Dysnatremia is a Predictor for Morbidity and Mortality in Hospitalized Patients with COVID-19.

CONTEXT: Dysnatremia is an independent predictor of mortality in patients with bacterial pneumonia. There is paucity of data about the incidence and prognostic impact of abnormal sodium concentration in patients with coronavirus disease 2019 (COVID-19). OBJECTIVE: This work aimed to examine the association of serum sodium during hospitalization with key clinical outcomes, including mortality, need for advanced respiratory support and acute kidney injury (AKI), and to explore the role of serum sodium as a marker of inflammatory response in COVID-19. METHODS: This retrospective longitudinal cohort study, including all adult patients who presented with COVID-19 to 2 hospitals in London over an 8-week period, evaluated the association of dysnatremia (serum sodium < 135 or > 145 mmol/L, hyponatremia, and hypernatremia, respectively) at several time points with inpatient mortality, need for advanced ventilatory support, and AKI. RESULTS: The study included 488 patients (median age, 68 years). At presentation, 24.6% of patients were hyponatremic, mainly due to hypovolemia, and 5.3% hypernatremic. Hypernatremia 2 days after admission and exposure to hypernatremia at any time point during hospitalization were associated with a 2.34-fold (95% CI, 1.08-5.05; P = .0014) and 3.05-fold (95% CI, 1.69-5.49; P < .0001) increased risk of death, respectively, compared to normonatremia. Hyponatremia at admission was linked with a 2.18-fold increase in the likelihood of needing ventilatory support (95% CI, 1.34-3.45, P = .0011). Hyponatremia was not a risk factor for in-hospital mortality, except for the subgroup of patients with hypovolemic hyponatremia. Sodium values were not associated with the risk for AKI and length of hospital stay. CONCLUSION: Abnormal sodium levels during hospitalization are risk factors for poor prognosis, with hypernatremia and hyponatremia being associated with a greater risk of death and respiratory failure, respectively. Serum sodium values could be used for risk stratification in patients with COVID-19.

Active management of severe hyponatraemia is associated with improved mortality.

OBJECTIVE: Severe hyponatraemia (plasma sodium concentration, pNa <120 mmol/L) is reported to be associated with mortality rates as high as 50%. Although there are several international guidelines for the management of severe hyponatraemia, there are few data on the impact of treatment. DESIGN AND METHODS: We have longitudinally reviewed rates of specialist input, active management of hyponatraemia, treatment outcomes and mortality rates in patients with severe hyponatraemia (pNa <120 mmol/L) in 2005, 2010 and 2015, and compared the recent mortality rate with that of patients with pNa 120-125 mmol/L. RESULTS: Between 2005 and 2010 there was a doubling in the rate of specialist referral (32 to 68%, P = 0.003) and an increase in the use of active management of hyponatraemia in patients with pNa <120 mmol/L (63 to 88%, P = 0.02), associated with a reduction in mortality from 51 to 15% (P < 0.001). The improved rates of intervention were maintained between 2010 and 2015, but there was no further reduction in mortality. When data from all three reviews were pooled, specialist consultation in patients with pNa <120 mmol/L was associated with a 91% reduction in mortality risk, RR 0.09 (95% CI: 0.03-0.26), P < 0.001. Log-rank testing on in-hospital survival in 2015 found no significant difference between patients with pNa <120 mmol/L and pNa 120-125 mmol/L (P = 0.56). CONCLUSION: Dedicated specialist input and active management of severe hyponatraemia are associated with a reduction in mortality, to rates comparable with moderate hyponatraemia.

Prognostic Significance of Hyponatremia in Acute Stroke: A Systematic Review and Meta-Analysis.

OBJECTIVE: Hyponatremia is a common electrolyte disorder in patients with stroke, which leads to various fatal complications. We performed a systematic review and meta-analysis to investigate the outcomes of acute stroke patients with hyponatremia. METHODS: We searched MEDLINE, EMBASE, and the Cochrane Library databases for relevant literature in English published up to March 2020. Two review authors independently screened and selected the studies by assessing the eligibility and validity based on the inclusion criteria. Mortality at 90 days was set as the primary end point, and in-hospital mortality and length of hospital stay were set as the secondary end points. We conducted the data synthesis and analyzed the outcomes by calculating the odds ratio (OR) and mean difference. RESULTS: Of 835 studies, 15 studies met the inclusion criteria (n = 10,745). The prevalence rate of stroke patients with hyponatremia was 7.0-59.2%. They had significantly higher 90-day mortality (OR, 1.73; 95% confidence interval (CI), 1.24-2.42) and longer length of hospital stay (mean difference, 10.68 days; 95% CI, 7.14-14.22) than patients without hyponatremia. Patients with hyponatremia had a higher tendency of in-hospital mortality than those without hyponatremia (OR, 1.61; 95% CI, 0.97-2.69). CONCLUSIONS: The development of hyponatremia in the clinical course of stroke is associated with higher short-term mortality and a longer hospital stay. Although the causal relationship is unclear, hyponatremia could be a significant predictor of poor outcomes after stroke.

