Severe Hypernatremia Research Articles

Pre-emptive use of glucose 5% as the standard drug solvent reduces hypernatremia in critically ill patients

Abstract Background Hypernatremia presents a common complication in ICU patients, associated with increased mortality and length of stay. This study investigates the effect of sodium chloride 0.9% compared with glucose 5% solution as the standard intravenous drug diluent on the prevalence of hypernatremia in a medical ICU. Methods This is a retrospective before-and-after study comparing two consecutive patient groups before- and after the standard drug solvent was changed from sodium chloride 0.9% to glucose 5% solution for compatible medications. A total of 265 adult COVID-19 patients admitted between October 2020 and March 2021 to the study intensive care unit were included, with 161 patients in the timeframe when sodium chloride 0.9% was employed as the standard drug solvent and 104 patients when glucose 5% was used. Routine sodium measurements from arterial and venous blood gases, along with heparinized lithium plasma, were analyzed. The daily sodium concentrations and the prevalence of severe hypernatremia (>150 mmol/l) were assessed during the first 8 days after ICU admission. Results Baseline characteristics were similar between the two groups. The cumulative volume of intravenous drug diluents was comparable. In the glucose 5% group, about half of the total drug diluent volume was glucose 5% (mean [SD]: 2251.6 [2355.4] mL), compared to 135.0 [746.9] mL (p < 0.001) in the control group. Average sodium concentrations diverged after day two, with the glucose 5% group consistently showing lower sodium levels (mean difference of approximately 2.5 mmol/L). Severe hypernatremia occurred less frequently in the glucose 5% group (6.6% vs. 20%). Conclusion Glucose 5% solution as the standard intravenous drug solvent significantly reduced sodium concentrations and the occurrence of severe hypernatremia. This simple modification in solvent choice may serve as a preventive strategy against hypernatremia in the ICU. Further prospective research is necessary to determine associated clinical outcomes. Trial registration: The trial was registered in the German Clinical Trials Register (DRKS00031877).

Effect of Change in Sodium after Slow Low-Efficiency Dialysis in Critically Ill Patients with Acute Kidney Injury

Introduction: The effect of sodium (Na) correction by slow low-efficiency dialysis (SLED) in dysnatremic (135 mEq/L <Na >145 mEq/L) critically ill patients is unclear. Methods: Prospective observational study enrolled dysnatremic critically ill adult patients with acute kidney injury undergoing the first SLED as cases and normonatremic patients as controls. Baseline and SLED-related parameters and 30-day mortality were noted. Results: 100 dysnatremic and 51 normonatremic patients were included, with a median age of 31 (25–52) years and median admission SOFA scores of 10 (9–12). Patients with dysnatremia at study inclusion had a mortality of 53%, with the highest mortality in severe hypernatremia (Na >160 mEq/L) (75%), followed by those with severe hyponatremia (Na <120 mEq/L) (68.6%). SLED-associated natremia change >10 mEq/L was significantly associated with mortality, in patients with mild dysnatremia and normonatremia (Na: 130–150) (p < 0.001), and not in those with moderate to severe dysnatremia (Na <130 and Na >150) (p = 0.72). Upon multivariate logistic regression analysis, a model with pre-SLED pH, dialyzate-pre-SLED Na difference, and duration of SLED significantly predicted SLED-associated natremia change (R2 0.18, p = 0.001). Conclusions: SLED can be safely and effectively performed in critically ill adults with dysnatremia requiring renal replacement therapy with mortality comparable to normonatremic controls.

