Syndrome Of Antidiuretic Hormone Secretion Research Articles

Syncope and Brugada-like ECG pattern in a patient with syndrome of inappropriate antidiuretic hormone secretion (SIADH)

Syncope is a brief loss of consciousness caused by reduced blood flow to the brain, characterised by sudden onset, short duration and full recovery without intervention. Anamnesis, physical examination and other diagnostic tests such as laboratory analysis and electrocardiogram (ECG) can be conducted to identify the underlying cause of syncope. A Brugada pattern on an ECG in individuals with syndrome of inappropriate antidiuretic hormone secretion (SIADH) who have syncope symptoms may indicate cardiac issues. A 69-year-old man with hypertension and a history of smoking presented with syncope. His vital signs were within normal limits, with no signs of a neurological deficit. The patient met the diagnostic criteria for SIADH, as evidenced by the presence of hyponatraemia (Na 118 mmol/l), a hyperosmolar condition and euvolemia. Upon arrival, a twelve-lead ECG showed ST-segment anomalies that reflected a Brugada ECG pattern. No ventricular arrhythmias were detected during the 24-hour Holter monitoring. Coronary angiography revealed no abnormalities in the coronary arteries. The ECG demonstrated the normalisation of ST elevations and the disappearance of the Brugada ECG pattern after the correction of hyponatraemia. After three months of follow-up the patient, with a normal sodium level, had no episodes of syncope.

Case report: Secondary failure to tolvaptan in a patient with SCLC and paraneoplastic SIADH

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is frequent in lung cancer patients. Here, we report a case with persistent hyponatremia, which suggested malignant SIADH and facilitated an early diagnosis of small cell lung cancer (SCLC). A combined radio-chemotherapy led to a partial remission and resolution of SIADH. An early relapse was indicated by reoccurring severe hyponatremia and increased copeptin levels, which were used as surrogate markers for the antidiuretic hormone (ADH). As palliative immunochemotherapy, together with fluid restriction and solute substitution, were unable to control hyponatremia, treatment with the ADH V2-receptor antagonist tolvaptan was initiated. Over time, the dose of tolvaptan needed to be increased, paralleled by a well-documented exponential increase of copeptin levels. In summary and conclusion, this is a rare case of a secondary failure to tolvaptan with unique documentary evidence of increasing copeptin levels. This observation supports the hypothesis that exceedingly high ADH levels may lead to competitive displacement of tolvaptan from the V2 receptor.

Vascular complications in craniopharyngioma-resected paediatric patients: a single-center experience.

Craniopharyngioma (CP), although slow growing and histologically benign, has high morbidity, mostly related to hypothalamus-pituitary dysfunction and electrolyte imbalance. Increased risk of vascular complications has been described. However, data are still poor, especially in the paediatric population. The aim of our study was to evaluate the occurrence, timing, and predisposing factors of deep venous thrombosis (DVT) and other vascular alterations in neurosurgical paediatric CP patients. In a single-centre, retrospective study, we investigated 19 CP patients (11 males, 8 females, mean age 10.5 ± 4.3 years), who underwent neurosurgery between December 2016 and August 2022, referred to Meyer Children's Hospital IRCCS in Florence. Five patients (26.3%) presented vascular events, which all occurred in connection with sodium imbalances. Three DVT (two with associated pulmonary embolism, in one case leading to death) developed in the post-operative period, most frequently at 7-10 days. Elevated D-dimers, a reduced partial activated thrombin time and a prolonged C-reactive protein increase were highly related to thrombotic vascular events. One case of posterior cerebral artery pseudoaneurysm was described soon after neurosurgery, requiring vascular stenting. Superficial vein thrombophlebitis was a late complication in one patient with other predisposing factors. CP patients undergoing neurosurgery are at risk of developing DVT and vascular alterations, thus careful follow-up is mandatory. In our study, we found that the phase of transition from central diabetes insipidus to a syndrome of inappropriate antidiuretic hormone secretion may be a period of significant risk for DVT occurrence. Careful vascular follow-up is mandatory in CP-operated patients.

Risk Factors for Development of Diabetes Insipidus and Syndrome of Inappropriate Antidiuretic Hormone Secretion after Transsphenoidal Resection of Pituitary Adenoma