Risks of severe hyponatremia in children receiving hypotonic fluids.

Intravenous fluids are frequently used in hospitalized children. Hypotonic fluids have been the standard of care in pediatrics for many years. This might be explained by the empiricism of early recommendations favoring fluids with dextrose, but an insufficient amount of sodium. The risk of hyponatremia (<135mmol/L) might be increased by the occurrence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in the course of common acute diseases (e.g., bronchiolitis, acute gastroenteritis, encephalitis, meningitis) in children. Severe hyponatremia (<130mmol/L) is often associated with neurologic complications leading to sequelae or even death. Over the last few years, hyponatremia induced by hypotonic fluids has been increasingly reported, and significant progress has been made in the understanding of cerebral edema and osmotic demyelination. Several randomized clinical trials have shown weak but significant evidence that isotonic fluids were superior to hypotonic solutions in preventing hyponatremia. However, clinical practices have not changed much in France, as suggested by the analysis of intravenous fluids ordered from the Assistance Publique-Hôpitaux de Paris (AP-HP) central pharmacy (PCH) in 2017. Therefore, it would be advisable that national guidelines be released under the French Health Authorities regarding the safe infusion of infants and children.

Risk of Adverse Clinical Outcomes in Hyponatremic Adult Patients Hospitalized for Acute Medical Conditions: A Population-Based Cohort Study.

CONTEXT: Hyponatremia has been associated with excess long-term morbidity and mortality. However, effects during hospitalization are poorly studied. OBJECTIVE: The objective of this work is to examine the association of hyponatremia with the risk of in-hospital mortality, 30-day readmission, and other short-term adverse events among medical inpatients. DESIGN AND SETTING: A population-based cohort study was conducted using a Swiss claims database of medical inpatients from January 2012 to December 2017. PATIENTS: Hyponatremic patients were 1:1 propensity-score matched with normonatremic medical inpatients. MAIN OUTCOME MEASURE: The primary outcome was a composite of all-cause in-hospital mortality and 30-day hospital readmission. Secondary outcomes were intensive care unit (ICU) admission, intubation rate, length-of-hospital stay (LOS), and patient disposition after discharge. RESULTS: After matching, 94 352 patients were included in the cohort. Among 47 176 patients with hyponatremia, 8383 (17.8%) reached the primary outcome compared with 7994 (17.0%) in the matched control group (odds ratio [OR] 1.06 [95% CI, 1.02-1.10], P = .001). Hyponatremic patients were more likely to be admitted to the ICU (OR 1.43 [95% CI, 1.37-1.50], P < .001), faced a 56% increase in prolonged LOS (95% CI, 1.52-1.60, P < .001), and were admitted more often to a postacute care facility (OR 1.38 [95% CI 1.34-1.42, P < .001). Of note, patients with the syndrome of inappropriate antidiuresis (SIAD) had lower in-hospital mortality (OR 0.67 [95% CI, 0.56-0.80], P < .001) as compared with matched normonatremic controls. CONCLUSION: In this study, hyponatremia was associated with increased risk of short-term adverse events, primarily driven by higher readmission rates, which was consistent among all outcomes except for decreased in-hospital mortality in SIAD patients.

The association between hyponatraemia and long-term functional outcome in patients with aneurysmal subarachnoid haemorrhage: A single centre prospective cohort study.

To assess the association between hyponatraemia and long-term functional outcome and other relevant outcomes in patients with aneurysmal subarachnoid haemorrhage (aSAH) we conducted a prospective cohort study in a Neurosciences Intensive Care Unit (ICU) in Sydney, Australia. The primary exposure variable was hyponatraemia (Na+ <135 mmol/L). The primary outcome was favourable outcome, a score of 5-8 on the extended Glasgow Outcome Score (GOSe) at 12 months. We also measured mortality, the incidence of delayed cerebral ischaemia (DCI) and cerebral arterial vasospasm and duration of ICU and hospital admission. There were 200 participants, 111 (56%) developed hyponatraemia. Hyponatraemia was not associated with favourable outcome at 12 months (unadjusted odds ratio [OR] OR 1.31, 95% confidence interval [CI] 0.65-2.65, p = 0.56). The result was similar after adjustment for baseline covariates (adjusted OR 0.60, 95% CI 0.16-1.99, p = 0.43). There was no association between hyponatraemia and the incidence of DCI (OR 0.95, 95% CI 0.46 to 2.0, p > 0.99) nor cerebral arterial vasospasm (OR 1.4, 95% CI 0.8 to 2.5, p = 0.27). Those who developed hyponatraemia had a longer median duration of ICU admission (17 days, interquartile range [IQR] 12 to 20, compared to 13 days, IQR 8-21, p = 0.02) and longer median duration of hospital admission (24 days, IQR 21-30, compared to 22 days IQR 14-31, p = 0.05). While hyponatraemia is common following aSAH, it is not associated with worse long-term functional outcome, increased rate of DCI, nor cerebral arterial vasospasm. Hyponatraemia in patients with aSAH was associated with longer duration of ICU and hospital admission.

