Syndrome Of Inappropriate Antidiuretic Hormone Research Articles

THU111 Diffuse Large B-Cell Lymphoma Pituitary Metastasis

Abstract Disclosure: M.S. Martinez Cruz: None. C.J. Haas: None. S.Z. Bhat: None. Background: The Hypothalamus-Pituitary axis (HPA) is a rare location for metastasis of non-Hodgkin’s lymphoma. Case description: A 57-year-old woman presented to the emergency department with a one day of acute, severe fatigue, nausea, and anorexia. She reported a history of stage IIIB diffuse large B-cell non-Hodgkin's lymphoma (DLBCL) treated with R-CHOP three months prior, complicated by a recent recurrence in the lumbar spine requiring a short dexamethasone taper and radiation therapy two weeks prior to admission. On presentation, she remained hemodynamically stable with an otherwise unremarkable exam. Diagnostics revealed severe hypotonic hyponatremia suggestive of syndrome of inappropriate antidiuretic hormone (SIADH). CT scan of the head revealed thickening of the paramedian hypothalamic structures and the pituitary infundibulum. Subsequent pituitary MRI w/wo contrast demonstrated marked thickening and enhancement of the infundibulum with restricted diffusion, as well as T2/FLAIR hyperintensity and thickening in multiple hypothalamic areas concerning for HPA metastasis. Hormonal workup demonstrated panhypopituitarism for which she was started on hydrocortisone and levothyroxine. Lumbar puncture was performed with CSF flow cytometry revealing phenotypically abnormal monoclonal B-cells consistent with DLBCL leptomeningeal metastasis. Three days prior to induction chemotherapy, she developed massive polyuria, with a rapid increase in the serum sodium and markedly low urine-specific gravity consistent with acute diabetes insipidus (DI). Management included vasopressin, as needed, followed by standing doses of desmopressin. She was initiated on methotrexate and leucovorin chemotherapy. However, three week later, she developed acute onset diplopia, headache, nausea and vomiting, urinary and bowel incontinence, and fatigue. Follow-up pituitary MRI revealed progression of her known HPA metastatic disease, and she passed away one month later. Conclusion: This is an unprecedented case of metastatic DLBCL to the leptomeninges, hypothalamus, and pituitary infundibulum confirmed by CSF cytologic analysis that presented in the context of associated panhypopituitarism that manifested initially as SIADH followed by sudden DI. Abbreviations: R-CHOP: Rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone Presentation: Thursday, June 15, 2023

OR2805 Plasma Sodium Increase Is Associated With An Increase In Bone Formation In Outpatients With Chronic SIAD—A Predefined Secondary Analysis Of The SANDx Trial

Abstract Disclosure: S. Monnerat: None. J. Refardt: None. C. Meier: None. M. Christ-Crain: None. INTRODUCTION Hyponatremia is the most common electrolyte disorder encountered in clinical practice and is associated with increased mortality and morbidity, including an increased risk for osteoporosis and fragility fractures. Preclinical studies suggest that hyponatremia upregulates osteoclasts. In a previous analysis of 88 hospitalized patients with a syndrome of inappropriate antidiuresis (SIAD), we observed that hyponatremia normalization after 4 days had a positive impact on osteoblast function. METHODS This is a secondary analysis of a double-blind, crossover, placebo-controlled trial investigating the effect of 4-week treatment with empagliflozin 25mg/day as compared to placebo in 14 outpatients with chronic SIAD (NCT03202667). Two patients with an antiresorptive osteoporosis treatment and 1 patient with recent hip arthroplasty were excluded (n=11). The primary objective was to investigate the relationship between the change in bone formation index (BFI), defined as PINP/CTX, and the change in plasma sodium levels. Secondary objectives included the relationship between the change in the osteoblasts markers procollagen type 1 N (P1NP) and osteocalcin and the osteoclasts markers C-telopeptide crosslink (CTX), and the change in plasma sodium levels over the treatment period. Linear mixed models and Spearman correlation were computed. RESULTS Six out of the 11 outpatients with a chronic SIAD were female (median [IQR] age 73 years [66, 78]). At baseline, median [IQR] CTX concentration was 0.47 ug/L [0.29, 0.65], median [IQR] osteocalcin was 18.00 ug/L [13.95, 25.87] and median [IQR] P1NP was 64.64 ug/L [45.62, 68.45]. The calculated median BFI [IQR] was 131.86 [96.21, 168.73]. A sodium increase of 1 mmol/L was associated with an increase of 5.21 in BFI (95%-CI: 1.41, 9.00, p = 0.013) and with an increase of 1.48 ug/L in P1NP (95%-CI: 0.26, 2.62, p = 0.03). Plasma sodium concentration was not associated with a change in osteocalcin (β = 0.32; 95%-CI: -0.09, 0.72, p = 0.18), nor with a change in CTX (β = 0.003; 95%-CI: -0.008, 0.014, p = 0.324). Empagliflozin was not a significant predictor for the change of any bone markers and there was no interaction between treatment allocation and sodium. Changes in plasma sodium were positively correlated with changes in BFI and P1NP (BFI: ρ = 0.55, p < 0.001; P1NP: ρ = 0.45, p = 0.004) but not with CTX and osteocalcin (CTX: ρ = -0.21, p = 0.184; Osteocalcin: ρ = 0.34, p = 0.149). CONCLUSION An increase in plasma sodium levels in outpatients with chronic SIAD was associated with an increase in bone formation index (P1NP/CTX), which seemed to be triggered by an increase in P1NP, a surrogate marker of osteoblast function. This supports the importance of treating hyponatremia, particularly in older adults in whom chronic hyponatremia is also associated with falls. Presentation: Sunday, June 18, 2023

