Intensive care unit-acquired hypernatremia is an independent predictor of increased mortality and length of stay

Hypernatremia in hospitalised adult patients: A protocol for a scoping review

BACKGROUND

Hypernatremia is a common electrolyte disturbance in hospitalised patients associated with adverse outcomes. The aetiology is diverse but often related to fluid therapy and sodium-containing medicaments. We aim to outline the evidence base on hypernatremia in adult hospitalised patients.

METHODS

We will conduct a scoping review and adhere to the preferred reporting items for systematic and meta-analysis extension for scoping reviews (PRISMA-ScR). We will systematically search the Cochrane Library, Medline, Pubmed, and Embase from inception with no limitations to language, and include all study designs. We will use the population, exposure, comparator, and outcome-based approach to define eligibility criteria. The population: adult hospitalised patients; exposure: hypernatremia; comparator: no hypernatremia or all types of treatments of hypernatremia; and outcomes: all reported outcomes. Two authors will independently screen and select studies followed by full-text assessment and data extraction in duplicate. All outcome measures will be reported, and descriptive analyses will be performed. The certainty of evidence will be assessed according to an adapted grading of recommendations assessment, development, and evaluation (GRADE) approach.

DISCUSSION

This scoping review will provide an overview of the current evidence regarding the incidence of hypernatremia, treatment modalities, and outcomes reported for hospitalised adult patients with hypernatremia.

Challenges in Diagnosing and Managing Severe Hypernatremia in Patients With Major Depressive Disorder: A Case Report

Hypernatremia, characterized by a plasma sodium concentration above 145 mmol/L, is frequently observed in critically ill patients, often due to factors such as gastrointestinal losses, dehydration, and diabetes insipidus. Psychiatric patients, particularly those with major depressive disorder, are also at risk of developing hypernatremia due to abnormalities in thirst sensation, mineralocorticoid excess, or medication side effects. Severe hypernatremia in psychiatric patients is associated with a high mortality rate, presenting challenges in diagnosis and management. The treatment of chronic hypernatremia (>48 hours) typically involves administering isotonic saline to hypovolemic patients until normalization of vital signs, followed by dextrose 5% in water (D5W) based on water deficit and losses. The goal is to decrease plasma sodium by 8-10 mmol/day. Acute hypernatremia (<48 hours) is corrected with a plasma sodium reduction of 1 mmol/L/hour in the first six to eight hours. While there are no clear guidelines for sodium correction in severe hypernatremia, the literature suggests a safe correction rate of 8-10 mmol/day for chronic hypernatremia and 1 mmol/L/hour for acute cases. In a specific case, a 51-year-old female with severe depression and reduced oral intake was admitted. She exhibited signs of dehydration and was found to have severe hypernatremia (191 mmol/L) with acute kidney injury. Treatment involved D5W, followed by D5W/half-normal saline at 150 mL/hr. Within 24 hours, her plasma sodium decreased to 178 mmol/L and gradually normalized to 143 mmol/L without neurological complications. This case highlights the challenges and underscores the importance of early recognition and management of severe hypernatremia in psychiatric patients. The primary treatment approach addresses water deficits and losses and administers D5W. Recent findings suggest that rapid correction of the condition is acceptable.

Development of a Nomogram Model Based on Lactate-To-Albumin Ratio for Prognostic Prediction in Hospitalized Patients with Intracerebral Hemorrhage

OBJECTIVE

This study aims to develop a nomogram model incorporating lactate-to-albumin ratio (LAR) to predict the prognosis of hospitalized patients with intracerebral hemorrhage (ICH) and demonstrate its excellent predictive performance.

METHODS

A total of 226 patients with ICH from the Medical information mart for intensive care III (MIMIC Ⅲ) database were randomly split into 8:2 ratio training and experimental groups, and 38 patients from the eICU-CRD for external validation. Univariate and multivariate Cox proportional hazards regression analysis was performed to identify independent factors associated with ICH, and multivariate Cox regression was used to construct nomograms for 7-day and 14-day overall survival (OS). The performance of nomogram was verified by the calibration curves, decision curves, and receiver operating characteristic (ROC) curves.

RESULTS

Our study identified LAR, glucose, mean blood pressure, sodium, and ethnicity as independent factors influencing in-hospital prognosis. The predictive performance of our nomogram model for predicting 7-day and 14 -day OS (AUCs: 0.845 and 0.830 respectively) are both superior to Oxford Acute Severity of Illness Score, Simplified acute physiology score II, and SIRS (AUCs: 0.617, 0.620 and 0.591 and AUCs: 0.709, 0.715 and 0.640, respectively) in internal validation, and also demonstrate favorable predictive performance in external validation (AUCs: 0.778 and 0.778 respectively).

CONCLUSIONS

LAR as a novel biomarker is closely associated with an increased risk of in-hospital mortality of patients with ICH. The nomogram model incorporating LAR along with glucose, mean blood pressure, sodium, and ethnicity demonstrate excellent predictive performance for predicting the prognosis of 7- and 14-day OS of hospitalized patients with ICH.

Dysnatremia as a Mortality Marker in Intensive Care Patients with SARS-CoV-2 Infection: A Retrospective Study

Background and Objectives: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection may cause acute respiratory failure, but also remains responsible for many other pathologies, including electrolyte disorders. SARS-CoV-2 infection causes disorders in many systems and can disrupt water homeostasis with thirst and appetite abnormalities. Dysnatremia affects prognosis, and may be associated with mortality in patients admitted to an intensive care unit (ICU) diagnosed with SARS-CoV-2. Materials and Methods: The study included 209 patients admitted to the ICU between 12 April 2021 and 1 March 2022 who were over 18 years old and diagnosed with SARS-CoV-2 infection by clinical and thoracic tomography findings or with a positive reverse transcription polymerase chain reaction (RT-PCR) test result. The laboratory markers, treatment modalities, nutritional, and respiratory support also for outcome evaluation, length of stay in the ICU, total hospitalization duration, and mortality in the ICU were recorded. The laboratory marker comparison was made using admission with the final assessment performed before the time of mortality in the ICU or after discharge. Results: Inotropic requirements among patients were high, which reflected mortality in the ICU. Hypernatremia presence was associated with an increase in enteral support, the inotropic support requirement, and mortality. Hypernatremia was correlated with diabetes mellitus, chronic renal failure, and a longer duration under mechanical ventilation. Conclusions: Hypernatremia was an important risk factor in ICU patients hospitalized for SARS-CoV-2 infection, which was also affected by the treatment regimens given themselves. This complex relationship underlies the importance of proper electrolyte management, especially in patients who were under severe stress and organ failure.

The impact of tubular dysfunction and its relationship with acute kidney injury in children

BACKGROUND

Tubular dysfunction can cause electrolyte disturbances with potentially serious consequences. We studied the epidemiology and outcomes of electrolyte disturbances and tubular dysfunction among critically ill children and evaluated their relationships with acute kidney injury (AKI).

METHODS

We conducted a prospective cohort study recruiting children aged 1 month to ≤ 18 years old admitted to the pediatric intensive care unit (PICU) from 6/2020 to 6/2021. The serum levels of sodium, potassium, calcium, phosphate, and magnesium were reviewed and simultaneous urinary investigations for tubular function were performed among children with electrolyte disturbances.

RESULTS

Altogether there were 253 episodes of admission. The median (interquartile) age was 4.9 (1.3-11.0) years and 58.1% were male. The median number of electrolyte disorders was 3 (2-4) types. Hypophosphatemia (74.2%), hypocalcemia (70.3%) and hypermagnesemia (52.9%) were the three commonest types of disturbances. Urinary electrolyte wasting was commonly observed among children with hypomagnesemia (70.6%), hypophosphatemia (67.4%) and hypokalemia (28.6%). Tubular dysfunction was detected in 82.6% of patients and urinary β2-microglobulin level significantly correlated with the severity of tubular dysfunction (p < 0.001). The development of tubular dysfunction was independent of AKI status. Tubular dysfunction was associated with mortality (p < 0.001) and was an independent predictor of PICU length of stay (LOS) (p < 0.001). The incorporation of the tubular dysfunction severity into the AKI staging system improved the prediction of PICU LOS.

CONCLUSIONS

Tubular dysfunction was associated with both morbidity and mortality in critically ill children and its assessment may help to capture a more comprehensive picture of acute kidney insult.

Association of admission serum sodium and outcomes following out-of-hospital cardiac arrest

BACKGROUND

The prognostic association between dysnatremia and outcomes in out-of-hospital cardiac arrest (OHCA) is not well understood. Given hypernatremia is associated with poor outcomes in critical illness and hyponatremia may exacerbate cerebral edema, we hypothesized that dysnatremia on OHCA hospital admission would be associated with worse neurological outcomes.

