The syndrome of inappropriate antidiuresis (SIAD)

Mechanisms of hyponatremia and diabetes insipidus after acute spinal cord injury: a critical review

The incidence of hyponatremia after spinal cord injury was reported to be between 25 and 80%. Hyponatremia can lead to a variety of clinical symptoms, from mild to severe and even life-threatening. Hyponatremia is often associated with diabetes insipidus, which refers to insufficient arginine vasopressin (AVP) secretion or defective renal response to AVP, with clinical manifestations of syndromes such as hypoosmolality, polydipsia, and polydipsia. Recent mechanistic studies on hyponatremia and diabetes insipidus after acute spinal cord injury have been performed in isolation, without integrating the above two symptoms into different pathological manifestations that occur in the same injury state and without considering the acute spinal cord injury patient's condition as a whole. The therapeutic principles of CSWS and SIADH are in opposition to one another. It is not easy to identify the mechanism of hyponatremia in clinical practice, which makes selecting the treatment difficult. According to the existing theories, treatments for hyponatremia and diabetes insipidus together are contraindicated, whether the mechanism of hyponatremia is thought to be CSWS or SIADH. In this paper, we review the mechanism of these two pathological manifestations and suggest that our current understanding of the mechanisms of hyponatremia and diabetes insipidus after high acute cervical SCI is insufficient, and it is likely that there are other undetected pathogenetic mechanisms.

An Increase in Plasma Sodium Levels Is Associated With an Increase in Osteoblast Function in Chronic SIAD

CONTEXT

Hyponatremia is associated with increased risk for osteoporosis. Preclinical studies in untreated hyponatremia suggest osteoclast upregulation, whereas a clinical study showed improved osteoblast function after hyponatremia normalization in hospitalized patients with syndrome of inappropriate antidiuresis (SIAD).

OBJECTIVE

This work aimed to investigate the effect of an increase in sodium on bone turnover, that is, the ratio of the osteoblast marker procollagen type 1 N-terminal propeptide (P1NP) to the osteoclast marker cross-linked C-terminal telopeptide of type 1 collagen (CTX), in outpatients with chronic SIAD.

METHODS

A predefined secondary analysis was conducted of the 2-month double-blind, crossover, placebo-controlled SANDx Trial (NCT03202667) performed from December 2017 to August 2021. Participants included 11 outpatients with chronic SIAD: 6 women, median age 73 years, who received a 4-week treatment with 25-mg empagliflozin or placebo. Main outcome measures included the relationship between the change in bone formation index (BFI), defined as P1NP/CTX, and the change in plasma sodium levels.

RESULTS

Changes in sodium were positively correlated with changes in BFI and P1NP (BFI: ρ=.55; P < .001; P1NP: ρ=.45; P = .004) but not with CTX (P = .184) and osteocalcin (P = .149). A sodium increase of 1 mmol/l was associated with an increase of 5.21 in BFI (95% CI, 1.41-9.00; P = .013) and with an increase of 1.48 µg/l in P1NP (95% CI, .26-2.62; P = .03). The effect of sodium change on bone markers was independent of the study medication empagliflozin.

CONCLUSION

An increase in plasma sodium levels in outpatients with chronic hyponatremia due to SIAD, even when mild, was associated with an increase in bone formation index (P1NP/CTX) triggered by an increase in P1NP, a surrogate marker of osteoblast function.

Syndrome of Inappropriate Antidiuresis: From Pathophysiology to Management

Hyponatremia is the most common electrolyte disorder, affecting more than 15% of patients in the hospital. Syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of hypotonic hyponatremia, mediated by nonosmotic release of arginine vasopressin (AVP, previously known as antidiuretic hormone), which acts on the renal V2 receptors to promote water retention. There are a variety of underlying causes of SIAD, including malignancy, pulmonary pathology, and central nervous system pathology. In clinical practice, the etiology of hyponatremia is frequently multifactorial and the management approach may need to evolve during treatment of a single episode. It is therefore important to regularly reassess clinical status and biochemistry, while remaining alert to potential underlying etiological factors that may become more apparent during the course of treatment. In the absence of severe symptoms requiring urgent intervention, fluid restriction (FR) is widely endorsed as the first-line treatment for SIAD in current guidelines, but there is considerable controversy regarding second-line therapy in instances where FR is unsuccessful, which occurs in around half of cases. We review the epidemiology, pathophysiology, and differential diagnosis of SIAD, and summarize recent evidence for therapeutic options beyond FR, with a focus on tolvaptan, urea, and sodium-glucose cotransporter 2 inhibitors.

A case report of severe hyponatremia secondary to Paxlovid-induced SIADH

Nirmatrelvir-ritonavir (Paxlovid) is a brand-new oral antiviral medication for treating mild to severe COVID-19. The Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for ritonavir-nirmatrelvir on December 22, 2021, to treat COVID-19. We describe a case of mild COVID-19 infection who developed severe hyponatremia following the administration of Paxlovid. Clinical and laboratory evaluations suggest SIADH, likely secondary to Paxlovid. The potential side effects of this medication still require further study.

Effect of protein supplementation on plasma sodium levels in the syndrome of inappropriate antidiuresis: a monocentric, open-label, proof-of-concept study-the TREASURE study

IMPORTANCE

The syndrome of inappropriate antidiuresis (SIAD) can be treated with oral urea; however, compliance is impaired by its poor palatability.

OBJECTIVE

To investigate whether dietary proteins could increase plasma sodium levels through urea-induced osmotic diuresis.

DESIGN

An open-label, proof-of-concept trial.

SETTING

University Hospital of Basel, Switzerland, between October 2021 and February 2023.

PARTICIPANTS

Outpatients with chronic SIAD.

INTERVENTIONS OR EXPOSURES

Ninety grams of protein daily for 7 days in the form of protein powder, followed by 30 g of oral urea daily for 7 days after a wash-out period of ≥1 week.

MAIN OUTCOMES AND MEASURES

The increase in sodium levels from baseline to the end of the 7-day protein supplementation.

RESULTS

Seventeen patients were included. After 7 days of 90 g daily protein supplementation (n = 17), plasma sodium levels increased from 131 (129-133) to 133 (132-137), that is, by a median of 3 mmol L-1 (0-5) (P = .01). Plasma urea levels increased by 3 mmol L-1 (1.7-4.9) (P < .01), and urine urea to creatinine ratio increased by 21.2 mmol mmol-1 (6.2-29.1) (P < .01). After 7 days of 30 g oral urea (n = 10), plasma sodium levels increased from 132 (130-133) to 134 (131-136), that is, by a median of 2 mmol L-1 (1-3) (P = .06). Plasma urea levels increased by 5.8 mmol L-1 (2.7-9.2) (P < .01), and urine urea to creatinine ratio increased by 31.0 mmol mmol-1 (18.7-45.1) (P < .01).

CONCLUSIONS AND RELEVANCE

Our findings suggest that protein powder increases plasma sodium levels in patients with chronic SIAD through protein-induced ureagenesis and osmotic diuresis. The effects are comparable with oral urea.

The Efficacy of Immunotherapy in Long-Term Survival in Non-Small Cell Lung Cancer (NSCLC) Associated with the Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)

INTRODUCTION

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of hyponatremia in cancer patients, occurring most frequently in patients with small cell lung cancer. However, this syndrome occurs extremely rarely in patients with non-small cell lung cancer. The results of the clinical trials have revealed that immuno-oncological therapies are effective for long periods of time, providing hope for long survival and with a good quality of life.

CASE PRESENTATION

We present the case of a female patient who was 62 years old at the time of diagnosis in 2016 who underwent surgery for a right pulmonary tumor (pulmonary adenocarcinoma) and subsequently underwent adjuvant chemotherapy. The patient had a left inoperable mediastinohilar relapse in 2018, which was treated using polychemotherapy The patient also had an occurrence of progressive metastasis and a syndrome of inappropriate antidiuretic hormone secretion (SIADH) in 2019 for which immunotherapy was initiated. The patient has continued with immunotherapy until the time this study began to be written (April 2023), the results being the remission of hyponatremia, the clinical benefits and long-term survival.

