Clinical factors within a week of birth influencing sodium level difference between an arterial blood gas analyzer and an autoanalyzer in VLBWIs: A retrospective study.

ABSTRACT: Neonatologists often experience sodium ion level difference between an arterial blood gas analyzer (direct method) and an autoanalyzer (indirect method) in critically ill neonates. We hypothesize that clinical factors besides albumin and protein in the blood that cause laboratory errors might be associated with sodium ion level difference between the 2 methods in very-low-birth-weight infants during early life after birth. Among very-low-birth-weight infants who were admitted to Jeonbuk National Hospital Neonatal Intensive Care Units from October 2013 to December 2016, 106 neonates were included in this study. Arterial blood sample was collected within an hour after birth. Blood gas analyzer and biochemistry autoanalyzer were performed simultaneously. Seventy-six (71.7%) were found to have sodium ion difference exceeding 4 mmol/L between 2 methods. The mean difference of sodium ion level was 5.9 ±â€Š6.1 mmol/L, exceeding 4 mmol/L. Based on sodium ion level difference, patients were divided into >4 and ≤4 mmol/L groups. The sodium level difference >4 mmol/L group showed significantly (P < .05) higher sodium level by biochemistry autoanalyzer, lower albumin, lower protein, and higher maximum percent of physiological weight than the sodium level difference ≤4 mmol/L group. After adjusting for factors showing significant difference between the 2 groups, protein at birth (odds ratio: 0.835, 95% confidence interval: 0.760-0.918, P < .001) and percent of maximum weight loss (odds ratio: 1.137, 95% confidence interval: 1.021-1.265, P = .019) were factor showing significant associations with sodium level difference >4 mmol/L between 2 methods. Thus, difference in sodium level between blood gas analyzer and biochemistry autoanalyzer in early stages of life could reflect maximum physiology weight loss. Based on this study, if the study to predict the body's composition of extracellular and intracellular fluid is proceeded, it will help neonatologist make clinical decisions at early life of preterm infants.

Hypernatremia and intercalated disc edema synergistically exacerbate long-QT syndrome type 3 phenotype.

Cardiac voltage-gated sodium channel gain-of-function prolongs repolarization in the long-QT syndrome type 3 (LQT3). Previous studies suggest that narrowing the perinexus within the intercalated disc, leading to rapid sodium depletion, attenuates LQT3-associated action potential duration (APD) prolongation. However, it remains unknown whether extracellular sodium concentration modulates APD prolongation during sodium channel gain-of-function. We hypothesized that elevated extracellular sodium concentration and widened perinexus synergistically prolong APD in LQT3. LQT3 was induced with sea anemone toxin (ATXII) in Langendorff-perfused guinea pig hearts (n = 34). Sodium concentration was increased from 145 to 160 mM. Perinexal expansion was induced with mannitol or the sodium channel ß1-subunit adhesion domain antagonist (ßadp1). Epicardial ventricular action potentials were optically mapped. Individual and combined effects of varying clefts and sodium concentrations were simulated in a computational model. With ATXII, both mannitol and ßadp1 significantly widened the perinexus and prolonged APD, respectively. The elevated sodium concentration alone significantly prolonged APD as well. Importantly, the combination of elevated sodium concentration and perinexal widening synergistically prolonged APD. Computational modeling results were consistent with animal experiments. Concurrently elevating extracellular sodium and increasing intercalated disc edema prolongs repolarization more than the individual interventions alone in LQT3. This synergistic effect suggests an important clinical implication that hypernatremia in the presence of cardiac edema can markedly increase LQT3-associated APD prolongation. Therefore, to our knowledge, this is the first study to provide evidence of a tractable and effective strategy to mitigate LQT3 phenotype by means of managing sodium levels and preventing cardiac edema in patients.NEW & NOTEWORTHY This is the first study to demonstrate that the long-QT syndrome type 3 (LQT3) phenotype can be exacerbated or concealed by regulating extracellular sodium concentrations and/or the intercalated disc separation. The animal experiments and computational modeling in the current study reveal a critically important clinical implication: sodium dysregulation in the presence of edema within the intercalated disc can markedly increase the risk of arrhythmia in LQT3. These findings strongly suggest that maintaining extracellular sodium within normal physiological limits may be an effective and inexpensive therapeutic option for patients with congenital or acquired sodium channel gain-of-function diseases.

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

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.

Incidence and Possible Predictors of Sodium Disturbance After Craniopharyngioma Resection Based on QST Classification.