METHODS

We studied adults (≥19 years) with non-traumatic OHCA between 2009 and 2016 who were enrolled in the British Columbia Cardiac Arrest Registry and survived to hospital admission at 2 quaternary urban hospitals. We stratified cases by admission serum sodium into hyponatremic (<135 mmol/L), normonatremic (135-145 mmol/L), and hypernatremic (>145 mmol/L) groups. We used logistic regression models, adjusted for age, sex, shockable rhythm, admission serum lactate, and witnessed arrest, to estimate the association between admission sodium and favorable neurological outcome (cerebral performance category 1-2 or modified Rankin scale 0-3).

RESULTS

Of 414 included patients, 63 were hyponatremic, 330 normonatremic, and 21 hypernatremic. In each respective group, 21 (33.3%), 159 (48.2%), and 3 (14.3%) experienced good neurological outcomes. In univariable models, hyponatremia (OR 0.53, 95% CI 0.30-0.93) and hypernatremia (OR 0.19, 95% CI 0.05-0.65) were associated with lower odds of good neurological outcomes compared to the normonatremia group. After adjustment, only hypernatremia was associated with lower odds of good neurological outcomes (OR 0.22, 95% CI 0.05-0.98).

CONCLUSIONS

Hypernatremia at admission was independently associated with decreased probability of good neurological outcomes at discharge post-OHCA. Future studies should focus on elucidating the pathophysiology of dysnatremia following OHCA.

Outcomes of Hospital-Acquired Hypernatremia

BACKGROUND

Hospital-acquired hypernatremia is highly prevalent, overlooked, and associated with unfavorable consequences. There are limited studies examining the outcomes and discharge dispositions of various levels of hospital-acquired hypernatremia in patients with or without CKD.

METHODS

We conducted an observational retrospective cohort study, and we analyzed the data of 1,728,141 patients extracted from the Cerner Health Facts database (January 1, 2000, to June 30, 2018). In this report, we investigated the association between hospital-acquired hypernatremia (serum sodium [Na] levels >145 mEq/L) and in-hospital mortality or discharge dispositions with kidney function status at admission using adjusted multinomial regression models.

RESULTS

Of all hospitalized patients, 6% developed hypernatremia after hospital admission. The incidence of in-hospital mortality was 12% and 1% in patients with hypernatremia and normonatremia, respectively. The risk of all outcomes was significantly greater for serum Na >145 mEq/L compared with the reference interval (serum Na, 135-145 mEq/L). In patients with hypernatremia, odds ratios (95% confidence interval) for in-hospital mortality, discharge to hospice, and discharge to nursing facilities were 14.04 (13.71 to 14.38), 4.35 (4.14 to 4.57), and 3.88 (3.82 to 3.94), respectively ( P < 0.001, for all). Patients with eGFR (Chronic Kidney Disease Epidemiology Collaboration) 60-89 ml/min per 1.73 m 2 and normonatremia had the lowest odds ratio for in-hospital mortality (1.60 [1.52 to 1.70]).

CONCLUSIONS

Hospital-acquired hypernatremia is associated with in-hospital mortality and discharge to hospice or to nursing facilities in all stages of CKD.

Electrolyte Imbalance Among Bangladeshi Patients With COVID-19

Introduction Infection with SARS-CoV-2 begins in the lower respiratory tract, but COVID-19 often involves the renal system, resulting in serum electrolyte imbalance. Monitoring serum electrolyte levels and parameters of liver and kidney function is essential to understand disease prognosis. Objectives This study aimed to determine the effect of imbalances in serum electrolytes and other parameters on COVID-19 severity. Material and method This retrospective study comprised 241 patients, ages 14 years and older, including 186 patients who were moderately affected and 55 who were categorized as severely affected by COVID-19. Serum electrolytes (sodium (Na⁺), potassium (K⁺), and chloride (Cl^-)) and biomarkers of kidney and liver function (creatinine and alanine aminotransferase (ALT)) were measured and correlated with disease severity. This research was conducted among admitted patients of Holy Family Red Crescent Medical College Hospital designated into two groups based on retrospective hospital records. Individuals with moderate illness had evidence of lower respiratory tract infection (cough, cold, breathless, etc.) during clinical assessment or imaging (chest X-ray and computed tomography (CT) scan of the lungs) and have an oxygen saturation by pulse oximetry (SpO₂) ≥ 94% on room air at sea level. The severely ill group involved individuals with SpO₂ ≤94% on room air at sea level and respiratory rate ≥ 30 breaths/minute, and critically ill patients are those who needed mechanical ventilation or required intensive care unit (ICU) care. This categorization was based on the Coronavirus Disease 2019 (COVID-19) Treatment Guidelines (https://www.covid19treatmentguidelines.nih.gov/about-the-guidelines/whats-new/). Results Average Na⁺ and creatinine increased by 2.30 parts (95% confidence interval (CI) = 0.20, 4.81, P = 0.041) and 0.35 units (95% CI = 0.03, 0.68, P = 0.043) in severe cases compared with moderate cases. Older participants had relatively Na⁺ lowered to -0.06 parts (95% CI = -0.12, -0.001, P = 0.045), significant Cl^- reduction by 0.09 units (95% CI = -0.14, -0.04, P = 0.001), and ALT by 0.47 units (95% CI = -0.88, -0.06, P = 0.024), whereas serum creatinine was increased by 0.01 parts (95% CI = 0.001, 0.02, P = 0.024). The creatinine and ALT of COVID-19 participants were significantly higher in males by 0.34 units and 23.2 units, respectively, compared with females. In severe COVID-19 cases compared with moderate cases, the risks of hypernatremia, elevated chloride levels, and elevated serum creatinine levels were increased by 2.83-fold (95% CI = 1.26, 6.36, P = 0.012), 5.37-fold (95% CI = 1.90, 15.3, P = 0.002), and 2.00-fold (95% CI = 1.08, 4.31, P = 0.039), respectively. Conclusion Serum electrolyte and biomarker levels can serve as good indicators of the condition and disease prognosis of patients with COVID-19. Our purpose in this study was to determine the association between serum electrolyte imbalance and disease severity. We collected data from ex post facto hospital records and did not intend to assess the mortality rate. Consequently, this study expects that the prompt diagnosis of electrolyte disparity or disturbance possibly minimizes COVID-19-related morbidity and mortality.

Clinical Outcomes Associated with Degree of Hypernatremia in Neurocritically Ill Patients

OBJECTIVE

Hypernatremia is a common complication encountered during the treatment of neurocritically ill patients. However, it is unclear whether clinical outcomes correlate with the severity of hypernatremia in such patients. Therefore, we investigated the impact of hypernatremia on mortality of these patients, depending on the degree of hypernatremia.

METHODS

Among neurosurgical patients admitted to the intensive care unit (ICU) in a tertiary hospital from January 2013 to December 2019, patients who were hospitalized in the ICU for more than 5 days and whose serum sodium levels were obtained during ICU admission were included. Hypernatremia was defined as the highest serum sodium level exceeding 150 mEq/L observed. We classified the patients into four subgroups according to the severity of hypernatremia and performed propensity score matching analysis.

RESULTS

Among 1146 patients, 353 patients (30.8%) showed hypernatremia. Based on propensity score matching, 290 pairs were included in the analysis. The hypernatremia group had higher rates of in-hospital mortality and 28-day mortality in both overall and matched population (both p<0.001 and p=0.001, respectively). In multivariable analysis of propensity score-matched population, moderate and severe hypernatremia were significantly associated with in-hospital mortality (adjusted odds ratio [OR], 4.58; 95% confidence interval [CI], 2.15-9.75 and adjusted OR, 6.93; 95% CI, 3.46-13.90, respectively) and 28-day mortality (adjusted OR, 3.51; 95% CI, 1.54-7.98 and adjusted OR, 10.60; 95% CI, 5.10-21.90, respectively) compared with the absence of hypernatremia. However, clinical outcomes, including in-hospital mortality and 28-day mortality, were not significantly different between the group without hypernatremia and the group with mild hypernatremia (p=0.720 and p=0.690, respectively). The mortality rates of patients with moderate and severe hypernatremia were significantly higher in both overall and matched population. Interestingly, the mild hypernatremia group of matched population showed the best survival rate.

CONCLUSION

Moderate and severe hypernatremia were associated with poor clinical outcomes in neurocritically ill patients. However, the prognosis of patients with mild hypernatremia was similar with that of patients without hypernatremia. Therefore, mild hypernatremia may be allowed during treatment of intracranial hypertension using hyperosmolar therapy.

Urinary sodium excretion is low prior to acute kidney injury in patients in the intensive care unit

Background

The incidence of acute kidney injury (AKI) is high in intensive care units (ICUs), and a better understanding of AKI is needed. Early chronic kidney disease is associated with urinary concentration inability and AKI recovery with increased urinary solutes in humans. Whether the inability of the kidneys to concentrate urine and excrete solutes at appropriate levels could occur prior to the diagnosis of AKI is still uncertain, and the associated mechanisms have not been studied.

Methods

In this single-center prospective observational study, high AKI risk in ICU patients was followed up for 7 days or until ICU discharge. They were grouped as "AKI" or "No AKI" according to their AKI status throughout admission. We collected daily urine samples to measure solute concentrations and osmolality. Data were analyzed 1 day before AKI, or from the first to the fifth day of admission in the "No AKI" group. We used logistic regression models to evaluate the influence of the variables on future AKI diagnosis. The expression of kidney transporters in urine was evaluated by Western blotting.

