The differential risk of severe hyponatraemia based on the use patterns of hyponatraemia-inducing medications in older adults.

BACKGROUND: the identification and minimization of hyponatraemia-inducing medication (HIM) usage is among the effective strategies for preventing hyponatraemia. However, the differential risk of severe hyponatraemia is unknown. OBJECTIVE: to evaluate the differential risk of severe hyponatraemia associated with newly started and concurrently used HIMs in older people. DESIGN AND SETTING: a case-control study using national claims databases. METHODS: we identified patients aged >65 years with severe hyponatraemia as those hospitalised with a primary diagnosis of hyponatraemia or who had received tolvaptan or 3% NaCl. A 1:20 matched control with the same visit date was constructed. Multivariable logistic regression was performed to assess the association of newly started or concurrently used HIMs comprising 11 medication/classes with severe hyponatraemia after covariate adjustment. RESULTS: among 47,766,420 older patients, we identified 9,218 with severe hyponatraemia. After adjusting for covariates, all HIM classes were found to be significantly associated with severe hyponatraemia. Compared with persistently used HIMs, newly started HIMs increased the likelihood of severe hyponatraemia for eight classes of HIMs, with the highest increase being observed for desmopressin (adjusted odds ratio: 3.82, 95% confidence interval: 3.01-4.85). Concurrent use increased the risk of severe hyponatraemia compared to that with individually administered HIMs: thiazide-desmopressin (4.86, 3.90-6.07), medications causing the syndrome of inappropriate anti-diuretic hormone secretion (SIADH)-desmopressin (2.65, 2.25-3.11), medications causing SIADH-thiazides (1.87, 1.75-1.98) and combination among medications causing SIADH (1.36, 1.28-1.45). CONCLUSIONS: in older adults, newly started and concurrently used HIMs increased the risk of severe hyponatraemia compared with persistently and singly used HIMs.

Analysis of the Frequency and Onset Time of Hyponatremia/Syndrome of Inappropriate Antidiuretic Hormone Induced by Antidepressants or Antipsychotics.

BACKGROUND: Hyponatremia and syndrome of inappropriate antidiuretic hormone (SIADH) is a potentially fatal adverse effect of antidepressants (ADs) and antipsychotics (APs), although its frequency and onset time have not been well documented. OBJECTIVE: To analyze the frequency and onset time of AD- or AP-induced hyponatremia/SIADH. METHODS: We used plural data-mining techniques to search the US Food and Drug Administration Adverse Event Reporting System (FAERS) database for reports on hyponatremia/SIADH induced by psychotropic drugs from January 2004 to June 2020. For each item, we assessed the reporting odds ratio, 95% CI, median onset time, and Weibull distribution parameters. RESULTS: We identified 36 422 reports related to hyponatremia/SIADH. Signals were detected for all psychotropic drugs that we analyzed, except for clozapine. The median onset time of total AD-induced hyponatremia/SIADH was shorter than that of AP. For all ADs and APs except clozapine, hazards were considered to be the early failure type. In contrast, the hazard of clozapine was considered to be the random failure type. The limitations of this study included several reporting biases and the presence of confounding variables, particularly age. CONCLUSION AND RELEVANCE: Most ADs and APs were found to be associated with a risk for hyponatremia/SIADH. In addition, sufficient attention should be paid to signs of hyponatremia/SIADH in the early phase when most ADs and APs are administered. These data are potentially useful for determining AD- or AP-induced hyponatremia/SIADH in the early stage and for preventing its further aggravation into a serious condition.

Syndrome of inappropriate antidiuretic hormone secretion is associated with different proton pump inhibitor use: a pharmacovigilance study.

