Evaluation and treatment of hypernatremia: a practical guide for physicians

Association between serum sodium levels within 24 h of admission and all-cause mortality in critically ill patients with non-traumatic subarachnoid hemorrhage: a retrospective analysis of the MIMIC-IV database

Objective

The study aimed to evaluate the relationship between serum sodium and mortality in critically ill patients with non-traumatic subarachnoid hemorrhage.

Methods

This is a retrospective investigation of critically ill non-traumatic patients with subarachnoid hemorrhage (SAH) utilizing the MIMIC-IV database. We collected the serum sodium levels at admission and determined the all-cause death rates for the ICU and hospital. We employed a multivariate Cox proportional hazard regression model and Kaplan-Meier survival curve analysis to ascertain the relationship between serum sodium and all-cause mortality. In order to evaluate the consistency of correlations, interaction and subgroup analyses were also conducted.

Results

A total of 864 patients with non-traumatic SAH were included in this study. All-cause mortality in the ICU and hospital was 32.6% (282/864) and 19.2% (166/864), respectively. Sodium levels at ICU admission showed a statistically significant J-shaped non-linear relationship with ICU and hospital mortality (non-linear P-value < 0.05, total P-value < 0.001) with an inflection point of ~141 mmol/L, suggesting that mortality was higher than normal serum sodium levels in hypernatremic patients. Multivariate analysis after adjusting for potential confounders showed that high serum sodium levels (≥145 mmol/L) were associated with an increased risk of all-cause mortality in the ICU and hospital compared with normal serum sodium levels (135-145 mmol/L), [hazard ratio (HR) = 1.47, 95% CI: 1.07-2.01, P = 0.017] and (HR = 2.26, 95% CI:1.54-3.32, P < 0.001). Similarly, Kaplan-Meier (K-M) survival curves showed lower survival in patients with high serum sodium levels. Stratified analysis further showed that the association between higher serum sodium levels and hospital all-cause mortality was stronger in patients aged < 60 years with a hospital stay of <7 days.

Conclusion

High serum sodium levels upon ICU admission are related to higher ICU and hospital all-cause mortality in patients with non-traumatic SAH. A new reference is offered for control strategies to correct serum sodium levels.

Evaluation and management of hypernatremia in adults: clinical perspectives

Hypernatremia is an occasionally encountered electrolyte disorder, which may lead to fatal consequences under improper management. Hypernatremia is a disorder of the homeostatic status regarding body water and sodium contents. This imbalance is the basis for the diagnostic approach to hypernatremia. We summarize the eight diagnostic steps of the traditional approach and introduce new biomarkers: exclude pseudohypernatremia, confirm glucose-corrected sodium concentrations, determine the extracellular volume status, measure urine sodium levels, measure urine volume and osmolality, check ongoing urinary electrolyte free water clearance, determine arginine vasopressin/copeptin levels, and assess other electrolyte disorders. Moreover, we suggest six steps to manage hypernatremia by replacing water deficits, ongoing water losses, and insensible water losses: identify underlying causes, distinguish between acute and chronic hypernatremia, determine the amount and rate of water administration, select the type of replacement solution, adjust the treatment schedule, and consider additional therapy for diabetes insipidus. Physicians may apply some of these steps to all patients with hypernatremia, and can also adapt the regimens for specific causes or situations.

Differential diagnosis of hyponatremia and hypernatremia

Dysnatremias are among the most common mineral imbalances encountered in clinical practice. Both hyponatremia and hypernatremia are associated with increased morbiditidy and mortality and represent negative prognostic factors regardless of their cause. Serum osmolality, extracellular fluid volume and sodium urine concentration are important parameters for evaluation the cause and differential diagnosis. The rate of onset of ionic disorder and severity of clinical symptoms are essential. While acute disorders with symptoms are treated immediately, in chronic disorders, thorough diagnostic evaluation and a careful approach to their correction are necessary. Especially with rapid substitution of chronic hyponatremia, there is a risk of osmotic demyelination syndrome. Therefore, a slow correction of the serum sodium level with frequent mineralogram checks is required.

Diagnosis and treatment of brain injury complicated by hypernatremia

Hypernatremia is a common electrolyte disorder in patients with brain injury. The mortality of brain injury patients with severe hypernatremia may be as high as 86.8%. The efficacy of conventional treatment for hypernatremia is limited. Continuous renal replacement therapy (CRRT) can slowly, controllably, and continuously reduce the blood sodium concentration and gradually become an important treatment for severe hypernatremia patients. This review aims to provide important information for clinicians and clinical researchers by describing the etiology, diagnosis, hazards, conventional treatment, and CRRT treatment of hypernatremia in patients with traumatic brain injury.