Results

We identified 29 patients as "No AKI" and 23 patients as "AKI," the latter being mostly low severity AKI. Urinary sodium excretion was lower in "AKI" patients prior to AKI diagnosis, particularly in septic patients. The expression of Na+/H+ exchanger (NHE3), a urinary sodium transporter, was higher in "AKI" patients.

Conclusions

Urinary sodium excretion is low before an AKI episode in ICU patients, and high expressions of proximal tubule sodium transporters might contribute to this.

Associations of Dysnatremia with COVID-19 Status and Mortality

Background

In patients without COVID-19, dysnatremia is associated with mortality. These relationships are not well established in patients with COVID-19. We tested the hypotheses that patients with COVID-19 were more likely to have dysnatremia than those without COVID-19 and that, among those with COVID-19, dysnatremia is associated with mortality.

Methods

We conducted a retrospective observational study of patients admitted to a tertiary care center in the Bronx, New York, during the COVID-19 surge from March 11 to April 26, 2020. Using multinomial logistic regression models, we compared the prevalence of hypernatremia (serum sodium ≥150 mEq/L) and hyponatremia (serum sodium <130 mEq/L) on admission between patients with and without COVID-19. Among patients with COVID-19, we used Cox proportional hazards models to examine the association of dysnatremia with mortality.

Results

Compared with those without COVID-19 (n=1265), patients with COVID-19 (n=3345) had a higher prevalence of hypernatremia (7% versus 4%, P<0.001) and hyponatremia (7% versus 6%, P=0.04). In adjusted models, COVID-19-positive patients had a higher likelihood of having hypernatremia (adjusted odds ratio=1.87, 95% CI, 1.3 to 2.57, P=0.001) compared with COVID-19-negative patients, whereas the association between hyponatremia and COVID-19 status was no longer significant (P=0.06). Among patients with COVID-19, 775 (23%) died after a median follow-up of 17 days (IQR 7-27 days). Among nonsurvivors, 15% had hypernatremia and 8% had hyponatremia on admission. Hypernatremia was associated with a higher risk of mortality (adjusted hazard ratio=1.28, 95% CI, 1.01 to 1.63, P=0.04) compared with patients with eunatremia.

Conclusions

In patients hospitalized during the spring 2020 COVID-19 surge, COVID-19 status was associated with hypernatremia on admission. Among patients with COVID-19, hypernatremia was associated with higher mortality. Hypernatremia may be a potential prognostic marker for mortality in COVID-19 patients.

The Impact of Hypernatremia in Preterm Infants on Neurodevelopmental Outcome at 18 Months of Corrected Age

OBJECTIVE

The study objective was to assess the correlation between hypernatremia during the first week of life and neurodevelopmental outcomes at 18 months of corrected age in premature infants.

STUDY DESIGN

A retrospective observational study of preterm infants born at less than 32 weeks of gestation who had a neurodevelopmental assessment with the Bayley scales of infant and toddler development III at 18 ± 6 months of corrected age. Serum sodium levels from birth through 7 days of life were collected. The study cohort was divided into two groups: infants with a peak serum sodium of >145 mmol/L (hypernatremia group) and infants with a peak serum sodium level of <145 mmol/L (no hypernatremia group). Prenatal, intrapartum, and postnatal hospital course and neurodevelopmental data at 18 ± 6 months were collected. Logistic regression analysis was used to assess the correlation between neonatal hypernatremia and neurodevelopment with adjustment for selected population characteristics.

RESULTS

Eighty-eight preterm infants with complete neurodevelopmental outcome data at 18 ± 6 months of corrected gestational age were included in the study. Thirty-five neonates were in the hypernatremia group and 53 were in the no hypernatremia group. Maternal and neonatal characteristics were similar between the two groups except that the hypernatremia group had a significantly lower average birth weight and gestational age. Comparison of the mean neurodevelopmental scores between the two groups showed that patients in the hypernatremia group as compared with those in the no hypernatremia group had significantly lower neurodevelopmental scaled scores in the fine motor domain (p = 0.01). This difference remained significant (p = 0.03, odds ratio [OR] = 0.8, 95% confidence interval [CI]: 0.6-0.97) when adjusted for birth weight and gestational age.

CONCLUSION

Preterm infants born at less than 32 weeks of gestation with hypernatremia in the first week of life have lower fine motor scores at 18 months of corrected age.

KEY POINTS

· Hypernatremia is a common electrolyte disturbance in preterm neonates.. · Hypernatremia may be associated with long-term neurodevelopmental outcomes in preterm infants.. · Hypernatremia is a potentially modifiable risk factor..

Hypernatremia in the intensive care unit

PURPOSE OF REVIEW

Hypernatremia is a relatively frequent electrolyte disorder seen in critically ill patients. As many as 27% of patients in intensive care units (ICUs) develop hypernatremia of variable severity during an ICU stay. Debate among specialists often ensues as to whether to correct hypernatremia or not. Some practitioners, particularly intensivists, believe that correction of hypernatremia with fluids may cause expansion of the extracellular fluid volume (ECFV) thereby worsening ventilation and impeding extubation. Other practitioners, including many nephrologists, do not expect correction of hypernatremia to lead to clinically apparent ECFV expansion, and fear other deleterious effects of hypernatremia. In this review we address the controversy regarding appropriate practice.

RECENT FINDINGS

There are no randomized, clinical trials (RCTs) to guide the administration of electrolyte-free fluid administration in hypernatremic patients. However, there are associations, demonstrated in the literature, suggesting that hypernatremia of any severity will increase the mortality and length of stay in these patients. These associations generally support the practice of correction of hypernatremia. In addition, our knowledge of the distribution of total body water influences us towards correcting hypernatremia as an appropriate therapy. We do not expect that adequate RCTs addressing this question will be performed.

SUMMARY

Allowing persistence of any degree of hypernatremia is associated with increased mortality, length of stay (LOS) and postdischarge mortality. We expect that proper use of electrolyte-free water intake will avoid adverse 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.

Hypophosphataemia is common in patients with aneurysmal subarachnoid haemorrhage

INTRODUCTION

Hypophosphataemia is common in critically ill patients, but neither its prevalence nor its association with outcome have been investigated specifically in patients with aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

Patients with aSAH and at least one phosphate measurement were included from two independent cohorts; an American cohort extracted from two open-access databases (Medical Information Mart for Intensive Care-III and eICU Collaborative Research Database v. 2.0) and a Danish cohort consisting of patients with aSAH admitted to Rigshospitalet, Denmark over a 4-year period. In each cohort, we calculated the prevalence of mild (0.32-0.80 mmol/L) and severe (<0.32 mmol/L) hypophosphataemia and their association with in-hospital mortality before and after propensity-score matching.

RESULTS

Hypophosphataemia occurred in 72.4% (95% CI: 68.1-76.3) of patients in the American cohort (n = 471) and 54.9% (50.0-59.7) in the Danish cohort (n = 419). However, it was not associated with mortality in neither full (American: Mild, Odds ratio (OR) 0.99 (0.91-1.07), Severe OR 1.20 (0.95-1.51); Danish: Mild, OR 1.01 (0.95-1.08), Severe OR 1.20 (0.95-1.51)) nor propensity-score matched cohorts (American (n = 168): Mild, OR 1.06 (0.88-1.28), Severe OR 1.46 (0.96-2.12); Danish (n = 44): Mild, OR 1.16 (0.82-1.65), Severe OR 0.45 (0.13-1.55)).

CONCLUSION

In this retrospective study of patients with aSAH, hypophosphataemia was common.

Electrolyte and acid-base imbalance in severe COVID-19

Acute systemic diseases, such as severe infections, can lead to electrolyte and acid-base alterations. To study the presence of electrolyte imbalance in severe COVID-19, we investigated the frequency and consequences of changes in electrolyte and acid-base patterns over time. We performed a retrospective cohort study including 406 patients with severe COVID-19. Levels of electrolytes, base excess, pH, serum osmolality, and hematocrit, the first 2 weeks of hospitalization, were collected daily from the laboratory database and clinical data from patients' medical records. We found that hyponatremia was present in 57% of the patients at admission and 2% in hypernatremia. However, within 2 weeks of hospitalization 42% of the patients developed hypernatremia, more frequently in critically ill patients. Lower levels of sodium and potassium during admission were associated with the need for mechanical ventilation. Decreased pH at admission was associated with both death and the need for mechanical ventilation. Hypernatremia in the ICU was combined with rising base excess and a higher pH. In the group without intensive care, potassium levels were significantly lower in the patients with severe hypernatremia. Presence of hypernatremia during the first 2 weeks of hospitalization was associated with 3.942 (95% CI 2.269-6.851) times higher odds of death. In summary, hypernatremia was common and associated with longer hospital stay and a higher risk of death, suggesting that the dynamics of sodium are an important indicator of severity in COVID-19.