DISCUSSION

The main therapeutic option for SIADH in cancer patients is the treatment of the underlying disease, and its correction depends almost exclusively on a good response to oncological therapy. The initiation of immunotherapy at the time of severe hyponatremia occurrence led to its remission as well as the remission of the other two episodes of hyponatremia, which the patient presented throughout the evolution of the disease, demonstrating an obvious causal relationship between SIADH and the favorable response to immunotherapy.

CONCLUSIONS

Each patient must be approached individually, taking into account the various particular aspects. Immunotherapy proves to be the innovative treatment that contributes to increasing the survival of patients with metastatic non-small cell lung cancer and to increasing their quality of life.

A profile of SGLT-2 inhibitors in hyponatremia: The evidence to date

Hyponatremia is the most common electrolyte disorder in clinical practice, which may lead to life-threatening complications. Several lines of evidence suggest that hyponatremia is associated not only with significant increases in length of stay, cost, and financial burden, but also with increased morbidity and mortality. Hyponatremia is also considered to be a negative prognostic factor in patients with heart failure and cancer. Although multiple therapeutic methods are available for treating hyponatremia, most have some limitations, such as poor compliance, rapid correction of serum Na⁺, other negative side effects and high cost. Given these limitations, identifying novel therapies for hyponatremia is essential. Recent clinical studies have shown that SGLT-2 inhibitors (SGLT 2i) significantly increased serum Na⁺ levels and were well tolerated by patients who underwent this treatment. Therefore, oral administration of SGLT 2i appears to be an effective treatment for hyponatremia. This article will briefly review the etiology of hyponatremia and integrated control of sodium within the kidney, current therapies for hyponatremia, potential mechanisms and efficacy of SGLT 2i for hyponatremia, and the benefits in cardiovascular, cancer, and kidney disease by regulating sodium and water balance.

Syndrome of Inappropriate Antidiuretic Hormone Secretion as a Presentation of Untreated Parkinson's Disease

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common electrolyte disorder associated with neurological conditions. Parkinson's disease (PD) has not been known to be causative of SIADH. We present the case of a 71-year-old male patient with diabetes type II (T2DM) and hypothyroidism admitted with progressive confusion, slow speech, and severe fatigue for one week, accompanied by sluggish body movements for a few months. A neurological exam revealed mild arm rigidity, bradykinesia, resting tremors, and stiff gait. The exam was otherwise normal. Initial blood work showed hypo-osmolar hyponatremia (Na 122 mEq/L, serum osmolarity (Osm) 275 mOsm/kg, and urine Osm 672 mOsm/Kg). CT chest showed localized infiltrate. The initial diagnosis was SIADH secondary to pulmonary process, most probably pneumonia. After starting him on a fluid restriction of 1.5 L/day and urea 15 mg BID, sodium improved gradually to 133 mEq/L on discharge. Urine osmolality continued to be elevated ranging between 700 and 800 mOsm/Kg. An active pulmonary process was ruled out by a pulmonologist. Parkinsonism was diagnosed four weeks after discharge by Neurology who started carbidopa/levodopa. As extrapyramidal symptoms improved, urine osmolality improved as well to 400 mOsm/Kg. Sodium level was maintained between 135 and 137 while urea treatment was stopped and fluid restrictions removed. New-onset SIADH was thought to be secondary to Parkinson's disease. Parkinson's disease treatment (carbidopa/levodopa) is known to cause SIADH. In this case, the treatment itself and a dose increase led to improvement in sodium levels and urine osmolality concomitantly with the improvement of the patient's extrapyramidal symptoms.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Complicated by Generalized Tonic-Clonic Seizures After a Course of Antibiotics: A Case Report

Nitrofurantoin and cephalexin are commonly used antibiotics for treating urinary tract infections. Hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIADH) has been reported as a rare side effect of nitrofurantoin but has never been a reported side effect of cephalexin. We report a case of a 48-year-old female who developed severe hyponatremia complicated by generalized tonic-clonic seizures after a course of antibiotics (nitrofurantoin followed by cephalexin) used for treating a urinary tract infection. She presented to the emergency department with a one-week history of dizziness, nausea, fatigue, and listlessness. She also had a two-week history of persistent urinary frequency despite completing a course of nitrofurantoin followed by a course of cephalexin. While in the emergency department waiting room, she had two episodes of generalized tonic-clonic seizures. Immediate post-ictal blood test results revealed severe hyponatremia and lactic acidosis. Results were consistent with severe SIADH and she was subsequently managed with hypertonic saline and fluid restriction. She was discharged after 48 hours of admission when her serum sodium levels normalized. Though we believe that nitrofurantoin was the culprit drug, we still asked the patient to avoid future use of both nitrofurantoin and cephalexin. Healthcare providers need to be aware of antibiotic-induced SIADH when assessing patients with hyponatremia.

Relationship between hyponatremia at hospital admission and cardiopulmonary profile at follow-up in patients with SARS-CoV-2 (COVID-19) infection

PURPOSE

Hyponatremia occurs in about 30% of patients with pneumonia, including those with SARS-CoV-2 (COVID-19) infection. Hyponatremia predicts a worse outcome in several pathologic conditions and in COVID-19 has been associated with a higher risk of non-invasive ventilation, ICU transfer and death. The main objective of this study was to determine whether early hyponatremia is also a predictor of long-term sequelae at follow-up.

METHODS

In this observational study, we collected 6-month follow-up data from 189 laboratory-confirmed COVID-19 patients previously admitted to a University Hospital. About 25% of the patients (n = 47) had hyponatremia at the time of hospital admission.

RESULTS

Serum [Na⁺] was significantly increased in the whole group of 189 patients at 6 months, compared to the value at hospital admission (141.4 ± 2.2 vs 137 ± 3.5 mEq/L, p < 0.001). In addition, IL-6 levels decreased and the PaO₂/FiO₂ increased. Accordingly, pulmonary involvement, evaluated at the chest X-ray by the RALE score, decreased. However, in patients with hyponatremia at hospital admission, higher levels of LDH, fibrinogen, troponin T and NT-ProBNP were detected at follow-up, compared to patients with normonatremia at admission. In addition, hyponatremia at admission was associated with worse echocardiography parameters related to right ventricular function, together with a higher RALE score.

CONCLUSION

These results suggest that early hyponatremia in COVID-19 patients is associated with the presence of laboratory and imaging parameters indicating a greater pulmonary and right-sided heart involvement at follow-up.

Hyponatremia Demystified: Integrating Physiology to Shape Clinical Practice

Hyponatremia is one of the most common problems encountered in clinical practice and one of the least-understood because accurate diagnosis and management require some familiarity with water homeostasis physiology, making the topic seemingly complex. The prevalence of hyponatremia depends on the nature of the population studied and the criteria used to define it. Hyponatremia is associated with poor outcomes including increased mortality and morbidity. The pathogenesis of hypotonic hyponatremia involves the accumulation of electrolyte-free water caused by either increased intake and/or decrease in kidney excretion. Plasma osmolality, urine osmolality, and urine sodium can help to differentiate among the different etiologies. Brain adaptation to plasma hypotonicity consisting of solute extrusion to mitigate further water influx into brain cells best explains the clinical manifestations of hyponatremia. Acute hyponatremia has an onset within 48 hours, commonly resulting in severe symptoms, while chronic hyponatremia develops over 48 hours and usually is pauci-symptomatic. However, the latter increases the risk of osmotic demyelination syndrome if hyponatremia is corrected rapidly; therefore, extreme caution must be exercised when correcting plasma sodium. Management strategies depend on the presence of symptoms and the cause of hyponatremia and are discussed in this review.