FRI321 Aggressive Prolactinoma Empirically Treated With Cabergoline Leading To Rapid CSF Leak

Abstract Disclosure: A. Yau: None. T. Reisman: None. Over two-thirds of pituitary tumors are prolactinomas. These are discovered as a result of symptoms of hypogonadism, menstrual irregularities, infertility or galactorrhea, as well as symptoms of mass effects including visual field deficit or acute severe headaches.1 A more rare subgroup, aggressive prolactinomas, in which the tumors are radiographically invasive and show resistance to dopamine agonist treatment as well as surgery, account for 10% of all hypophyseal neoplasia. 2 During medical treatment of prolactinomas, there is a known rare complication of CSF rhinorrhea; recorded time of onset of leak following treatment ranges from 14 days to 5 years.3 We present a case in which a patient with an aggressive prolactinoma rapidly developed a CSF leak within 48 hours of starting cabergoline treatment. Case: A 36-year-old male with type 2 diabetes, erectile dysfunction and infertility presents to Endocrine clinic after initial evaluation by Urology revealed elevated prolactin. He reported headaches, gynecomastia associated with liquid discharge from nipples, and minor issues with peripheral vision. He was started empirically on cabergoline for probable prolactinoma and within 48 hours developed worsening frontal headache, cough and clear fluid leakage from his right nostril. Labs revealed prolactin over 2600 ng/ml. MRI pituitary showed evidence of pituitary adenoma as well as likely CSF leak. Cabergoline was stopped and the patient was sent to the emergency room. The patient was underwent urgent neurosurgical transsphenoidal endoscopic surgery and CSF leak repair with resolution of rhinorrhea and cough. Post-operative MRI was consistent with minimal residual tumor. He was monitored in the NICU with no obvious post-operative pituitary hormone imbalance, diabetes insipidus, adrenal insufficiency or syndrome of inappropriate ADH. Months after discharge, the patient’s prolactin remained elevated to the 600’s ng/ml and repeat MRI showed a mass occupying the entire sella and suprasellar cistern, compressing the optic chiasm. Conclusion: In this case of a patient with the subtype of aggressive prolactinoma, there seems to be a more rapid presentation of complications. When treating these rare subtypes, physicians need to stay vigilant of developing complications or even consider nonstandard therapies as first-line management. 1. Molitch ME, Drummond J, Korbonits M. Prolactinoma Management. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext. South Dartmouth (MA): MDText.com, Inc.; January 6, 2022.2. Lasolle H, Ilie MD, Raverot G. Aggressive prolactinomas: how to manage?. Pituitary. 2020;23(1):70-77. doi:10.1007/s11102-019-01000-73. Arimappamagan A, Sadashiva N, Kandregula S, Shukla D, Somanna S. CSF Rhinorrhea Following Medical Treatment for Prolactinoma: Management and Challenges. J Neurol Surg B Skull Base. 2019;80(6):620-625. doi:10.1055/s-0039-1677686 Presentation: Friday, June 16, 2023

THU112 Effect Of Protein Supplementation On Plasma Sodium Levels And Urinary Urea Excretion In Patients With Chronic Siad—A Monocentric Open-Label Proof-Of-Concept Study—The Treasure Study