OBJECTIVE: Serum sodium abnormalities are one of the most common manifestations after radical craniopharyngioma (CP) excision. The aim of this study was to report the incidence and possible predictors of serum sodium disturbance and explore features of sodium destabilization manifestation among QST classification results after CP resection. METHODS: A retrospective analysis was performed of clinical, biochemical, radiologic, and operative data for 134 successive patients who underwent primary CP removal between September 2016 and March 2018. Univariate and multivariate analyses were conducted to determine predictors. RESULTS: Sixty patients (44.8%) experienced hyponatremia and 67 patients (50%) hypernatremia; the median time of onset was 6 days and the first day after surgery, respectively. The incidence, onset, severity, and type of sodium disturbance among different types of CP differed significantly based on statistical tests (P < 0.05). Sodium disturbance was more common and severe in patients with type T tumors (P < 0.05). Age, tumor type, and preoperative diabetes insipidus were independent prognostic factors for obvious disorders of serum sodium. CONCLUSIONS: Hyponatremia/hypernatremia is common after primary CP resection. The site of tumor origin has a direct effect on the growth pattern of CP, which may serve as a useful index for anticipating sodium perturbation after surgery. The level of sodium in children and patients with type T tumors, preoperative diabetes insipidus should be monitored closely throughout hospitalization.

Frequency and Impact of Hyponatremia on All-Cause Mortality in Patients With Aortic Stenosis.

Asymptomatic aortic stenosis (AS) is a frequent condition that may cause hyponatremia due to neurohumoral activation. We examined if hyponatremia heralds poor prognosis in patients with asymptomatic AS, and whether AS in itself is associated with increased risk of hyponatremia. The study question was investigated in 1,677 individuals that had and annual plasma sodium measurements in the SEAS (Simvastatin and Ezetimibe in AS) trial; 1,873 asymptomatic patients with mild-moderate AS (maximal transaortic velocity 2.5 to 4.0 m/s) randomized to simvastatin/ezetimibe combination versus placebo. All-cause mortality was the primary endpoint and incident hyponatremia (P-Na+ <137 mmol/L) a secondary outcome. At baseline, 4% (n = 67) had hyponatremia. After a median follow-up of 4.3 (interquartile range 4.1 to 4.6) years, 140 (9%) of those with initial normonatremia had developed hyponatremia, and 174 (10%) had died. In multiple regression Cox models, both baseline hyponatremia (hazard ratio [HR] 2.1, [95% confidence interval 1.1 to 3.8]) and incident hyponatremia (HR 1.9, [95% confidence interval 1.0 to 3.4], both p ≤ .03) was associated with higher all-cause mortality as compared with normonatremia. This association persisted after adjustment for diuretics as a time-varying covariate. Higher N-terminal pro b-type natriuretic peptide levels and lower sodium levels at baseline was associated with higher risk of incident hyponatremia. Conversely, assignment to simvastatin/ezetimibe protected against incident hyponatremia. In conclusion, both prevalent and incident hyponatremia associate with increased mortality in patients with AS. The prevalence of hyponatremia is around 4% and the incidence about 2% per year, which is comparable to that of older adults without AS.

Serum sodium variability and acute kidney injury: a retrospective observational cohort study on a hospitalized population.

Aim of our study was to analyze the association between serum sodium (Na) variability and acute kidney injury (AKI) development. We performed a retrospective observational cohort study on the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 1, 2010 and December 31, 2014 with inclusion of adult patients with ≥ 2 Na and ≥ 2 serum creatinine measurements. We included only patients with ≥ 2 Na measurements before AKI development. The outcome of interest was AKI. The exposures of interest were hyponatremia, hypernatremia and Na fluctuations before AKI development. Na variability was evaluated using the coefficient of variation (CV). Multivariable Cox proportional hazards and logistic regression models were fitted to obtain hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (CIs) for the association between the exposures of interest and AKI. Overall, 56,961 patients met our inclusion criteria. During 1541 person-years of follow-up AKI occurred in 1450 patients. In multivariable hazard models, patients with pre-existent dysnatremia and those who developed dysnatremia had a higher risk of AKI compared with patients with normonatremia. Logistic models suggested a higher risk for AKI in the 3rd (OR 1.41, 95% CI 1.18, 1.70, p < 0.001) and 4th (OR 1.53, 95% CI 1.24, 1.91, p < 0.001) highest quartiles of Na CV with a significant linear trend across quartiles (p trend < 0.001). This association was also independent from Na highest and lowest peak value. Dysnatremia is a common condition and is positive associated with AKI development. Furthermore, high Na variability might be considered an independent early indicator for kidney injury development.

Tolvaptan-induced hypernatremia related to low serum potassium level accompanying high blood pressure in patients with acute decompensated heart failure.