Outcome of Hospitalized Cancer Patients with Hypernatremia: A Retrospective Case-Control Study

Hypernatremia (>145 mmol/L) is a relatively rare event, and the data regarding its role in the outcome of inpatients on an oncology ward are weak. The aim of this study was to describe the prevalence, prognosis, and outcome of hospitalized cancer patients with hypernatremia. We performed a retrospective case-control study of data obtained from inpatients with a solid tumor at the St. Claraspital, Basel, Switzerland, who were admitted between 2017 and 2020. The primary endpoint was overall survival. Hypernatremia was found in 93 (3.16%) of 2945 inpatients bearing cancer or lymphoma. From 991 eligible normonatremic control patients, 93 were matched according to diagnosis, age, and sex. The median overall survival time (OS) of patients with hypernatremia was 1.5 months compared to 11.7 months of the normonatremic controls (HR 2.69, 95% CI 1.85-3.90, p < 0.0001). OS of patients with irreversible compared to reversible hypernatremia was significantly shorter (23 versus 88 days, HR 4.0, 95% CI 2.04-7.70, p < 0.0001). The length of hospital stay was significantly longer for the hypernatremic than for the normonatremic group (p < 0.0001). Significantly more patients with hypernatremia died in the hospital (30.1% versus 8.6%, p < 0.001). These results suggest hypernatremia to be associated with an unfavorable outcome and a very short OS.

Diagnostic and therapeutic approach to hypernatremia

Hypernatremia occurs when the plasma sodium concentration is greater than 145 mmol/L. Depending on the duration, hypernatremia can be differentiated into acute and chronic. According to severity: mild, moderate and threatening hypernatremia. Finally, depending on pathogenesis, hypernatremia can be defined as hypervolemic, hypovolemic, and euvolemic. Acute hypervolemic hypernatremia is often secondary to increased sodium intake (hypertonic NaCl and NaHCO₃ solutions). Instead, chronic hypervolemic hypernatremia may be an expression of primary hyperaldosteronism. Euvolemic hypernatremia occurs in diabetes insipidus: depending on the underlying pathogenesis, it can be classified into two basic types: neurogenic (or central) and nephrogenic. The neurogenic form may be triggered by traumatic, vascular or infectious events; the nephrogenic form may be due to pharmacological causes, such as lithium, or non-pharmacological ones, such as hypokalemia. For hypovolemic hypernatremia, possible explanations are renal or extrarenal losses. The main goal of treatment of hypernatremia is the restoration of plasma tonicity. In particular, if the imbalance has occurred acutely, rapid correction improves the prognosis by preventing the effects of cellular dehydration; if hypernatremia has developed slowly, over a period of days, a slow correction rate (no more than 0.4 mmol/L/h) is recommended.

Hypernatremia in Hospitalized Patients: A Large Population-Based Study

Background

Hypernatremia is a frequently encountered electrolyte disorder in hospitalized patients. Controversies still exist over the relationship between hypernatremia and its outcomes in hospitalized patients. This study examines the relationship of hypernatremia to outcomes among hospitalized patients and the extent to which this relationship varies by kidney function and age.

Methods

We conducted an observational study to investigate the association between hypernatremia, eGFR, and age at hospital admission and in-hospital mortality, and discharge dispositions. We analyzed the data of 1.9 million patients extracted from the Cerner Health Facts databases (2000-2018). Adjusted multinomial regression models were used to estimate the relationship of hypernatremia to outcomes of hospitalized patients.

Results

Of all hospitalized patients, 3% had serum sodium (Na) >145 mEq/L at hospital admission. Incidence of in-hospital mortality was 12% and 2% in hyper- and normonatremic patients, respectively. The risk of all outcomes increased significantly for Na >155 mEq/L compared with the reference interval of Na=135-145 mEq/L. Odds ratios (95% confidence intervals) for in-hospital mortality and discharge to a hospice or nursing facility were 34.41 (30.59-38.71), 21.14 (17.53-25.5), and 12.21 (10.95-13.61), respectively (all P<0.001). In adjusted models, we found that the association between Na and disposition was modified by eGFR (P<0.001) and by age (P<0.001). Sensitivity analyses were performed using the eGFR equation without race as a covariate, and the inferences did not substantially change. In all hypernatremic groups, patients aged 76-89 and ≥90 had higher odds of in-hospital mortality compared with younger patients (all P<0.001).