Sex Differences in Clinical Characteristics and 1- and 10-Year Mortality Among Patients Hospitalized With Acute Heart Failure.

BACKGROUND: The impact of sex on mortality in patients with acute heart failure (AHF) is unresolved. We aimed to investigate the impact of sex on both short- and long-term mortality outcomes after hospitalization for AHF. METHODS: We analyzed data of 2,328 patients with AHF who were enrolled in the multicenter national survey in Israel between March and April 2003 and followed up until December 2014. RESULTS: Women comprised 45% of the study population. In comparison with men, women were older, had higher rates of heart failure with preserved ejection fraction as well as hypertensive heart disease and had a lower rate of coronary artery disease (all P < 0.001). Survival analysis showed that at 1 year the rate of all-cause mortality was 31% among women compared to 28% among men (P = 0.19). At 10-year follow-up mortality rates were significantly higher among women compared to men (87% vs. 83%, P = 0.048). However, this sex association disappeared once multivariable analysis was carried out, (hazard ratio [HR] = 0.93; CI = 0.79-1.09, P = 0.36). Renal dysfunction, older age and severe heart failure were consistent independent predictors of mortality among men and women. Hyponatremia was a prognostic predictor only among men, whereas digoxin use predicted mortality only among women. CONCLUSIONS: There are important differences in the clinical characteristics between women and men hospitalized with AHF. There were no significant differences in both short- and long-term mortality following multivariable analysis. Although, most independent predictors of mortality were consistent among both sexes, few sex-based differences in prognostic predictors were identified.

The prognostic importance of serum sodium levels at hospital discharge and one-year mortality among hospitalized patients.

BACKGROUND: The optimal range of serum sodium at hospital discharge is unclear. Our objective was to assess the one-year mortality based on discharge serum sodium in hospitalized patients. METHODS: We analyzed a cohort of hospitalized adult patients between 2011 and 2013 who survived hospital admission at a tertiary referral hospital. We categorized discharge serum sodium into five groups; ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L. We assessed one-year mortality risk after hospital discharge based on discharge serum sodium, using discharge sodium of 138-142 mEq/L as the reference group. RESULTS: Of 55 901 eligible patients, 4.9%, 29.8%, 56.1%, 8.9%, 0.3% had serum sodium of ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L, respectively. We observed a U-shaped association between discharge serum sodium and one-year mortality, with nadir mortality in discharge serum sodium of 138-142 mEq/L. When adjusting for potential confounders, including admission serum sodium, one-year mortality was significantly higher in both discharge serum sodium ≤137 and ≥143 mEq/L, compared with discharge serum sodium of 138-142 mEq/L. The mortality risk was the most prominent in elevated discharge serum sodium of ≥148 mEq/L (HR 3.86; 95% CI 3.05-4.88), exceeding the risk associated with low discharge serum sodium of ≤132 mEq/L (HR 1.43; 95% CI 1.30-1.57). CONCLUSION: The optimal range of serum sodium at discharge was 138-142 mEq/L. Both hypernatremia and hyponatremia at discharge were associated with higher one-year mortality. The impact on higher one-year mortality was more prominent in hypernatremia than hyponatremia.

Trajectories of Serum Sodium on In-Hospital and 1-Year Survival among Hospitalized Patients.