Hyponatremia and Cancer: From Bedside to Benchside

Hyponatremia is the most common electrolyte disorder encountered in hospitalized patients. This applies also to cancer patients. Multiple causes can lead to hyponatremia, but most frequently this electrolyte disorder is due to the syndrome of inappropriate antidiuresis. In cancer patients, this syndrome is mostly secondary to ectopic secretion of arginine vasopressin by tumoral cells. In addition, several chemotherapeutic drugs induce the release of arginine vasopressin by the hypothalamus. There is evidence that hyponatremia is associated to a more negative outcome in several pathologies, including cancer. Many studies have demonstrated that in different cancer types, both progression-free survival and overall survival are negatively affected by hyponatremia, whereas the correction of serum [Na⁺] has a positive effect on patient outcome. In vitro studies have shown that cells grown in low [Na⁺] have a greater proliferation rate and motility, due to a dysregulation in intracellular signalling pathways. Noteworthy, vasopressin receptors antagonists, which were approved more than a decade ago for the treatment of euvolemic and hypervolemic hyponatremia, have shown unexpected antiproliferative effects. Because of this property, vaptans were also approved for the treatment of polycystic kidney disease. In vitro evidence indicated that this family of drugs effectively counteracts proliferation and invasivity of cancer cells, thus possibly opening a new scenario among the pharmacological strategies to treat cancer.

Electrolyte imbalances as poor prognostic markers in COVID-19: a systemic review and meta-analysis

PURPOSE

Serum electrolyte imbalances are highly prevalent in COVID-19 patients. However, their associations with COVID-19 outcomes are inconsistent, and of unknown prognostic value. We aim to systematically clarify the associations and prognostic accuracy of electrolyte imbalances (sodium, calcium, potassium, magnesium, chloride and phosphate) in predicting poor COVID-19 clinical outcome.

METHODS

PubMed, Embase and Cochrane Library were searched. Odds of poor clinical outcome (a composite of mortality, intensive-care unit (ICU) admission, need for respiratory support and acute respiratory distress syndrome) were pooled using mixed-effects models. The associated prognostic sensitivity, positive and negative likelihood ratios (LR + , LR-) and predictive values (PPV, NPV; assuming 25% pre-test probability), and area under the curve (AUC) were computed.

RESULTS

We included 28 observational studies from 953 records with low to moderate risk-of-bias. Hyponatremia (OR = 2.08, 95% CI = 1.48-2.94, I² = 93%, N = 8), hypernatremia (OR = 4.32, 95% CI = 3.17-5.88, I² = 45%, N = 7) and hypocalcemia (OR = 3.31, 95% CI = 2.24-4.88, I² = 25%, N = 6) were associated with poor COVID-19 outcome. These associations remained significant on adjustment for covariates such as demographics and comorbidities. Hypernatremia was 97% specific in predicting poor outcome (LR + 4.0, PPV = 55%, AUC = 0.80) despite no differences in CRP and IL-6 levels between hypernatremic and normonatremic patients. Hypocalcemia was 76% sensitive in predicting poor outcome (LR- 0.44, NPV = 87%, AUC = 0.71). Overall quality of evidence ranged from very low to moderate.

CONCLUSION

Hyponatremia, hypernatremia and hypocalcemia are associated with poor COVID-19 clinical outcome. Hypernatremia is 97% specific for a poor outcome, and the association is independent of inflammatory marker levels. Further studies should evaluate if correcting these imbalances help improve clinical outcome.

Treatment Effect of the SGLT2 Inhibitor Empagliflozin on Chronic Syndrome of Inappropriate Antidiuresis: Results of a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

BACKGROUND

The syndrome of inappropriate antidiuresis (SIAD) is characterized by a reduction of free water excretion with consecutive hypotonic hyponatremia and is therefore challenging to treat. The sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin promotes osmotic diuresis via urinary glucose excretion, likely leading to increased electrolyte free water clearance.

METHODS

In this randomized, double-blind, placebo-controlled, crossover trial, we compared 4-week treatment with empagliflozin 25 mg/d to placebo in outpatients with chronic SIAD-induced hyponatremia. At baseline and after both treatment cycles, patients underwent different assessments including neurocognitive testing (Montreal Cognitive Assessment [MoCA]). The primary end point was the difference in serum sodium levels between treatments.

RESULTS

Fourteen patients, 50% female, with a median age of 72 years (interquartile range [IQR], 65-77), completed the trial. Median serum sodium level at baseline was 131 mmol/L (IQR, 130-132). After treatment with empagliflozin, median serum sodium level rose to 134 mmol/L (IQR, 132-136), whereas no increase was seen with placebo (130 mmol/L; IQR, 128-132), corresponding to a serum sodium increase of 4.1 mmol/L (95% confidence interval [CI], 1.7 to 6.5; P =0.004). Exploratory analyses showed that treatment with empagliflozin led to improved neurocognitive function with an increase of 1.16 (95% CI, 0.05 to 2.26) in the MoCA score. Treatment was well tolerated; no serious adverse events were reported.

CONCLUSION

The SGLT2 inhibitor empagliflozin is a promising new treatment option for chronic SIAD-induced hyponatremia, possibly improving neurocognitive function. Larger studies are needed to confirm the observed treatment effects.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT03202667.

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Differentiating Ductal Adenocarcinoma of the Pancreas from Benign Conditions Using Routine Health Records: A Prospective Case-Control Study

The study aimed to develop a prediction model for differentiating suspected PDAC from benign conditions. We used a prospective cohort of patients with pancreatic disease (n = 762) enrolled at the Barts Pancreas Tissue Bank (2008-2021) and performed a case-control study examining the association of PDAC (n = 340) with predictor variables including demographics, comorbidities, lifestyle factors, presenting symptoms and commonly performed blood tests. Age (over 55), weight loss in hypertensive patients, recent symptoms of jaundice, high serum bilirubin, low serum creatinine, high serum alkaline phosphatase, low red blood cell count and low serum sodium were identified as the most important features. These predictors were then used for training several machine-learning-based risk-prediction models on 75% of the cohort. Models were assessed on the remaining 25%. A logistic regression-based model had the best overall performance in the validation cohort (area-under-the-curve = 0.90; Spiegelhalter's z = -1·82, p = 0.07). Setting a probability threshold of 0.15 guided by the maximum F2-score of 0.855, 96.8% sensitivity was reached in the full cohort, which could lead to earlier detection of 84.7% of the PDAC patients. The prediction model has the potential to be applied in primary, secondary and emergency care settings for the early distinction of suspected PDAC patients and expedited referral to specialist hepato-pancreatico-biliary services.

Hyponatremia due to excessive water intake in COVID-19 patients: case series study

Background

Literatures revealed syndrome of inappropriate antidiuretic hormone (SIADH) as the most common mechanism of hyponatremia in COVID-19. However, it is important to rule out other etiologies of hyponatremia.

Methods

This is a case series, retrospective study. Four patients were reviewed from the Mesaieed Hospital, Hamad Medical Corporation, Qatar. The patients were admitted during the second wave of pandemic because of mild to moderate COVID pneumonia. The patients received medications according to the protocol; after few days of treatment, their blood laboratory results showed hyponatremia; as compared to the initial readings, hyponatremia workup excluded SIADH. History revealed that the patients were drinking large amounts of water, around 4–5 L/day, due of certain reasons: one patient had dysgeusia, and the other three patients thought that excessive drinking of water is beneficial for COVID-19 infection.

Results

The hyponatremia level was less than 135 mmol/L, other laboratory tests excluded SIADH, and the provisional diagnosis was dilutional hyponatremia. Male/female ratio was 3/1, age from 29- to 45-year-old patients with no associated comorbidities. Fluid restriction up to 1.5 L/day showed dramatic improvement of their sodium blood level. The patients are discharged in a stable condition.

Conclusions

In COVID-19 patients, hyponatremia not only is secondary to SIADH but can also be due to other etiologies. Hyponatremia can be induced by excessive water drinking and considered an extremely rare reported cases.