Abstract Background We aimed to determine the incidence and risk factors for development of diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone secretion (SIADH) after transsphenoidal hypophysectomy (TSH) for resection of a pituitary adenoma. Methods This was a retrospective study of 403 adult patients undergoing TSH for pituitary adenoma. Clinical variables, tumor characteristics, and operative factors were collected. Incidences of DI and SIADH were determined, including timing in the perioperative period. Independent predictors of developing DI and SIADH were identified using multivariable logistic regression. Results Following TSH, 21.3% of patients developed DI at a mean 2.6 days and 7.4% developed SIADH at a mean 4.7 days. DI was negatively associated with older age (odds ratio [OR] = 0.98, 95% confidence interval [CI]: 0.96–0.99, p = 0.029). DI was positively associated with female sex (OR = 2.26, 95% CI: 1.24–4.11, p = 0.008), increase in anteroposterior tumor size (OR = 1.54, 95% CI: 1.11–2.13, p = 0.010), intraoperative cerebrospinal fluid (CSF) leak (OR = 2.29, 95% CI: 1.25–4.19, p = 0.008), and every 100 mL of estimated blood loss (EBL) (OR = 1.18, 95% CI: 1.01–1.39, p = 0.046). Development of SIADH was positively associated with intraoperative CSF leak (OR = 3.56, 95% CI: 1.24–10.21, p = 0.018) on multivariate analysis. Conclusion DI and SIADH occur in the minority of patients undergoing TSH, but vigilance for their development must be maintained for days after the surgery. Development of DI after TSH is multifactorial, having possible patient-specific risk factors and risk related to the complexity of surgical dissection, reflected by tumor size, intraoperative CSF leak, and EBL. Development of SIADH could be associated with intraoperative CSF leak occurrence.

70 - Severe hyponatremia in an elderly patient due to syndrome of inappropriate antidiuretic hormone secretion: can chronic opioid pump be the culprit?

70 - Severe hyponatremia in an elderly patient due to syndrome of inappropriate antidiuretic hormone secretion: can chronic opioid pump be the culprit?

Right-sided Herpes Zoster Ophthalmicus Complicated by Bilateral Third, Fourth, and Sixth Cranial Nerve Palsies and Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Case Report.

Cases of herpes zoster ophthalmicus (HZO) complicated by bilateral ophthalmoplegia are rare, and no cases of bilateral third, fourth, or sixth cranial nerve palsies have been reported. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a rare complication of HZO. We herein report an 80-year-old Japanese woman with right-sided HZO complicated by meningoencephalitis and discuss the pathogenesis of this condition. She developed bilateral third, fourth, and sixth cranial nerve palsies and SIADH almost simultaneously during treatment for HZO. The bilateral cranial palsy spontaneously resolved within a few months.

Traumatic brain injury inducing swift transition from syndrome of inappropriate antidiuretic hormone secretion to central diabetes insipidus: a case report

Traumatic brain injury inducing swift transition from syndrome of inappropriate antidiuretic hormone secretion to central diabetes insipidus: a case report

Pramipexole induced syndrome of inappropriate antidiuretic hormone secretion in a patient with young onset Parkinson’s disease

Abstract Pramipexole, a dopaminergic agonist, has rarely been implicated as a cause of hyponatremia in patients with Parkinson’s disease (PD). Pramipexole-induced stimulation of anti-diuretic hormone results in euvolemic hyponatremia. This is often neglected, and hyponatremia may lead to worsening of the motor symptoms with PD and an unnecessary increase in dopaminergic medications, causing disabling dyskinesias. This case report describes a patient with young-onset PD who developed new-onset hyponatremia due to pramipexole-induced syndrome of inappropriate anti-diuretic hormone within 3 months of starting the drug.

Primary central nervous system lymphoma with initial presentation of cerebral salt-wasting syndrome shifting to syndrome of inappropriate antidiuretic hormone secretion: A case report

Background. Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma which may affect brain parenchyma. Hyponatremia can be present as one of the complications, either due to neuronal injury arising from in-situ tumor and/or surgical resection (resulting in cerebral salt wasting syndrome/CSWS) or indolent, slowly progressing and often asymptomatic one as a consequence of ongoing chronic illness (so-called syndrome of inappropriate antidiuretic hormone/SIADH). Differentiating between the two is critical, since each diagnosis has a starkly different treatment approach which may exacerbate one another. Case presentation. Herein, we reported a case of a 48-year-old immunocompetent male who presented with diplopia, hallucination, imbalance, and dizziness, later to be diagnosed with PCNSL on multiple brain regions. He suffered from symptomatic hyponatremia post-surgically as a result of CSWS which in turn responding well to intensive dose of desmopressin acetate and fluid replenishment. However, as the disease progressed, hyponatremia also relapsed but was refractory to the same treatment approach. After subsequent investigations, patient was known to have SIADH. Treatments tailored to SIADH including fluid restriction and administration of hypertonic saline as well as tolvaptan lead to stabilization of sodium levels and significant clinical improvements. Conclusion. Post-operative hyponatremia in the setting of a PCNSL continues to be a complex issue. It underscores the importance of careful clinical assessment, monitoring, and the need for flexibility in diagnosis and management strategies. Furthermore, it highlights the challenges of distinguishing between CSWS and SIADH, two conditions with similar laboratory findings but divergent management approaches. Recognizing the subtleties in clinical presentation and responding appropriately can greatly influence patient outcomes. The rising incidence of PCNSL in immunocompetent individuals also needs a heightened awareness and understanding of its presentations and potential post-operative complications among clinicians.

Acid base homeostasis and serum bicarbonate concentration in syndrome of inappropriate anti-diuretic hormone secretion (SIADH) with hyponatremia.