AIM: The objective of this study was to evaluate the reported associations between the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and a variety of proton pump inhibitors (PPI) through analysis of the reports extracted from the Food and Drug Administration Adverse Event Reporting System (FAERS). METHODS: FAERS reports from January 2004 to March 2020 were used to conduct disproportionality and Bayesian analyses. The definition of SIADH relied on the preferred terms provided by the Medical Dictionary for Regulatory Activities. The time to onset, mortality, and hospitalization rates of PPI-related SIADH were also investigated. RESULTS: The study identified a total of 273 reports of PPI-associated SIADH, which appeared to influence more elderly than middle-aged patients (71.1% vs. 12.5%). Women were more affected than men (48.7% vs. 41.8%). Rabeprazole had a stronger SIADH association than other PPIs based on the highest reporting odds ratio (reporting odds ratio = 13.3, 95% confidence interval (CI) = 7.2, 24.9), proportional reporting ratio (proportional reporting ratio = 13.3, χ2 = 113.7), and empirical Bayes geometric mean (empirical Bayes geometric mean = 13.3, 95% CI = 7.9). The median time to SIADH onset was 22 (interquartile range 6-692) days after PPI administration. PPI-associated SIADH generally led to a 2.95% fatality rate and a 79.7% hospitalization rate. The highest hospitalization death rate occurred in esomeprazole (91.2%). CONCLUSION: According to our findings, more attention should be paid to SIADH within the first several months after the administration of PPIs. For women older than 65 years, dexlansoprazole may reduce the incidence of PPI-associated SIADH. Nonetheless, larger epidemiological studies are suggested to verify this conclusion.

Prevalence of Dysnatremia in Pulmonary Tuberculosis.

Pulmonary tuberculosis is one of the common diseases with high prevalence of mortality and morbidity in developing countries. It is one of the rare pulmonary infections which can induce hyponatremia and it is important to recognise hyponatremia because of its potential hazards. OBJECTIVES: To assess the serum sodium levels in patients with pulmonary tuberculosis and to establish a relation between the serum sodium levels and its effect on illness in these patients. MATERIAL: This is a single-center prospective observational Study conducted on patients with Pulmonary Tuberculosis, irrespective of treatment, in the department of General Medicine, B. R. Ambedkar Medical College, Bangalore from August 2019 to June 2021after obtaining ethical clearance. A total of 100 patients were enrolled in the study who met the predefined inclusion criteria of age more than 18 years and having been diagnosed with active tuberculosis. The collected data was analysed using student's T test and Chi-Square Test and the analysis was done using SPSS software version 24.0. OBSERVATION: The mean age was 46.46+/- 15.69, with majority of participants in the age group 46-60 years. Gender wise there was male preponderance in our study with 60%. The average serum sodium concentration in our study was 134.20 +/- 5.59 mmol/l, with 44% prevalence of hyponatremia and 4% SIADH Conclusion: Although mild hyponatremia was seen in more than 50% of patients, we found out that hyponatremia in pulmonary tuberculosis is detected in 44% of our patients with male preponderance. The predominant mechanism of hyponatremia was syndrome of inappropriate anti- diuretic hormone secretion (SIADH), which was present in 65% of cases with hyponatremia. Early detection and treatment of underlying electrolyte abnormality can potentially reduce mortality and morbidity associated with tuberculosis and reduce duration of hospitalization. Further research into the prevalence of potassium, magnesium and chloride abnormalities can add to the lacunae of knowledge.

Diabetes insipidus and syndrome of inappropriate antidiuresis (SIADH) after pituitary surgery: incidence and risk factors.

Electrolyte disorders are relatively frequent and potentially serious complications after pituitary surgery. Both DI (diabetes insipidus) and SIADH (syndrome of inappropriate antidiuresis) can complicate and prolong hospital and intensive care unit stay, and the latter may even be preventable. We aim to assess the incidence of both electrolyte disorders and their risk factors. From a prospective registry of patients who underwent endoscopic transnasal transsphenoidal surgery (TSS) for pituitary adenoma, patients with postoperative DI and SIADH were identified. Univariable and multivariable statistics were carried out to identify factors independently associated with the occurrence of either DI or SIADH. A total of 174 patients were included, of which 73 (42%) were female. Mean age was 54 years (range 20-88). During postoperative hospital stay, 13 (7.5%) patients presenting with DI and 11 (6.3%) with SIADH were identified. Patients who developed DI after surgery had significantly longer hospital stays (p = 0.022), as did those who developed SIADH (p = 0.002). Four (2.3%) patients were discharged with a diagnosis of persistent DI, and 2 (1.1%) with the diagnosis of SIADH. At the last follow-up, 5 (2.9%) patients presented with persistent DI, while none of the patients suffered from SIADH. Younger age (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.94-1.01, p = 0.166) and pituitary apoplexy (OR 2.69, 95% CI 0.53-10.65, p = 0.184) were weakly associated with the occurrence of DI. We identified younger age (OR 0.96, 95% CI 0.92-0.99, p = 0.045) and lower preoperative serum sodium (OR 0.83, 95% CI 0.71-0.95, p = 0.008) as independent risk factors for SIADH. Although we found a weak association among age, pituitary apoplexy, and the occurrence of DI, no independent predictor was identified for DI. For postoperative SIADH however, lower age and preoperative serum sodium were identified as significant predictors. None of these findings were sufficiently supported by preexisting literature. Both electrolyte disorders are exquisitely hard to predict preoperatively, and further research into their early detection and prevention is warranted.