Hyperintensity in Bilateral Posterior Limbs of Internal Capsule Due to Hypernatremia

Abstract Purpose: Osmotic demyelination syndrome is usually caused by rapid correction of hyponatremia but sometimes develops from acute severe hypernatremia. Studies suggested that serum sodium increasing at the rate of &lt;6~8 mmol/L in 24 hours has a low risk of osmotic demyelination syndrome, but sometimes exceptions present. Aside from the classical sites of involvement, such as pons and basal ganglia, internal capsules are rarely affected. We report a case with acute paraparesis caused by acute hypernatremia-induced extrapontine myelinolysis involving the posterior limbs of bilateral internal capsules. Case: A 54-year-old man was admitted for aseptic encephalitis and moved to the intensive care unit due to poor consciousness and respiratory failure. Although cerebrospinal fluid pleocytosis was improved later, acute hypernatremia due to partial diabetes insipidus developed. He presented acute paraplegia two days later with a negative result on the whole spine MRI. Although the increasing rate of serum sodium did not exceed the recommended safety range, the extrapontine myelinolysis involving posterior limbs of the bilateral internal capsule, as long as the corpus callosum, still developed. The patient regained partial walking ability after one year. Conclusion: This case report extends the spectrum of classical osmotic demyelination in clinical manifestations, image findings, and the causal range of electrolyte derangements.

Cerebral edema in an adolescent patient with diabetic ketoacidosis: a case report with a review of literature

The objective was to describe a case of cerebral edema (CE) in an adolescent patient with type 1 diabetes mellitus (DM) complicated with diabetic ketoacidosis (DKA), and to perform an analysis and review of publications devoted to this topic.Materials and methods. We describe the rare clinical case of CE complicated with DKA in the 14-year-old adolescent patient, including the dynamics of the patient’s clinical condition and laboratory test results. The topic of interest was researched through analysis of publications found in the Cochrane Library, PubMed, eLibrary.ru and Medscape databases using the following search terms: diabetic ketoacidosis, children and adolescents, cerebral edema, intensive therapy. A total of 38 publications in Russian and English were selected for being fully compliant with the purpose of this work. The features of the reported clinical case were analyzed and compared with information obtained from the current scientific literature.Results: This case demonstrates specific features presenting in the course of CE and describes aspects of the intensive treatment provided to the patient. Manifestations of severe hypokalemia and hypernatremia have been recorded as rare electrolyte disturbances in CE in the adolescent with DKA. The report demonstrates that the steps and specific parameters of the provided intensive treatment are unlikely to have triggered the development of CE in the clinic in this particular clinical case. It cannot be ruled out that the development of this complication was triggered by the delayed initiation of treatment (caused by the patient) at the prehospital stage, including the patient’s rude noncompliance with the prescribed insulin treatment scheme.Conclusions. CE is the rare but severe (with a high fatality rate) complication of DKA in patients with type 1 DM. Timely initiation of emergency care for CE may reduce risks associated with this complication and improve treatment outcomes and patient prognosis.

Effects of Acute Hypernatremia on the Electrophysiology of Single Human Ventricular Cardiomyocytes: An In Silico Study.

Clinical and experimental data on the cardiac effects of acute hypernatremia are scarce and inconsistent. We aimed to determine and understand the effects of different levels of acute hypernatremia on the human ventricular action potential. We performed computer simulations using two different, very comprehensive models of the electrical activity of a single human ventricular cardiomyocyte, i.e., the Tomek-Rodriguez model following the O'Hara-Rudy dynamic (ORd) model and the Bartolucci-Passini-Severi model as published in 2020 (known as the ToR-ORd and BPS2020 models, respectively). Mild to extreme levels of hypernatremia were introduced into each model based on experimental data on the effects of hypernatremia on cell volume and individual ion currents. In both models, we observed an increase in the intracellular sodium and potassium concentrations, an increase in the peak amplitude of the intracellular calcium concentration, a hyperpolarization of the resting membrane potential, a prolongation of the action potential, an increase in the maximum upstroke velocity, and an increase in the threshold stimulus current at all levels of hypernatremia and all stimulus rates tested. The magnitude of all of these effects was relatively small in the case of mild to severe hypernatremia but substantial in the case of extreme hypernatremia. The effects on the action potential were related to an increase in the sodium-potassium pump current, an increase in the sodium-calcium exchange current, a decrease in the rapid and slow delayed rectifier potassium currents, and an increase in the fast and late sodium currents. The effects of mild to severe hypernatremia on the electrical activity of human ventricular cardiomyocytes are relatively small. In the case of extreme hypernatremia, the effects are more pronounced, especially regarding the increase in threshold stimulus current.