Association Between an Increase in Serum Sodium and In-Hospital Mortality in Critically Ill Patients

Supplemental Digital Content is available in the text.

OBJECTIVES:

In critically ill patients, dysnatremia is common, and in these patients, in-hospital mortality is higher. It remains unknown whether changes of serum sodium after ICU admission affect mortality, especially whether normalization of mild hyponatremia improves survival.

DESIGN:

Retrospective cohort study.

SETTING:

Ten Dutch ICUs between January 2011 and April 2017.

Patients:

Adult patients were included if at least one serum sodium measurement within 24 hours of ICU admission and at least one serum sodium measurement 24–48 hours after ICU admission were available.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

A logistic regression model adjusted for age, sex, and Acute Physiology and Chronic Health Evaluation-IV–predicted mortality was used to assess the difference between mean of sodium measurements 24–48 hours after ICU admission and first serum sodium measurement at ICU admission (Δ48 hr-[Na]) and in-hospital mortality. In total, 36,660 patients were included for analysis. An increase in serum sodium was independently associated with a higher risk of in-hospital mortality in patients admitted with normonatremia (Δ48 hr-[Na] 5–10 mmol/L odds ratio: 1.61 [1.44–1.79], Δ48 hr-[Na] > 10 mmol/L odds ratio: 4.10 [3.20–5.24]) and hypernatremia (Δ48 hr-[Na] 5–10 mmol/L odds ratio: 1.47 [1.02–2.14], Δ48 hr-[Na] > 10 mmol/L odds ratio: 8.46 [3.31–21.64]). In patients admitted with mild hyponatremia and Δ48 hr-[Na] greater than 5 mmol/L, no significant difference in hospital mortality was found (odds ratio, 1.11 [0.99–1.25]).

CONCLUSIONS:

An increase in serum sodium in the first 48 hours of ICU admission was associated with higher in-hospital mortality in patients admitted with normonatremia and in patients admitted with hypernatremia.

Increased sodium intake and decreased sodium excretion in ICU-acquired hypernatremia: A prospective cohort study

PURPOSE

To provide more in-depth insight in the development of early ICU-acquired hypernatremia in critically ill patients based on detailed, longitudinal and quantitative data.

MATERIALS AND METHODS

A comparative analysis was performed using prospectively collected data of ICU patients. All patients requiring ICU admission for more than 48 h between April and December 2018 were included. For this study, urine samples were collected daily and analyzed for electrolytes and osmolality. Additionally, plasma osmolality analyses were performed. Further data collection consisted of routine laboratory results, detailed fluid balances and medication use.

RESULTS

A total of 183 patient were included for analysis, of whom 38% developed ICU-acquired hypernatremia. Whereas the hypernatremic group was similar to the non-hypernatremic group at baseline and during the first days, hypernatremic patients had a significantly higher sodium intake on day 2 to 5, a lower urine sodium concentration on day 3 and 4 and a worse kidney function (plasma creatinine 251 versus 71.9 μmol/L on day 5). Additionally, hypernatremic patients had higher APACHE IV scores (67 versus 49, p < 0.05) and higher ICU (23 versus 12%, p = 0.07) and 90-day mortality (33 versus 14%, p < 0.01).

CONCLUSIONS

Longitudinal analysis shows that the development of early ICU-acquired hypernatremia is preceded by increased sodium intake, decreased renal function and decreased sodium excretion.

Distinct osmoregulatory responses to sodium loading in patients with altered glycosaminoglycan structure: a randomized cross-over trial

Background

By binding to negatively charged polysaccharides called glycosaminoglycans, sodium can be stored in the body—particularly in the skin—without concurrent water retention. Concordantly, individuals with changed glycosaminoglycan structure (e.g. type 1 diabetes (DM1) and hereditary multiple exostosis (HME) patients) may have altered sodium and water homeostasis.

Methods

We investigated responses to acute (30-min infusion) and chronic (1-week diet) sodium loading in 8 DM1 patients and 7 HME patients in comparison to 12 healthy controls. Blood samples, urine samples, and skin biopsies were taken to investigate glycosaminoglycan sulfation patterns and both systemic and cellular osmoregulatory responses.

Results

Hypertonic sodium infusion increased plasma sodium in all groups, but more in DM1 patients than in controls. High sodium diet increased expression of nuclear factor of activated t-cells 5 (NFAT5)—a transcription factor responsive to changes in osmolarity—and moderately sulfated heparan sulfate in skin of healthy controls. In HME patients, skin dermatan sulfate, rather than heparan sulfate, increased in response to high sodium diet, while in DM1 patients, no changes were observed.

Conclusion

DM1 and HME patients show distinct osmoregulatory responses to sodium loading when comparing to controls with indications for reduced sodium storage capacity in DM1 patients, suggesting that intact glycosaminoglycan biosynthesis is important in sodium and water homeostasis.

Trial registration These trials were registered with the Netherlands trial register with registration numbers: NTR4095 (https://www.trialregister.nl/trial/3933 at 2013-07-29) and NTR4788 (https://www.trialregister.nl/trial/4645 at 2014-09-12).

Association Between ICU-Acquired Hypernatremia and In-Hospital Mortality: Data From the Medical Information Mart for Intensive Care III and the Electronic ICU Collaborative Research Database

Objectives

Describe the relationship between ICU-acquired hypernatremia and in-hospital mortality and investigate the optimal hypernatremia correction rate.

Design Setting Participants and Measurements

Observational study including two individual ICU cohorts. We used the Medical Information Mart for Intensive Care III v. 1.4 database consists of all ICU patients admitted to the Beth Israel Deaconess Medical Center in Boston from 2001 to 2012 (n = 46,476). The electronic ICU v. 2.0 database consists of all ICU patients admitted to 208 distinct hospitals across the United States from 2014 to 2015 (n = 200,859). We included all adult patients admitted to an ICU with two consecutive sodium samples within normal range (135-145 mmol/L) and without two consecutive hyponatremic samples (< 135 mmol/L) during the ICU stay.

Results

Of 23,445 patients identified in Medical Information Mart for Intensive Care III, 9% (n = 2,172) developed hypernatremia during their ICU stay. In electronic ICU, 88,160 patients were identified and 7% (n = 5,790) developed hypernatremia. In both cohorts, patients with hypernatremia had a higher mortality (Medical Information Mart for Intensive Care III: 20% vs 42%; p < 0.01 and electronic ICU: 6% vs 22%; p < 0.01), with hypernatremia increasing the risk of in-hospital mortality (Medical Information Mart for Intensive Care III: odds ratio, 1.15; 95% CI, 1.13-1.17 and electronic ICU: odds ratio, 1.11; 95% CI, 1.10-1.12) and over time using a Cox regression. Rapid sodium correction rate (> 0.5 mmol/L/hr) was associated with an increased in-hospital mortality in both cohorts (Medical Information Mart for Intensive Care III: odds ratio, 1.08; 95% CI, 1.03-1.13 and electronic ICU: odds ratio, 1.10; 95% CI, 1.06-1.13). In the electronic ICU cohort, rapid correction rates were associated with a significant difference in in-hospital mortality, but there was no statistically significant association in the Medical Information Mart for Intensive Care III cohort.

Conclusions

ICU-acquired hypernatremia is associated with increased in-hospital mortality. Furthermore, a rapid sodium correction rates may be harmful. This suggests it is important to both prevent ICU-acquired hypernatremia and to avoid rapid correction rates if a patient becomes hypernatremic.

Natremia and liver transplantation: The right amount of salt for a good recipe

An adequate balance between electrolytes and clear water is of paramount importance to maintaining physiologic homeostasis. Natremia imbalance and, in particular, hyponatremia is the most frequent electrolyte abnormality observed in hospitalized subjects, involving approximately one-fourth of them. Pathological changes occurring during liver cirrhosis predispose patients to an increased risk of sodium imbalance, and hypervolemic hyponatremia has been reported in nearly 50% of subjects with severe liver disease and ascites. Splanchnic vasodilatation, portal-systemic collaterals’ opening and increased excretion of vasoactive modulators are all factors impairing clear water handling during liver cirrhosis. Of concern, sodium imbalance has been consistently reported to be associated with increased risk of complications and reduced survival in liver disease patients. In the last decades clinical interest in sodium levels has been also extended in the field of liver transplantation. Evidence that [Na⁺] in blood is an independent risk factor for in-list mortality led to the incorporation of sodium value in prognostic scores employed for transplant priority, such as model for end-stage liver disease-Na and UKELD. On the other hand, severe hyponatremic cirrhotic patients are frequently delisted by transplant centers due to the elevated risk of mortality after grafting. In this review, we describe in detail the relationship between sodium imbalance and liver cirrhosis, focusing on its impact on peritransplant phases. The possible therapeutic approaches, in order to improve transplant outcome, are also discussed. 

ICU acquired hypernatremia treated by enteral free water - A retrospective cohort study

PURPOSE

ICU acquired hypernatremia (IAH) is associated with increased morbidity and mortality, however treatment remains controversial. This study aims to determine the effect of enteral free water suppletion in patients with IAH.