Hyponatremia in the cancer patient.

Hyponatremia is a common electrolyte disorder observed in a wide variety of malignancies and is associated with substantial morbidity and mortality. Newer cancer therapies have improved patient outcomes while contributing to new cases of hyponatremia. Patients should be monitored closely for the development of vasopressin- and non-vasopressin-mediated hyponatremia. Acute and symptomatic forms of hyponatremia require urgent intervention, and recent findings support the correction of chronic "asymptomatic" hyponatremia. Optimizing hyponatremia may reduce medical costs, and improve cancer survival likelihood and quality of life. In this article, we review the epidemiology, pathophysiology, etiology, diagnosis, and treatment of hyponatremia in the cancer patient.

Evolution and evolving resolution of controversy over existence and prevalence of cerebral/renal salt wasting.

PURPOSE OF REVIEW: The topic of hyponatremia is in a state of flux. We review a new approach to diagnosis that is superior to previous methods. It simplifies identifying the causes of hyponatremia, the most important issue being the differentiation of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) from cerebral/renal salt wasting (RSW). We also report on the high prevalence of RSW without cerebral disease in the general wards of the hospital. RECENT FINDINGS: We applied our new approach to hyponatremia by utilizing sound pathophysiologic criteria in 62 hyponatremic patients. Seventeen (27%) had SIADH, 19 (31%) had a reset osmostat, 24 (38%) had RSW with 21 having no evidence of cerebral disease, 1 had Addison's disease, and 1 was because of hydrochlorothiazide. Many had urine sodium concentrations (UNa) less than 30 mmol/l. SUMMARY: RSW is much more common than perceived in the general wards of the hospital. It is important to change the terminology from cerebral to RSW and to differentiate SIADH from RSW. These changes will improve clinical outcomes because of divergent therapeutic goals of water-restricting in SIADH and administering salt and water to a dehydrated patient with RSW. The present review will hopefully spur others to reflect and act on the new findings and different approaches to hyponatremia.

Hyponatraemia in patients with community-acquired pneumonia; prevalence and aetiology, and natural history of SIAD.

OBJECTIVE: Hyponatraemia is common in community-acquired pneumonia (CAP) and is associated with increased mortality. The mechanism of hyponatraemia in CAP is not completely understood and treatment is therefore ill-defined. We aimed to define the causation of hyponatraemia in CAP. DESIGN: Prospective, single-centre, observational study of all patients with CAP and hyponatraemia (≤ 130 mmol/L) during a 9-month period. PATIENTS: The prevalence of each subtype of hyponatraemia, and the associated mortality, was determined in 143 admissions with CAP (Study 1). A sub-cohort of patients with SIAD (n = 10) was prospectively followed, to document the natural history of SIAD associated with CAP (Study 2). MEASUREMENTS: In Study 2, blood and urine were collected on day 1, 3, 5 and 7 following admission for measurement of plasma vasopressin, sodium, osmolality and urine osmolality. RESULTS: In study 1, 143/1723(8.3%) of CAP patients had hyponatraemia (≤130 mmol/L). About 66 had SIAD (46%), 60(42%) had hypovolaemic hyponatraemia (HON), 13(9%) had hypervolaemic hyponatraemia (HEN) and 4(3%) patients had hyponatraemia due to glucocorticoid hormone deficiency. Mortality was higher in the HEN than in the HON, SIAD or normonatraemic groups (P < 0.01). In Study 2, plasma sodium concentration normalized in 8/10 (80%) by day 7. Two patients with persistent hyponatraemia were discovered to have underlying bronchiectasis. CONCLUSIONS: Hyponatraemia in CAP is most commonly secondary to SIAD or hypovolaemia. HEN is less common, but has worse prognosis. Prospective observation demonstrates that in SIAD, plasma AVP and sodium concentrations normalize with antimicrobials; failure of reversal of suggests underlying lung disease, such as bronchiectasis.