Conclusions

Hypernatremia was significantly associated with in-hospital mortality and discharge to a hospice or nursing facility. The risk of in-hospital mortality and other outcomes was highest among those with Na >155 mEq/L. This work demonstrates that hypernatremia is an important factor related to discharge disposition and supports the need to study whether protocolized treatment of hypernatremia improves outcomes.

A Wearable Microneedle-Based Extended Gate Transistor for Real-Time Detection of Sodium in Interstitial Fluids

Sodium is a prominent prognostic biomarker for assessing health status, such as dysnatremia. As of now, detection and monitoring of sodium levels in the human body is carried out by means of laborious and bulky laboratory equipmentand/or by offline analysis of various body fluids. Herein, an innovative stretchable, skin-conformal and fast-response microneedle extended-gate FET biosensor is reported for real-time detection of sodium in interstitial fluids for minimally invasive health monitoring along with high sensitivity, low limit of detection, excellent biocompatibility, and on-body mechanical stability. The integration of the reported device with a wireless-data transmitter and the Internet-of-Things cloud for real-time monitoring and long-term analysis is reported and discussed. This platform would eventually help bringing unlimited possibilities for effecient medical care and accurate clinical decision-making.

Sodium Abnormalities in Cardiac Surgery With Cardiopulmonary Bypass in Adults: A Narrative Review

Perioperative sodium abnormalities or dysnatremia is not uncommon in patients presenting for cardiac surgery and is associated with increased morbidity and mortality. Both the disease process of heart failure and its treatment may contribute to abnormalities in serum sodium concentration. Serum sodium is the main determinant of serum osmolality, which in turn affects cell volume. Brain cells are particularly vulnerable to changes in serum osmolality because of the nondistensible cranium. The potentially catastrophic neurologic sequelae of rapidly correcting chronic dysnatremia and the time-sensitive nature of cardiac surgery can make the management of these patients challenging. The use of cardiopulmonary bypass to facilitate surgery adds another layer of complexity in the intraoperative management of sodium and water balance. This narrative review examines the definition and classification of dysnatremia. It also covers the etiology and pathophysiology of dysnatremia, implications during cardiac surgery requiring cardiopulmonary bypass, and the perioperative management of dysnatremia.

Dapagliflozin-associated euglycemic diabetic ketoacidosis in a patient with type 2 diabetes mellitus: A case report

RATIONALE

Rare cases of euglycemic diabetic ketoacidosis (eu-DKA) have been reported after the administration of sodium-glucose cotransporter-2 (SGLT-2) inhibitors. No reports have described eu-DKA complicated by hypernatremia due to SGLT-2 inhibitors.

PATIENT CONCERNS

A 76-year-old woman with a 40-year history of type 2 diabetes mellitus (DM), for which metformin (1000 mg/day) and dapagliflozin (10 mg/day) were prescribed, presented with malaise, fever, and oliguria. On presentation, her white blood cell count (11,800/μL), serum creatinine (3.2 mg/dL), and C-reactive protein (54 mg/L) were abnormal. Bilateral pyeloureteritis and diffuse paralytic ileus were present. She received intravenous antibiotics and total parenteral nutrition, and was asked to fast. Her renal function and ileus briefly improved. Oral hypoglycemic agents, metformin and dapagliflozin, along with enteral feeding were reinstituted on day 3 of hospitalization. However, on day 6 of hospitalization, the patient developed an altered state of consciousness including confusion, lethargy, and stupor. Several laboratory abnormalities suggestive of ketoacidosis with euglycemia were noted.

DIAGNOSES

The patient was diagnosed with eu-DKA accompanied by severe hypernatremia (corrected serum Na concentration, 163 mEq/L) and hypokalemia following dapagliflozin re-administration.

INTERVENTIONS

The patient was treated with indicated intravenous fluid therapy. Dapagliflozin use was discontinued.

OUTCOMES

The patient's mental status and laboratory findings improved gradually, and she was discharged on maintenance doses of insulin and metformin on day 14 of hospitalization.

