Point-of-care ultrasound is a useful adjunct tool to a clinician's assessment in the evaluation of severe hyponatraemia.

INTRODUCTION: Hyponatraemia is the most common electrolyte disorder in inpatients resulting mainly from an imbalance in water homeostasis. Intravascular fluid status assessment is pivotal but is often challenging given multimorbidity, polypharmacy and diuretics use. We evaluated the utility of point-of-care ultrasound (POCUS) as an adjunct tool to standard practice for fluid assessment in severe hyponatraemia patients. METHODS: Patients presenting with severe hyponatremia (Serum Sodium [Na] < 120 mmol/L; Normal range: 135-145 mol/L), managed by standard care were included. Hyponatraemia biochemistry work-up and POCUS examination were undertaken. Both clinician and POCUS independently assigned one of the three fluid status groups of hypovolaemia, hypervolaemia or euvolaemia. The final diagnosis of three fluid status groups at admission was made at the time of discharge by retrospective case review. Clinician's (standard of care) and POCUS fluid assessments were compared to that of the final diagnosis at the time of discharge. RESULTS: n = 19 patients were included. Median Na on admission was 113 mmol/L (109-116), improved to 129 ± 3 mmol/L on discharge. POCUS showed the higher degree of agreement with the final diagnosis (84%; n = 16/19), followed by the clinician (63%; n = 12/19). A trend towards higher accuracy of POCUS compared to clinician assessment of fluid status was noted (84% vs. 63%, p = 0.1611). Biochemistry was unreliable in 58% (n = 11/19) likely due to renal failure, polypharmacy or diuretic use. Inappropriate emergency fluid management was undertaken in 37% (n = 7/19) of cases based on initial clinician assessment. Thirst symptom correlated to hypovolaemia in 80% (4/5) cases. CONCLUSION: As subjective clinical and biochemistry assessments of fluid status are often unreliable due to co-morbidities and concurrent use of medications, POCUS can be a rapid objective diagnostic tool to assess fluid status in patients with severe hyponatraemia, to guide accurate emergency fluid management.

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

OBJECTIVES: To determine all-cause in-hospital mortality associated with severe hypernatraemia and the causes, comorbidities, time to treatment, discharge destination and postdischarge mortality. DESIGN: Retrospective observational cohort study. PATIENTS: Severe hypernatraemia, (sodium concentration ≥ 155 mmol/L), at any time during a tertiary hospital admission in Melbourne, Australia, 1 January 2019 to 31 December 2019 (pre-COVID19). MEASUREMENTS: Deaths, Charlson Comorbidity Index (CCI), hypernatraemia causes, time to treatment, discharge destination. RESULTS: One hundred and one inpatients: 64 community-acquired, 37 hospital-acquired. In-hospital mortality was 38%, but cumulative mortality was 65% by 1 month after discharge, with only a minor further increase at 6 and 12 months. After adjusting for peak sodium concentration, the community acquired group had significantly reduced odds of in-hospital mortality (odds ratio 0.15, 95% confidence interval [0.04-0.54], p = .003). Iatrogenic factors were present in 57% (21/37) of the hospital-acquired group. Only 55% of all cases received active sodium directed treatment. Time to start treatment did not affect outcomes. High levels of comorbidity were present, median CCI (IQR) was 6 (5-8) in the community and 5 (4-7) in the hospital group. Dementia prevalence was higher in the community group, 66% (42/64) versus 19% (7/37) (p = .001). Infection was the most common precipitant with 52% (33/64) in the community and 32% (12/37) in the hospital group. Of the survivors, 32% who had been living independently required residential care after discharge. CONCLUSIONS: Mortality was high and loss of independence in survivors common. To potentially improve outcomes, hypernatraemia-specific guidelines should be formulated and efforts made to reduce system and iatrogenic factors.

Association of initial serum sodium change and clinical outcome in patients with diabetes receiving sodium-glucose cotransporter-2 inhibitor therapy: A multicentre database analysis in Taiwan.

