Severity of community acquired hypernatremia is an independent predictor of mortality

Systemic and iatrogenic factors contribute to the development of severe hypernatraemia in vulnerable inpatients

OBJECTIVES

To determine all-cause in-hospital mortality associated with severe hypernatraemia and the causes, comorbidities, time to treatment, discharge destination and postdischarge mortality.

DESIGN

Retrospective observational cohort study.

PATIENTS

Severe hypernatraemia, (sodium concentration ≥ 155 mmol/L), at any time during a tertiary hospital admission in Melbourne, Australia, 1 January 2019 to 31 December 2019 (pre-COVID19).

MEASUREMENTS

Deaths, Charlson Comorbidity Index (CCI), hypernatraemia causes, time to treatment, discharge destination.

RESULTS

One hundred and one inpatients: 64 community-acquired, 37 hospital-acquired. In-hospital mortality was 38%, but cumulative mortality was 65% by 1 month after discharge, with only a minor further increase at 6 and 12 months. After adjusting for peak sodium concentration, the community acquired group had significantly reduced odds of in-hospital mortality (odds ratio 0.15, 95% confidence interval [0.04-0.54], p = .003). Iatrogenic factors were present in 57% (21/37) of the hospital-acquired group. Only 55% of all cases received active sodium directed treatment. Time to start treatment did not affect outcomes. High levels of comorbidity were present, median CCI (IQR) was 6 (5-8) in the community and 5 (4-7) in the hospital group. Dementia prevalence was higher in the community group, 66% (42/64) versus 19% (7/37) (p = .001). Infection was the most common precipitant with 52% (33/64) in the community and 32% (12/37) in the hospital group. Of the survivors, 32% who had been living independently required residential care after discharge.

CONCLUSIONS

Mortality was high and loss of independence in survivors common. To potentially improve outcomes, hypernatraemia-specific guidelines should be formulated and efforts made to reduce system and iatrogenic factors.

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

Background and objectives

The 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 methods

Retrospective 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.

Results

Our 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.

Conclusions

Brain 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.

Disorders of Sodium

Sodium imbalances are a common occurrence in the emergency department. Although recognition and diagnosis are relatively straightforward, discovering the cause and management should be approached systematically. The most important history items to ascertain is if the patient has symptoms and how long this imbalance has taken to develop. Treatment rapidity depends on severity of symptoms with the most rapid treatment occurring in only the severely symptomatic. Overcorrection has dire consequences and must be approached in a careful and systematic fashion in order to prevent these devastating consequences.

Impact of serum sodium concentrations, and effect modifiers on mortality in the Irish Health System

BACKGROUND

Abnormalities of serum sodium are associated with increased mortality risk in hospitalised patients, but it is unclear whether, and to what extent other factors influence this relationship. We investigated the impact of dysnatraemia on total and cause-specific mortality in the Irish health system while exploring the concurrent impact of age, kidney function and designated clinical work-based settings.

METHODS

A retrospective cohort study of 32,666 participants was conducted using data from the National Kidney Disease Surveillance System. Hyponatraemia was defined as < 135 mmol/L and hypernatraemia as > 145 mmol/L with normal range 135-145 mmol/L. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR's) and 95% Confidence Intervals (CIs) while penalised spline models further examined patterns of risk.

RESULTS

There were 5,114 deaths (15.7%) over a median follow up of 5.5 years. Dysnatraemia was present in 8.5% of patients overall. In multivariable analysis, both baseline and time-dependent serum sodium concentrations exhibited a U-shaped association with mortality. Hyponatremia was significantly associated with increased risk for cardiovascular [HR 1.38 (1.18-1.61)], malignant [HR: 2.49 (2.23-2.78)] and non-cardiovascular/non-malignant causes of death [1.36 (1.17-1.58)], while hypernatremia was significantly associated with cardiovascular [HR: 2.16 (1.58-2.96)] and non-cardiovascular/ non-malignant deaths respectively [HR: 3.60 (2.87-4.52)]. The sodium-mortality relationship was significantly influenced by age, level of kidney function and the clinical setting at baseline (P < 0.001). For hyponatraemia, relative mortality risks were significantly higher for younger patients (interaction term P < 0.001), for patients with better kidney function, and for patients attending general practice [HR 2.70 (2.15-3.36)] than other clinical settings. For hypernatraemia, age and kidney function remained significant effect modifiers, with patients attending outpatient departments experiencing the greatest risk [HR 9.84 (4.88-18.62)] than patients who attended other clinical locations. Optimal serum sodium thresholds for mortality varied by level of kidney function with a flattening of mortality curve observed for patients with poorer kidney function.