BACKGROUNDS: Tolvaptan significantly increases urine volume in acute decompensated heart failure (ADHF); serum sodium level increases due to aquaresis in almost all cases. We aimed to elucidate clinical factors associated with hypernatremia in ADHF patients treated with tolvaptan. METHODS: We enrolled 117 ADHF patients treated with tolvaptan in addition to standard therapy. We examined differences in clinical factors at baseline between patients with and without hypernatremia in the initial three days of hospitalization. RESULTS: Systolic (p = 0.045) and diastolic (p = 0.004) blood pressure, serum sodium level (p = 0.002), and negative water balance (p = 0.036) were significantly higher and serum potassium level (p = 0.026) was significantly lower on admission day in patients with hypernatremia (n = 22). In multivariate regression analysis, hypernatremia was associated with low serum potassium level (p = 0.034). Among patients with serum potassium level ≤ 3.8 mEq/L, the cutoff value obtained using receiver operating characteristic curve analysis, those with hypernatremia related to tolvaptan treatment showed significantly higher diastolic blood pressure on admission day (p = 0.004). CONCLUSION: In tolvaptan treatment combined with standard therapy in ADHF patients, serum potassium level ≤ 3.8 mEq/L may be a determinant factor for hypernatremia development. Among hypokalemic patients, those with higher diastolic blood pressure on admission may be carefully managed to prevent hypernatremia.

Hypernatremia-A Manifestation of COVID-19: A Case Series.

We report for the first time therapy-resistant hypernatremia (plasma sodium concentration ≥150 mmol per liter) developing in 6 of 12 critically ill coronavirus disease 2019 (COVID-19) patients age 57-84 years requiring mechanical ventilation. There was no correlation between plasma sodium concentrations and sodium input. Plasma concentrations of chloride were elevated, those of potassium decreased. These findings are consistent with abnormally increased renal sodium reabsorption, possibly caused by increased angiotensin II activity secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced downregulation of angiotensin-converting enzyme 2 (ACE2) receptors. As hypernatremia was associated with increased length of intensive care unit stay, special attention should be paid to the electrolyte status of COVID-19 patients.

Hypernatremia at admission predicts poor survival in patients with terminal cancer: a retrospective cohort study.

BACKGROUND: Although palliative care providers, patients, and their families rely heavily on accurate prognostication, the prognostic value of electrolyte imbalance has received little attention. METHODS: As a retrospective review, we screened inpatients with terminal cancer admitted between January 2017 and May 2019 to a single hospice-palliative care unit. Clinical characteristics and laboratory results were obtained from medical records for multivariable Cox regression analysis of independent prognostic factors. RESULTS: Of the 487 patients who qualified, 15 (3%) were hypernatremic upon admission. The median survival time was 26 days. Parameters associated with shortened survival included male sex, advanced age (> 70 years), lung cancer, poor performance status, elevated inflammatory markers, azotemia, impaired liver function, and hypernatremia. In a multivariable Cox proportional hazards model, male sex (hazard ratio [HR] = 1.53, 95% confidence interval [CI]: 1.15-2.04), poor performance status (HR = 1.45, 95% CI: 1.09-1.94), leukocytosis (HR = 1.98, 95% CI: 1.47-2.66), hypoalbuminemia (HR = 2.06, 95% CI: 1.49-2.73), and hypernatremia (HR = 1.55, 95% CI: 1.18-2.03) emerged as significant predictors of poor prognosis. CONCLUSION: Hypernatremia may be a useful gauge of prognosis in patients with terminal cancer. Further large-scale prospective studies are needed to corroborate this finding.

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.

Central diabetes insipidus related to anti-programmed cell-death 1 protein active immunotherapy.

Cancer immunotherapy is a breakthrough strategy entwined with toxicity. Immune-related hypophysitis is conventionally considered distinctive of cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitors. Immune-related central diabetes insipidus (CDI) is exceptional. CDI rarely manifests as hypernatremia, which is almost always euvolemic. We report a 71-years-old male patient with advanced lung cancer who experienced severe chronic hypernatremia presented as alterations in mental status five months after initiation of treatment with the anti-PD-1 checkpoint inhibitor nivolumab. Combination of persistenthypernatremia, polyuria, high plasma osmolality and hyposthenuria raised suspicion of diabetes insipidus, prompting measurement of serum concentration of arginine vasopressin(AVP). The inappropriately undetectable serum levels of AVP confirmed central diabetes insipidus (CDI). Nivolumab-related hypophysitis was recognized as possible cause of CDI. Further hormonal assessment excluded any endocrinopathy indicating disorder of posterior pituitary. Pituitary MRI was normal with persistence of hyperintensity of posterior pituitary on T1-weighted images (bright spot). The patient was scheduled to receive 1-deamino-8-D-arginine vasopressin (DDAVP), but he died suddenly due to cardiac arrest before initiation of treatment. Our report describes the first case of nivolumab related CDI, building on existing literature through: (I) underscoring hypovolemic hypernatremia as CDI manifestation; (ii) bringing into spotlight the rare anti-PD-1 treatment related hypophysitis; (iii) enriching the limited evidence on immune-related CDI. Increased awareness of nivolumab related CDI will enable prompt recognition and therapeutic intervention.