BACKGROUND AND OBJECTIVES: This study aimed to investigate the association between in-hospital trajectories of serum sodium and risk of in-hospital and 1-year mortality in patients in hospital. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This is a single-center cohort study. All adult patients who were hospitalized from years 2011 through 2013 who had available admission serum sodium and at least three serum sodium measurements during hospitalization were included. The trend of serum sodium during hospitalization was analyzed using group-based trajectory modeling; the five main trajectories were grouped as follows: (1) stable normonatremia, (2) uncorrected hyponatremia, (3) borderline high serum sodium, (4) corrected hyponatremia, and (5) fluctuating serum sodium. The outcome of interest was in-hospital mortality and 1-year mortality. Stable normonatremia was used as the reference group for outcome comparison. RESULTS: A total of 43,539 patients were analyzed. Of these, 47% had stable normonatremia, 15% had uncorrected hyponatremia, 31% had borderline high serum sodium, 3% had corrected hyponatremia, and 5% had fluctuating serum sodium trajectory. In adjusted analysis, there was a higher in-hospital mortality among those with uncorrected hyponatremia (odds ratio [OR], 1.33; 95% CI, 1.06 to 1.67), borderline high serum sodium (OR, 1.66; 95% CI, 1.38 to 2.00), corrected hyponatremia (OR, 1.50; 95% CI, 1.02 to 2.20), and fluctuating serum sodium (OR, 4.61; 95% CI, 3.61 to 5.88), compared with those with the normonatremia trajectory. One-year mortality was higher among those with uncorrected hyponatremia (hazard ratio [HR], 1.28; 95% CI, 1.19 to 1.38), borderline high serum sodium (HR, 1.18; 95% CI, 1.11 to 1.26), corrected hyponatremia (HR, 1.24; 95% CI, 1.08 to 1.42), and fluctuating serum sodium (HR, 2.10; 95% CI, 1.89 to 2.33) compared with those with the normonatremia trajectory. CONCLUSIONS: More than half of patients who had been hospitalized had an abnormal serum sodium trajectory during hospitalization. This study demonstrated that not only the absolute serum sodium levels but also their in-hospital trajectories were significantly associated with in-hospital and 1-year mortality. The highest in-hospital and 1-year mortality risk was associated with the fluctuating serum sodium trajectory. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_03_25_CJN.12281019.mp3.

Age Difference in the Association between Hyponatremia and Infection-Related Mortality in Peritoneal Dialysis Patients.

OBJECTIVES: This study aimed to examine the association of serum sodium with infection-related mortality and its age difference among continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: A total of 1,656 CAPD patients from January 2006 to December 2013 were included in this study. All patients were followed up until December 2018. Hyponatremia was defined as serum sodium <135 mmol/L. Cox proportional hazards regression model was used to investigate the relationship between baseline serum sodium levels and infection-related mortality. RESULTS: Participants were aged 47.5 ± 15.3 years, 666 (40.2%) patients were female. Glomerulonephritis was the main cause of end-stage renal disease (61.1%). After a median of 46 months of follow-up, 507 patients died. Among the deaths, 252 (49.7%) died from cardiovascular diseases, 105 (20.7%) from infections, and 150 (29.6%) from other causes. The overall infection-related mortality was 14.8 events per 1,000 patients-year, which was higher in patients aged ≥50 years than those younger than 50 years (28.3 vs. 5.3 events per 1,000 patients-year). In the entire cohort, hyponatremia at was not associated with infection-related (hazards ratios [HR] 1.66, 95% CI 0.91-3.02) and all-cause mortality (HR 1.14, 95% CI 0.83-1.57) after adjusting for potential confounders. There was a significant interaction by age of association of serum sodium with infection-related (p = 0.002) and all-cause (p = 0.0002) death. Age-stratified analysis showed that compared with control group, hyponatremia was independently related to increased risks of infection-related death, but not all-cause mortality in patients aged ≥50 years, with HR of 2.32 (95% CI 1.25-4.32) and 1.33 (95% CI 0.95-1.87), respectively. CONCLUSIONS: Hyponatremia was associated with increased risk of infection-related mortality in CAPD patients aged ≥50 years.

Abnormal Serum Sodium is Associated With Increased Mortality Among Unselected Cardiac Intensive Care Unit Patients.

Background Abnormal serum sodium levels have been associated with higher mortality among patients with acute coronary syndromes and heart failure. We sought to describe the association between sodium levels and mortality among unselected cardiac intensive care unit (CICU) patients. Methods and Results We retrospectively reviewed consecutive adult patients admitted to our cardiac intensive care unit from 2007 to 2015. Hyponatremia and hypernatremia were defined as admission serum sodium <135 and >145 mEq/L, respectively. In-hospital mortality was assessed by multivariable regression, and postdischarge mortality was evaluated by Cox proportional-hazards analysis. We included 9676 patients with a mean age of 68±15 years (37.5% females). Hyponatremia occurred in 1706 (17.6%) patients, and hypernatremia occurred in 322 (3.3%) patients; these groups had higher illness severity and a greater number of comorbidities. Risk of hospital mortality was higher with hyponatremia (15.5% versus 7.5%; unadjusted odds ratio, 2.41; 95% CI, 2.06-2.82; P<0.001) or hypernatremia (17.7% versus 8.6%; unadjusted odds ratio, 2.82; 95% CI, 2.09-3.80; P<0.001), with a J-shaped relationship between admission sodium and mortality. After multivariate adjustment, only hyponatremia was significantly associated with in-hospital mortality (adjusted odds ratio, 1.42; 95% CI, 1.14-1.76; P=0.002). Among hospital survivors, risk of postdischarge mortality was higher in patients with hyponatremia (adjusted hazard ratio, 1.28; 95% CI, 1.17-1.41; P<0.001) or hypernatremia (adjusted hazard ratio, 1.36; 95% CI, 1.12-1.64; P=0.002). Conclusions Hyponatremia and hypernatremia on admission to the cardiac intensive care unit are associated with increased unadjusted short- and long-term mortality. Further studies are needed to determine whether correcting abnormal sodium levels can improve outcomes in cardiac intensive care unit patients.