A Study of Hyponatremia in Acute Encephalitis Syndrome: A Prospective Study From a Tertiary Care Center in India.

PURPOSE:: To evaluate the frequency and causes of hyponatremia in acute encephalitis syndrome (AES) and its effect on outcome. PATIENTS AND METHODS:: Consecutive patients with AES were subjected to neurological evaluation including Glasgow Coma Scale, focal weakness, movement disorder, and reflex changes. The etiology of AES was based on blood and cerebrospinal fluid enzyme-linked immunosorbent assay and polymerase chain reaction. We have categorized patients into neurological or systemic AES. Hyponatremia was diagnosed if 2 consecutive serum sodium levels were below 135 mEq/L, 24 hours apart. Serum and urinary osmolality and electrolytes were measured on alternate days. Fluid intake, output, and body weight were measured daily. The hyponatremia was categorized into syndrome of inappropriate secretion of antidiuretic hormone (SIADH), cerebral salt wasting (CSW), or miscellaneous group. Outcome at 1 month was assessed by modified Rankin scale. RESULTS:: Of 79 patients, 34 had neurologic AES and 45 had systemic AES; 22 (27.8%) patients had hyponatremia. The neurologic AES as compared to systemic AES was more commonly associated with hyponatremia (38.2% vs 20%, P = .07), need longer hospitalization (25.0 vs 12.5 days, P = .003), and longer time for sodium correction (13.3 vs 8.2 days, P = .05). The hyponatremia was due to CSW in 12 patients, SIADH in 2 patients, and indeterminate in 8 patients. Thirty-six patients had poor outcome (15 died) and 43 had good outcome which was not related to hyponatremia. CONCLUSION:: Hyponatremia occurs in one-third of patients with AES, being commoner in neurologic AES, and CSW is the commonest cause.

Medication-induced SIADH: distribution and characterization according to medication class.

AIMS: The aims of the current study were to determine the distribution of aetiologies for the drug-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH) in hospitalized patients, and to characterize them according to the different drug groups. METHODS: A single-centre retrospective study was carried out, including all patients diagnosed with SIADH in a large community hospital and tertiary centre between 1 January 2007 and 1 January 2013 who were treated with drugs known to be associated with SIADH. Two physicians reviewed every patient's medical file for predetermined relevant clinical data. RESULTS: The study cohort included 198 patients who had SIADH and received drugs associated with SIADH. Most patients [146 (73.7%)] were diagnosed with drug-associated SIADH, while 52 (26.3%) were diagnosed with SIADH due to other aetiologies. The Naranjo algorithm differentiated well between the two groups (P < 0.001). Five drug classes (antidepressants, anticonvulsants, antipsychotic agents, cytotoxic agents and pain medications) were implicated in 82.3% of patients diagnosed with drug-associated SIADH. Specific serotonin reuptake inhibitors and carbamazepine were commonly implicated. There were no clinically significant differences in the characteristics or severity of SIADH according to drug class. CONCLUSIONS: The clinical characteristics of SIADH caused by different drugs are comparable. Patients with SIADH treated with drugs from five common medication classes will probably be diagnosed with drug-induced SIADH. Physicians should be aware of the significance of these medication classes as SIADH aetiologies.

Lack of appropriate investigations in making a diagnosis of syndrome of inappropriate antidiuretic hormone.

The syndrome of inappropriate antidiuretic hormone (SIADH) is reported as the most common cause of hyponatraemia. This retrospective cross-sectional study evaluated the diagnosis of SIADH in 110 hospitalised patients in an Australian tertiary hospital with reference to recently published clinical guidelines. Investigation of SIADH was incomplete in all but 20% of cases. Adrenal insufficiency and hypothyroidism were not excluded in a significant number of cases.

The Syndrome of Inappropriate Secretion of Anti-Diuretic Hormone (SIADH) and Brucellosis.