AIM: The study aimed to assess the impact of varying degrees of initial serum sodium change among patients with type 2 diabetes (T2D) starting sodium-glucose cotransporter-2 inhibitor (SGLT2i) therapy and their subsequent clinical outcome. METHODS: We used medical data from a multicentre health care provider in Taiwan and recruited 4400 patients with T2D with baseline normal serum sodium (135-145 mmol/L) and follow-up serum sodium measures available after 3 months of SGLT2i treatment from 1 June 2016 to 31 December 2021. RESULTS: After a median of 2.9 (2.4, 3.4) months of SGLT2i treatment, overall, there was a minimal change in serum sodium levels (from 139.6 ± 2.4 to 139.5 ± 3.7 mmol/L). Most patients (87.8%) maintained normal sodium levels, while 8.6% (n = 378) experienced hyponatraemia (<135 mmol/L) and 3.6% (n = 158) hypernatraemia (>145 mmol/L). Factors independently associated with hyponatraemia included cancer history, chronic lung disease, insulin use, higher glycated haemoglobin, impaired liver function, lower baseline sodium and greater initial decline in kidney function. Conversely, factors linked to hypernatraemia included older age, absence of cancer history, loop diuretic and non-steroidal anti-inflammatory drug use, higher baseline sodium and a lesser initial decline in kidney function. Over a median of 26.0 months of follow-up, hyponatraemia shortly after starting SGLT2i therapy was associated with significantly increased risks of major adverse cardiovascular events [hazard ratio (HR): 2.52; 95% confidence interval (CI): 1.83-3.48], heart failure for hospitalization (HR: 1.66; 95% CI: 1.16-2.37), major adverse renal events (HR: 2.27; 95% CI: 1.73-2.96) and all-cause death (HR: 2.98; 95% CI: 2.17-4.11) after adjusting for clinically relevant factors. Non-linear analysis indicated that a more pronounced initial decline in serum sodium levels correlated steeply with higher risks of these adverse events. CONCLUSION: While most patients with T2D maintain stable serum sodium homeostasis on SGLT2i therapy, a subset may experience dysnatraemic events with potential worse clinical consequences. Physicians should be vigilant about monitoring sodium levels and considering the associated risks when initiating SGLT2i therapy in patients with risk.

Tolvaptan and urea in paediatric hyponatraemia.

BACKGROUND: The syndrome of inappropriate antidiuretic hormone (SIADH) is usually treated with fluid restriction. This can be challenging in patients with obligate fluid intake for nutrition or medication. Pharmaceutical treatment with tolvaptan and urea is available but minimal paediatric data are available. We review the efficacy and safety of tolvaptan and urea in paediatric patients with SIADH. METHODS: Retrospective review of paediatric inpatients with clinical diagnosis of SIADH. Patients were identified from pharmacy records based on tolvaptan and urea prescriptions. Relevant information was extracted from patient electronic records. The main outcome measures included the number of days to sodium normalisation, the daily change in plasma sodium concentration, and the maximum increase of plasma sodium concentration in 24 h. Reported side effects were captured. RESULTS: Thirteen patients received tolvaptan and six urea. Five patients had both agents (tolvaptan converted to urea). Tolvaptan led to plasma sodium normalisation in 10/13 (77%) within 6 days (median 2.5 days, range [1, 6]), with a median change of sodium concentration of 7 mmol/L (- 1, 14) within the first 24 h of treatment. Three patients experienced a change in plasma sodium > 10 mmol/l/day but had no apparent side effects. Urea led to sodium normalisation in 5/6 (83%) patients. The median number of days to normalisation with urea was 2 (1, 10) with a median change of plasma sodium concentration of 2 mmol/L (- 1, 6) within the first 24 h. All patients tolerated tolvaptan and/or urea without unexpected side effects. CONCLUSIONS: Tolvaptan and urea appear to be safe and effective when fluid restriction is challenging in paediatric SIADH. A higher resolution version of the Graphical abstract is available as Supplementary information.

Congenital chloride diarrhoea in a Chinese infant with a compound heterozygous SLC26A3 mutation.

INTRODUCTION: Congenital chloride diarrhoea (CCD) is an autosomal recessive condition that causes secretory diarrhoea and potentially deadly electrolyte imbalances in infants because of solute carrier family 26 member 3 (SLC26A3) gene mutations. CASE PRESENTATION: A 7-month-old Chinese infant with a history of maternal polyhydramnios presented with frequent watery diarrhoea, severe dehydration, hypokalaemia, hyponatraemia, failure to thrive, metabolic alkalosis, hyperreninaemia, and hyperaldosteronaemia. Genetic testing revealed a compound heterozygous SLC26A3 gene mutation in this patient (c.269_270dup and c.2006 C > A). Therapy was administered in the form of oral sodium and potassium chloride supplements, which decreased stool frequency. CONCLUSIONS: CCD should be considered when an infant presents with prolonged diarrhoea during infancy, particularly in the context of maternal polyhydramnios and dilated foetal bowel loops.