Frequency and outcome of sodium disturbances in children admitted with acute watery diarrhea in a tertiary hospital of Bangladesh

Background: Acute watery diarrhea (AWD) is one of the common causes of hospital admissions in pediatric age group. Majority of children with dehydration suffer from different electrolyte abnormalities which needs to be identified and treated. Objectives: To investigate the frequency and outcome of sodium disturbances in AWD among children admitted in a tertiary hospital in Bangladesh. Method: In this prospective observational study, 121 children of 2 months to 5 years of age admitted in the Department of Pediatrics, Chittagong Medical College Hospital with AWD were included. Clinical features and sodium levels on admission were recorded. Patients were followed up during their hospital stay to record the outcomes. Children were grouped in hyponatremia (serum sodium &lt;135mmol/l), hypernatremia (serum sodium &gt;145mmol/l) and normonatremia (serum sodium 135–145mmol/l) and compared. Results: Of the 121 children, 38.0% and 62.0% had moderate and severe dehydration, respectively. The majority (58.7%) had normal sodium levels. Sodium disturbances was found in 41.3% cases. There were 26.4% cases of hypernatremia and 14.9% cases of hyponatremia among them. Out of 18 hyponatremic patients, 77.8% had mild hyponatremia and the rest 22.2% had moderate hyponatremia. Among 32 hypernatremic children, 62.4% had mild, 18.8% had moderate and 18.8% had severe hypernatremia. The case fatality rate was 2.6% and all of them had hypernatremic dehydration at admission. Conclusion: Sodium disturbances particularly hypernatremia is more frequent and is associated with high case fatality rate among children hospitalized with acute watery diarrhoea. BANGLADESH J CHILD HEALTH 2022; VOL 46 (3) : 110-114

Permissive Hypotension in a Patient with Severe Hypernatremia: A Case Report.

Severe hypernatremia is a critical situation, and when coupled with intravascular depletion and hypotension can create a treatment dilemma. We present the case of a medically complex patient who had gradually worsening alteration of mental status and mean arterial pressures in the 50s on presentation to the emergency department. Final diagnoses included severe hypernatremia and hypovolemic shock secondary to poor oral intake. We used judicious fluid repletion with gradual improvement in sodium levels and permissive hypotension to avoid rapid osmotic shifts. Balancing reperfusion and the risk for osmotic effects of aggressive fluid resuscitation can be a challenging situation for the multidisciplinary team.

Serum sodium level fluctuations following the resection of childhood-onset craniopharyngioma.

Craniopharyngiomas are low-grade malignancies (WHO I) in the sellar region. Most cases of childhood-onset craniopharyngioma are adamantinomatous craniopharyngioma, and neurosurgery is the treatment of choice. Affected patients have postoperative complications, including water and electrolyte disturbances, because these malignancies develop near the hypothalamus and pituitary gland. Determining postoperative serum sodium fluctuation patterns in these patients can reduce postoperative mortality and improve prognosis. To measure changes in serum sodium levels in pediatric patients who underwent craniopharyngioma surgery and identify influencing factors. This retrospective study measured the serum sodium levels of 202 patients aged 0-18 years who underwent craniopharyngioma resection in Beijing Tiantan Hospital and Beijing Children's Hospital and identified predictors of severe hyponatremia and hypernatremia. The mean age of the cohort was 8.35±4.35 years. The prevalence of hypernatremia, hyponatremia, and their severe forms (serum Na+ >150mmol/L and serum Na+ <130mmol/L) within 14 days after surgery was 66.3%, 72.8%, 37.1%, and 40.6%, respectively. The mean postoperative serum sodium level showed a triphasic pattern, characterized by two peaks separated by a nadir. Sodium levels peaked on days 2 (143.6±7.6mmol/L) and 14 (143.2±6.7mmol/L) and reached their lowest on day 6 (135.5±7.5mmol/L). A total of 31 (15.3%) patients met the diagnostic threshold for hyponatremia and hypernatremia of the triphase response, whereas 116 (57.4%) patients presented this pattern, regardless of met the diagnostic criteria or not. The prevalence of severe hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach. Serum sodium levels after craniopharyngioma resection in children showed a triphasic pattern in most cases. The risk of postoperative hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach.