Abstract Disclosure: S. Monnerat: None. C. Atila: None. F.E. Baur: None. M. Dickenmann: None. M. Christ-Crain: None. INTRODUCTION The syndrome of inappropriate antidiuresis (SIAD) is the most common cause of euvolemic hyponatremia. Besides fluid restriction, increasing free-water clearance is an effective treatment approach that can be achieved through osmotic diuresis by administering oral urea. However, oral urea has a very peculiar taste that impedes long-term compliance. Dietary proteins are metabolized into soluble excretable urea by the liver. We hypothesized that dietary protein could increase free water clearance through urea-induced osmotic diuresis and therefore aimed to investigate the effect of high-protein supplementation on plasma sodium levels in outpatients with chronic SIAD. METHODS This is an interim analysis of a monocentric open-label proof-of-concept trial conducted at the University Hospital of Basel since October 2021. Adult outpatients with chronic SIAD of any etiology were eligible. Patients received 90g protein daily for 7 days in the form of protein powder dissolved in a maximum of 1L of liquid of choice. After a wash-out period of at least a week, patients received 30g of oral urea daily for 7 days. Patients were asked to keep their baseline fluid intake unchanged throughout the study. The primary endpoint was the increase in sodium levels from baseline to the end of the 7-day protein supplementation. RESULTS Thirteen patients, 10 females and 3 males, with chronic SIAD were included. Median [IQR] age was 63 [61, 80] and the median [IQR] duration of hyponatremia was 33 months [12, 42]. At baseline, median [IQR] plasma sodium concentration was 130 mmol/L [129, 133]. Eight patients had mild hyponatremia (130-134 mmol/L), 4 had moderate hyponatremia (125-129 mmol/L), and 1 patient had profound hyponatremia (<125 mmol/L). After 7 days of 90g daily protein supplementation (n = 13), sodium levels increased by a median [IQR] of 3 mmol/L [0, 5], blood urea nitrogen increased by a median [IQR] of 4.3 mmol/L [1.7, 5.1] and urinary urea corrected for urine creatinine increased by a median [IQR] of 26.0 mmol/mmol [17.1, 32.3]. After 7 days of oral urea (n = 8), sodium levels increased by a median [IQR] of 2 mmol/L [1, 3], blood urea nitrogen increased by a median [IQR] of 8.5 mmol/L [3.8, 10.2] and urinary urea corrected for urine creatinine increased by a median [IQR] of 31 mmol/mmol [21.1, 39.8]. CONCLUSION This interim analysis suggests that high-protein supplementation with protein powder increases plasma sodium levels in patients with chronic SIAD. The increase in urea concentration in both plasma and urine upon protein supplementation is comparable to the increase upon oral urea administration, which supports protein-induced ureagenesis to be the underlying mechanism of action. Presentation: Thursday, June 15, 2023

SAT619 Post-operative Fluid Restriction Prevents Hyponatremia And Readmissions After Pituitary Surgery

Abstract Disclosure: J.J. Chang: None. D. Veruttipong: None. O. Chu: None. W. Erin: None. V. Gates-Bazarbay: None. S. Kling: None. K. Vinluan: None. S. Chittum: None. M. Alhadha: None. J. Fernandez-Miranda: None. Background: Delayed hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion is the most common cause of readmission after pituitary transsphenoidal surgery (TSS). Post-operative fluid restriction (FR) after discharge may effectively reduce hyponatremia and related readmissions. Methods: Our aim was to assess the effectiveness of FR after TTS. We compared post-operative day (POD) 8 hyponatremia and related readmission rates pre- and post- FR protocol implementation at our institution. Pre-FR (July 1, 2018-March 15, 2020) post-TSS patients were instructed to drink ad lib or to thirst on discharge. Post-FR (March 16, 2020-December 31, 2020), post-TSS patients were routinely provided education and documentation on the outpatient protocol that recommended 1 liter/day FR from POD 3-5 to POD 8-10. Serum sodium was assessed at POD-8 for all patients. Patients hospitalized for more than 5 days after surgery, had untreated adrenal insufficiency, or had pre-existing AVP deficiency were excluded. Results: The average POD-8 sodium level was lower in the 115 patients in the pre-FR cohort than the 216 patients in the post-FR cohort (135.8±6.7 vs. 138.1±4.4 mEq/L; Wilcoxon-Mann-Whitney test p=0.0081). POD-8 hyponatremia (Na ≤134 mEq/L) occurred in a lower proportion of patients post-FR (15.0%; 32/214) than pre-FR (28.9%; 30/104) (Chi-Square test p=0.0033). Similarly, severe hyponatremia (Na ≤124 mEq/L) occurred in a lower proportion of patients post-FR (1.4%; 3/214) than pre-FR (8.7%; 9/104) (Fisher test p= 0.01). Only 1.4% (3/216) of patients were readmitted post-FR compared to the 8.7% (10/115) pre-FR (Fisher test p=0.0020). Conclusions: Our retrospective evaluation showed that implementation of post-TSS FR protocol significantly decreased hyponatremia by nearly 50% and readmissions by over 80% compared to the prior standard of care of drink ad lib or to thirst. FR should be considered standard-of-care for eligible patients without ongoing AVP deficiency to reduce hyponatremia and readmission burden to both patient and healthcare system. Presentation: Saturday, June 17, 2023