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.

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.

Diagnosis and Management of Disorders of Body Tonicity-Hyponatremia and Hypernatremia: Core Curriculum 2020.

Overall body fluid concentration is regulated within a narrow range by the concerted action of the hypothalamic-pituitary axis to influence water intake through thirst and water excretion via the effect of vasopressin, or antidiuretic hormone, on renal collecting duct water permeability. Sodium is the principal extracellular cation; abnormalities in overall effective body fluid concentration, or tonicity, manifest as disturbances in serum sodium concentration. Depending on its severity and chronicity, hyponatremia can lead to significant symptoms, primarily related to central nervous system function. Failure to correct hyponatremia can lead to permanent neurologic damage, as can over rapid correction. It is thus essential to stay within specific limits for correction, particularly for chronic hyponatremia. Hypernatremia also leads to central nervous system dysfunction, although goals for its correction rate are less well established. This Core Curriculum article discusses the normal regulation of tonicity and serum sodium concentration and the diagnosis and management of hypo- and hypernatremia.

Regional Citrate Anticoagulation versus No-Anticoagulation for Continuous Venovenous Hemofiltration in Acute Severe Hypernatremia Patients with Increased Bleeding Risk: A Retrospective Cohort Study.

PURPOSE: This study was aimed at evaluating the efficacy and safety of regional citrate anticoagulation (RCA) versus no-anticoagulation continuous venovenous hemofiltration (CVVH) in acute severe hypernatremia patients with increased bleeding risk. MATERIALS AND METHODS: Acute severe hypernatremia patients with high bleeding risk who underwent CVVH in our center between January 2011 and October 2017 were considered as candidates. Patients who were <18 years old, with hypovolemic hypernatremia, and had systemic anticoagulation were excluded. The included patients were divided into RCA and no-anticoagulation groups according to their anticoagulation strategy during CVVH and matched by age, sequential organ failure assessment scores, and vasopressor dependency. RESULTS: Of the 64 included patients, no-anticoagulation and RCA were employed for CVVH in 23 and 41 patients, respectively. The serum sodium reduction rate (RRSeNa) was not significantly different between the no-anticoagulation and RCA groups (p = 0.729). Compared to no-anticoagulation, RCA significantly prolonged the circuit survival time (15 h [4.1-23.9] vs. 51 h [21.3-80.7], p = 0.001). The incidence of filter failure was 65.2% (15/23) in the no-anticoagulation group and 2.4% (1/41) in the RCA group (p < 0.001), respectively. In the matched cohort, the RRSeNas were not different between the 2 groups (p = 0.569), and the filter lifespan was significantly longer in the RCA group as well (p < 0.001). CONCLUSION: RCA might be safe and effective for acute severe hypernatremia patients who underwent CVVH treatment. Further prospective, randomized, control trials are warranted to obtain robust evidences.

Increased rates of hypernatraemia during modest heatwaves in temperate climates.

BACKGROUND: Hypernatraemia is associated with morbidity and mortality, particularly in the older person. Last summer, Ireland experienced prolonged periods of excessive heat. The Irish meteorological service defines a heatwave as temperatures exceeding 25°C for five consecutive days. AIM: This study sought to compare the frequency of hypernatraemia (sodium (Na+) >145 mmol/l) observed during a modest heatwave with that during average ambient temperature in the temperate Irish climate. DESIGN: Retrospective cross-sectional analysis with nested case-control study. METHODS: The 10-day period from 24 June to 3 July in 2017 and 2018 were chosen as the control and heatwave periods, respectively. Patients aged >65 with at least one Na+ value recorded on the laboratory information system were included. Local meteorological data, age, gender and Na+ levels were evaluated. RESULTS: Maximum air temperatures were significantly higher during the heatwave period (mean 27°C vs. 16.8°C, P < 0.0001). Hypernatraemia was present in 3.6% (66/1840) of samples collected during the heatwave compared to 1.4% (23/1593) in the control period. The mean age of affected patients was similar in both groups, 75 years ±7 (P = 1.000). Almost half of participants (49.5%) were male. The frequency of hypernatraemia observed was not influenced by gender, P = 0.33. The median sodium concentrations were similar in both groups, P = 1.00. CONCLUSION: Hypernatraemia was 2.5 times more frequent in samples drawn during the heatwave compared to the control period. In this study, neither age nor gender impacted the profile of patients diagnosed with hypernatraemia. A modest rise in temperatures increases hypernatraemia rates in temperate climates.