Primary Sjogren’s syndrome with secondary distal renal tubular acidosis unmasked during pregnancy: A rare presentation

ABSTRACT Renal tubular acidosis (RTA) comprises transport defects in renal reabsorption of bicarbonate, impaired acidification of urine, or both. It is broadly classified into distal, proximal, and hyperkalemic RTA. Distal RTA (dRTA) is characterized by reduced net acid excretion in urine. It can be primary or secondary, and hypokalemia is often a central presenting feature. Hypokalemia may present with flaccid quadriparesis, arrhythmia, and respiratory failure. Hypokalemia also causes nephrogenic diabetes insipidus (NDI) due to the downregulation of vasopressin-responsive aquaporin-2 water channel and inhibition of renal response to vasopressin. Primary Sjogren’s syndrome (pSS) is the most common autoimmune disorder associated with secondary dRTA. Here, we present the case of a 22-year-old critically ill pregnant lady with adverse pregnancy outcomes, diagnosed to be pSS with dRTA, who presented with severe hypokalemia and hypernatremia (due to NDI). Both pSS and chronic acidosis are associated with adverse pregnancy outcomes.

Rhabdomyolysis induced by hyperosmolarity secondary to severe hypernatremia in a patient with trauma brain injury: A case report

Rhabdomyolysis induced by hyperosmolarity secondary to severe hypernatremia in a patient with trauma brain injury: A case report

Rectus Sheath and Subcostal Transversus Abdominis Plane Blocks as Main Anesthetic Technique for Open Cholecystectomy: A Case Report

Anesthetic techniques used for open cholecystectomy are traditionally general anesthesia, neuraxial anesthesia, or both due to convenience and safety profile. Peripheral nerve blocks are usually only used for postoperative analgesia for this type of surgery. We report a case of a patient with obstructive jaundice in severe cholangitis and hypovolemic hypernatremia who underwent open cholecystectomy and T-tube drain under right-sided rectus sheath and subcostal transversus abdominis plane blocks.

Long-Term Developmental Assessment of Children Recovered from Hypernatremia

Purpose: Imbalances in sodium result in acute neurologic symptoms such as seizures and impaired mental status. Studies investigating the long-term consequences of hypernatremia on cognitive, motor, and language development in children are limited. The aim of this study was to assess the long-term impact of hypernatremia on children’s cognitive, motor, and language development. Methodology:It was an observational study conducted from March 2016 to March 2017 in Dhaka Hospital of icddr,b. In this study,211 children with acute watery diarrhea accompanied with hypernatremia (serum sodium level 150 mmol/L) who had already been enrolled in a previous observational study were prospectively followed for one year.The objective was to investigate if there are any long term neurologic and developmental consequences of hypernatremia in those children. Physical, cognitive, motor, and language development as well as expressive or receptive expression of the children were assessed using a standard tool at the time of discharge (Baseline) and 12 months after discharge (End line). We also assessed IQ in a subgroup of children &gt; 36 months (n=57) using the Wechsler Preschool and Primary Scale of Intelligence in parallel. Results: Among the 211 participants, developmental assessment on motor, cognitive, and language development test was done on 140 (66.3%) children. The mean age of the children at the time of discharge from the hospital (baseline) was 7.9±4.5 months. Compared to mild (serum Na 150 mmol/L to less than 160 mmol/L), and moderately (serum Na 160 mmol/L to 169 mmol/L) hypernatremia, children with severe hypernatremia (serum sodium &gt;170mmol/L) significantly had lower mean scores on the motor, fine motor, and language development score at baseline after adjusting age and weight for the age z score. Although there was an improvement in motor, language, and socioemotional scores, significant improvement was only observed with cognitive function at the end line (p=0.002). In Mmultiple regression after adjusting for potential confounders such as levels of hypernatremia, parents’ education, age of the child, and WAZ, these factors were showed significantly associated with the cognitive function of children. There was no difference in mean IQ level performed at the end-line among the children with different level of hypernatremia (mild, moderate or severe). Conclusion: Children with hypernatremia had poor developmental scores in cognitive, motor, language, and socio-emotional domains at the time of recovery from hypernatremia. However, other than cognitive score, there was no significant improvement in motor or language development at 12 months in children recovering from hypernatremia. Further studies are therefore warranted to reveal any association of motor or language deficit with neurological deficit in those children beyond 12 months. Bioresearch Commu. 10(1): 1386-1392, 2024 (January)