FRI357 A Rare Case Of Paraneoplastic Syndrome Of Inappropriate Secretion Of Antidiuretic Hormone In Oropharyngeal Squamous Cell Carcinoma

Abstract Disclosure: N. Torres: None. H. Rios: None. G. Rios: None. Y. Medina: None. L. Valerio: None. S. Rosa: None. A. Ortiz: None. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by hyponatremia that results from water retention attributable to persistent arginine vasopressin release. SIADH is considered the most common cause of euvolemic hyponatremia. Head and neck cancers are linked with 1.5% of SIADH cases. Cases reported in the literature about this association with oropharyngeal squamous cell carcinoma (SCC) were few, and no incidence data is currently available. We present a rare case of a patient with SIADH secondary to well-differentiated oropharyngeal squamous cell carcinoma. A case of 63 y/o male with Oropharyngeal SCC, previous gastrostomy, and tracheostomy due to malignancy. The patient initially presented with general malaise and weakness. Maxillofacial and neck CT scans were remarkable for a mass at the left lateral floor of the mouth, measuring approximately 5.7 cm AP x 2.5 cm transverse x 3.7 cm CC. Physical examination was remarkable for cachexia, but normal skin turgor and moist oral mucosa. An incidental finding of severe hyponatremia of 114 mEq was found. Confirmation of hypotonic euvolemic hyponatremia was performed with a urine osmolality of >100 mOsm per kg and high urine sodium (>40 mEq). These findings presented a strong case for our differential diagnosis of SIADH. Other differential diagnoses were hypothyroidism or adrenal insufficiency. The patient’s thyroid stimulating hormone was within normal levels, and adrenal insufficiency workup was negative, making paraneoplastic SIADH the more likely diagnosis due to SCC. Initial treatment was started with a 3% hypertonic solution drip running at 15 ml/hr. The chemistry panel was monitored every six hours to achieve a 6 mEq change, at a slow rate to avoid osmotic demyelination syndrome, a goal of 122 mEq. Sodium was corrected in 24 hours; 3% saline solution drip was discontinued. Once this level was reached, we continued the fluid restriction (<1L daily), and salt packets with meals. After consultation, Nephrology and Endocrinology services agreed with our diagnosis of hypotonic euvolemic hyponatremia due to ectopic production of paraneoplastic SIADH due to the oropharyngeal SCC. The patient’s hypotonic euvolemic hyponatremia was corrected, symptoms improved, and he was discharged with close follow-up with Hematology/Oncology, Nephrology, and Endocrinology services. Paraneoplastic SIADH due to squamous cell carcinoma is rarely observed in the hospital setting. It is important to consider paraneoplastic SIADH from SCC in the differential diagnosis of hypotonic euvolemic hyponatremia since early diagnosis and treatment can decrease long-term complications. We could have also considered pharmacological therapy for SIADH including the use of demeclocycline, vaptans, and furosemide if the patient had not responded to our interventions. We followed guideline therapy with intravenous hypertonic saline at the start, then transitioned to only using oral salt tablets and fluid restrictions. The patient's hyponatremia steadily improved with our interventions and was able to be discharged with close outpatient follow-up. Presentation: Friday, June 16, 2023

FRI356 SIADH In Acromegaly And Cerebrovascular Accident

Abstract Disclosure: S. Siddiqui: None. I.A. Guatemala Funes: None. G. Simranpreet: None. T. Zahedi: None. F. Zhang: None. Introduction: Acromegaly is characterized by excess growth hormone secretion with distinctive features of acral overgrowth, soft tissue swelling, arthralgia, jaw prognostication, hyperglycemia, hyperhidrosis, and frontal bone bossing. Hypotonic hyponatremia may occur in patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH), hypothyroidism, hypocortisolism, polydipsia, medications, heart failure, liver disease, or renal dysfunction. We reported a rare case of a patient with acromegaly treated with octreotide (somatostatin analogue) who was admitted for cerebrovascular accident and developed hyponatremia due to SIADH. Case Report: Patient is an 81 year old female with typical clinical features of acromegaly who presented with expressive aphasia and left sided facial droop. MRI and CT head revealed a 26 x 14 x 29 mm densely calcified/ossified extra-axial mass in the posterior fossa, displacing the brainstem and small vessel ischemia. Patient was treated with monthly intramuscular injection of octreotide for more than 20 years before she was switched to oral octreotide formula two weeks ago. Patient had nausea, vomiting, and altered mental status. Labs showed hyponatremia with serum Na 118 mmol/L, low serum osmolality 247 mOsm/kg, high urine osmolality 437 mOsm/kg, and urine Na 104 mmol/L. Serum Na further dropped to 115 mmol/L after IV normal saline which may be related to the desalination phenomenon of SIADH. Tolvaptan and hypertonic saline were initiated followed by treatment with salt tablets and furosemide. After several days, her serum Na level slowly trending up back to normal 135 mmol/L and patient recovered with no focal neurological deficits. Discussion: Treatment for acromegaly involves multiple approaches, such as somatostatin receptor ligands, GH antagonism, surgery, radiotherapy, and dopamine receptor agonists. Life-treating endocrine disorder may result from pituitary infarction or hemorrhage in patient with acromegaly. Although gastrointestinal sodium loss may precipitate hyponatremia in our patient, her elevated urine sodium and urine osmolality were consistent with SIADH. Clinicians should be cautious of the sudden onset of hyponatremia due to SIADH in acromegaly patients and prompt treatment is warranted. Presentation: Friday, June 16, 2023