MATERIALS AND METHODS

Retrospective single center study in a tertiary ICU.

INCLUSION CRITERIA

patients with IAH and treatment with enteral free water.

EXCLUSION CRITERIA

patients with renal replacement therapy, diabetic ketoacidosis or hyperosmolar hyperglycaemic state.

PRIMARY OUTCOME

change in plasma sodium (in mmol/l) after 5 days treatment. Responders were defined as patients with a decrease in sodium level of 5 mmol/l or more.

RESULTS

In total 382 consecutive patients were included. The median sodium level at the start of water therapy was 149 mmol/l (IQR 147-150). The median volume of enteral water was 4423 ml (IQR 3349-5379 ml) after 5 days and mean sodium decrease was 1.87 mmol/l (SD 4.84). There was no significant correlation between the volume of enteral water and sodium decrease (r² = 0.01).

CONCLUSIONS

Treatment with enteral free water did not result in a clinically relevant decrease in serum sodium level in patients with IAH. In addition, the volume of enteral free water and the use of diuretics was unrelated with sodium change over 5 days.

Renal Function is a Major Determinant of ICU-acquired Hypernatremia: A Balance Study on Sodium Handling

Background and Objectives

The development of ICU-acquired hypernatremia (IAH) is almost exclusively attributed to ‘too much salt and too little water’. However, intrinsic mechanisms also have been suggested to play a role. To identify the determinants of IAH, we designed a prospective controlled study.

Methods

Patients with an anticipated length of stay ICU > 48 hours were included. Patients with hypernatremia on admission and/or on renal replacement therapy were excluded. Patients without IAH were compared with patients with borderline hypernatremia (≥ 143 mmol/L, IAH 143) and more severe hypernatremia (≥ 145 mmol/L, IAH 145).

Results

We included 89 patients, of which 51% developed IAH 143 and 29% IAH 145. Sodium intake was high in all patients. Fluid balances were slightly positive and comparable between the groups. Patients with IAH 145 were more severely ill on admission, and during admission, their sodium intake, cumulative sodium balances, serum creatinine and copeptin levels were higher. According to the free water clearance, all the patients conserved water. On multivariate analysis, the baseline serum creatinine was an independent risk factor for the development of IAH 143 and IAH 145. Also, the copeptin levels remained significant for IAH 143 and IAH 145. Sodium intake remained only significant for patients with IAH 145.

Conclusions

Our data support the hypothesis that IAH is due to the combination of higher sodium intake and a urinary concentration deficit, as a manifestation of the renal impairment elicited by severe illness.

Glucocorticoid treatment is associated with ICU-acquired hypernatremia: a nested case-control study

BACKGROUND

Hypernatremia is a major electrolyte disorder associated with death among critically ill patients. Glucocorticoid therapy may cause hypernatremia in refractory septic shock patients, but the association between glucocorticoid and intensive care unit (ICU)-acquired hypernatremia (IAH) remains unclear. The aim of this study was to clarify whether glucocorticoid administration was associated with IAH.

METHODS

This was a nested case-control study using data from an established cohort including 121 IAH cases identified from 1756 patients who were admitted to ICU in a tertiary care facility in Japan. We included patients who were admitted with a normal range of serum sodium concentrations (130-149 mEq/L) from January 1, 2013 to December 31, 2015 and remained in ICU for ≥ 2 days. Hypernatremia was defined as serum sodium concentration ≥ 150 mEq/L. Each case was matched to one control.

RESULTS

Multivariable conditional logistic regression revealed high-dose glucocorticoid {odds ratio (OR), 4.15 [95% confidence interval (CI) 1.29-13.4]}, acute kidney injury (AKI) [OR, 2.72 (95% CI 1.31-5.62)], and osmotic diuretics [OR, 3.44 (95% CI 1.41-8.39)] to be significantly associated with IAH. The contents and amounts of fluid infusion were not significantly associated with IAH. There were also significant duration-response effects between duration of glucocorticoid use and IAH; however, pulse glucocorticoid administration was not associated with IAH.

CONCLUSION

In this nested case-control study, we demonstrated a significant association between IAH and high-dose glucocorticoid with significant duration-response effects. Serum sodium concentrations should be monitored carefully in critically ill patients administered prolonged high-dose glucocorticoid.

Saline versus 5% dextrose in water as a drug diluent for critically ill patients: a retrospective cohort study

Background

The choice of intravenous infusion products for critically ill patients has been studied extensively because it can affect prognosis. However, there has been little research on drug diluents in this context. The purpose of this study is to evaluate the impact of diluent choice (saline or 5% dextrose in water [D5W]) on electrolyte abnormalities, blood glucose control, incidence of acute kidney injury (AKI), and mortality.

Methods

This before-after, two-group comparative, retrospective study enrolled adult patients who stayed for more than 48 h in a general intensive care unit from July 2015 to December 2018. We changed the default diluent for intermittent drug sets in our electronic ordering system from D5W to saline at the end of 2016.

Results

We included 844 patients: 365 in the D5W period and 479 in the saline period. Drug diluents accounted for 21.4% of the total infusion volume. The incidences of hypernatremia and hyperchloremia were significantly greater in the saline group compared to the D5W group (hypernatremia 27.3% vs. 14.6%, p < 0.001; hyperchloremia 36.9 % vs. 20.4%, p < 0.001). Multivariate analyses confirmed the similar effects (hypernatremia adjusted odds ratio (OR), 2.43; 95% confidence interval (CI), 1.54–3.82; hyperchloremia adjusted OR, 2.09; 95% CI, 1.31–3.34). There was no significant difference in the incidences of hyperglycemia, AKI, and mortality between the two groups.

Conclusions

Changing the diluent default from D5W to saline had no effect on blood glucose control and increased the incidences of hypernatremia and hyperchloremia.

Prevalence and Prognostic Impact of Hypernatremia in Sepsis and Septic Shock Patients in the Intensive Care Unit: A Single Centre Experience

Introduction

Hypernatremia is a commonly associated electrolyte disturbance in sepsis and septic shock patients in the ICU. The objective of this study was to identify the prognostic value of hypernatremia in sepsis and septic shock

Material and Methods

A prospective study conducted on sepsis and septic shock patients diagnosed prior to admission in the ICU in King Hamad University Hospital, Bahrain from January 1st 2017 to February 28th 2019. Data including age, sex, comorbidities, source of sepsis, sodium levels on days one, three, and seven. Data was correlated with the outcome (survival/death and the length of ICU stay).

Results

Patients included were 168, 110 survived, and 58 died. Hypernatraemia at day seven was associated with significantly higher mortality (P= 0.03). Hypernatraemia at Day1was associated with a significantly prolonged stay in the ICU (p= 0.039).Multivariate analysis to identify the independent predictors of mortality revealed that immunosuppression and hypernatraemia at Day7 proved to be independent predictors of mortality (P= 0.026 and 0.039 respectively).

Conclusion

Hypernatremia can be an independent predictor of poor outcome in septic and septic shock patients in the ICU.

Excess sodium is deleterious on endothelial and glycocalyx barrier function: A microfluidic study

BACKGROUND

Hypernatremia is a common problem affecting critically ill patients, whether due to underlying pathology or the subsequent result of hypertonic fluid resuscitation. Numerous studies have been published, suggesting that hypernatremia may adversely affect the vascular endothelial glycocalyx. Our study aimed to evaluate if high sodium concentration would impair the endothelial and glycocalyx barrier function and if stress conditions that simulate the shock microenvironment would exacerbate any observed adverse effects of hypernatremia.

METHODS

Human umbilical vein endothelial cells (HUVEC) were cultured in microfluidic channels subjected to flow conditions overnight to stimulate glycocalyx growth. Cells were then subjected to sodium (Na) concentrations of either 150 mEq/L or 160 mEq/L, with Hepes solution applied to media to maintain physiologic pH. Subsets of HUVEC were also exposed to hypoxia/reoxygenation and epinephrine (HR + Epi) to simulate shock insult, then followed by Na treatment. Perfusate was then collected 60 minutes and 120 minutes following treatments. Relevant biomarkers were then evaluated and HUVEC underwent fluorescent staining followed by microscopy.

RESULTS

Glycocalyx degradation as indexed by hyaluronic acid and syndecan-1 was elevated in all subgroups, particularly those subjected to HR + Epi with Na 160 mEq/L. Thickness of the glycocalyx as evaluated by fluorescent microscopy was reduced to half of baseline with Na 160 mEq/L and to one third of baseline with additional insult of HR + Epi. Endothelial activation/injury as indexed by soluble thrombomodulin was elevated in all subgroups. A profibrinolytic coagulopathy phenotype was demonstrated in all subgroups with increased tissue plasminogen activator levels and decreased plasminogen activator inhibitor-1 levels.

CONCLUSION

Our data suggest that hypernatremia results in degradation of the endothelial glycocalyx with further exacerbation by shock conditions. A clinical study using clinical measurements of the endothelial glycocalyx in critically ill or injured patients with acquired hypernatremia would be warranted.