Abstract #1603999: Audit on Management of Moderate and Severe Hypernatremia in Hospitalized Patients in a District General Hospital in England

Abstract #1603999: Audit on Management of Moderate and Severe Hypernatremia in Hospitalized Patients in a District General Hospital in England

Association of postoperative hypernatremia with outcomes after elective craniotomy

Study objectiveHypernatremia is a treatable biochemical disorder associated with significant morbidity and mortality in patients undergoing surgery. However, its impact on patients who undergo elective craniotomy is not well understood. This study aimed to investigate the prognostic implications of postoperative hypernatremia on the 30-day mortality of patients undergoing elective craniotomy. DesignRetrospective cohort study. SettingThe Department of Neurosurgery of a high-volume center. PatientsAdult patients undergoing elective craniotomy except those with pituitary tumors, intracerebral hemorrhage, subarachnoid hemorrhage, or traumatic brain injury. InterventionsNone. MeasurementsPerioperative laboratory data were collected for all study participants, including sodium levels, neutrophil count, serum albumin, lymphocyte count, and blood glucose. These measurements were obtained as part of routine clinical care and provided valuable information for data analysis. Main resultsOf the 10,223 identified elective craniotomy patients who met our inclusion and exclusion criteria, 14.9% (1519) developed postoperative hypernatremia. This population's overall postoperative 30-day mortality rate was 1.7% (175). After performing an adjusted logistic regression analysis, we found that the odds of 30-day mortality increased gradually with increasing severity of hypernatremia: 2.9 deaths (OR, 3.79; 95% CI, 2.46–5.85) in patients with mild hypernatremia, 13.9 deaths (OR, 17.73; 95% CI, 11.17–28.12) in those with moderate hypernatremia, and 38.3 deaths (OR, 67.00; 95% CI, 40.44–111.00) in those with severe hypernatremia. ConclusionsHypernatremia is common after elective craniotomy, and its presence is associated with increased mortality and complications, particularly in cases of severe hypernatremia. These results emphasize the significance of risk evaluation in neurosurgical patients and propose the advantages of closely monitoring serum sodium levels in high-risk individuals. Future randomized controlled trials could provide more insight into the effect of treating postoperative hypernatremia in these patients.

Risk factors for mortality in brain injury patients who have severe hypernatremia and received continuous venovenous hemofiltration