THU239 Tolvaptan For SIADH Management In Children

Abstract Disclosure: M. Igarashi: None. T. Kashima: None. H. Doi: None. K. Yoshii: None. Y. Naiki: None. R. Horikawa: None. [Background] Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is common after brain surgery and its’ management is difficult. In Japan, tolvaptan was approved for SIADH management in adults, but there are limited reports on the use of tolvaptan for SIADH in children.We presented two cases which showed triphasic response after neurosurgery and was treated with tolvaptan for SIADH phase. We will also summarize other cases which were treated with tolvaptan for SIADH phase after neurosurgery in discussion. [Case] Case1 is a 5-month-old boy with choroid plexus papilloma.A tumor resection was performed after chemotherapy. After tumor resection, serum sodium level went up to 171 mEq/L with diluted polyuria. So he was diagnosed as diabetes insipidus and treated with vasopressin. The dose of vasopressin was decreased and it was stopped on postoperative day (POD) 6, but serum sodium level further decreased and he was diagnosed as SIADH. Water restriction and hypertonic saline administration were performed. Tolvaptan at a dose of 0.1mg/kg was administered and sodium level improved from 123 mEq/L to 137 mEq/L.However, urine volume was decreased again and sodium level went down to 132 mEq/L, so tolvaptan was administered again. After second administration of tolvaptan, polyuria lasted and sodium level went up to 145 mEq/L, which was managed with temporary use of vasopressin. Case 2 is a 6-year-old girl with craniopharyngioma. After tumor resection, polyuria was observed and she was diagnosed as diabetes insipidus, which was treated with vasopressin.On POD 4, she was diagnosed as SIADH. Since water restriction was not effective, tolvaptan was administered twice (0.1mg/kg and 0.4mg/kg respectively). After second administration of tolvaptan, due to polyuria and diluted urine sodium level went up to 161 mEq/L, which was treated with vasopressin. Diluted urine and polyuria lasted, so finally she was diagnosed as diabetes insipidus. [Discussion] Tolvaptan was used for the management of SIADH that was resistant to water restriction or salt supplementation and it was useful for improving or maintaining sodium level. However, in some case, hypernatremia due to excessive free water excretion was caused after the dose of tolvaptan was increased. The appropriate dosage of tolvaptan has not yet been established. The risk of rapid sodium elevation should be considered and monitoring of water balance and sodium level was needed after using tolvaptan. [Conclusion] Tolvaptan could be an effective option for the management of SIADH, but frequent monitoring of sodium level is needed. Presentation: Thursday, June 15, 2023

Copeptin analysis in endocrine disorders.

Copeptin is cleaved from the same precursor as arginine vasopressin and is released in equimolar amounts with arginine vasopressin from the posterior pituitary in response to the same stimuli. Its level of stability in the blood, quick and simple analysis, and ease of automation make it much easier to analyze than arginine vasopressin, thereby offering a suitable alternative to measuring arginine vasopressin in endocrine disorders. Research has demonstrated the suitability of copeptin in adults for the differentiation of arginine vasopressin resistance and arginine vasopressin deficiency from primary polydipsia, in addition to the early identification of arginine vasopressin deficiency following pituitary surgery; however, further research is still required in the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) and the pediatric population.

A Case Report of an Effective Treatment for Syndrome of Inappropriate Secretion of Antidiuretic Hormone with Integration of Western Medicine and Traditional Chinese Medicine

Background: Syndrome of Inappropriate secretion of Antidiuretic Hormone (SIADH) is a group of disorders in which free water excretion is impaired due to increased Arginine Vaso Pressin (AVP) secretion in the absence of renal or endocrine dysfunction, which in turn leads to hypotonic hyponatremia. In this case report, we describe the diagnostic process of a patient with SIADH and the treatment with integration of Western and Chinese medicine. Case Presentation: A 69-year-old man was admitted to our hospital for intermittent hand tremors. He was diagnosed with hyponatremia based on laboratory tests. However, after 2 weeks of sodium supplementation, his condition did not improve. Combined with Pituitary MRI, 24h urine sodium and other laboratory tests, he was diagnosed with SIADH. After taking oral tolvaptan and traditional Chinese medicine Rehmanniae Decoction of Six Ingredients granules, his symptoms were alleviated and the serum sodium normalized. Conclusion: SIADH could be as an etiology for hyponatremia that is difficult-to-correct, and traditional Chinese medicine may have some efficacy and advantages.