Hypernatremia is associated with poorer outcomes following aneurysmal subarachnoid hemorrhage: a nationwide inpatient sample analysis

BACKGROUND

Hypernatremia is one of the most common electrolyte disturbances following aneurysmal subarachnoid hemorrhage (aSAH) and has been correlated with increased mortality in single institution studies. We investigated this association using a large nationwide healthcare database.

METHODS

We performed a retrospective analysis of adults between 2002 and 2011 with a primary diagnosis of aSAH using the Nationwide Inpatient Sample (NIS). Patients were grouped according to whether or not an inpatient diagnosis of hypernatremia was present. The primary outcome was the NIS-SAH outcome measure. Secondary outcomes included in-hospital mortality, length of stay (LOS), and non-routine hospital discharge. Outcomes analyses adjusted for SAH severity using the NIS-SAH Severity Score, Charlson Comorbidity Index, and the presence of cerebral edema.

RESULTS

A total of 18,377 patients were included in the study. The incidence of a poor outcome as defined by the NIS-SAH outcome measure was 65.9% in the hypernatremia group and 33.4% in the normonatremia group (OR 1.96, 95% CI 1.68 - 2.27). There was higher mortality in the hypernatremia group (OR 1.60, 95% CI 1.37 - 1.87). Patients with hypernatremia had a significantly higher rate of non-routine hospital discharge and gastrostomy. The incidences of poor outcome, in-hospital mortality, and non-routine disposition were higher in the hypernatremia group regardless of treatment type (clipping vs. endovascular embolization). Pulmonary complications and acute kidney injury were more common in the hypernatremia group as well.

CONCLUSIONS

In patients with aSAH, hypernatremia is associated with poorer functional outcomes regardless of SAH severity.

Estimation of sodium and chloride storage in critically ill patients: a balance study

BACKGROUND

Nonosmotic sodium storage has been reported in animals, healthy individuals and patients with hypertension, hyperaldosteronism and end-stage kidney disease. Sodium storage has not been studied in ICU patients, who frequently receive large amounts of sodium chloride-containing fluids. The objective of our study was to estimate sodium that cannot be accounted for by balance studies in critically ill patients. Chloride was also studied. We used multiple scenarios and assumptions for estimating sodium and chloride balances.

METHODS

We retrospectively analyzed patients admitted to the ICU after cardiothoracic surgery with complete fluid, sodium and chloride balance data for the first 4 days of ICU treatment. Balances were obtained from meticulously recorded data on intake and output. Missing extracellular osmotically active sodium (MES) was calculated by subtracting the expected change in plasma sodium from the observed change in plasma sodium derived from balance data. The same method was used to calculate missing chloride (MEC). To address considerable uncertainties on the estimated extracellular volume (ECV) and perspiration rate, various scenarios were used in which the size of the ECV and perspiration were varied.

RESULTS

A total of 38 patients with 152 consecutive ICU days were analyzed. In our default scenario, we could not account for 296 ± 35 mmol of MES in the first four ICU days. The range of observed MES in the five scenarios varied from 111 ± 27 to 566 ± 41 mmol (P < 0.001). A cumulative value of 243 ± 46 mmol was calculated for MEC in the default scenario. The range of cumulative MEC was between 62 ± 27 and 471 ± 56 mmol (P = 0.001 and P = 0.003). MES minus MEC varied from 1 ± 51 to 123 ± 33 mmol in the five scenarios.

CONCLUSIONS

Our study suggests considerable disappearance of osmotically active sodium in critically ill patients and is the first to also suggest rather similar disappearance of chloride from the extracellular space. Various scenarios for insensible water loss and estimated size for the ECV resulted in considerable MES and MEC, although these estimates showed a large variation. The mechanisms and the tissue compartments responsible for this phenomenon require further investigation.

Could sodium imbalances predispose to postoperative venous thromboembolism? An analysis of the NSQIP database

Background

Hyponatremia is common among patients with pulmonary embolism, while hypernatremia increases the risk of venous thromboembolism (VTE). Our objective was to evaluate the association between sodium imbalances and the incidence of VTE and other selected perioperative outcomes.

Methods

We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and identified 1,108,704 patients undergoing major surgery from 2008 to 2012. We evaluated 30-day perioperative outcomes, including mortality and cardiac, respiratory, neurological, urinary, wound, and VTE outcomes. Multivariate logistic regressions were used to estimate the odds of 30-day perioperative outcomes.

Results

Compared with the normal sodium group, in which VTE occurred in 1.0% of patients, 1.8% of patients in the hyponatremia group (unadjusted odds ratio (OR) 1.84) and 2.4% of patients in the hypernatremia group (unadjusted OR 2.49) experienced VTE. Crude mortality was 1.3% in the normal sodium group, 4.9% in the hyponatremia group (unadjusted OR 3.93) and 8.4% in the hypernatremia group (unadjusted OR 7.01). Crude composite morbidity was 7.1% for the normal sodium group, 16.7% for the hyponatremia group (unadjusted OR 2.63) and 20.6% for the hypernatremia group (unadjusted OR 3.43). After adjusting for potential confounders, hyponatremia and hypernatremia remained significantly and independently associated with an increased risk of VTE (adjusted OR 1.43 and 1.56, respectively), mortality (adjusted OR 1.39 and 1.39, respectively) and composite morbidity (adjusted OR 2.15 and 3.34, respectively).

Conclusions

Pre-operative hyponatremia and hypernatremia are potential prognostic markers for perioperative 30-day morbidity, mortality and VTE.

Severity of disease scoring systems and mortality after non-cardiac surgery

Background

Mortality after surgery is frequent and severity of disease scoring systems are used for prediction. Our aim was to evaluate predictors for mortality after non-cardiac surgery.

Methods

Adult patients admitted at our surgical intensive care unit between January 2006 and July 2013 was included. Univariate analysis was carried using Mann–Whitney, Chi-square or Fisher's exact test. Logistic regression was performed to assess independent factors with calculation of odds ratio and 95% confidence interval (95% CI).

Results

4398 patients were included. Mortality was 1.4% in surgical intensive care unit and 7.4% during hospital stay. Independent predictors of mortality in surgical intensive care unit were APACHE II (OR = 1.24); emergent surgery (OR = 4.10), serum sodium (OR = 1.06) and FiO₂ at admission (OR = 14.31). Serum bicarbonate at admission (OR = 0.89) was considered a protective factor. Independent predictors of hospital mortality were age (OR = 1.02), APACHE II (OR = 1.09), emergency surgery (OR = 1.82), high-risk surgery (OR = 1.61), FiO₂ at admission (OR = 1.02), postoperative acute renal failure (OR = 1.96), heart rate (OR = 1.01) and serum sodium (OR = 1.04). Dying patients had higher scores in severity of disease scoring systems and longer surgical intensive care unit stay.

Conclusion

Some factors influenced both surgical intensive care unit and hospital mortality.

[Severity of disease scoring systems and mortality after non-cardiac surgery]

BACKGROUND

Mortality after surgery is frequent and severity of disease scoring systems are used for prediction. Our aim was to evaluate predictors for mortality after non-cardiac surgery.

METHODS

Adult patients admitted at our surgical intensive care unit between January 2006 and July 2013 was included. Univariate analysis was carried using Mann-Whitney, Chi-square or Fisher's exact test. Logistic regression was performed to assess independent factors with calculation of odds ratio and 95% confidence interval (95% CI).

RESULTS

4398 patients were included. Mortality was 1.4% in surgical intensive care unit and 7.4% during hospital stay. Independent predictors of mortality in surgical intensive care unit were APACHE II (OR=1.24); emergent surgery (OR=4.10), serum sodium (OR=1.06) and FiO₂ at admission (OR=14.31). Serum bicarbonate at admission (OR=0.89) was considered a protective factor. Independent predictors of hospital mortality were age (OR=1.02), APACHE II (OR=1.09), emergency surgery (OR=1.82), high-risk surgery (OR=1.61), FiO₂ at admission (OR=1.02), postoperative acute renal failure (OR=1.96), heart rate (OR=1.01) and serum sodium (OR=1.04). Dying patients had higher scores in severity of disease scoring systems and longer surgical intensive care unit stay.

CONCLUSION

Some factors influenced both surgical intensive care unit and hospital mortality.

Hospital-Associated Hypernatremia Spectrum and Clinical Outcomes in an Unselected Cohort

BACKGROUND

Although hypernatremia is associated with adverse outcomes, most studies examined selected populations.

METHODS

Discharge data of 19,072 unselected hospitalized adults were analyzed. The crude relationship between serum sodium [Na⁺] and mortality defined hypernatremia as serum [Na⁺] >142 mEq/L. Patients with community-acquired hypernatremia or hospital-acquired hypernatremia were compared with normonatremic patients (admission [Na⁺] 138-142 mEq/L) regarding in-hospital mortality, length of stay, and discharge disposition. Patients with community-acquired hypernatremia whose hypernatremia worsened during hospitalization were compared with those without aggravation.