BACKGROUND Our study aimed to demonstrate the frequency of the syndrome of inappropriate ADH secretion (SIADH) and associated factors during the course of brucellosis in children and adolescents. MATERIAL AND METHODS The study included children and adolescents aged 0-18 years old diagnosed with brucellosis between 2012 and 2014. The data were collected from patient charts. The diagnosis of brucellosis was made based on titrations >1:160 in standard Wright tube agglutination tests and/or positive culture tests. SIADH diagnosis was made based on the following criteria: euvolemic hyponatremia, serum Na+ <135 mmol/L, presence of serum hypoosmolarity (serum osmolarity <275 mOsm/L), increased urinary sodium (>25 mmol/L with normal dietary salt intake), low uric acid (<2 mg/dL), absence of kidney, thyroid or adrenal disease, and any anti-diuretic use. RESULTS The study included 160 children and adolescents with mean age of 9.58±3.95 years (range: 2-18 years) including 70 girls (43.8%) and 90 boys (56.2%). When the patients were stratified based on SIADH, it was found that SIADH was present in 35 patients (21.9%). SIADH was associated with elevated glucose (p<0.001), ALT (p<0.05), AST (p<0.05), LDH (p<0.001), CRP (p<0.001), and MPV (p<0.001); and decreased potassium (p<0.05), chloride (p<0.001), albumin (p<0.001), total protein (p<0.05), and hemoglobin (p<0.05) levels. CONCLUSIONS Our study reports on the frequency, clinical characteristics, predisposing factors, and management of SIADH that can develop in children and adolescents diagnosed with brucellosis.

Comparison of hyponatremia and SIADH frequency in patients with tick borne encephalitis and meningitis of other origin.

AIM: The aim of the study was the evaluation of frequency and origin of hyponatremia in tick borne encephalitis (TBE) in comparison to non-TBE viral meningitis and bacterial meningitis. METHODS: A total of 124 patients aged 18-80 years, with TBE were included to the study. The mild form of TBE was diagnosed in 59 patients, while the severe form was diagnosed in 65 patients. The first control group (VMG) consisted of 72 patients with viral meningitis, but excluded TBE. The second control group (BMG) consisted of 16 patients diagnosed with bacterial meningitis. RESULTS: Hyponatremia was diagnosed in 55 (44.4%) patients with TBE. In 12 (9.7%) patients (mean age 56.6 ± 19.9 years; 9 men, 3 women) syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was diagnosed. In VMG hyponatremia was diagnosed in 7 (9.7%) patients. In the age group <35 years and in the age group of 50-64 years the frequency of hyponatremia and SIADH was higher in TBE than in VMG (p < 0.05). In BMG hyponatremia was diagnosed in 6 (37.5%) patients. No statistically significant differences in frequency of hyponatremia between BMG and TBE groups were observed. CONCLUSIONS: (1) Hyponatremia is a common disorder in TBE and is more frequent than in other viral types of meningitis, especially in young patients (< 35 years). (2) The most common cause of hyponatremia in TBE patients is dehydration and fluid supplementation should be a treatment of choice. (3) Overall, 16.9% of the patients with the severe form of TBE develop SIADH syndrome and they required treatment based on fluid restriction and hypertonic saline infusion.

Hyponatremia: incidence, risk factors, and consequences in the elderly in a home-based primary care program.

AIMS: To determine the incidence, risk factors, etiology, and associations of hyponatremia in community-dwelling elderly with geriatric morbidity and mortality. MATERIALS: Elderly participants of a single center home-based primary care program were included. METHOD: Retrospective chart review was conducted on demographic and clinical variables, comorbid diseases, frailty by Fried criteria and biochemical tests over a 1-year period. Primary outcome measure was a composite of falls, fractures due to falls, and hospitalization witnessed within the first year of enrollment into the program. Secondary outcome was all-cause mortality. RESULTS: The study population (n = 608) had a mean age of 84.3 ± 9.3 years and was largely female (77.1%) and African-American (89.5%). Mean follow-up was 41.5 months. Frailty was seen in 44.4%. Incidence of allcause mortality was 26.9%. Initial hyponatremia occurred in 8.71% (n = 53), and persistent hyponatremia (> 6 months of low serum sodium) in 4.1% (n = 25) of the study population. The major causes of hyponatremia included multiple potential causes, idiopathic syndrome of inappropriate antidiuretic hormone (SIADH) and medications (thiazides and selective serotonin reuptake inhibitor (SSRI)). Primary outcome was independently associated with frailty (Odds ratio (OR) of 2.33) and persistent but not initial hyponatremia (OR 3.52). Secondary outcome was independently associated with age > 75 years (OR 2.88) and Afro-American race (OR 2.09) only but not to frailty or hyponatremia. CONCLUSIONS: Hyponatremia is common in home-bound elderly patients and its persistence independently contributes to falls, fractures, and hospitalization but not mortality. Our study highlights a new association of hyponatremia with frailty and underscores the need to study time-dependent association of hyponatremia with epidemiological outcomes.