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

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

Isolated Third Cranial Nerve Palsy Associated with Sudden Worsening of Hypotonic Hyponatremia Secondary to Ischemic Pituitary Apoplexy

Pituitary apoplexy (PA) is a rare medical emergency. The sudden pressure increase in the sella turcica may determine compression on the surrounding structures determining the classical symptomatology associated, especially visual field impairment and/or ocular palsies and hypopituitarism; hypotonic hyponatremia may occur too, even if it is not common. Although already described in the literature, cases of isolated III cranial nerve palsies are extremely rare events. We report the case of a mid-60-year-old man with a known pituitary adenoma accessing the Emergency Department (ED) for worsening headaches unresponsive to analgesics, with a morphological picture consistent with ischemic PA, despite no dimensional increase of the pituitary lesion; upon ED access, a mild paucisymptomatic hyponatremia was also observed. Dexamethasone and mannitol were empirically introduced upon neurosurgical indication and tramadol and ketorolac were promptly administered as well, but without benefit. In the next days, a severe hypotonic hyponatremia was evidenced and a clear left III cranial nerve palsy developed, but no clear signs of cerebral bleeding or ischemia, nor a significant compression on the homolateral cavernous sinus, were observed. Upon ruling out other possible causes, a likely diagnosis of syndrome of inappropriate antidiuresis (SIAD) was made, confirmed by the quick response to fluid restriction. Overall, the sudden fall in tonicity plasma levels seemed to contribute to the exacerbation of the neurological deficit since the normalization of sodium levels was associated with a rapid and complete reversion of the III cranial nerve palsy.

P04.03.B VENOUS THROMBOEMBOLISM AND OTHER VASCULAR COMPLICATIONS IN PAEDIATRIC PATIENTS FOLLOWING CRANIOPHARYNGIOMA SURGERY: A SINGLE-CENTER, RETROSPECTIVE STUDY

Abstract BACKGROUND Craniopharyngioma (CP), although slow growing and histologically benign, carries considerable morbidity, particularly in the postoperative period: hypothalamus-pituitary dysfunction and electrolyte disorders represent common complications. Moreover, in these patients, the increased risk of deep venous thrombosis (DVT) and the possible development of fusiform intracranial aneurysms are well known. However, data are still poor, especially in the pediatric population. The aim of our study was to describe the occurrence and timing of DVT and other vascular alterations in neurosurgical operated CP patients and to evaluate the role of predisposing factors in the development of post-surgical and late vascular events. MATERIAL AND METHODS This was a single-center, retrospective study. We investigated 19 patients (11 males, 8 females, mean age 10.47±4.29) diagnosed with CP, who had been subjected to neurosurgery between December 2016 and August 2022 in Meyer Children’s Hospital IRCCS in Florence. Demographic and clinical characteristics and surgical data were recorded for each participant. RESULTS Five patients (26.3%, 3 females, 2 males, median age 15 years) presented vascular events, all during sodium imbalance. Calcium at lower limits was detected in four of them. Three DVT (two with associated pulmonary embolism, including one female patient’s death) developed after surgery, more frequently at 7-10 days (two patients were central catheter carriers, one obese patient showed hypercholesterolemia and hypertriglyceridemia). In a patient in hyponatraemic state a vascular parietal alteration compatible with pseudoaneurysm was described soon after neurosurgery, requiring vascular stenting and prolonged intensive care. Superficial vein thrombophlebitis was a late complication in an overweight female patient on estrogenic replacement therapy. CONCLUSION Patients with CP undergoing neurosurgical brain tumor resection are at a higher risk of developing DVT and vascular alterations, thus careful follow-up should be done in these patients. In our study, we found that the phase of transition from central diabetes insipidus (CDI) to syndrome of inappropriate antidiuretic hormone secretion (SIADH) is probably a significative time for developing this complication; so, we recommend careful monitoring of symptoms suggestive of vascular events in CP operated patients. However, we suggest the execution of a deep vein ultrasound examination in the post-neurosurgical two-four weeks for an early diagnosis of this problem for reducing the risk of severe complications.

Triphasic response after endoscopic craniopharyngioma resection and its dependency on infundibular preservation or sacrifice.