Intensive Care Management of Severe Hyponatraemia-An Observational Study.

Background and Subject: Hyponatraemia is a common electrolyte disorder. For patients with severe hyponatraemia, intensive care unit (ICU) admission may be required. This will enable close monitoring and allow safe management of sodium levels effectively. While severe hyponatraemia may be associated with significant symptoms, rapid overcorrection of hyponatraemia can lead to complications. We aimed to describe the management and outcomes of severe hyponatraemia in our ICU and identify risk factors for overcorrection. Materials and Methods: This was a retrospective single-centre cohort that included consecutive adults admitted to the ICU with serum sodium < 120 mmol/L between 1 January 2017 and 8 March 2023. Anonymised data were collected from electronic records. We included 181 patients (median age 67 years, 51% male). Results: Median admission serum sodium was 113 mmol/L (IQR: 108-117), with an average rate of improvement over the first 48 h of 10 mmol/L/day (IQR: 5-15 mmol/L). A total of 62 patients (34%) met the criteria for overcorrection at 48 h, and they were younger, presented with severe symptoms (seizures/arrythmias), and had lower admission sodium concentration. They were more likely to be treated with hypertonic saline infusions. Lower admission sodium was an independent risk factor for overcorrection within 48 h, whereas the presence of liver cirrhosis and fluid restriction was associated with normal correction. No difference was identified between the normal and overcorrected cohorts for ICU/hospital length of stay or mortality. Conclusions: In some patients with severe hyponatraemia, overcorrection is inevitable to avoid symptoms such as seizures and arrhythmias, and consequently, we highlight the key factors associated with overcorrection. Overall, we identified that overcorrection was common and concordant with the current literature.

Sterile water and regional citrate anticoagulation: A simple CRRT strategy for safe correction of severe hyponatraemia.

BACKGROUND: Hyponatraemia is a prevalent electrolyte disturbance observed in critically ill patients. The rapid correction of low plasma sodium levels by continuous renal replacement therapy (CRRT) carries the risk of developing osmotic demyelination syndrome (ODS), which can be prevented by implementing an individualized CRRT method. AIM: This study aims to introduce a CRRT protocol for the safe and gradual correction of severe hyponatraemia. STUDY DESIGN: This retrospective case series study was conducted in an intensive care unit (ICU). All four patients with severe hyponatraemia (<125 mmol/L) and renal failure between October 1, 2022, and September 30, 2023, were treated by CRRT with sterile water and regional citrate anticoagulation (RCA). Data on patient demographics, laboratory biochemical parameters, urine outputs and CRRT-related adverse events were collected. Laboratory parameters and urine outputs were compared by paired t-tests before and after CRRT. RESULTS: After CRRT, sodium levels were significantly increased (112.7 ± 6.7 vs. 141.9 ± 2.8 mmol/L, p = .005). Abnormal urine outputs, potassium, creatinine and bicarbonate were corrected (p for all <.05). Safe and gradual correction of hyponatraemia and internal environmental dysregulation was achieved in all patients without any complications related to CRRT, particularly ODS. CONCLUSION: It is a novel and simple strategy to correct severe hyponatraemia effectively while ensuring the safety of patients that can be easily implemented by experienced nurse staff. RELEVANCE TO CLINICAL PRACTICE: The sterile water-based protocol for postfilter dilution is safe to correct severe hyponatraemia with RCA and can be easily performed by experienced critical care nurses according to the precalculated formula. CRRT-trained, experienced ICU nurses are competent to initiate and adjust sterile water infusion discretely to prevent overcorrection of hyponatraemia.

Symptoms, Electrolyte Disturbances and Serum Albumin Levels in Palliative Oncology Patients Admitted Through Emergency: Characteristics and Survival Outcomes.