CONCLUSION

Serum sodium concentrations outside the standard normal range adversly impact mortality and are associated with specific causes of death. The thresholds at which these risks appear to vary by age, level of kidney function, and are modified in specific clinical settings within the health system.

Hypernatremia at presentation to the emergency department: a case series

Disorders of serum sodium are common findings in patients presenting to the emergency department (ED). The aim of this study was to systematically investigate the prevalence, symptoms, etiology, treatment as well as the course of hypernatremia present on admission to the ED. All adult patients with measurements of serum sodium presenting to the ED between 01 January 2017 and 31 December 2020 were included in this retrospective cohort study. Chart reviews were performed for all patients with hypernatremia defined as serum sodium > 147 mmol/L. 376 patients (0.7%) had a serum sodium > 145 mmol/L on admission and 109 patients (0.2%) had clinically relevant hypernatremia > 147 mmol/L. Main symptoms included somnolence (42%) followed by disorientation (30%) and recent falls (17%). An impaired sense of thirst was the main cause of hypernatremia as present in 76 patients (70%), followed by a lack of free access to water in 50 patients (46%). Regarding treatment, only one patient received targeted oral hydration and 38 patients (35%) experienced inadequate correction of hypernatremia as defined as either a correction of < 2 mmol/L or further increasing sodium during the first 24 h. 25% of patients with hypernatremia died during the course of their hospital stay. Patients who died had significantly lower correction rates of serum sodium (0 mmol/L (-3 - 1.5) versus - 6 mmol/L (-10 - 0), p < 0.001). Hypernatremia is regularly encountered in the ED and patients present with unspecific neurologic symptoms. Initial treatment and correction of hypernatremia are frequently inadequate with no decrease or even increase in serum sodium during the first 24 h.

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.

Prognostic value of dysnatremia for survival in neuroendocrine neoplasm patients

OBJECTIVE

Hyponatremia and hypernatremia are common electrolyte abnormalities in patients with malignancy and have been independently associated with worse survival outcomes. To date, there are no data on the impact of dysnatremia on survival outcomes in patients with neuroendocrine neoplasms (NENs).

DESIGN

This study involves retrospective cohort analysis from a tertiary care center of NEN patients treated with peptide receptor radionuclide therapy (PRRT) with a cumulative activity of at least 3.7 GBq 177Lu-DOTATATE between the years 2000 and 2015.

METHODS

Comparison of overall survival of patients with the occurrence of hyponatremia (serum sodium < 135 mmol/L) or hypernatremia (serum sodium > 145 mmol/L) before starting or during PRRT was perfomed.

RESULTS

A total of 649 patients were included. Hyponatremia occurred in 57 patients during the observation period and was associated with a shorter median overall survival (95% CI) of 25 months (14-36) compared to 55 months (48-61) of the 512 normonatremic patients (P < 0.001), adjusted hazard ratio (HR): 1.48 (95% CI: 1.04-2.12). Overall survival time was reduced regardless of whether hyponatremia was present at baseline or during PRRT. In contrast, hypernatremia occurred in 80 patients and was associated with a longer median overall survival (95% CI) of 94 months (47-140) compared with the 512 normonatremic patients (P = 0.018), adjusted HR: 0.61 (95% CI: 0.40-0.92). This association was driven by the patients with hypernatremia during PRRT. No association between dysnatremia and progression-free survival after PRRT was observed.

CONCLUSIONS

The occurrence of hypo- or hypernatremia in PRRT-treated NET patients is associated with opposing outcomes with regard to overall survival. Sodium levels might have a prognostic role in these patients.

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.

Hypernatremia at a Tertiary Hospital Intensive Care Unit in South Africa

Background

Hypernatremia in the critical care setting is a major cause of morbidity and mortality. However, data pertaining to this has not been evaluated in South African hospitals. The aim of this study was to evaluate hypernatremia with regards to its prevalence, associated factors, and outcomes at an academic hospital intensive care unit (ICU) in Johannesburg, South Africa.