Surgery is the primary treatment for craniopharyngioma with the preservation of hypothalamic function of paramount importance. Infundibular preservation is debated, as maximal resection decreases recurrence rates but causes hypopituitarism. A triphasic response of diabetes insipidus (DI), syndrome of inappropriate antidiuretic hormone secretion (SIADH), and recurrent DI has been described after pituitary surgery, but the impact of infundibular preservation on the triphasic response following craniopharyngioma resection has not been well established. The authors' objective was to assess postoperative fluid and sodium balance and differences in ADH imbalance management following endonasal craniopharyngioma resection based on infundibular transection status. This is a retrospective cohort study of 19 patients with craniopharyngioma treated with endoscopic endonasal resection between 2014 and 2021. Resection was dichotomized into infundibular transection or preservation. Postoperative triphasic response, time to DI, and time to ADH replacement were compared using Fisher's exact test and Kaplan-Meier analysis. Based on surgeon impression, 10 patients had infundibular transection and 9 had infundibular preservation. Overall, 16 patients experienced DI, 12 experienced persistent DI, and 6 experienced SIADH. A postoperative triphasic response occurred in 40% (n = 4) of transection patients without preoperative DI and 11% (n = 1) of preservation patients without preoperative DI. The median time to postoperative DI (0.5 vs 18.0 hours, p = 0.022) and median time to ADH replacement therapy (4.5 vs 24 hours, p = 0.0004) were significantly shorter in the transection group than in the preservation group. Following endonasal craniopharyngioma resection, the triphasic response occurs in nearly half of infundibular transection cases. DI begins earlier with infundibular transection. On the basis of the study findings in which no patients met the criteria for SIADH or were endocrinologically unstable after postoperative day 6, it is reasonable to suggest that otherwise stable patients can be discharged at or before postoperative day 6 when ADH fluctuations have normalized and endocrinopathy is appropriately managed with oral desmopressin. Infundibular transection status may impact postoperative hormonal replacement strategies, but additional studies should evaluate their efficacies.

Syndrome of Inappropriate Secretion of Antidiuretic Hormone Associated with H1N1 Infection

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is related to several conditions. However, there are few reports associated with H1N1 virus infection. We describe a 36 year old patient with SIADH admitted to our department if internal medicine with fever, cough and myalgias. The labooratory analysis showed serum hypo-osmolar hyponatremia and high level of urinary sodium concentration. All other biological analysis were within normal range. Moreover, All bacterial and fungal cultures, blood and urine cultures were all negative for any microbial pathogen. The thoraco-abdominal CT scan was normal. Rapid flu test was positive for influenza type A 15 days after. The patient recovered with intravenous infusion of hypertonic saline and fluid restriction and he did not received any anti-viral drug. Despite a strong relationship betwwen H1N1 virus infection and SIADH needs to be established, physicians should be aware of this potential seroius effect and should monitor the serum sodium closely.
 Keywords : H1N1 infection, inappropriate secretion of antidiuretic hormone, hyponatremia

Safety and Efficacy of Vaptans in the Treatment of Hyponatremia from Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH): A Systematic Review and Meta-Analysis.

The utilization of vasopressin receptor antagonists, known as vaptans, in the management of hyponatremia among patients afflicted with the syndrome of inappropriate antidiuretic hormone (SIADH) remains a contentious subject. This meta-analysis aimed to evaluate the safety and efficacy of vaptans for treating chronic hyponatremia in adult SIADH patients. Clinical trials and observational studies were identified by a systematic search using MEDLINE, EMBASE, and Cochrane Database from inception through September 2022. The inclusion criteria were the studies that reported vaptans' safety or efficacy outcomes compared to placebo or standard therapies. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD 42022357307). Five studies were identified, comprising three RCTs and two cohort studies, enrolling a total of 1840 participants. Regarding short-term efficacy on days 4-5, vaptans exhibited a significant increase in serum sodium concentration from the baseline in comparison to the control group, with a weighted mean difference of 4.77 mmol/L (95% CI, 3.57, 5.96; I2 = 34%). In terms of safety outcomes, the pooled incidence rates of overcorrection were 13.1% (95% CI 4.3, 33.6; I2 = 92%) in the vaptans group and 3.3% (95% CI 1.6, 6.6; I2 = 27%) in the control group. Despite the higher correction rate linked to vaptans, with an OR of 5.72 (95% CI 3.38, 9.70; I2 = 0%), no cases of osmotic demyelination syndrome were observed. Our meta-analysis comprehensively summarizes the efficacy and effect size of vaptans in managing SIADH. While vaptans effectively raise the serum sodium concentration compared to placebo/fluid restriction, clinicians should exercise caution regarding the potential for overcorrection.