Increased mortality risk associated with serum sodium variations and borderline hypo- and hypernatremia in hospitalized adults.

BACKGROUND: This study aimed to evaluate short-term and long-term mortalities in a cohort of unselected hospitalized patients with serum sodium concentration ([Na+]) variations within and outside of reference range. METHODS: All adult patients admitted to the Mayo Clinic, Rochester, MN, USA from January 2011 to December 2013 (n = 147358) were retrospectively screened. Unique patients admitted during the study period were examined. The main exposure was serum [Na+] variation. Outcome measures were hospital and 1-year all-cause mortalities. RESULTS: A total of 60944 patients, mean age 63 ± 17 years, were studied. On admission, 17% (n = 10066) and 1.4% (n = 852) had hypo- and hypernatremia, respectively. During the hospital stay, 11044 and 4128 developed hypo- and hypernatremia, respectively, accounting for 52.3 and 82.9% of the total hypo- and hypernatremic patients. Serum [Na+] variations of ≥6 mEq/L occurred in 40.6% (n = 24 740) of the 60 944 patients and were significantly associated with hospital and 1-year mortalities after adjusting potential confounders (including demographics, comorbidities, estimated glomerular filtration rate, admission serum [Na+], number of [Na+] measurements and length of hospital stay). Adjusted odds ratios for hospital and 1-year mortalities increased with increasing [Na+] variations in a dose-dependent manner, from 1.47 to 5.48 (all 95% confidence intervals >1.0). Moreover, in fully adjusted models, [Na+] variations (≥6 mEq/L) within the reference range (135-145 mEq/L) or borderline hypo- or hypernatremia (133-137 and 143-147 mEq/L, respectively) compared with 138-142 mEq/L were associated with increased hospital and 1-year mortalities. CONCLUSION: In hospitalized adults, [Na+] fluctuation (≥6 mEq/L) irrespective of admission [Na+] and borderline hypo- or hypernatremia are independent predictors of progressively increasing short- and long-term mortality burdens.

Combination and sequential evaluation of acute-on-chronic liver failure (ACLF) and hyponatremia and prognosis in cirrhotic patients.

BACKGROUND: Few studies have evaluated whether combination and sequential evaluation of ACLF (acute-on-chronic liver failure) and hyponatremia aids prognosis. AIMS: Describe clinical course and determine prognostic capability of assessing ACLF and hyponatremia at specific time-points. METHODS: Prospective study with inclusion of 376 patients. ACLF and hyponatremia were evaluated at days 1 and 7 and classified as persistent, transient, de novo or absent. Follow-up was 90 days. RESULTS: At inclusion, ACLF was diagnosed in 99 patients. Reversal was observed in 57 patients and was associated with lower creatinine and ACLF grade. De novo ACLF developed in 19 patients, and MELD (model of end-stage liver disease) score and lower albumin were predictive factors. Hyponatremia was present in 76 patients (persistent, transient and de novo in 27, 24 and 25 respectively). ACLF at D7 had the lowest survival compared to transient or no ACLF (21, 57 and 80%, p < 0.0001). Hyponatremia at admission was associated with low survival (35%) whereas survival was higher for de novo or absent cases (70%), p < 0.001. In multivariate analysis ACLF at D7 and hyponatremia at D1 were predictors of survival. CONCLUSION: ACLF and hyponatremia are dynamic and evaluation of both conditions at different time-points identifies patients at higher risk of short-term mortality.

Analysis of Factors Influencing the Prognostic Significance of Hyponatremia in Peritoneal Dialysis Patients.