RESULTS

Community-acquired hypernatremia occurred in 21% of hospitalized patients and was associated with an adjusted odds ratio (OR) of 1.67 (95% confidence interval [CI], 1.38-2.01) for in-hospital mortality and 1.44 (95% CI, 1.32-1.56) for discharge to a short-/long-term care facility and an adjusted 10% (95% CI, 7-13) increase in length of stay. Hospital-acquired hypernatremia developed in 25.9% of hospitalized patients and was associated with an adjusted OR of 3.17 (95% CI, 2.45-4.09) for in-hospital mortality and 1.45 (95% CI, 1.32-1.59) for discharge to a facility, and an adjusted 49% (95% CI, 44-53) increase in length of stay. Hospital-aggravated hypernatremia developed in 11.7% of patients with community-acquired hypernatremia and was associated with greater risk of in-hospital mortality (adjusted OR, 1.84; 95% CI, 1.32-2.56) and discharge to a facility (adjusted OR, 2.14; 95% CI, 1.71-2.69), and an adjusted 16% (95% CI, 7-27) increase in length of stay.

CONCLUSIONS

The hypernatremia spectrum in unselected hospitalized patients is independently associated with increased in-hospital mortality and heightened resource consumption.

Severity of community acquired hypernatremia is an independent predictor of mortality

Hypernatremia develops commonly in critically ill patients during hospitalization, and is associated with adverse outcomes. However, community acquired hypernatremia (CAH) has been rarely studied. We conducted a study in patients who presented to an urban referral hospital, and were admitted with CAH. We retrospectively analyzed patients admitted to an urban tertiary care hospital from January 1, 2012 to December 31, 2014. CAH is defined as more than 147 mEq/L at admission in patients not transferred from other hospitals. Severity of hypernatremia is categorized as mild (148-150 mEq/L), moderate (151-154 mEq/L) or severe (≥155 mEq/L). All data were extracted from electronic medical records and the major outcome is hospital mortality. During the study period, 79,998 patients were admitted to the hospital. Of them, 178 patients (0.2%) had hypernatremia at the time of admission. 121 (68.0%) had mild hypernatremia, 33 (18.5%) had moderate hypernatremia, and 24 (13.5%) had severe hypernatremia at admission. During the hospital stay, 91 (51.1%) developed mild hypernatremia, 31 (17.4%) developed moderate hypernatremia and 56 (31.5%) developed severe hypernatremia. Mean duration of hypernatremia was 2.3 ± 2.0 days. The length of hospital stay was 7 (interquartile range 3-23) days and hospital mortality was 24.3%. Multivariate analysis shows that a peak sodium level that qualified as moderate [OR = 11.50, 95% CI (2.67-49.42)] or severe hypernatremia [OR = 5.18, 95% CI (1.43-18.79)] is an independent risk factor for hospital mortality compared to mild hypernatremia. Admission from the emergency department (ED), oral intake restriction, mean arterial pressure (MAP) and respiratory rate (RR) at admission time are also independently associated with hospital mortality. Maximum sodium level in CAH is independently associated with hospital mortality.

The association between intensive care unit-acquired hypernatraemia and mortality in critically ill patients with cerebrovascular diseases: a single-centre cohort study in Japan

OBJECTIVES

Hypernatraemia is one of the major electrolyte disorders associated with mortality among critically ill patients in intensive care units (ICUs). It is unclear whether this applies to patients with cerebrovascular diseases in whom high sodium concentrations may be allowed in order to prevent cerebral oedema. This study aimed to examine the association between ICU-acquired hypernatraemia and the prognosis of patients with cerebrovascular diseases.

DESIGN

A retrospective cohort study.

SETTING

The incidence of ICU-acquired hypernatraemia was assessed retrospectively in a single tertiary care facility in Japan.

PARTICIPANTS

Adult patients (≥18 years old) whose length of stay in ICU was >2 days and those whose serum sodium concentrations were 130-149 mEq/L on admission to ICU were included.

OUTCOME MEASURES

28-day in-hospital mortality risk was assessed by Cox regression analysis. Hypernatraemia was defined as serum sodium concentration ≥150 mEq/L. Using multivariate analysis, we examined whether ICU-acquired hypernatraemia and the main symptom present at ICU admission were associated with time to death among ICU patients. We also evaluated how the maximum and minimum sodium concentrations during ICU stay were associated with mortality, using restricted cubic splines.

RESULTS

Of 1756 patients, 121 developed ICU-acquired hypernatraemia. Multivariate Cox proportional hazard analysis revealed an association between ICU-acquired hypernatraemia and 28-day mortality (adjusted HR, 3.07 (95% CI 2.12 to 4.44)). The interaction between ICU-acquired hypernatraemia and cerebrovascular disease was significantly associated with 28-day mortality (HR, 3.03 (95% CI 1.29 to 7.15)). The restricted cubic splines analysis of maximum serum sodium concentration in ICU patients determined a threshold maximum of 147 mEq/L. There was no significant association between minimum sodium concentration and mortality.

CONCLUSIONS

ICU-acquired hypernatraemia was associated with an increased mortality rate among critically ill patients with cerebrovascular diseases; the threshold maximum serum sodium concentration associated with mortality was 147 mEq/L.

Could dysnatremias play a role as independent factors to predict mortality in surgical critically ill patients?

Several studies have demonstrated the impact of dysnatremias on mortality of intensive care unit (ICU) patients. The objective of this study was to assess whether dysnatremia is an independent factor to predict mortality in surgical critically ill patients admitted to ICU in postoperative phase.One thousand five hundred and ninety-nine surgical patients (58.8% males; mean age of 60.6 ± 14.4 years) admitted to the ICU in the postoperative period were retrospectively studied. The patients were classified according to their serum sodium levels (mmol/L) at admission as normonatremia (135-145), hyponatremia (<135), and hypernatremia (>145). APACHE II, SAPS III, and SOFA were recorded. The capability of each index to predict mortality of ICU and hospital mortality of patients was analyzed by multiple logistic regression.Hyponatremia did not have an influence on mortality in the ICU with a relative risk (RR) = 0.95 (0.43-2.05) and hospital mortality of RR = 1.40 (0.75-2.59). However, this association was greater in patients with hypernatremia mortality in the ICU (RR = 3.33 [95% confidence interval, CI 1.58-7.0]) and also in hospital mortality (RR = 2.9 [ 95% CI = 1.51-5.55). The pairwise comparison of ROC curves among the different prognostic indexes (APACHE II, SAPS III, SOFA) did not show statistical significance. The comparison of these indexes with serum sodium levels for general population, hyponatremia, and normonatremia was statistically significant (P < .001). For hypernatremia, the AUC and 95% CI for APACHE II, SAPS III, SOFA, and serum sodium level were 0.815 (0.713-0.892), 0.805 (0.702-0.885), 0.885 (0.794-0.945), and 0.663 (0.549-0.764), respectively. The comparison among the prognostic indexes was not statistically significant. Only SOFA score had a statistic difference compared with hypernatremia (P < .02).The serum sodium levels at admission, especially hypernatremia, may be used as an independent predictor of outcome in the surgical critically ill patients.

Hydrochlorothiazide in intensive care unit-acquired hypernatremia: A randomized controlled trial

PURPOSE

Thiazides are suggested as a treatment for intensive care unit (ICU)-acquired hypernatremia (IAH). The primary aim of the study was reducing serum sodium concentration (sNa) in patients with IAH with hydrochlorothiazide (HCT) in comparison to placebo. Secondary end points were a difference in urine sodium concentration (uNa) and duration of severe IAH.

MATERIALS

A monocentric, double-blind, placebo-controlled trial was conducted in 50 patients with IAH and urine potassium + uNa less than sNa in a spot urine sample. Patients were randomized to HCT 25 mg or placebo 1 qd for maximal 7 days. Patients on renal replacement therapy, on medication inducing diabetes insipidus, or with recent use of diuretics were excluded. IAH was defined as sNa of at least 143 mmol/L.

RESULTS

At baseline, sNa and uNa were comparable between groups. During the study period, sNa decreased significantly with median 4 mmol/L in both groups, with no significant difference between groups (P=.32). Median uNa increased significantly in both groups (46 [16-86] mmol/L in the HCT-group; 20 [10-66]mmol/L in the placebo group), with no difference between groups (P=.34). Median duration of sNa of at least 145 mmol/L was 3 days in both groups (P=.91).

CONCLUSION

HCT 25 mg 1 qd did not significantly affect sNa or uNa in patients with IAH.

Differences between prolonged weaning patients from medical and surgical intensive care units

BACKGROUND

It is not clear whether patients entering a specialized, interdisciplinary weaning unit from surgical or medical intensive care units (ICU) distinguish substantially. The purpose of the present study was to assess differences in patients with prolonged weaning being referred from surgical and medical ICU.

METHODS

Data collected from April 2013 to April 2014 was conducted for retrospective analysis. Mortality rates, demographic data, clinical, and microbial differences in 150 patients with prolonged weaning were assessed (80 surgical and 70 medical).