Clinical evaluation of hyponatremia and hypovolemia in critically ill adult neurologic patients: contribution of the use of cumulative balance of sodium.

PURPOSE: Knowledge of the cumulative balance of sodium (CBS) is important for the diagnosis of salt disorders and water homeostasis and has the potential to predict hypovolemic status in acute neurological patients. However, an extensive application of the use of CBS is still lacking in the intensive care setting, where salt and water homeostasis represents a priority. METHODS: Records of consecutive series of acute neurological patients admitted to a neurointensive care unit over a 6-month period were retrospectively reviewed. CBS was calculated at the admission to the Emergency Department. Discrimination between cerebral salt-wasting syndrome (CSWS) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was performed on the basis of the classical criteria. Additionally, we used the findings of a negative CBS exceeding 2 mEq/kg for the diagnosis of CSWS. Two independent clinicians who were blinded to the CBS results performed diagnosis of the causes of hyponatremia and estimated the daily volemic status of the patients on the basis of clinical parameters. Logistic regression analysis was used to determine the independent prognostic factors of hypovolemia. RESULTS: Thirty-five patients were studied for a total of 418 days. Four patients (11.4%) fitted the criteria of CSWS and three patients (8.5%) had SIADH. The unavailability of the CBS led to a wrong diagnosis in three of the eight hyponatremic patients (37.5%). The risk of developing hypovolemia in patients with negative CBS was 7.1 times higher (CI 3.86-13.06; p < 0.001). Multivariate analysis revealed that negative cumulative fluid balance, negative CBS >2 mEq/kg, and CVP ≤5 cmH2O were independent prognostic factors for hypovolemia. CONCLUSIONS: CBS is likely to be a useful parameter in the diagnosis of CSWS and a surrogate parameter for estimating hypovolemia in acute neurological patients.

Epidemiology, symptoms, and treatment characteristics of hyponatremic psychiatric inpatients.

Hyponatremia is a common phenomenon in psychiatry occurring as an adverse effect to drugs or following polydipsia. We performed a retrospective in-depth analysis of hyponatremia cases in a large unselected population of psychiatric inpatients. During a 3-year period, all cases of hyponatremia were identified among patients admitted to a large psychiatric state and university hospital by the institution's electronic laboratory database. Demographic, treatment-related, and laboratory data were obtained by consecutive chart review, respectively. Hyponatremia occurred in 347 (4.9%) of 7113 cases, of which the majority (78%) displayed only a mild manifestation. Symptoms were recorded in 28.8% of cases, already occurred in mild forms, and comprised gait impairment (45%, including falls), confusion (30%), sedation (26%), and dyspepsia (41%). Age, female sex, nonpsychiatric drug polypharmacy-particularly with thiazides and/or angiotensin-converting enzyme inhibitors-and diagnosis of a mood disorder were associated with more severe hyponatremia, respectively. The proportion of hyponatremic patients treated with venlafaxine, trazodone, carbamazepine, oxcarbazepine, and first-generation antipsychotics, respectively, was significantly higher in the hyponatremia sample than in the normonatremic population. This was, surprisingly, not the case with selective serotonin reuptake inhibitors or any other antidepressant drug class. We found prescription with second-generation antipsychotics to be significantly associated with less severe hyponatremia.Hyponatremia may be mainly attributed to the syndrome of inappropriate antidiuretic hormone secretion, as indicated by decreased serum osmolarity in our sample. Besides old age and female sex, treatment with certain drugs-rather than whole drug classes-carries a substantially increased risk.

Altered mental status in a young, healthy female.

A young previously healthy patient presented with fever and altered mental status. Her evaluation would eventually reveal a profound hyponatremia in the setting of a viral meningoencephalitis. This case report reviews the evaluation of hyponatremia and treatment options for syndrome of inappropriate antidiuretic hormone hypersecretion, her ultimate diagnosis.

Cerebral salt wasting syndrome in post-operative pediatric brain tumor patients.