Objectives: Our research aimed to examine the characteristics of palliative oncology patients hospitalised through an emergency to look for the symptom profile, characteristics of dyselectrolytemia and blood investigations, and possible associations with mortality. Materials and Methods: After institutional review board approval, a retrospective, observational study of patients hospitalised in our tertiary care specialty oncology hospital was undertaken. Records of hospitalised cancer patients admitted from the emergency department under palliative care from January 2019 to October 2021 were examined. As all admissions during this period were through emergency due to institution COVID-19 protocols, all elective admissions were excluded from the study. Data collected included patient characteristics, blood investigations, and comorbid history of systemic diseases and factors that could be associated with electrolyte imbalance. Results: There were 157 emergency admissions during the study period. A majority were patients with solid tumours (92.4%). Pain was the most frequent cardinal symptom, along with other symptoms (68/157) or in isolation (33/157), followed by reduced oral intake (32/157) and altered sensorium (24/157). sixty-six patients died within the hospitalisation period. On long-term follow-up, only 8 (5.1%) were surviving. Hyponatraemia (43%), Hypoalbuminaemia (66%), and altered renal function (33.1%) were prevalent. We observed a weak positive correlation between sodium levels and outcome (r = 0.199, P = 0.016) and a strong positive correlation between albumin levels and survival outcomes (r = 0.329, P = 0.000). Patients with normal albumin had a higher chance of survival (odds ratio: 33.1225, 95% confidence interval: 3.415-321.20, P = 0.003). Conclusion: Pain-reduced oral intake and altered sensorium are common emergency symptoms in oncology palliative care. Mortality is high in these patients. Hyponatraemia, hypoalbuminaemia, and deranged renal functions were commonly seen. Normal sodium and albumin levels were associated with higher chances of survival, and the association was strong for serum albumin levels. This may have prognostic utility.

Hyponatraemia and fluid overload are associated with higher risk of mortality in dialysis patients.

BACKGROUND: The 5-year mortality rate for haemodialysis patients is over 50%. Acute and chronic disturbances in salt and fluid homeostasis contribute to poor survival and are established as individual mortality risk factors. However, their interaction in relation to mortality is unclear. METHODS: We used the European Clinical Database 5 to investigate in a retrospective cohort analysis the relationship between transient hypo- and hypernatremia, fluid status and mortality risk of 72 163 haemodialysis patients from 25 countries. Incident haemodialysis patients with at least one valid measurement of bioimpedance spectroscopy were followed until death or administrative censoring from 1 January 2010 to 4 December 2019. Fluid overload and depletion were defined as >2.5 L above, and -1.1 L below normal fluid status, respectively. N = 2 272 041 recorded plasma sodium and fluid status measurements were available over a monthly time grid and analysed in a Cox regression model for time-to-death. RESULTS: Mortality risk of hyponatremia (plasma sodium <135 mmol/L) was slightly increased when fluid status was normal [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.18-1.35], increased by half when patients were fluid depleted (HR 1.56, 95% CI 1.27-1.93) and accelerated during fluid overload (HR 1.97, 95% CI 1.82-2.12). CONCLUSIONS: Plasma sodium and fluid status act independently as risk factors on mortality. Patient surveillance of fluid status is especially important in the high-risk subpopulation of patients with hyponatremia. Prospective patient-level studies should examine the effects of chronic hypo- and hypernatremia, risk determinants, and their outcome risk.

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.

Hyponatraemia caused by transient syndrome of inappropriate antidiuresis to urinary retention.

Hyponatraemia is frequently seen in the emergency department, possibly caused by the syndrome of inappropriate antidiuresis (SIAD). We report three cases in which we believe urinary retention with bladder distention caused hyponatraemia. Laboratory findings fulfilled the criteria for SIAD, for which no cause was found. Possibly pain or sympathetic nerve system activation leads to SIAD. Brisk diuresis occurred after placement of an indwelling urinary catheter with overly correction of sodium for which treatment was necessary. Clinicians should be aware that placement of an indwelling urinary catheter may prompt brisk water diuresis and a tendency to overcorrection.

Osmotic demyelination syndrome: novel risk factors and proposed pathophysiology.

BACKGROUND: Osmotic demyelination syndrome (ODS) is non-inflammatory demyelination in response to an osmotic challenge. It can be pontine or extrapontine in presentation. AIMS: To retrospectively review cases involving ODS and define the spectrum of causes, risk factors, clinical and radiological presentations, and functional outcomes. RESULTS: The study utilised data from 15 patients with a mean age of 53.6 years. Malnutrition (9; 60%) and chronic alcoholism (10; 66.7%) were the most common associated disorders. Two (13.3%) patients had severe hyponatraemia (<120 mmol/L). The average highest single-day change was 5.1 mmol/L. Radiologically, 14 (93.3%) had pontine and 6 (40%) had extra-pontine lesions. Hypokalaemia (14; 93.3%) and hypophosphataemia (9; 60%) were commonly associated. Common clinical manifestations include altered consciousness/encephalopathy (9; 60%), dysphagia (4; 26.7%) and limb weakness (4; 26.7%). At 3 months, two (14.3%) had died and six (40%) were functionally independent (modified Rankin scale 0-2). CONCLUSION: We found that ODS occurred despite appropriate correction rates of hyponatraemia. Factors such as malnutrition, chronic alcoholism, hypokalaemia and hypophosphataemia are thought to play a role in its pathogenesis. Approximately half of the patients survived and became functionally independent.