Endocrine Disorders in Children with Brain Tumors: At Diagnosis, after Surgery, Radiotherapy and Chemotherapy

INTRODUCTION

Brain tumors are the second most frequent type of all pediatric malignancies. Depending on their localization, patients with brain tumors may present neurological or ophthalmological symptoms, but also weight anomalies and endocrine disorders ranging from growth hormone deficiency, anomalies of puberty, diabetes insipidus to panhypopituitarism. Immediately at diagnosis, all patients with brain tumors require a complete assessment of the hypothalamic-pituitary function in order to address eventual endocrine disorders. Moreover, children and adolescents undergoing brain surgery must receive peri- and postoperative hydrocortisone stress therapy. Post-operative disorders of water homeostasis are frequent, ranging from transient diabetes insipidus, as well as syndrome of inappropriate antidiuretic hormone secretion to persistent diabetes insipidus. Late endocrine disorders may result from surgery near or within the hypothalamic-pituitary region. Pituitary deficits are frequent after radiotherapy, especially growth hormone deficiency. Thyroid nodules or secondary thyroid cancers may arise years after radiotherapy. Gonadal dysfunction is frequent after chemotherapy especially with alkylating agents.

CONCLUSION

Early detection and treatment of specific endocrine disorders at diagnosis, perioperatively, and during long-term follow-up result in improved general and metabolic health and quality of life.

Effect of vasopressin V2-receptor antagonist tolvaptan on syndrome of inappropriate antidiuresis (SIAD) after transsphenoidal pituitary surgery: recovery of measured osmolality

Background

Delayed hyponatremia after pituitary surgery can be treated with the V2-receptor antagonist, oral tolvaptan. We investigated the pharmacological effect of oral tolvaptan against SIAD in patients with hyponatremia after pituitary surgery.

Methods

Thirty-nine patients with pituitary adenoma treated by endoscopic transsphenoidal surgery developed SIAD according to the major guidelines, and 7 patients (17.9%) were treated with tolvaptan. Tolvaptan was administrated orally half a tablet (3.75 mg) once in the first two cases, and half a tablet twice in the other five cases. Serum osmolality, urinary osmolality, urinary sodium concentration, urinary volume, and serum sodium and potassium concentration were evaluated before administration, and after the last oral administration of tolvaptan. Serum osmolality and urine osmolality were physically measured.

Results

Serum sodium concentration was significantly increased from 132.1 ± 4.0 to 143.0 ± 2.9 mmol/L (mean ± standard deviation, n = 7, P < 0.001). Serum osmolality was significantly increased from 266.3 ± 7.7 to 289.6 ± 6.7 mOsm/kg (n = 7, P < 0.001). Urine osmolality was significantly reduced from 607.1 ± 240.4 to 262.7 ± 115.6 mOsm/kg (n = 7, P = 0.01). Urinary sodium concentration was significantly decreased from 121.3 ± 48.4 to 36.9 ± 35.0 mOsm/kg (n = 7, P = 0.001). Urine output (24-hour including the first administration) was significantly increased from 1384.2 ± 550.7 to 3291.3 ± 1710.9 mL/day (n = 6, P = 0.026).

Conclusions

Oral tolvaptan administration corrects SIAD after pituitary surgery. Hyponatremia after pituitary surgery was confirmed to be due to SIAD.

Demystifying hyponatremia: A clinical guide to evaluation and management

Hyponatremia (serum sodium <135 mEq/L) is a frequent electrolyte abnormality complicating the clinical care of hospitalized patients. Hyponatremia has been associated with an increased risk of mortality. Hyponatremia can be seen in patients with euvolemia, hypovolemia, or hypervolemia. Evaluation of hyponatremia relies on clinical assessment and estimation of serum sodium, urine electrolytes, and serum and urine osmolality in addition to other case-specific laboratory parameters. In addition, point-of-care ultrasonography is an important adjunct to physical assessment in estimation of volume status. Understanding the pathophysiology of the underlying process can lead to a timely diagnosis and appropriate management of hyponatremia.

The Mutual Relationship among Cardiovascular Diseases and COVID-19: Focus on Micronutrients Imbalance

Micronutrients are ions and vitamins humbly required by the human body. They play a main role in several physiological mechanisms and their imbalance is strongly associated with potentially-fatal complications. Micronutrient imbalance is associated with many cardiovascular diseases, such as arrythmias, heart failure, and ischemic heart disease. It has been also observed in coronavirus disease 2019 (COVID-19), particularly in most severe patients. The relationship between cardiovascular diseases and COVID-19 is mutual: the latter triggers cardiovascular disease onset and worsening while patients with previous cardiovascular disease may develop a more severe form of COVID-19. In addition to the well-known pathophysiological mechanisms binding COVID-19 and cardiovascular diseases together, increasing importance is being given to the impact of micronutrient alterations, often present during COVID-19 and able to affect the balance responsible for a good functioning of the cardiovascular system. In particular, hypokalemia, hypomagnesemia, hyponatremia, and hypocalcemia are strongly associated with worse outcome, while vitamin A and D deficiency are associated with thromboembolic events in COVID-19. Thus, considering how frequent the cardiovascular involvement is in patients with COVID-19, and how it majorly affects their prognosis, this manuscript provides a comprehensive review on the role of micronutrient imbalance in the interconnection between COVID-19 and cardiovascular diseases.

Hyponatremia and SARS-CoV-2 infection: A narrative review

A novel rapid spreading and changing virus called SARS-CoV-2 appeared in Wuhan city in December 2019. It was announced by the World Health Organization (WHO) as a pandemic disease in March 2020. It commonly presents with respiratory symptoms; however, it may be asymptomatic. Electrolyte abnormalities are not uncommon features of SARS-CoV-2 infection. Hyponatremia is one of these electrolyte disturbances among SARS-CoV-2 patients, and it may produce symptoms such as weakness and seizure as the initial presenting symptoms. The underlying mechanism(s) of hyponatremia due to SARS-CoV-2 infection is (are) not established. The aim of this review is to evaluate the possible mechanism of hyponatremia in patients with COVID-19. Understanding and categorizing the hyponatremia in these patients will lead to better treatment and correction of the hyponatremia. A review of the literature between December 2019 and March 2022 was conducted searching for the possible reported mechanism(s) of hyponatremia in SARS-CoV-2. Although SIADH is the commonly reported cause of hyponatremia in SARS-CoV-2 infection, other causes such as diarrhea, vomiting, and kidney salt loss must be considered before SIADH.

High Urinary Sodium Concentrations in Severe SIADH: Case Reports of 2 Patients and Literature Review

We present two cases of severe hyponatremia secondary to syndrome of inappropriate secretion of antidiuretic hormone (SIADH) with very high urine sodium concentrations (>130 mmol/L). The first patient had hyponatremia from traumatic brain injury (TBI) while the second case had a history of recurrent SIADH triggered by various causes including gastritis. In both cases, fluid administration and/or consumption worsened the hyponatremia. Although a low urine sodium of <30 mmol/L is highly suggestive of hypovolemic hyponatremia and good response to saline infusion, there is lack of clarity of the threshold of which high urine sodium concentration can differentiate various causes of natriuresis such as SIADH, renal or cerebral salt wasting. Apart from high urine osmolality (>500 mOsm/kg), persistence of high urine sodium concentrations may be useful to predict poor response to fluid restriction in SIADH. More studies are needed to delineate treatment pathways of patients with very high urine osmolality and urine sodium concentrations in SIADH.

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.

Hyponatraemia and the syndrome of inappropriate antidiuresis (SIAD) in cancer

Hyponatraemia is a common electrolyte abnormality seen in a wide range of oncological and haematological malignancies and confers poor performance status, prolonged hospital admission and reduced overall survival, in patients with cancer. Syndrome of inappropriate antidiuresis (SIAD) is the commonest cause of hyponatraemia in malignancy and is characterised by clinical euvolaemia, low plasma osmolality and concentrated urine, with normal renal, adrenal and thyroid function. Causes of SIAD include ectopic production of vasopressin (AVP) from an underlying tumour, cancer treatments, nausea and pain. Cortisol deficiency is an important differential in the assessment of hyponatraemia, as it has an identical biochemical pattern to SIAD and is easily treatable. This is particularly relevant with the increasing use of immune checkpoint inhibitors, which can cause hypophysitis and adrenalitis, leading to cortisol deficiency. Guidelines on the management of acute, symptomatic hyponatraemia recommend 100 mL bolus of 3% saline with careful monitoring of the serum sodium to prevent overcorrection. In cases of chronic hyponatraemia, fluid restriction is recommended as first-line treatment; however, this is frequently not feasible in patients with cancer and has been shown to have limited efficacy. Vasopressin-2 receptor antagonists (vaptans) may be preferable, as they effectively increase sodium levels in SIAD and do not require fluid restriction. Active management of hyponatraemia is increasingly recognised as an important component of oncological management; correction of hyponatraemia is associated with shorter hospital stay and prolonged survival. The awareness of the impact of hyponatraemia and the positive benefits of active restoration of normonatraemia remain challenging in oncology.

