In a prospective study, patients with hyponatremia more frequently reported a history of falling compared with people with normal serum sodium levels (23.8% vs 16.4%, respectively; P < .01) and had a higher rate of new fractures over a mean follow-up of 7.4 years (23.3% vs 17.3%; P < .004). Hyponatremia is a secondary cause of osteoporosis. When evaluating patients, clinicians should categorize them according to their fluid volume status (hypovolemic hyponatremia, euvolemic hyponatremia, or hypervolemic hyponatremia). For most patients, the approach to managing hyponatremia should consist of treating the underlying cause. Urea and vaptans can be effective treatments for the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure, but have adverse effects (eg, poor palatability and gastric intolerance with urea; and overly rapid correction of hyponatremia and increased thirst with vaptans). Severely symptomatic hyponatremia (with signs of somnolence, obtundation, coma, seizures, or cardiorespiratory distress) is a medical emergency. US and European guidelines recommend treating severely symptomatic hyponatremia with bolus hypertonic saline to reverse hyponatremic encephalopathy by increasing the serum sodium level by 4 mEq/L to 6 mEq/L within 1 to 2 hours but by no more than 10 mEq/L (correction limit) within the first 24 hours. This treatment approach exceeds the correction limit in about 4.5% to 28% of people. Overly rapid correction of chronic hyponatremia may cause osmotic demyelination, a rare but severe neurological condition, which can result in parkinsonism, quadriparesis, or even death. Hyponatremia affects approximately 5% of adults and 35% of patients who are hospitalized. Most patients should be managed by treating their underlying disease and according to whether they have hypovolemic, euvolemic, or hypervolemic hyponatremia. Urea and vaptans can be effective in managing the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure; hypertonic saline is reserved for patients with severely symptomatic hyponatremia.

Hyponatraemia, defined as a serum sodium concentration <135 mmol/l, is the most common disorder of body fluid and electrolyte balance encountered in clinical practice. It can lead to a wide spectrum of clinical symptoms, from subtle to severe or even life threatening, and is associated with increased mortality, morbidity and length of hospital stay in patients presenting with a range of conditions. Despite this, the management of patients remains problematic. The prevalence of hyponatraemia in widely different conditions and the fact that hyponatraemia is managed by clinicians with a broad variety of backgrounds have fostered diverse institution- and speciality-based approaches to diagnosis and treatment. To obtain a common and holistic view, the European Society of Intensive Care Medicine (ESICM), the European Society of Endocrinology (ESE) and the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA), represented by European Renal Best Practice (ERBP), have developed the Clinical Practice Guideline on the diagnostic approach and treatment of hyponatraemia as a joint venture of three societies representing specialists with a natural interest in hyponatraemia. In addition to a rigorous approach to methodology and evaluation, we were keen to ensure that the document focused on patient-important outcomes and included utility for clinicians involved in everyday practice.