BACKGROUND: The evidence linking low serum sodium levels with the risk of mortality in peritoneal dialysis (PD) patients is controversial. Considering the different mechanisms contributing to hyponatremia in these patients, it is conceivable that the prognostic significance of this factor may vary, according to the clinical setting. METHODS: Following a retrospective, observational design, we analyzed the association between hyponatremia and mortality in 748 patients incident on PD. We applied multivariate strategies of analysis, with the main objective of identifying subgroups of patients in whom hyponatremia could sustain different degrees of association with mortality (main outcome variable). For this purpose, we performed preliminary analyses to: (1) disclose predictors of serum sodium levels before and after (mean of first 3 months) initiation of PD (main study variable) and (2) investigate the overall prognostic significance of hyponatremia, in our patients. RESULTS: Comorbidity, hypoalbuminemia, and lower glomerular filtration rate (GFR) were main predictors of hyponatremia. Use of icodextrin was another inverse correlate of serum sodium, and the only consistent predictor of a decline of natremia, once PD was started. Multivariate analysis confirmed early hyponatremia as an independent marker of survival. However, stratified analyses showed that this association was most apparent in specific subsets, namely, hypoalbuminemic, more anemic patients with higher baseline levels of GFR and C-reactive protein and faster peritoneal solute transport rates. Other factors potentially reinforcing the prognostic significance of hyponatremia included lower lean body mass levels, nonprescription of renin-angiotensin-aldosterone system antagonists, and use of icodextrin-based PD solution. On the contrary, baseline overhydration or categorization by classic predictors of mortality (age, comorbidity, diabetes) did not appear to influence the risk pattern associated with lower serum sodium levels. CONCLUSIONS: Our results suggest that hyponatremia performs as a consistent correlate of the risk of mortality mainly in PD patients manifesting direct or indirect signs of inflammation and wasting, while this association is not apparently linked to the presence of overhydration or nominal, preexisting comorbid conditions.

[The prevalence and causes of hyponatremia in hospitalized patients].

Objective: The study was aimed to investigate the prevalence and causes of hyponatremia in hospitalized patients, and to analyze the relationship between hyponatremia and mortality. Methods: A retrospective analysis was carried out in 525 patients with hyponatremia, who were older than 14 years old and hospitalized in the Zhoushan Hospital from Jan. 2014 to Apr. 2014. Based on the severity of the hyponatremia the patients were divided into three groups: the mild, moderate and severe hyponatremia groups. The underlying causes of hyponatremia were analyzed, and the association between hyponatremia and mortality was explored using logistic regression analyses. Results: (1) The prevalence of hyponatremia was 5.26% in whole hospitalized patients (n=9 989) during the study period. It was 6.1% in the elderly population (≥60 years old). (2) Malignant tumors and infectious diseases were the main primary diseases of hyponatremia in all three groups. Among them, lung cancer was the most common malignant tumor, and pneumonia was the most common infectious disease associated with hyponatremia. Cerebral hemorrhage was common in patients with moderate and severe hyponatremia, in which subarachnoid hemorrhage was the major primary disease associated with moderate to severe hyponatremia. In the subgroup of elderly patients, malignant tumor and infectious diseases were the major basic diseases. (3) Among the 525 cases, 13.7% and 3.8% of them were diagnosed with syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral salt-wasting syndrome (CSWS), respectively. The proportions of SIADH and CSWS increased to 17.4% and 4.2%, respectively, in the elderly hyponatremic patients (n=264). (4) More patients were prescribed with sodium-excretion drugs in the moderate and severe hyponatremia groups than those in the mild one(42.2% vs.21.4%, 43.2% vs.21.4%, all P<0.05). (5) Patients with moderate or severe hyponatremia had a higher mortality compared to those with mild hyponatremia (moderate vs. mild group: OR 6.92, 95%CI 2.53-18.92, P<0.001; severe vs. mild group: OR 4.54, 95%CI 1.05-19.58, P=0.043). Conclusions: Hyponatremia was common in hospitalized patients. The major primary diseases were malignant tumor (lung cancer), infectious diseases (pneumonia) and cerebral hemorrhage complicated with SIADH and CSWS. Use of sodium-excretion drugs increased the risk of moderate to severe hyponatremia. Patients with moderate to severe hyponatremia had a higher risk of death in hospitals.

Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort / Possível associação entre distúrbios do sódio e mortalidade hospitalar em pacientes submetidos a hemodiálise aguda: análise de uma coorte retrospectiva peruana