Background and objectivesThe mortality rate for people with brain injuries is increased when hypernatremia is present. Patients with severe hypernatremia, who have a significant short-term mortality rate, were shown to benefit from continuous venovenous hemofiltration (CVVH), which has been indicated to be successful. Exploring the risk factors for short-term mortality in brain injury patients who underwent CVVH and had severe hypernatremia was the aim of the current study. Materials and methodsRetrospective screening was performed on patients with brain injuries who underwent CVVH at Xijing Hospital between 1 December 2010 and 31 December 2021 and who have a diagnosis of severe hypernatremia. The outcomes included 28-day patient mortality and hospital stay duration. The patient survival rate was examined using the Kaplan-Meier survival curve. To determine the risk factors for short-term death for patients, univariate and multivariate Cox regression analysis models were used. ResultsOur current study included a total of 83 individuals. The included patients had a median age of 49 (IQR 35–59) years. Of the included patients, 58 patients (69.9 %) died within 28 days. The median length of hospital stay for the patient was 13 (IQR 7–21) days. The APACHE II score, SOFA score, GCS, PLT count, INR, stroke, mechanical ventilation, and vasopressor reliance were related to 28-day mortality according to the univariate Cox analysis. INR (HR = 1.004, 95 % Cl: 1.001–1.006, P = 0.008), stroke (HR = 1.971, 95 % Cl: 1.031–3.768, P = 0.04), mechanical ventilation (HR = 3.948, 95 % Cl: 1.090–14.294, P = 0.036), and vasopressor dependency (HR = 2.262, 95 % Cl: 1.099–4.655, P = 0.027) were independently associated with the risk of 28-day death rates, according to multivariate Cox regression analysis. ConclusionsBrain injuries who have severe hypernatremia requires CVVH, which has high short-term patient mortality. Mechanical ventilation, INR increase, stroke, and vasopressor dependence are independently associated with increased patient mortality risk.

Unintended Consequences: Severe Hypernatremia and Metabolic Alkalosis Following Baking Soda Ingestion for Urine Drug Screen Evasion

Unintended Consequences: Severe Hypernatremia and Metabolic Alkalosis Following Baking Soda Ingestion for Urine Drug Screen Evasion

Extreme hypernatraemia and rhabdomyolysis in a child with hyperosmolar hyperglycaemic state mixed with diabetic ketoacidosis

Abstract Diabetic ketoacidosis (DKA) is present at diagnosis for about 40% of children with type 1 diabetes mellitus (DM).1 Hyperosmolar hyperglycaemic state (HHS) is another acute complication of DM more typically associated with type 2 DM in adults or adolescents. Recent evidence indicates that a mixed picture of HHS and DKA also occurs in children with type 1 DM2 but it is not frequently reported and therefore at risk of under‐recognition.Here, we report a rare case of HHS mixed with DKA as the first presentation for type 1 DM in a five‐year‐old child with underlying neurodevelopmental problems. Failure to recognise the HHS aspects led to severe hypernatraemia, hyperosmolarity, acute renal impairment and rhabdomyolysis but ultimately the child made a full recovery. This case highlights the importance of early recognition and potential pitfalls in management of mixed HHS with type 1 DM. Copyright © 2023 John Wiley &amp; Sons.

Severe hypernatremia during postoperative care in patients with craniopharyngioma.

We aimed to describe and predict the risk of severe hypernatremia after surgical resection of craniopharyngioma and to identify the association of water intake, urine output, and sodium level change in the patients. The outcome was postoperative severe hypernatremia. We identified risk factors associated with hypernatremia using multivariable regression. We trained machine learning models to predict the outcome. We compared serum sodium change, intravenous input, oral input, total input, urine output, and net fluid balance according to different nurse shifts. Among 234 included patients, 125 developed severe hypernatremia after surgery. The peak incidence occurred during day 0 and day 6 after surgery. The risk was increased in patients with gross total resection (odds ratio (OR) 2.41, P < 0.001), high Puget classification (OR 4.44, P = 0.026), preoperative adrenal insufficiency (OR 2.01, P = 0.040), and preoperative hypernatremia (OR 5.55, P < 0.001). The random forest algorithm had the highest area under the receiver operating characteristic curve (0.770, 95% CI, 0.727-0.813) in predicting the outcome and was validated in the prospective validation cohort. Overnight shifts were associated with the highest serum sodium increase (P = 0.010), less intravenous input (P < 0.001), and less desmopressin use (P < 0.001). The overall incidence of severe hypernatremia after surgical resection of craniopharyngioma was significant, especially in patients with gross total resection, hypothalamus distortion, preoperative adrenal insufficiency, and preoperative severe hypernatremia. Less intravenous input and less desmopressin use were associated with serum sodium increases, especially during overnight shifts.