RESULTS

Surgical ICU referrals tended to be older (70.7 ± 11.3 vs. 67.3 ± 12.3, P = 0.051) and had fewer underlying pulmonary diseases (45% vs. 60%, P = 0.067). Sodium values at the time of referral to the weaning unit were significantly higher in surgical (147.1 ± 9.6) vs. medical (141.3 ± 6.7 mmol/l) patients (P < 0.001). Each 10-unit increase in sodium at the time of referral to the weaning unit was associated with a 2.5-day (95% CI -0.4, 5.4; P = 0.09) prolongation of stay in the weaning unit. Although significant differences in microbiological agents from tracheal aspiration were seen, the infection rate on the weaning unit was similar in both groups. There was no difference in weaning unit mortality between surgical and medical ICU patients (18% vs. 23%; P = 0.41).

CONCLUSION

Few differences were found between patients being referred to a specialized weaning unit from surgical vs. medical ICUs. Besides differences in microbiological characteristics of tracheal secretions, there were also differences in sodium levels, which appear to influence on treatment duration.

The Reduction Rate of Serum Sodium and Mortality in Patients Undergoing Continuous Venovenous Hemofiltration for Acute Severe Hypernatremia

BACKGROUND

The excessive correction of acute hypernatremia is not known to be harmful. This study aimed to evaluate whether a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour in acute severe hypernatremia is an independent risk factor for mortality in critically ill patients undergoing continuous venovenous hemofiltration (CVVH) treatment.

MATERIALS AND METHODS

For this retrospective study, we reviewed records of 75 critically ill patients undergoing CVVH treatment for acute severe hypernatremia between March 2011 and March 2015.

RESULTS

The 28-day mortality rate of all patients was 61.3%. In multivariate Cox regression analyses, a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour (hazard ratio = 1.89; 95% CI: 1.03-3.47; P = 0.04), Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency (yes or no) had a statistically significantly effect on mortality. Once we excluded patients with an RRSeNa ≤ 0.5mEq/L/hour, only RRSeNa > 1mEq/L/hour (hazard ratio = 2.611; 95% CI: 1.228-5.550; P = 0.013) and vasopressor dependency had a statistically significant influence on mortality in multivariate regression.

CONCLUSIONS

In addition to the Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency, the excessive correction of acute severe hypernatremia was possibly associated with mortality in critically ill patients undergoing CVVH treatment. The optimal reduction rate of acute hypernatremia should be extensively studied in critically ill patients.

The Development of Intensive Care Unit Acquired Hypernatremia Is Not Explained by Sodium Overload or Water Deficit: A Retrospective Cohort Study on Water Balance and Sodium Handling

Background. ICU acquired hypernatremia (IAH, serum sodium concentration (sNa) ≥ 143 mmol/L) is mainly considered iatrogenic, induced by sodium overload and water deficit. Main goal of the current paper was to answer the following questions: Can the development of IAH indeed be explained by sodium intake and water balance? Or can it be explained by renal cation excretion? Methods. Two retrospective studies were conducted: a balance study in 97 ICU patients with and without IAH and a survey on renal cation excretion in 115 patients with IAH. Results. Sodium intake within the first 48 hours of ICU admission was 12.5 [9.3-17.5] g in patients without IAH (n = 50) and 15.8 [9-21.9] g in patients with IAH (n = 47), p = 0.13. Fluid balance was 2.3 [1-3.7] L and 2.5 [0.8-4.2] L, respectively, p = 0.77. Urine cation excretion (urine Na + K) was < sNa in 99 out of 115 patients with IAH. Severity of illness was the only independent variable predicting development of IAH and low cation excretion, respectively. Conclusion. IAH is not explained by sodium intake or fluid balance. Patients with IAH are characterized by low urine cation excretion, despite positive fluid balances. The current paradigm does not seem to explain IAH to the full extent and warrants further studies on sodium handling in ICU patients.

Prognostic value of ICU-acquired hypernatremia in patients with neurological dysfunction

Many studies have indicated that hypernatremia is associated with increased mortality. In this study, we aimed to explore the relationship between intensive care unit (ICU)-acquired hypernatremia and the prognosis of critically neurological patients.Based on serum sodium level in the ICU, 450 patients were divided into 3 groups: 222 had normal serum sodium, 142 had mild hypernatremia, and 86 had severe hypernatremia. Kaplan-Meier and multivariable binary logistic regression analyses were performed to evaluate the prognostic value of hypernatremia in critically neurological patients. Receiver operating characteristic (ROC) curve was constructed for serum sodium levels to determine their roles in predicting ICU mortality.Hypernatremia was significantly related with age, Glasgow Coma Scale (GCS) score, serum sodium, APACHE II score, and serum creatinine. Moreover, the different treatment outcome including mechanical ventilation, the days of stayed in ICU, and Glasgow Outcome Scale score had correlation with serum sodium levels. Old ages, GCS score, therapeutic intervention scoring system (TISS) score, APACHE II score, serum sodium peak, and so on were all associated with the mortality. In addition, hypernatremia was an independent prognostic factor for critically neurological patients by logistic regression analysis (odds ratio = 1.192, 95% confidence interval = 1.135-1.252, P = 0.000). Moreover, we got the sensitivity of 79.4% and specificity of 74.5% in the ROC analysis between peak serum sodium and the mortality. The area under the ROC curve was 0.844, and the optimal cutoff value was 147.55.Our results showed that ICU-acquired hypernatremia may be a potential prognosis marker for critically neurological patients.

Risk Factors and Outcomes in Patients With Hypernatremia and Sepsis

BACKGROUND

Hypernatremia is an uncommon but important electrolyte abnormality in intensive care unit patients. Sepsis is one of the most common causes of intensive care unit admission, but few studies about the role of hypernatremia in sepsis has been published yet. In this study, we aimed to explore the risk factors for developing hypernatremia in patients with sepsis, and the prognosis of patients with sepsis with or without hypernatremia was also assessed.

MATERIALS AND METHODS

In this retrospective cohort study of 51 septic intensive care unit patients at a single center, we examined the risk factors for the development of hypernatremia and the association of hypernatremia with clinical outcomes using univariate and multivariable analyses. Clinical outcomes such as mortality and hospital duration of patients with or without hypernatremia were also compared.

RESULTS

Acute Physiology and Chronic Health Evaluation II score (odds ratio = 1.15; 95% CI: 1.022-1.294) was found to be the only independent risk factor for hypernatremia in patients with sepsis. Moreover, patients developing hypernatremia during hospitalization showed significantly higher morbidity and mortality.

CONCLUSIONS

Acute Physiology and Chronic Health Evaluation II score may be an independent risk factor for hypernatremia in patients with sepsis. Moreover, hypernatremia is strongly associated with worse outcome in sepsis.

Long-term changes in dysnatremia incidence in the ICU: a shift from hyponatremia to hypernatremia

Background

Dysnatremia is associated with adverse outcome in critically ill patients. Changes in patients or treatment strategies may have affected the incidence of dysnatremia over time. We investigated long-term changes in the incidence of dysnatremia and analyzed its association with mortality.

Methods

Over a 21-year period (1992–2012), all serum sodium measurements were analyzed retrospectively in two university hospital ICUs, up to day 28 of ICU admission for the presence of dysnatremia. The study period was divided into five periods. All serum sodium measurements were collected from the electronic databases of both ICUs. Serum sodium was measured at the clinical chemistry departments using standard methods. All sodium measurements were categorized in the following categories: <120, 120–124, 125–129, 130–134, 135–139, 140–145, 146–150, 151–155, 156–160, >160 mmol/L. Mortality was determined at 90 days after ICU admission.

Results

In 80,571 ICU patients, 913,272 serum sodium measurements were analyzed. A striking shift in the pattern of ICU-acquired dysnatremias was observed: The incidence of hyponatremia almost halved (47–25 %, p < 0.001), whereas the incidence of hypernatremia nearly doubled (13–24 %, p < 0.001). Most hypernatremias developed after ICU admission, and the incidence of severe hypernatremia (sodium > 155 mmol/L) increased dramatically over the years. On ICU day 10 this incidence was 0.7 % in the 1992–1996 period, compared to 6.3 % in the 2009–2012 period (p < 0.001). More severe dysnatremia was associated with significantly higher mortality throughout the 21-year study period (p < 0.001).

Conclusions

In two large Dutch cohorts, we observed a marked shift in the incidence of dysnatremia from hyponatremia to hypernatremia over two decades. As hypernatremia was mostly ICU acquired, this strongly suggests changes in treatment as underlying causes. This shift may be related to the increased use of sodium-containing infusions, diuretics, and hydrocortisone. As ICU-acquired hypernatremia is largely iatrogenic, it should be—to an important extent—preventable, and its incidence may be considered as an indicator of quality of care. Strategies to prevent hypernatremia deserve more emphasis; therefore, we recommend that further study should be focused on interventions to prevent the occurrence of dysnatremias during ICU stay.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0124-x) contains supplementary material, which is available to authorized users.