Red urine and a red herring - diagnosing rare diseases in the light of the COVID-19 pandemic

Background The COVID-19 pandemic has occupied the time and resources of health care professionals for more than 1 year. The risk of missed diagnoses has been discussed in the medical literature, mainly for common diseases such as cancer and cardiovascular events. However, rare diseases also need appropriate attention in times of a pandemic.

Case Report We report a 34-year-old woman with fever, pinprick sensation in her chest and thoracic spine, and dizziness after receiving the first dose of ChAdOx1 nCoV-19 vaccination. The patient’s condition worsened with abdominal pain, red urine, and hyponatremia, needing intensive care admission. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) was diagnosed. Vaccine-induced thrombocytopenia and thrombosis were ruled out. Acute hepatic porphyria was finally diagnosed, and the patient recovered completely after treatment with hemin.

Conclusion Currently, the focus of physicians is on COVID-19 and associated medical problems, such as vaccine side effects. However, it is important to be vigilant for other uncommon medical emergencies in medically exceptional situations that may shift our perception.

Simple demographic characteristics and laboratory findings on admission may predict in-hospital mortality in patients with SARS-CoV-2 infection: development and validation of the covid-19 score

Background

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitutes a major health burden worldwide due to high mortality rates and hospital bed shortages. SARS-CoV-2 infection is associated with several laboratory abnormalities. We aimed to develop and validate a risk score based on simple demographic and laboratory data that could be used on admission in patients with SARS-CoV-2 infection to predict in-hospital mortality.

Methods

Three cohorts of patients from different hospitals were studied consecutively (developing, validation, and prospective cohorts). The following demographic and laboratory data were obtained from medical records: sex, age, hemoglobin, mean corpuscular volume (MCV), platelets, leukocytes, sodium, potassium, creatinine, and C-reactive protein (CRP). For each variable, classification and regression tree analysis were used to establish the cut-off point(s) associated with in-hospital mortality outcome based on data from developing cohort and before they were used for analysis in the validation and prospective cohort. The covid-19 score was calculated as a sum of cut-off points associated with mortality outcome.

Results

The developing, validation, and prospective cohorts included 129, 239, and 497 patients, respectively (median age, 71, 67, and 70 years, respectively). The following cut of points associated with in-hospital mortality: age > 56 years, male sex, hemoglobin < 10.55 g/dL, MCV > 92.9 fL, leukocyte count > 9.635 or < 2.64 10³/µL, platelet count, < 81.49 or > 315.5 10³/µL, CRP > 51.14 mg/dL, creatinine > 1.115 mg/dL, sodium < 134.7 or > 145.4 mEq/L, and potassium < 3.65 or > 6.255 mEq/L. The AUC of the covid-19 score for predicting in-hospital mortality was 0.89 (0.84–0.95), 0.850 (0.75–0.88), and 0.773 (0.731–0.816) in the developing, validation, and prospective cohorts, respectively (P < 0.001The mortality of the prospective cohort stratified on the basis of the covid-19 score was as follows: 0–2 points,4.2%; 3 points, 15%; 4 points, 29%; 5 points, 38.2%; 6 and more points, 60%.

Conclusion

The covid-19 score based on simple demographic and laboratory parameters may become an easy-to-use, widely accessible, and objective tool for predicting mortality in hospitalized patients with SARS-CoV-2 infection.

Can treatment response to SGLT2-inhibitors in syndrome of inappropriate antidiuresis be predicted by copeptin, natriuretic peptides and inflammatory markers?

PURPOSE

The syndrome of inappropriate antidiuresis (SIAD) is the main cause of hyponatremia and the SGLT2-inhibitor empagliflozin is a promising new treatment option. A biomarker predicting treatment response could optimize treatment success.

MATERIALS AND METHODS

Secondary analysis of a trial including 84 hospitalized patients with SIAD-induced hyponatremia. Patients were randomized to four days of treatment with empagliflozin 25 mg/d (n = 43) or placebo (n = 41) with both groups receiving fluid restriction <1000 ml/d. Baseline levels of copeptin, the natriuretic peptides MR-proANP and NT-proBNP and C-reactive protein (CRP) were evaluated as predictors for treatment response defined as absolute sodium change, using linear regression models. Additionally, urinary sodium was assessed as predictor for non-response to fluid restriction alone by constructing the receiver-operating characteristic (ROC) curve.

RESULTS

No clinically relevant predictive value for treatment response to empagliflozin could be found for copeptin, MR-proANP, NT-proBNP or CRP. A urinary sodium cut-off of >76 mmol/l led to a specificity of 91.7% [95% confidence interval (CI): 75%, 100%] and sensitivity of 51.9% [33.3%, 70.4%] to predict non-response to fluid restriction alone.

CONCLUSIONS

Based on our data, no biomarker could be identified as predictor for treatment response to empagliflozin. Urinary sodium was confirmed as a good marker for non-response to fluid restriction in SIAD patients. Clinical trial registration: ClinicalTrials.gov (Number: NCT02874807).

Syndrome of Inappropriate Antidiuretic Hormone Secretion and Trimethoprim-Related Hyponatremia Following Transurethral Bladder Wall Biopsy

Postoperative hyponatremia is common. It results from the physiological antidiuretic hormone (ADH) response to surgery and associated exacerbating factors. Common exacerbating factors include medications, excessive fluid administration, and syndrome of inappropriate antidiuretic hormone (SIADH) secretion. High-dose trimethoprim can cause transient salt-losing nephropathy, resulting in SIADH-like hyponatremia associated with hypovolemia, hyperkalemia, and metabolic acidosis. We present a patient who developed symptoms of vomiting, loss of appetite, fatigue, and abdominal discomfort six days after having a transurethral bladder wall biopsy. He had also started a course of trimethoprim two days prior to the onset of the symptoms. Initial investigations demonstrated severe hyponatremia, concentrated urine, and compensated metabolic acidosis. These results suggested postoperative SIADH possibly exacerbated by trimethoprim-related hyponatremia. Cautious IV normal sodium chloride infusion resulted in a rapid recovery. While raising the awareness of postoperative hyponatremia, this case also highlights the difficulty distinguishing between SIADH and trimethoprim-related hyponatremia.

Routine postoperative fluid restriction to prevent syndrome of inappropriate antidiuretic hormone secretion after transsphenoidal resection of pituitary adenoma

OBJECTIVE

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common problem during the postoperative course after pituitary surgery. Although treatment of this condition is well characterized, prevention strategies are less studied and reported. The authors sought to characterize outcomes and predictive factors of SIADH after implementation of routine postoperative fluid restriction for patients undergoing endoscopic transsphenoidal surgery for pituitary adenoma.

METHODS

In March 2018, routine postoperative fluid restriction to 1000 ml/day for 7 days was instituted for all patients who underwent surgery for pituitary adenoma. These patients were compared with patients who underwent surgery for pituitary adenoma between March 2016 and March 2018, prior to implementation of routine fluid restriction. Patients with preoperative history of diabetes insipidus (DI) or concern for postsurgical DI were excluded. Patients were followed by neuroendocrinologists and neurosurgeons, and sodium levels were checked between 7 and 10 days postoperatively. SIADH was defined by a serum sodium level less than 136 mmol/L, with or without symptoms within 10 days after surgery. Thirty-day readmission was recorded and reviewed to determine underlying reasons.