Abstract Objective: To evaluate the association between dysnatremias or dyschloremias and mortality during hospitalization in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) undergoing acute hemodialysis. Methods: We carried out a retrospective cohort study on adult patients undergoing acute hemodialysis with AKI or CKD diagnosis at a public hospital in Lima, Peru. Dysnatremias were categorized as hyponatremia (Na < 135mmol/L) or hypernatremia (Na > 145mmol/L), and dyschloremias were defined as hypochloremia (Cl < 98 mmol/L) or hyperchloremia (Cl > 109mmol/L). The outcome of interest was mortality during hospitalization. We performed generalized lineal Poisson family models with bias-corrected and accelerated non-parametric bootstrap to estimate the risk ratios at crude (RR) and adjusted analysis (aRR) by gender, age, HCO3 (for all patients) and Liaño score (only for AKI) with CI95%. Results: We included 263 patients (mean age: 54.3 years, females: 43%): 191 with CKD and 72 with AKI. Mortality was higher in patients with AKI (59.7%) than in patients with CKD (14.1%). In overall, patients with hypernatremia had a higher mortality during hospitalization compared to those who had normal sodium values (aRR: 1.82, 95% CI: 1.17-2.83); patients with hyponatremia did not have different mortality (aRR: 0.19, 95% CI: 0.69-2.04). We also found that hyperchloremia (aRR: 1.35, 95% CI: 0.83-2.18) or hypochloremia (aRR: 0.66, 95% CI: 0.30-14.78) did not increase mortality in comparison to normal chloride values. No association between dysnatremias or dyschloremias and mortality during hospitalization was found in CKD and AKI subgroups. Conclusions: In our exploratory analysis, only hypernatremia was associated with mortality during hospitalization among patients with AKI or CKD undergoing acute hemodialysis.

Resumo Objetivo: Avaliar a associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar de pacientes com insuficiência renal aguda (IRA) ou doença renal crônica (DRC) submetidos a hemodiálise aguda. Métodos: O presente estudo de coorte retrospectiva incluiu pacientes adultos submetidos a hemodiálise aguda com diagnóstico de IRA ou DRC em um hospital público de Lima, Peru. Os distúrbios do sódio foram classificados como hiponatremia (Na < 135mmol/L) ou hipernatremia (Na > 145mmol/L), enquanto os distúrbios do cloro foram classificados como hipocloremia (Cl < 98 mmol/L) ou hipercloremia (Cl > 109mmol/L). O desfecho de interesse foi mortalidade hospitalar. Utilizamos modelos de Poisson da família de modelos lineares generalizados com bootstrap não-paramétrico e correção de viés acelerado para estimar os riscos relativos na análise bruta (RR) e ajustada (RRa) para sexo, idade, HCO3 (para todos os pacientes) e escore de Liaño (apenas para IRA) com IC 95%. Resultados: Foram incluídos 263 pacientes (idade média 54,3 anos; 43% do sexo feminino), 191 com DRC e 72 com IRA. A mortalidade foi mais elevada nos pacientes com IRA (59,7%) do que nos indivíduos com DRC (14,1%). No geral, os pacientes com hipernatremia tiveram mortalidade hospitalar mais elevada do que os indivíduos com valores normais de sódio (RRa: 1,82; IC 95%: 1,17-2,83). Os pacientes com hiponatremia não apresentaram mortalidade diferente (RRa: 0,19; IC 95%: 0,69-2,04). Também identificamos que hipercloremia (RRa: 1,35; IC 95%: 0,83-2,18) e hipocloremia (RRa: 0,66; IC 95%: 0,30-14,78) não elevaram a mortalidade em comparação a indivíduos com níveis normais de cloro. Não foi encontrada associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar nos subgrupos com DRC e IRA. Conclusões: Em nossa análise exploratória, apenas hipernatremia apresentou associação com mortalidade hospitalar em pacientes com IRA ou DRC submetidos a hemodiálise aguda.

Weighing the prognostic role of hyponatremia in hospitalized patients with metastatic solid tumors: the HYPNOSIS study.

Previous works linked low sodium concentration with mortality risk in cancer. We aimed at weighing the prognostic impact of hyponatremia in all consecutive patients with metastatic solid tumors admitted in a two-years period at our medical oncology department. Patients were included in two cohorts based on serum sodium concentration on admission. A total of 1025 patients were included, of whom 279 (27.2%) were found to be hyponatremic. The highest prevalence of hyponatremia was observed in biliary tract (51%), prostate (45%) and small-cell lung cancer (38.9%). With a median follow-up of 26.9 months, median OS was 2 months and 13.2 months for the hyponatremia versus control cohort, respectively (HR, 2.65; P < 0.001). In the multivariable model, hyponatremia was independently associated with poorer OS (HR, 1.66; P < 0.001). According to the multivariable model, a nomogram system was developed and validated in an external set of patients. We weighed over time the influence of hyponatremia on survival of patients with metastatic solid tumors and pointed out the possibility to exploit serum sodium assessment to design integrated prognostic tools. Our study also highlights the need for a deeper characterization of the biological role of extracellular sodium levels in tumor development and progression.

Impact of preoperative hyponatraemia on paediatric perioperative mortality.