Prolonged hyponatremia due to syndrome of inappropriate secretion of antidiuretic hormone in a preterm infant

Hyponatremia, defined as a serum sodium concentration < 135 mmol/L, is associated with significant morbidity and mortality Hyponatremia occurs in one third of preterm infants in the first week of life. The patient was a preterm infant born to a G2P0A1 mother at 25 weeks of gestation

A Conspectus of Euvolemic Hyponatremia, Its Various Etiologies, and Treatment Modalities: A Comprehensive Review of the Literature.

Hyponatremia is the most prevalent electrolyte imbalance encountered among hospitalized patients, athletes, the elderly, patients with chronic ailments, postoperative patients, and a few asymptomatic individuals. Clinical manifestations of hyponatremia can be diverse, with characteristic neurological symptoms. Depending on in-depth medical history, physical examination (including volume status assessment), laboratory investigation, and drug history, patients can be classified broadly as undergoing hypervolemic, euvolemic, or hypovolemic hyponatremia. However, patients with hypervolemic hyponatremia often present with distinctive signs such as edema or ascites, and the clinical presentation of hypovolemic and euvolemic hyponatremia poses significant challenges for clinicians. The convolution in clinical manifestations of patients is due to the varied etiologies of euvolemic hyponatremia, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH), adrenocortical insufficiency, hypothyroidism, psychogenic polydipsia, different classes of drugs (chemotherapeutics, antipsychotics, antidepressants), endurance exercise events, and reset osmostat syndrome (ROS). The management of hyponatremia depends on the rate of hyponatremia onset, duration, severity of symptoms, levels of serum sodium, and underlying comorbidities. Over the last decade, the clinical understanding of hyponatremia has been scattered due to the introduction of innovative laboratory markers and new drugs. This article will be a conspectus of all the recent advancements in the field of diagnosis, investigations, management, and associations of hyponatremia, along with traditional clinical practices. Subsequently, a holistic overview has been laid out for the clinicians to better understand and identify knowledge deficiencies on this topic.

Prevalence of Electrolyte Imbalance in Patients With Acute Stroke: A Systematic Review.

Electrolyte abnormalities are common in acute stroke patients and have a substantial impact on the course and prognosis of the disease. Electrolyte imbalances such as hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia, and phosphate abnormalities are frequently seen in this patient population. The incidence, root causes, and medical ramifications of electrolyte abnormalities in acute stroke patients are investigated in this comprehensive study. According to our research, hyponatremia is the most prevalent electrolyte imbalance. The most common reason for hyponatremia in stroke patients is the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Higher mortality rates, longer hospital admissions, and less favorable functional outcomes are all linked to hyponatremia. Acute stroke patients also typically experience hypokalemia, which affects the severity of the stroke and the recovery of functional abilities. The review furthermore emphasizes the incidence and clinical consequences of hypercalcemia, hypomagnesemia, hypophosphatemia, and hypocalcemia in patients with acute stroke. The results highlight the significance of early electrolyte imbalance detection and treatment in acute stroke patients. To better comprehend therapeutic approaches, evaluate their influence on stroke outcomes, and analyze prognostic implications, more research is required.

Hyponatremia and Outcome: Is Severity More Important Than Etiology?

Hyponatremia is the most commonelectrolyte abnormality encountered in a hospital setting, and the data regarding the contribution of hyponatremia to overall mortality are conflicting. The study objective was to determine patients' clinical profiles and outcomes with hyponatremia. This prospective cross-sectional study was conducted at Dayanand Medical College and Hospital, Ludhiana, and included 375 adult patients aged more than 18 years with a confirmed diagnosis of hyponatremia. Patients were subdivided into three groups based on the severity of hyponatremia: mild (130-135 mmol/L), moderate (125-129 mmol/L), and profound (<125 mmol/L). The most common symptom was confusion (57.3%) followed by deep somnolence (40%) and nausea (36.8%). The most common cause of hyponatremia was diuretics (30.7%), followed by the syndrome of inappropriate antidiuretic hormone secretion (SIADH) (17.8%) and chronic liver disease (CLD) (14.1%). The severity of hyponatremia did not significantly influence the outcome. Patients with CLD and chronic kidney disease (CKD) as the etiology of hyponatremia had significantly worse outcomes compared to other causes of hyponatremia. The most common type was hypovolemic hypotonic followed by euvolemic hypotonic and hypervolemia hypotonic hyponatremia. Nearly half of the total deaths were observed in the hypervolemic hyponatremia group and were significantly higher compared to the other two groups (p=0.001). Correction of hyponatremia (i.e., serum sodium >135 mmol/L) was significantly linked with good outcomes (p=0.003). Our study showed that the etiology of hyponatremia was a more important prognostic indicator rather than the severity of hyponatremia. Normalization of serum sodium was associated with improved survival.