Severe and complicated soft tissue infections: a single-centre case series.

OBJECTIVE: To assess the demographic and clinical characteristics, laboratory findings, and economic burden of patients with a diagnosis of complicated skin and soft tissue infection (cSSTI). METHOD: The demographic and clinical characteristics, laboratory findings, surgical interventions, cost of treatment, and outcome of patients diagnosed with cSSTIs between January 2017 and December 2019 were retrospectively analysed. RESULTS: A total of 24 patients with cSSTIs were included in the study. The median age was 53 (22-85) years, and 14 (58%) were female. The most common comorbidity was diabetes (54%). On admission, 75% of patients presented with sepsis, and 70% had a high-grade Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score. The causative microorganism was isolated from 21 (87%) patients, and the multidrug resistance rate of Gram-negative bacteria was 50%. The median number of debridements was 3 (1-12). In all, 11 patients were followed up in the intensive care unit, and the mortality rate was 29%. The presence of confusion (p=0.025), causative Gram-negative microorganisms (p=0.009), hyponatraemia (p=0.034), the need for intensive care (p=0.001), anti-meticillin-resistant Staphylococcus aureus antibiotics (p=0.023) and the rate of antibiotic changes during treatment (p=0.019) were significantly higher in the non-survival patient group. Hyponatraemia was a significant independent risk factor for mortality (p=0.048). The median cost of per-patient treatment was $9453 USD in the non-surviving and $1536 in the surviving group. CONCLUSION: It is important to know possible factors and local resistance rates at the beginning of empirical antibacterial and surgical treatment. The presence of hyponatraemia, sepsis and a high LRINEC score can be considered to be the mortality predictors.

Vaptans for oedematous and hyponatraemic disorders in childhood: A systematic literature review.

AIMS: The aim of this study was to systematically review the use of vaptans (nonpeptide vasopressin receptor antagonists) in children. METHODS: Through a database search (Web of Science, the National Library of Medicine, Excerpta Medica), we identified case series and case reports and extracted clinical and laboratory data. RESULTS: Twenty-six articles, published since 2008, reported on 226 patients. Among 115 children with hyponatraemic (n = 63) and oedematous disorders (n = 52), a 48 hour course of tolvaptan with an initial dose of 0.38 ± 0.27 mg/kg was administered in 106 cases, while intravenous conivaptan was reported in nine cases. An increase (P < .02) in urine output was shown in both oedematous (from 3.2 ± 2.0 to 5.3 ± 6.7 mL/kg/day) and hyponatraemic (from 3.0 ± 1.5 to 4.4 ± 2.3 mL/kg/day) patients. In these latter, sodium increased from 125 ± 6 to 133 ± 6 mmol/L (P < .0001). The increase in sodium level correlated with its basal value, but not with the administered vaptan dose. Among 111 children undergoing cardiac surgery, after tolvaptan 0.21 ± 0.01 mg/kg/day, mostly combined with conventional diuretics, an increase in diuresis by 41 ± 4% was seen within 24 hours (P < .0001). Similarly, a single add-on dose of tolvaptan 0.45 mg/kg allowed a reduced additional intravenous furosemide administration (0.26 ± 0.23 vs 0.62 ± 0.48 mg/kg, P < .005). Side effects were rarely reported, and included excessive thirst and xerostomia in seven, skin rash in one and elevated aminotransferases in one patient(s). CONCLUSION: Vaptans appear to be safe for oedematous and hyponatraemic disorders also in children. Although they increase diuresis and natraemia, no superiority to traditional diuretics and sodium supplements has been demonstrated. Reported side effects are rare and non-serious.

Investigation of the risk factors of vomiting during linezolid therapy: a retrospective observational study.