RESULTS

In total, 82 patients in the fluid-unrestricted cohort and 135 patients in the fluid-restricted cohort were analyzed. The patients in the fluid-restricted cohort had a significantly lower rate of postoperative SIADH than patients in the fluid-unrestricted cohort (5% vs 15%, adjusted OR [95% CI] 0.1 [0.0-0.6], p = 0.01). Higher BMI was associated with lower rate of postoperative SIADH (adjusted OR [95%] 0.9 [0.9-1.0], p = 0.03), whereas female sex was associated with higher rate of SIADH (adjusted OR [95% CI] 3.1 [1.1-9.8], p = 0.03). There was no difference in the 30-day readmission rates between patients in the fluid-unrestricted and fluid-restricted cohorts (4% vs 7%, adjusted OR [95% CI] 0.5 [0-5.1], p = 0.56). Thirty-day readmission was more likely for patients with history of hypertension (adjusted OR [95% CI] 5.7 [1.3-26.3], p = 0.02) and less likely for White patients (adjusted OR [95% CI] 0.3 [0.1-0.9], p = 0.04).

CONCLUSIONS

Routine fluid restriction reduced the rate of SIADH in patients who underwent surgery for pituitary adenoma but was not associated with reduction in 30-day readmission rate.

Levels of C-Reactive Protein and Sodium May Differentiate a Perforated Appendix from a Nonperforated Appendix in Children

Background

Acute appendicitis (AA) might be amenable to conservative antibiotic treatment, whereas a perforated appendix (PA) necessitates surgery. We investigated the value of clinical–laboratory markers in distinguishing AA from a PA.

Methods

Retrospectively obtained preoperative parameters for 306 consecutive patients (<18 years) with histologically confirmed appendicitis (AA (n = 237) vs. PA (n = 69)), treated at our institution between January 2014 and December 2017.

Results

A PA was associated with male preponderance, younger age, decreased sodium level and increased white blood cell count, Tzanakis score, C-reactive protein (CRP) level, and CRP-to-lymphocyte ratio (CLR). Upon discrimination analysis, CLR and CRP displayed the highest accuracy in differentiating a PA from AA. Regression analysis identified levels of CRP, sodium, and the Tzanakis score as independent predictors for a PA.

Conclusion

Levels of CLR, CRP, sodium, and Tzanakis score might support decision-making regarding treatment options for pediatric appendicitis.

The Prognostic Value of Hyponatremia for Predicting Poor Outcome in Patients With COVID-19: A Systematic Review and Meta-Analysis

Background: This meta-analysis aimed to assess the prognostic value of hyponatremia in patients with COVID-19.

Methods: We performed a systematic literature search on PubMed, Scopus, ScienceDirect, and Wiley up until January 26, 2021. The key exposure was hyponatremia, defined as sodium level below the reference level. The outcome of interest was poor outcome, which was a composite of mortality, severe COVID-19, and prolonged hospitalization. Severe COVID-19 was defined severe CAP or needing ICU care or IMV. The pooled effect estimate was odds ratio (OR). Sensitivity, specificity, positive and negative likelihood ratio (PLR and NLR), diagnostic OR (DOR), and area under curve (AUC) were generated.

Results: There were 11,493 patients from eight studies included in this systematic review and meta-analysis. The incidence of hyponatremia was 24%, and incidence of poor outcome was 20%. Hyponatremia was associated with poor outcome in COVID-19 (OR 2.65 [1.89, 3.72], p < 0.001; I²: 67.2%). Meta-regression analysis showed that the association between hyponatremia and poor outcome was reduced by age (OR 0.94 [0.90, 0.98], p = 0.006) and hypertension (OR 0.96 [0.93, 0.94], p < 0.001). Hyponatremia has a sensitivity of 0.37 [0.27, 0.48], specificity of 0.82 [0.72, 0.88], PLR of 2.0 [1.5, 2.7], NLR of 0.77 [0.69, 0.87], DOR of 3 [2, 4], and AUC of 0.62 [0.58, 0.66] for predicting poor outcome. In this pooled analysis, hyponatremia has a 33% posttest probability for poor outcome, and absence of hyponatremia confers to a 16% posttest probability.

Conclusion: Hyponatremia was associated with poor outcome in patients with COVID-19.

Systematic Review Registration: PROSPERO, CRD42021233592.

COVID-19 and the pituitary

BACKGROUND

Despite COVID-19 being identified as severe respiratory viral infection, progressively many relevant endocrine manifestations have been reported greatly contributing to the severity of the clinical presentation. Systemic involvement in COVID-19 is due to the ubiquitous expression of angiotensin-converting enzyme 2 (ACE2) receptor, responsible for the entry in the cells of SARS-CoV-2, Several reports in humans and animal models showed a significant ACE2 mRNA expression in hypothalamus and pituitary cells. Moreover, higher mortality and poorer outcomes have been widely described in COVID-19 patients with obesity, diabetes and vertebral fractures, which are all highly prevalent in subjects with pituitary dysfunctions.

AIM

To review the main endocrine manifestations of COVID-19 with their possible implications for pituitary diseases, the possible direct and indirect involvement of the pituitary gland in COVID-19, the impact of COVID-19 on the management of established pituitary diseases which can be already at increased risk for worse outcomes and on neurosurgical activities as well as vaccination.

CONCLUSIONS

Our review underlines that there could be a specific involvement of the pituitary gland which fits into a progressively shaping endocrine phenotype of COVID-19. Moreover, the care for pituitary diseases need to continue despite the restrictions due to the emergency. Several pituitary diseases, such as hypopituitarism and Cushing disease, or due to frequent comorbidities such as diabetes may be a risk factor for severe COVID-19 in affected patients. There is the urgent need to collect in international multicentric efforts data on all these aspects of the pituitary involvement in the pandemic in order to issue evidence driven recommendations for the management of pituitary patients in the persistent COVID-19 emergency.

Serum sodium alterations in SARS CoV-2 (COVID-19) infection: impact on patient outcome

OBJECTIVE

Hyponatremia is the most common electrolyte disorder in hospitalized patients and occurs in about 30% of patients with pneumonia. Hyponatremia has been associated with a worse outcome in several pathologic conditions The main objective of this study was to determine whether serum sodium alterations may be independent predictors of the outcome of hospitalized COVID-19 patients.

DESIGN AND METHODS

In this observational study, data from 441 laboratory-confirmed COVID-19 patients admitted to a University Hospital were collected. After excluding 61 patients (no serum sodium at admission available, saline solution infusion before sodium assessment, transfer from another hospital), data from 380 patients were analyzed.

RESULTS

274 (72.1%) patients had normonatremia at admission, 87 (22.9%) patients had hyponatremia and 19 (5%) patients had hypernatremia. We found an inverse correlation between serum sodium and IL-6, whereas a direct correlation between serum sodium and PaO2/FiO2 ratio was observed. Patients with hyponatremia had a higher prevalence of non-invasive ventilation and ICU transfer than those with normonatremia or hypernatremia. Hyponatremia was an independent predictor of in-hospital mortality (2.7-fold increase vs normonatremia) and each mEq/L of serum sodium reduction was associated with a 14.4% increased risk of death.

CONCLUSIONS

These results suggest that serum sodium at admission may be considered as an early prognostic marker of disease severity in hospitalized COVID-19 patients.

Regulation of Serum Sodium Levels during Chemotherapy Using Selective Arginine Vasopressin V2-Receptor Antagonist Tolvaptan in a Four-Year-Old Girl with a Suprasellar Germ Cell Tumor

There are limited reports on the use of tolvaptan for syndrome of inappropriate antidiuretic hormone secretion (SIADH) in children. Managing serum sodium levels in SIADH patients during chemotherapy is often difficult because of the need for massive fluid infusions. We report the course of the use of tolvaptan for the treatment of hyponatremia during chemotherapy in a four-year-old girl with a suprasellar germ cell tumor. The patient was a Japanese girl who presented with left ptosis with a mass in the pituitary gland and cavernous sinus. She was diagnosed with an intermediate-grade germ cell tumor and was treated with carboplatin and etoposide combination chemotherapy. She developed hyponatremia due to SIADH caused by intravenous infusion therapy before chemotherapy. Subsequently, tolvaptan (3.25 mg; 0.20 mg/kg/dose) was administered orally to control serum sodium levels. After 4 h of administration, a marked increase in urine volume of up to 15 mL/kg/h was observed, and serum sodium level increased from 126 to 138 mEq/L after 10 h of tolvaptan administration, followed by a decrease in urine volume. The use of tolvaptan in pediatric patients with SIADH who require intravenous hydration during chemotherapy can be useful for the management of serum sodium balance.