BACKGROUND: Cerebral salt wasting syndrome (CSWS) and the syndrome of inappropriate antidiuretic hormone (SIADH) are both causes of hyponatremia in pediatric neurosurgical patients often with similar presenting symptoms; however, despite similar clinical characteristics the treatment for CSWS and SIADH can be drastically different, which makes the distinction critical for post-operative treatment. Further complicating matters, are the exact mechanism for CSWS which remains unclear, and the incidence and severity of CSWS is not well studied in pediatric neurosurgical patients. We hypothesized that CSWS occurs frequently in post-operative brain tumor patients and is an important cause of post-operative hyponatremia in these patients. METHODS: We designed a single institution retrospective cohort study of all pediatric brain tumor patients undergoing craniotomy for tumor resection at our institution between January 2005 and December 2009. RESULTS: Of the 282 patients undergoing 291 operations, post-operative CSWS was identified in 15 cases (5%), and was more frequently observed than SIADH (nine cases, 3%). Median onset of CSWS was on post-operative day 3, lasting a median of 2.5 days. Patients with CSWS were more likely to have suffered post-operative stroke (40 vs. 4.6%, P < 0.001), have chiasmatic/hypothalamic tumors (40 vs. 3.8%, P = 0.002), and be younger (mean age 5.9 vs. 9.7 years, P = 0.01) than eunatremic patients. In addition, nearly half of the patients with CSWS (47%) had post-operative hyponatremic seizures. CONCLUSION: The diagnosis of CSWS should be strongly considered in hyponatremic pediatric patients with significant natriuresis following brain tumor resection, and a treatment initiated promptly to prevent neurologic sequeleae.

Syndrome of inappropriate anti-diuretic hormone in Kawasaki disease.

BACKGROUND: The pathogenesis of hyponatremia in acute Kawasaki disease (KD) remains unclear. A recent case report of KD complicated by syndrome of inappropriate anti-diuretic hormone (SIADH) led us to determine the prevalence of SIADH in acute KD patients. METHODS: Subjects were 39 Japanese KD patients (2-84 months of age, 25 males and 14 females) treated with intravenous immunoglobulin (IVIG), 2 g/kg/day and oral aspirin. SIADH was defined when hyponatremic patients (serum sodium concentration <135 mEq/L) had decreased serum osmolality <280 mOsm/kg H(2) O, elevated urine sodium concentration >20 mEq/L and elevated urine osmolality >100 mOsm/kg H(2) O without dysfunctions of renal, thyroid or adrenal gland. We also studied the relation between clinical course of SIADH and the amount of infused fluid during IVIG. RESULTS: Before IVIG, 27 patients (69%) had hyponatremia and 11 (28% of total; 41% of hyponatremic patients) had SIADH while after IVIG, 13 (33%) hyponatremia and four (10%; 31% of hyponatremic patients) SIADH. Among 11 patients with SIADH before IVIG, SIADH improved in 10 after IVIG, but hyponatremia persisted in five. Significant correlation was observed between serum sodium concentration after IVIG and infusion amount in SIADH patients (r=-0.64, P= 0.03), but not in non-SIADH patients. CONCLUSIONS: This is the first report to show that SIADH is common as a cause of hyponatremia in acute KD and hence careful management of water and sodium is warranted.

Utility of laboratory tests for children in the emergency department with a first seizure.

OBJECTIVE: The objective of the study was to evaluate the factors associated with abnormal laboratory findings in patients visiting the emergency department (ED) after having their first seizure. METHODS: We included ED patients with first seizures and divided them into groups based on normal and abnormal laboratory results for serum levels of sodium, potassium, calcium, and glucose. We evaluated the differences in age, sex, the presence of fever, the presence of gastrointestinal symptoms, the duration and pattern of the seizure, and whether the seizure was still present at the ED. RESULTS: We evaluated 240 patients. Among them, abnormalities were found in 83 (34.8%) of 238 for serum sodium, 16 (6.7%) of 238 for potassium, 11 (6.2%) of 177 for calcium, and 121 (52.3%) of 231 for glucose. In the serum sodium and calcium group, no differences in associated factors between patients with and without abnormal laboratory results were found. However, results revealed differences in seizure duration between patients with and without abnormal laboratory glucose results (P = 0.005) and in age between patients with normal and abnormal potassium results (P = 0.002). CONCLUSIONS: There was no significant association among the factors of sex, fever, gastrointestinal symptoms, seizure duration, and seizures in patients who came to the ED with electrolyte abnormalities after a first seizure. However, glucose level abnormalities may have an association with increased seizure duration. We still do not have any suggestions as to which associated factors should be considered when doing common blood examinations in these patients.