PURPOSE: Some clinical studies have reported the occurrence of nausea and vomiting with linezolid (LZD) administration. However, no studies have evaluated nausea and vomiting as primary endpoints. In a previous study, we noted a possible relationship between LZD and vomiting, but risk factors were not identified. Therefore, the aim of the present study was to identify them. METHODS: Patients who received LZD 600 mg twice daily at Hokkaido University Hospital from September 2008 to April 2019 were enrolled in this retrospective observational study. Patient characteristics, concomitant medications, laboratory data, and the occurrence of vomiting were obtained from electronic medical records. Logistic regression analysis was performed to identify risk factors for vomiting, including age, sex, body weight, concomitant medications, and surgeries. RESULTS: A total of 496 patients were included in this study, of which 90 experienced vomiting. By multivariate logistic regression analysis, female sex (adjusted odds ratio [aOR], 2.69; 95% confidence interval [CI], 1.62-4.47), ≥ 10 days of LZD administration (aOR, 2.57; CI, 1.46-4.50), and hyponatraemia (aOR, 2.96; CI, 1.72-5.10) were identified as independent risk factors for vomiting; administration of serotonergic agents (aOR, 0.23; CI, 0.07-0.82) was negatively associated. CONCLUSIONS: This study is the first to successfully identify risk factors for LZD-induced vomiting. Careful monitoring of patients with these risk factors may lead to safer and sustainable LZD administration.

Prospective determination of the incidence and severity of hyponatraemia in older hospitalised patients with acute urinary tract obstruction.

INTRODUCTION: acute urinary tract obstruction (aUTO) is a common finding in older hospitalised patients. Anecdotal reports described hyponatraemia in patients with aUTO, which subsides rapidly with relief of the obstruction.The aim of this study was to determine the incidence, severity and subsequent correction of hyponatraemia in patients with aUTO. METHODS: this is a prospective, single-centre, observational study including inpatients in the internal medicine and geriatric wards. A total of 204 patients were investigated, 104 with aUTO and 100 controls. The prevalence, severity and associations of hyponatraemia between aUTO and control patients were compared. RESULTS: the incidence of hyponatraemia was similar in aUTO and control groups 28% versus 22%, respectively (P = 0.42). However, the incidence of severe hyponatraemia was significantly higher in the study group 7% versus 1% (P = 0.04). Mean sodium level was lower in hyponatremic patients with aUTO 127.7 ± 5.9 mEq/l versus 130.8 ± 3 mEq/l (P = 0.013). Serum sodium remained largely unchanged in the control group (∆Na 1.5 ± 2.3 mEq/l) but increased significantly within 48 hours following catheter insertion in patients with urinary retention (∆Na 5.3 ± 4.2 mEq/l overall in the aUTO group and 9.6 ± 3 mEq/l in those with urinary retention and severe hyponatraemia (P = 0.002)).

Relationships between sodium levels, haemodynamics and metalloproteinases in heart failure patients.

To estimate the associations between dysnatraemia and inflammatory marker [including interleukin-6 (IL-6)], and tissue remodelling marker [matrix metalloproteinase (MMP)-9 and tissue inhibitor of MMP (TIMP)-1], the pulmonary capillary wedge pressure (PCWP), mean pulmonary artery pressure (PAP), and left ventricular end-diastolic pressure (EDP), and the prognostic relevance in patients with heart failure. The serum sodium level and circulating levels of IL-6, MMP-9, and TIMP-1 were measured in 173 heart failure patients. Dual heart catheterisation was performed to measure PCWP, mean PAP, and EDP. All-cause mortality was assessed during the follow-up period (mean 88 ± 49 months). Restricted cubic spline (RCS) regression showed a U-shaped association of serum sodium level with TIMP-1, with the lowest values in the 138-140 mmol/L range (P for effect = 0.042, P for non-linearity = 0.017). IL-6 and MMP-9 levels showed non-significant associations with serum sodium level. U-shaped associations of serum sodium level with PCWP (P for effect = 0.004, P for non-linearity = 0.001) and mean PAP (P for effect = 0.042, P for non-linearity = 0.017) were found with the RCS regression model. The random forest model revealed that TIMP-1, MMP-9, and IL-6 were important predictors for serum sodium levels. Restricted cubic spline Cox regressions demonstrated that TIMP-1 levels indicated a U-shaped, concaved, non-linear association with all-cause mortality (P for effect = 0.011, P for non-linearity = 0.022). Dysnatraemia is an index of TIMP-1 aggravation and elevated PCWP, mean PAP; hence, it is associated with worsening all-cause mortality.Clinical Trial Registration: UMIN000023840.