Sterile necrotizing cellulitis in boat immigrants’ limbs after long journeys across the ocean

BackgroundIn the past few years, the Canary Islands received immigrants from sub-Saharan countries that arrive to the coast after long boat trips in extreme adverse conditions.The named “trench foot” is a previously described infectious entity developed after feet wounds that get infected by being in contact with water, urine and excrements in these small and crowded boats.We describe a new clinical entity, not published yet, that consists in massive edema in the extremities associating necrosis of the skin and subcutaneous tissue that characteristically respects the muscle and with a non-infectious etiology. Material and methodsA Database including 86 patients arrived by boat (“patera”) from sub-Saharan countries from September 2020 to January 2022 was made and 39 qualitative and quantitative items were analyzed. The Research Unit performed an observational prospective statistical analysis. ResultsA total of 16 patients developed the entity described as necrotizing cellulitis. Its physiopatology completely differs from the one described in the trench foot, since all the cultures resulted sterile. ConclusionsWe postulate an inflammatory theory due to the osmotic effect from ingesting sea water and/or the aggressive fluid reposition when they arrive to the emergency room with severe dehydration and hypernatremia. Early surgical evacuation of the edema with escharotomies incisions alleviate the symptoms and prevents progression of the disorder.

Rate of Correction and All-Cause Mortality in Patients With Severe Hypernatremia

Hypernatremia is common among hospitalized patients and is associated with high mortality rates. Current guidelines suggest avoiding fast correction rates but are not supported by robust data. To investigate whether there is an association between hypernatremia correction rate and patient survival. This retrospective cohort study examined data from all patients admitted to the Tel Aviv Medical Center between 2007 and 2021 who were diagnosed with severe hypernatremia (serum sodium ≥155 mmol/L) at admission or during hospitalization. Statistical analysis was performed from April 2022 to August 2023. Patients were grouped as having fast correction rates (>0.5 mmol/L/h) and slow correction rates (≤0.5 mmol/L/h) in accordance with current guidelines. All-cause 30-day mortality. A total of 4265 patients were included in this cohort, of which 2621 (61.5%) were men and 343 (8.0%) had fast correction rates; the median (IQR) age at diagnosis was 78 (64-87) years. Slow correction was associated with higher 30-day mortality compared with fast correction (50.7% [1990 of 3922] vs 31.8% [109 of 343]; P < .001). These results remained significant after adjusting for demographics (age, gender), Charlson comorbidity index, initial sodium, potassium, and creatinine levels, hospitalization in an ICU, and severe hyperglycemia (adjusted odds ratio [aOR], 2.02 [95% CI, 1.55-2.62]), regardless of whether hypernatremia was hospital acquired (aOR, 2.19 [95% CI, 1.57-3.05]) or documented on admission (aOR, 1.64 [95% CI, 1.06-2.55]). There was a strong negative correlation between absolute sodium correction during the first 24 hours following the initial documentation of severe hypernatremia and 30-day mortality (Pearson correlation coefficient, -0.80 [95% CI, -0.93 to -0.50]; P < .001). Median (IQR) hospitalization length was shorter for fast correction vs slow correction rates (5.0 [2.1-14.9] days vs 7.2 [3.5-16.1] days; P < .001). Prevalence of neurological complications was comparable for both groups, and none were attributed to fast correction rates of hypernatremia. This cohort study of patients with severe hypernatremia found that rapid correction of hypernatremia was associated with shorter hospitalizations and significantly lower patient mortality without any signs of neurologic complications. These results suggest that physicians should consider the totality of evidence when considering the optimal rates of correction for patients with severe hypernatremia.