Methods

The ICU charts of patients admitted to the Charlotte Maxeke Johannesburg Academic Hospital adult general ICU from June 1, 2016 to May 31, 2017 were retrospectively reviewed. Subjects were categorized into three groups namely, ICU-acquired hypernatremia (IAH), pre-admission hypernatremia (PAH), and normonatremia. Data was compared between the three groups.

Results

Of the 833 subjects that were enrolled, 310 (37.2%) were hypernatremic. IAH was present in 144 (17.2%) and PAH in 166 (19.9%) subjects. Hypernatremia was significantly (p <0.05) associated with a higher rate of altered mental status, higher Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II) scores, a higher rate and duration of mechanical ventilation, a greater need for inotropic/vasopressor support, longer ICU stay and higher ICU mortality.

Conclusion

Hypernatremia in ICU patients remains a significant contributor to morbidity, mortality, and ICU length of stay. The prevalence of hypernatremia was much higher than that reported in higher-income countries.

Predicting 30-day mortality using point-of-care testing; an external validation and derivation study

Background

Early risk stratification for guiding treatment priority in the emergency department (ED) is becoming increasingly important. Existing prediction models typically use demographics, vital signs and laboratory parameters. Laboratory-based models require blood testing, which may cause substantial delay. However, these delays can be prevented by the use of point-of-care testing (POCT), where results are readily available. We aimed to externally validate a laboratory-based model for mortality and subsequently assessed whether a POCT model yields comparable performance.

Methods

All adult patients visiting the ED of a university hospital between January 1^st, 2012 and December 31^st, 2016 were retrospectively reviewed for inclusion. Primary outcome was defined as 30-day mortality after ED presentation. We externally validated one existing prediction model including age, glucose, urea, sodium, haemoglobin, platelet count and white blood cell count. We assessed the predictive performance by discrimination, expressed as Area under the Curve (AUC). We compared the existing model to an equivalent model using predictors that are available with POCT (i.e. glucose, urea, sodium and haemoglobin). Additionally, we internally validated these models with bootstrapping.

Results

We included 34,437 patients of whom 1,942 (5.6%) died within 30 days. The AUC of the laboratory-based model was 0.794. We refitted this model to our ED population and found an AUC of 0.812, which decreased only slightly to 0.790 with only POCT parameters.

Conclusions

Our POCT-model performs similar to existing laboratory-based models in identifying patients at high risk for mortality, with results available within minutes. Although the model needs further validation and evaluation, it shows the potential of POCT for early risk stratification in the ED.

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.

Progression to Severe Hypernatremia in Hospitalized General Medicine Inpatients: An Observational Study of Hospital-Acquired Hypernatremia

Background and objectives: Hypernatremia can be community or hospital-acquired, and there may be specific factors unique to the hospital environment, such as intravenous fluid treatment, which contribute to hypernatremia. The aim of this study was to determine the factors associated with the progression from moderate to severe hospital-acquired hypernatremia among patients admitted under general medicine. Materials and Methods: In this retrospective, single-center cohort study (2012 to 2017), we used ICD-10 coding and medical records to identify adult patients who developed moderate hypernatremia and followed them for progression to severe hypernatremia. We profiled the serum biochemistry and the volume and composition of prescribed intravenous fluids. We applied logistic regression to determine the factors associated with the progression to severe hypernatremia, using the patients with moderate hypernatremia as reference. Results: Of the 180 medical inpatients (median age of 81 years) with moderate hospital-acquired hypernatremia, 9.4% progressed to severe hypernatremia. Normal saline comprised 76% of intravenous fluid volume administered prior to onset of moderate hypernatremia. After the onset, 38% of fluid volume prescribed remained normal saline. The factors independently associated with progression to severe hypernatremia included chronic kidney disease stage (odds ratio 2.38, 95% CI: 1.26-4.50, P = 0.008) and serum creatinine increase (per 10 µmol/L, OR 1.29, 95% CI: 1.07-1.57, P = 0.009). Conclusions: Patients with chronic kidney disease and acute kidney injury may have an increased risk of severe hospital-acquired hypernatremia.