A suspected case of hyponatraemia induced rhabdomyolysis: a case report.

BACKGROUND: Hyponatraemia is a documented but under-recognised cause of rhabdomyolysis, with the contrasting treatment strategies for the two conditions posing a unique challenge. Balancing the need for aggressive fluid replacement for the treatment of rhabdomyolysis, with the risk of rapidly correcting hyponatraemia is imperative. CASE PRESENTATION: A 52-year-old gentleman with a background of HIV infection and hypertension presented with seizures following methamphetamine use, acute water intoxication, and thiazide use. He was found to have severe hyponatraemia, and following initial correction with hypertonic saline, was commenced on a fluid restriction. After two days he developed abdominal wall and thigh pain, along with oliguria. Laboratory data demonstrated markedly elevated creatine kinase levels and deteriorating renal function. A diagnosis of rhabdomyolysis and severe acute kidney injury was made and aggressive fluid replacement commenced, leading to full resolution of the hyponatraemia, rhabdomyolysis and acute kidney injury. CONCLUSION: Hyponatraemia-induced rhabdomyolysis is rare but can cause significant morbidity and mortality if left untreated. Physicians should consider measuring creatine kinase levels in all patients presenting with severe hyponatraemia, particularly in the presence of other risk factors for rhabdomyolysis. Fluid replacement strategies must be considered in relation to the relative onset and risk of over-correcting hyponatraemia.

The incidence, hospitalisations and deaths in acutely ill children with dysnatraemias.

AIM: The aim was to evaluate the incidence, hospitalisations and deaths in acutely ill children with dysnatraemias. METHODS: This was a register-based cohort study of 46 518 acutely ill children aged <16 years who visited a paediatric emergency department. Risk factors were assessed using two nested case-control studies. RESULTS: Moderate to severe hypernatraemia occurred in 92 children (0.20%; 95% confidence interval [CI]: 0.16%-0.24%) and moderate to severe hyponatraemia in 131 children (0.28%; 95% CI: 0.24%-0.33%). Underlying medical conditions increased the risk of both moderate to severe hypernatraemia (odds ratio [OR]: 17; 95% 5.5-51) and moderate to severe hyponatraemia (OR: 3.5; 95% CI: 2.0-5.9). The use of a feeding tube (OR: 14; 95% CI: 3.2-66) and intellectual disability (OR: 7.3; 95% CI: 3.0-18) was associated with moderate to severe hypernatraemia. The risk of death was associated with moderate to severe hypernatraemia (OR: 19; 95% CI: 2.0-2564) and moderate to severe hyponatraemia (OR: 33; 95% CI: 3.7-4311). CONCLUSIONS: Severe dysnatraemias were more prevalent in acutely ill children with underlying medical conditions and were markedly associated with the risk for death.

The management and outcome of hyponatraemia following transsphenoidal surgery: a retrospective observational study.

PURPOSE: Hyponatraemia is a common complication following transsphenoidal surgery. However, there is sparse data on its optimal management and impact on clinical outcomes. The aim of this study was to evaluate the management and outcome of hyponatraemia following transsphenoidal surgery. METHODS: A prospectively maintained database was searched over a 4-year period between January 2016 and December 2019, to identify all patients undergoing transsphenoidal surgery. A retrospective case-note review was performed to extract data on hyponatraemia management and outcome. RESULTS: Hyponatraemia occurred in 162 patients (162/670; 24.2%) with a median age of 56 years. Female gender and younger age were associated with hyponatraemia, with mean nadir sodium being 128.6 mmol/L on postoperative day 7. Hyponatraemic patients had longer hospital stay than normonatraemic group with nadir sodium being inversely associated with length of stay (p < 0.001). In patients with serum sodium ≤ 132 mmol/L, syndrome of inappropriate antidiuretic hormone secretion (SIADH) was the commonest cause (80/111; 72%). Among 76 patients treated with fluid restriction as a monotherapy, 25 patients (25/76; 32.9%) did not achieve a rise in sodium after 3 days of treatment. Readmission with hyponatraemia occurred in 11 cases (11/162; 6.8%) at a median interval of 9 days after operation. CONCLUSION: Hyponatraemia is a relatively common occurrence following transsphenoidal surgery, is associated with longer hospital stay and risk of readmission and the effectiveness of fluid restriction is limited. These findings highlight the need for further studies to better identify and treat high-risk patients, including the use of arginine vasopressin receptor antagonists.