LESSONS

Acute illnesses such as diffuse paralytic ileus and urinary tract infection, and dietary restrictions or fasting in patients with DM can be considered potential predisposing factors for SGLT-2 inhibitor-associated eu-DKA. For patients with diabetes in the setting of acute morbidity, timely resumption of the SGLT-2 inhibitor therapy should be carefully determined. In addition, eu-DKA due to SGLT-2 inhibitor use may be accompanied by electrolyte disturbances such as hypernatremia and hypokalemia.

Lithium treatment, nephrogenic diabetes insipidus and the risk of hypernatraemia: a retrospective cohort study

BACKGROUND

Hypernatraemia is a serious condition that can potentially become life threatening. It is known that lithium is associated with polyuria and nephrogenic diabetes insipidus, risk factors for hypernatraemia. In this study, we tested the hypothesis that lithium treatment was a risk factor for hypernatraemia.

METHODS

We performed a retrospective cohort study in the Swedish region of Norrbotten into the effects and potential adverse effects of lithium treatment and other mood stabilizers (LiSIE). For this particular study, we included all patients who had experienced at least one episode with a sodium concentration ⩾150 mmol/L between 1997 and 2013. Medical records were reviewed regarding past or current lithium exposure, diabetes insipidus and other potential risk factors for hypernatraemia.

RESULTS

Of 2463 patients included, 185 (7.5%) had experienced 204 episodes of hypernatraemia within the 17-year review period. In patients 65 years or older, infections dominated as the cause with 51%. In patients younger than 65 years, intoxications, particularly with alcohol, dominated as the cause with 35%. In the whole sample, dehydration accounted for 12% of episodes, 25% of which in the context of suspected or confirmed nephrogenic diabetes insipidus. Of all episodes, 25% resulted in death, with infection being the most common cause of death in 62% of cases.

CONCLUSIONS

In our sample, infections and harmful use of substances including alcohol were the most common causes of hypernatraemia. Both current and past use of lithium also led to episodes of hypernatraemia, when associated with nephrogenic diabetes insipidus. Clinicians should remain vigilant, have a low threshold for checking sodium concentrations and consider even risk factors for hypernatraemia beyond lithium.

Recommendations for active correction of hypernatremia in volume-resuscitated shock or sepsis patients should be taken with a grain of salt: A systematic review

Background:

Healthcare-acquired hypernatremia (serum sodium >145 mEq/dL) is common among critically ill and other hospitalized patients and is usually treated with hypotonic fluid and/or diuretics to correct a “free water deficit.” However, many hypernatremic patients are eu- or hypervolemic, and an evolving body of literature emphasizes the importance of rapidly returning critically ill patients to a neutral fluid balance after resuscitation.

Objective:

We searched for any randomized- or observational-controlled studies evaluating the impact of active interventions intended to correct hypernatremia to eunatremia on any outcome in volume-resuscitated patients with shock and/or sepsis.

Data sources:

We performed a systematic literature search with studies identified by searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ClinicalTrials.gov, Index-Catalogue of the Library of the Surgeon General’s Office, DARE (Database of Reviews of Effects), and CINAHL and scanning reference lists of relevant articles with abstracts published in English.

Data synthesis:

We found no randomized- or observational-controlled trials measuring the impact of active correction of hypernatremia on any outcome in resuscitated patients.

Conclusion:

Recommendations for active correction of hypernatremia in resuscitated patients with sepsis or shock are unsupported by clinical research acceptable by modern evidence standards.

The Prevalence and Management of Dehydration amongst Neonatal Admissions to General Paediatric Wards in Kenya-A Clinical Audit

An audit of randomly selected case records of 810 patients admitted to 13 hospitals between December 2015 and November 2016 was done. Prevalence of dehydration was 19.7% (2293 of 11 636) [95% CI: 17.1-22.6%], range across hospitals was 9.4% to 27.0%. Most cases with dehydration were clinically diagnosed (82 of 153; 53.6%), followed by excessive weight loss (54 of 153; 35.3%) and abnormal urea/electrolytes/creatinine (23 of 153; 15.0%). Documentation of fluids prescribed was poor but, where data were available, Ringers lactate (30 of 153; 19.6%) and 10% dextrose (18 of 153; 11.8%) were mostly used. Only 17 of 153 (11.1%) children had bolus fluid prescription, and Ringer's lactate was most commonly used for bolus at a median volume per kilogram body weight of 20 ml/kg (interquartile range, 12-30 ml/kg). Neonatal dehydration is common, but current documentation may underestimate the burden. Heterogeneity in practice likely reflects the absence of guidelines that in turn reflects a lack of research informing practical treatment guidelines.