BACKGROUND: Preoperative hyponatraemia is an independent risk factor for postoperative mortality in adults. To our knowledge, this has not been investigated in children. METHODS: Using data from the 2014 and 2015 data sets of the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P), we conducted a retrospective study of children undergoing surgery. The primary outcome was 30-day all-cause mortality. The secondary outcomes of interest were postoperative seizure within 30 days and prolonged length of stay. To identify any independent association between preoperative hyponatraemia, defined as mild (serum sodium of 131-135 mEq L-1) or severe (≤130 mEq L-1), and death, postoperative seizures, or prolonged length of stay, multivariable logistic regression models were generated. RESULTS: A total of 152 894 patients were identified, and of these 35 291 were included in the final analysis. Preoperative hyponatraemia was present in 5422 patients or 15.4% of the final cohort. There were 432 (0.80%) deaths at 30 days. Compared with patients with a normal preoperative sodium concentration, those with mild (P=0.003; odds ratio [OR]: 1.59; 95% confidence interval [CI]: 1.17-2.18) and severe (P=0.002; OR: 2.16; 95% CI: 1.32-3.54) hyponatraemia had increased rates of death, after adjusting for co-morbidity and procedural complexity. Both mild (P<0.001; OR: 1.53; 95% CI: 1.42-1.65) and severe (P<0.001; OR: 1.51; 95% CI: 1.19-1.93) hyponatraemia were independently associated with prolonged length of stay, after adjusting for relevant co-variates. CONCLUSIONS: This retrospective analysis identified an association between preoperative hyponatraemia and perioperative mortality and length of stay in paediatric patients.

Mild hyponatremia discovered within the first 24 hours of ischemic stroke is a risk factor for early post stroke mortality.

BACKGROUND: Comorbidities, complications and laboratory abnormalities are common in stroke patients. One of the common problems is hyponatremia (serum sodium (Na) level <135 mmol/L), but the relationship between hyponatremia and the prognosis in patients with stroke is not well understood. OBJECTIVES: The aim of this study was to investigate the prevalence and severity of hyponatremia, as well as its impact on prognosis in stroke patients on admission to hospital. MATERIAL AND METHODS: The study involved the analysis of the first measurement of the Na level after the admission and its correlations with comorbidities, the scale of clinical assessment of stroke severity (NIHSS), the size and location of the stroke, and mortality. A retrospective study was conducted on 502 patients (among them 263 women) admitted to the hospital on stroke onset (440 ischemic stroke (IS) and 62 hemorrhagic stroke (HS) patients). The post-stroke mortality was defined as early if death occurred within 30 days. RESULTS: Hyponatremia was found in 18.4% of patients with IS and 25.8% of patients with HS, irrespective of age and gender. Hyponatremia is an independent prognostic factor of mortality in people with IS (p = 0.003). Na levels were lower in IS patients who died than in those who remained alive (134.8 ±4.99 mmol/L vs 136.6 ±3.01 mmol/L; p = 0.02). Higher mortality rate was observed among IS patients under 75 years of age and Na level ≤132 mmol/L. In patients with IS, hyponatremia correlates with NIHSS (p = 0.005) and the size and location of the stroke (p = 0.002). CONCLUSIONS: Hyponatremia is more frequently observed in patients with HS than IS. Mild hyponatremia is already known to be an independent prognostic factor in the mortality of people with IS and it may also have value as a prognostic factor in the mortality of the IS population. In a patient with a suspected stroke, there is a need to control electrolyte levels at the onset of the stroke, especially in patients with comorbidities, irrespective of age.

Sex-specific risks of death in patients hospitalized for hyponatremia: a population-based study.

PURPOSE: Several studies have reported an association between hyponatremia and lethality. However, it remains elusive whether hyponatremia independently contributes to lethality. The aim of the study was to investigate associations between hyponatremia and lethality and differences in lethality between men and women hospitalized due to hyponatremia. METHODS: Four registries were utilized in this population-based retrospective study: The National Patient Registry, the Cause of Death Register, the Swedish Prescribed Drug Register and the Total Population Register (NPR) from which the controls were sampled. All hospitalized patients with a first-ever principal ICD10 diagnosis of hyponatremia or syndrome of inappropriate ADH secretion in the NPR between 1 October 2005 and 31 December 2014 were defined as cases. Cox regression with adjustment for potential confounders was used. RESULTS: 14,359 individuals with a principal diagnosis of hyponatremia, and 57,382 matched controls were identified. Median age was 76 years and the majority were women (72%). Median age for women and men was 79 and 68 years, respectively. Adjusted hazard ratios (and 95% CI) for lethality in those with hyponatremia compared with controls were for the entire population 5.5 (4.4-7.0) and in the subgroup free from previously known underlying disease 6.7 (3.3-13.3). Lethality in women with hyponatremia was lower compared with men: HR: 0.56 (0.49-0.64). In the healthier group the lethality remained lower for women: HR: 0.49 (0.34-0.71). CONCLUSIONS: Patients hospitalized due to hyponatremia faced an increased subsequent lethality that was independent of concomitant disease. This increase was nearly twice as large among men compared with women.