[Central nervous system toxicity caused by bortezomib: five case reports and a review of literature]

目的

探讨硼替佐米中枢神经系统（CNS）毒性的临床特点、诊断和治疗。

方法

报道5例由硼替佐米引起的CNS毒性患者并结合现有文献探讨其临床特点。

结果

5例患者中有4例在应用硼替佐米后出现了中枢性发热，主要表现为持续性高热、周身无汗、未能找到感染病灶、对退热药不敏感，停用硼替佐米后症状好转。4例患者中有3例伴随顽固性低钠血症，1例明确诊断为抗利尿不当综合征（SIAD），可能是硼替佐米同时影响了下丘脑体温调节中枢和抗利尿激素神经分泌细胞所致。1例患者诊断为可逆性后部脑病综合征（PRES），表现为应用硼替佐米后出现意识障碍，头CT示双侧半卵圆中心白质密度减低，停用硼替佐米后患者症状消失且未再复发。此外，我们还发现血小板计数可能与硼替佐米CNS毒性的严重程度相关。

结论

硼替佐米的CNS毒性非常罕见，表现为3种形式：SIAD、PRES和中枢性发热，及时识别和治疗对于预防不可逆的神经并发症非常重要。

Successful Treatment with Percutaneous Balloon Kyphoplasty for Syndrome of Inappropriate Secretion of Antidiuretic Hormone Associated with Vertebral Compression Fracture: A Case Report

BACKGROUND The etiology of syndrome of inappropriate antidiuretic hormone secretion (SIADH) is highly variable. With little evidence, much of the guidance and recommendations available for management are based on clinical judgement. Although percutaneous balloon kyphoplasty can effectively relieve the severe pain associated with osteoporotic vertebral compression fractures that do not respond to conventional treatments, the effect of balloon kyphoplasty on SIADH associated with vertebral compression fracture remains unknown. CASE REPORT A 72-year-old woman was admitted to our hospital due to severe pain associated with lumbar compression fracture and pain-related SIADH. Since her pain could not be relieved by analgesics, she underwent percutaneous balloon kyphoplasty, a minimally invasive procedure intended to relieve pain. After the surgery, the patient's pain almost completely disappeared and her sodium level was gradually corrected within 3 days without any adverse events. CONCLUSIONS Percutaneous balloon kyphoplasty is a novel treatment option for SIADH associated with vertebral compression fracture. In the case presented here, it rapidly reduced pain and disability and also improved severe pain-associated SIADH without adverse effects. It may offer an alternative to pain regimens consisting of drugs, such as duloxetine, pregabalin, and opioids, that may exacerbate SIADH and hyponatremia. This case suggests treatment for new-onset or worsening hyponatremia in patients with vertebral compression fracture.

Small cell carcinoma of the cervix complicated by syndrome of inappropriate antidiuretic hormone secretion: a case report

Small cell carcinoma of the cervix is a rare malignant tumor in the clinical setting. Clinical manifestations of this tumor are mostly similar to those of normal types of cervical cancer. Small cell carcinoma of the cervix only shows symptoms of neuroendocrine tumors, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Most of the hyponatremia caused by SIADH can be managed after removal of the cause. Hyponatremia is a predictor of poor prognosis and can be used as an indicator of partial recurrence. We report a case of small cell carcinoma of the cervix complicated by SIADH. Our patient presented with irregular vaginal bleeding after menopause. After one cycle of chemotherapy, there was trembling of the limbs, and a laboratory examination showed low Na⁺ and low Cl⁻ levels. After limited water intake, intravenous hypertonic saline, and intermittent diuretic treatment, the patient’s blood Na⁺ levels returned to normal. After a radical operation, the above-mentioned symptoms disappeared.

Brucellosis manifesting as reversible ataxia caused by SIADH-related hyponatremia

Brucellosis is an infectious disease commonly presents with fever, fatigue, arthralgia, and muscle pain. Nonetheless, hyponatremia and its related symptoms have been reported as presenting features of brucellosis. Herein, we report a 56-year-old male presenting with ataxia and SIADH-related hyponatremia induced by brucellosis. The ataxia improved following hyponatremia correction. Up to our knowledge, this is the first case of reversible cerebellar ataxia occurring in the setting of brucellosis-related SIADH.

Is There a Relationship between COVID-19 and Hyponatremia?

Nowadays, humanity faces one of the most serious health crises, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. The severity of coronavirus disease 2019 (COVID-19) pandemic is related to the high rate of interhuman transmission of the virus, variability of clinical presentation, and the absence of specific therapeutic methods. COVID-19 can manifest with non-specific symptoms and signs, especially among the elderly. In some cases, the clinical manifestations of hyponatremia may be the first to appear. The pathophysiological mechanisms of hyponatremia among patients with COVID-19 are diverse, including syndrome of inappropriate antidiuretic hormone secretion (SIADH), digestive loss of sodium ions, reduced sodium ion intake or use of diuretic therapy. Hyponatremia may also be considered a negative prognostic factor in patients diagnosed with COVID-19. We need further studies to evaluate the etiology and therapeutic management of hyponatremia in patients with COVID-19.

Adherence to the Sociedad Española de Oncología Médica (SEOM) Algorithm for the Treatment of Hyponatremia in Oncology Patients in Spain: The ALGA Study

INTRODUCTION

The ALGA study explored adherence of Spanish treatment centers to the Sociedad Española de Oncología Médica (SEOM) treatment algorithm for oncology patients with hyponatremia that requires treatment as the main cause of hospitalization, and evaluated the impact of adherence to this algorithm on patient outcomes.

METHODS

This retrospective study recruited patients aged at least 18 years with cancer, treated for at least one episode of hyponatremia secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). The primary outcome was the proportion of patients whose treatment adhered to the SEOM algorithm, evaluated using a pre-defined decision tree. Secondary outcomes included length of hospitalization, and time to serum sodium level improvement. Perceived center adherence to the SEOM algorithm was also assessed.

RESULTS

Seventy patients from four treatment centers were included. Twenty (28.6%; 95% confidence interval [CI] 18.0, 39.2) patients on hyponatremia treatment adhered to the SEOM algorithm, with a perceived adherence of 51.0-75.0%. Algorithm adherence in candidates for chemotherapy was 36.4% (n = 8) versus 25.0% (n = 12) for non-candidates for chemotherapy. Median time to serum sodium level improvement in patients managed adherently was 80.5 h (95% CI 38.3, 331.4) versus 134.6 h (33.2, 444.9) in patients managed non-adherently. Median time to hospital discharge was 16.5 days (95% CI 8.0, 27.0) in patients managed adherently versus 9.5 days (7.0, 22.0) in patients managed non-adherently.

CONCLUSION

In Spanish centers, the SEOM algorithm was adhered to in less than one-third of patients, in contrast to higher levels of perceived adherence. This requires further investigation; however, algorithm use could require further clarification, especially in non-candidates for chemotherapy.

Distribution of plasma copeptin levels and influence of obesity in children and adolescents

In recent years, a more stable AVP surrogate, called copeptin, has been used as an adjuvant diagnostic tool for dysnatremia in adults and appears to be promising even in the pediatric age. The aim of this study is to present the distribution of plasma copeptin in a large pediatric cohort and to observe the influence of fluid consumption and obesity on its values. A cohort of 128 children and adolescents was divided into two groups on the basis of nocturnal deprivation (group A) or free access to oral fluids in the 6-8 h before blood collection (group B). At all distribution percentiles, copeptin levels were higher (p < 0.0001) in group A, as were plasma sodium levels and osmolality (p = 0.02 and p = 0.008, respectively). The influence of BMI on copeptin levels was investigated by dividing the cohort into nonobese (group C) and obese children and adolescents (group D). Copeptin levels were higher in group D (p = 0.04).Conclusion: The measurement of copeptin could represent a useful tool for the diagnostic pathway of dysnatremic conditions, but its interpretation should take into consideration the state of hydration. Furthermore, it could also be a promising marker for obesity and metabolic syndrome, although this hypothesis needs further studies to be confirmed. What is Known: • Copeptin use as a diagnostic tool in AVP-related disorders, such as diabetes insipidus or syndrome of inappropriate secretion of antidiuretic hormone, is well established in adults • In pediatric age, few studies are available, but the preliminary data, including our previous study, seems to be promising. What is New: • In this study, we represent the distribution of copeptin levels in a pediatric cohort and show the significant influence of fluid ingestion on its plasma levels. • Also BMI seems to be a significant variable on copeptin levels and may be used as an obesity marker in pediatric age.

Distant Organ Damage in Acute Brain Injury

Acute brain injuries pose a great threat to global health, having significant impact on mortality and disability. Patients with acute brain injury may develop distant organ failure, even if no systemic diseases or infection is present. The severity of non-neurologic organs' dysfunction depends on the extremity of the insult to the brain. In this comprehensive review we sought to describe the organ-related consequences of acute brain injuries. The clinician should always be aware of the interplay between central nervous system and non-neurological organs, that is constantly present. Cerebral injury is not only a brain disease, but also affects the body as whole, and thus requires holistic therapeutical approach.

COVID-19 presented with syndrome of inappropriate ADH secretion(SIADH): A case report from Bangladesh

Backgound

Novel corona virus(SARS-CoV-2) which emerged from Wuhan, China, has spread to whole worlds very rapidly causing enormous health effect and death. Current publications worldwide showed that COVID-19 is a disease involving multiple system of the body with many unusual presentations. So physicians face the challenges to manage it in the hospital.

Case report

The syndrome of inappropriate secretion of anti diuretic hormone (SIADH) is one of the most common causes of hyponatremia accounts for approximately one-third of all cases. In the diagnosis of SIADH it is important to ascertain the euvolemic state of extra cellular fluid volume, both clinically and laboratory measurement. Several infections associated with SIADH have been reported. Howover, Coronavirus disease 2019(COVID-19) associated with SIADH were only few cases reported. We are presenting a case of 70 year old female admitted with unconsciousness later diagnosed as severe hyponatremia along with COVID-19 complicated with severe pneumonia.

Advances in paediatrics in 2019: current practices and challenges in allergy, endocrinology, gastroenterology, public health, neonatology, nutrition, nephrology, neurology, respiratory diseases and rheumatic diseases

We highlight the main developments that have been published during the first semester of the last year in the Italian Journal of Pediatrics. We have carefully chosen information from numerous exciting progresses issued in the Journal in the field of allergy, endocrinology, gastroenterology, neonatology, nutrition, nephrology, neurology, public health, respiratory diseases and rheumatic diseases. The impact on the care of patients has been placed in the broader context of studies that appeared in other journals. We think that many observations can be used directly to upgrade management of patients.

A Randomized Trial of Empagliflozin to Increase Plasma Sodium Levels in Patients with the Syndrome of Inappropriate Antidiuresis

BACKGROUND

Treatment options to address the hyponatremia induced by the syndrome of inappropriate antidiuresis (SIAD) are inadequate. The sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin promotes osmotic diuresis via urinary glucose excretion and therefore, might offer a novel treatment option for SIAD.

METHODS

In this double-blind, randomized trial, we recruited 88 hospitalized patients with SIAD-induced hyponatremia <130 mmol/L at the University Hospital Basel from September 2016 until January 2019 and assigned patients to receive, in addition to standard fluid restriction of <1000 ml/24 h, a once-daily dose of oral empagliflozin or placebo for 4 days. The primary end point was the absolute change in plasma sodium concentration after 4 days of treatment. Secondary end points included predisposing factors for treatment response and safety of the intervention.

RESULTS

Of the 87 patients who completed the trial, 43 (49%) received treatment with empagliflozin, and 44 (51%) received placebo. Baseline plasma sodium concentrations were similar for the two groups (median 125.5 mmol/L for the empaflozin group and median 126 mmol/L for the placebo group). Patients treated with empagliflozin had a significantly higher increase of median plasma sodium concentration compared with those receiving placebo (10 versus 7 mmol/L, respectively; P=0.04). Profound hyponatremia (<125 mmol/L) and lower baseline osmolality levels increased the likelihood of response to treatment with empagliflozin. Treatment was well tolerated, and no events of hypoglycemia or hypotension occurred among those receiving empagliflozin.

CONCLUSIONS

Among hospitalized patients with SIAD treated with fluid restriction, those who received empagliflozin had a larger increase in plasma sodium levels compared with those who received placebo. This finding indicates that empagliflozin warrants further study as a treatment for the disorder.

Calcium sensing receptor exerts a negative regulatory action toward vasopressin-induced aquaporin-2 expression and trafficking in renal collecting duct

Vasopressin (AVP) plays a major role in the regulation of water homeostasis by its antidiuretic action on the kidney, mediated by V2 receptors. An increase in plasma sodium concentration stimulates AVP release, which in turn promotes water reabsorption. Upon binding to the V2 receptors in the renal collecting duct, AVP induces the expression and apical membrane insertion of the aquaporin-2 (AQP2) water channels and subsequent water reabsorption. AVP regulates two independent mechanisms: the short-term regulation of AQP2 trafficking and long-term regulation of the total abundance of the AQP2 protein in the cells. On the other hand, several hormones, acting through specific receptors, have been reported to antagonize AVP-mediated water transport in kidney. In this respect, we previously described that high luminal Ca²⁺ in the renal collecting duct attenuates short-term AVP-induced AQP2 trafficking through activation of the Ca²⁺-sensing receptor (CaSR). This effect is due to reduction of AVP-dependent cAMP generation and possibly hydrolysis. Moreover, CaSR signaling reduces AQP2 abundance both via AQP2-targeting miRNA-137 and the proteasomal degradation pathway. This chapter summarizes recent data elucidating the molecular mechanisms underlying the physiological role of the CaSR-dependent regulation of AQP2 expression and trafficking.

Clinical Approach to Sodium Homeostasis Disorders in Children with Pituitary-Suprasellar Tumors

Children with pituitary-suprasellar tumors are at high risk of developing sodium metabolism disorders since the tumoral mass itself or surgical and medical treatment can damage AVP release circuits. Additional risk factors are represented by the use of hypotonic fluids, the young age, total parenteral nutrition, and obstructive hydrocephalus secondary to tumor pathology. The most frequent hyponatremic disorders related to AVP in these patients are the syndrome of inappropriate ADH secretion and the cerebral/renal salt wasting syndrome, while hypernatremic conditions include central diabetes insipidus (CDI) and adipsic CDI. The main challenge in the management of these patients is to promptly distinguish the AVP release disorder at the base of the sodium imbalance and treat it correctly by avoiding rapid sodium fluctuations. These disorders can coexist or follow each other in a few hours or days; therefore, careful clinical and biochemical monitoring is necessary, especially during surgery, the use of chemotherapeutic agents, or radiotherapy. This monitoring should be performed by experienced healthcare professionals and should be multidisciplinary, including pediatric endocrinologists, neurosurgeons, and oncologists since maintaining sodium homeostasis also plays a prognostic role in terms of disease survival, therapeutic response, hospitalization rate, and mortality. In this review, we analyze the management of sodium homeostasis disorders in children with pituitary-suprasellar tumors and discuss the main challenges in the diagnosis and treatment of these conditions based on literature data and over 30 years of clinical experience at our Department of Pediatric Endocrinology.