The Syndrome of Inappropriate ADH secretion (SIADH) presents with excess ADH release caused by a range of conditions; including pneumonia, brain tumors, certain lung cancers, and diseases of the hypothalamus. It presents with significant reduction in both sodium and chloride concentrations in the blood. However, reports examining the acid base status indicate a normal serum bicarbonate concentration and systemic acid base homeostasis. The mechanisms for the absence of abnormalities in acid base homeostasis remain speculative. This mini review is highlighting the recent advances in renal molecular physiology to provide answers for the maintenance of acid base status and serum bicarbonate in a physiological range.

Pituitary macroadenoma apoplexy as a rare complication of Bruton tyrosine kinase inhibitor in chronic lymphoid leukaemia

BackgroundPituitary apoplexy is a neurosurgical emergency and is a known yet rare complication of pituitary macroadenoma. Patients typically present with visual field defects, headache and altered sensorium. There are multiple risk factors for this complication and a thorough drug history is essential to exclude iatrogenic causes of disease. We present an extremely rare case of newly diagnosed pituitary insufficiency unveiled by ibrutinib therapy (a Bruton tyrosine kinase inhibitor). Furthermore, after initial withdrawal of ibrutinib because of the erroneous diagnosis of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH), its re-administration led to the development of classical pituitary apoplexy 4 months after treatment was restarted.Case presentationA male patient in his 60s with a background of chronic lymphocytic leukaemia (CLL) on ibrutinib and venetoclax presents with acute confusion and deranged electrolytes. He is found to be hyponatraemic and is diagnosed with Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) and treated with fluid restriction. He represents again 3 weeks later with hyponatraemia and further investigations reveal pituitary insufficiency and macroadenoma. He was restarted on ibrutinib and venetoclax at the time of discharge.Four months later, he presents with sudden retro-orbital headache associated with vomiting. Clinical findings include cranial nerve III, IV and XI palsy. Humphrey’s visual field examination revealed a left visual field index (VFI) of only 1% while the right was 64% with temporal hemianopia. Both pupils were mid-dilated and poorly reactive to light. MRI pituitary with contrast showed features of pituitary apoplexy and optic nerve compression. He was urgently referred to the neurosurgical team and underwent an emergency trans-sphenoidal hypophysectomy with circumferential excision of the macroadenoma. Post-operative recovery was uneventful with marked improvement in vision bilaterally.The patient was restarted on ibrutinib and venetoclax 2 weeks post-operatively. Approximately 1 year post-treatment, he remains in radiological, clinical and biochemical remission from CLL and all medications have been withdrawn.ConclusionsThis is a unique and rare case of pituitary macroadenoma apoplexy following the commencement of ibrutinib for CLL. Central nervous system haemorrhage is a rare side effect of ibrutinib due to its platelet dysfunction effects. A thorough assessment is required to assess the risks and benefits of using ibrutinib in patients with pituitary macroadenoma to avoid serious complications.

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

FRI165 BIUXX

Abstract Disclosure: A. Haider: None. M. Sadiq: None. J. Shakesprere: None. G.K. Sidhu: None. Background: Syndrome of inappropriate anti-diuretic hormone (ADH) secretion (SIADH) is characterized by inappropriate ADH secretion causing hyponatremia due to free water retention. Plasma volume expansion leads to renin inhibition by the renal juxtaglomerular complex, resulting in decreased aldosterone secretion with inappropriate natriuresis. However, when autonomous renin-independent aldosterone production is present, natriuresis can be suppressed, causing normal sodium levels despite inappropriately high ADH. Case: 58-year-old male with history of resistant hypertension & bipolar disorder on Oxcarbazepine presented with dizziness, lightheadedness, and severe hypokalemia (2.7 mmol/L, n 3.5-5.0 mmol/L). CT Adrenals revealed an incidental 1.2 cm left-sided adrenal adenoma [HU 6, 40% washout]. Serum aldosterone and plasma renin activity (PRA) were obtained in the supine position via LC/MS/MS assay; concurrent serum K+ was 3.4 mmol/L. Spironolactone was started and titrated to 50 mg BID for blood pressure control due to high suspicion of hyperaldosteronism. The patient was continued on Oxcarbazepine 900 mg BID. A 3 mg Dexamethasone suppression test showed suppressed morning cortisol (1.0 μg/dL, n <1.8 μg/dL). Urine catecholamines and metanephrines were obtained and normal. 3-4 days after starting Spironolactone, the patient developed severe subacute hyponatremia (119 mmol/L, n 135-145 mmol/L) from an admission level of 137 mmol/L. No active renal or GI losses, diuretic use, or untreated hypothyroidism were documented. Serum osmolality was low (262 mOsm/kg, n 275-295 mOsm/kg) with urine osmolality of 357 mOsm/kg (n 50-1200 mOsm/kg) and urine sodium of 92 mEq/L (n >20 mEq/L). Serum aldosterone and PRA levels returned with normal aldosterone (7 ng/dL, n 2-9 ng/dL) but suppressed PRA (0.07 ng/mL/hr, n 0.7-3.3 ng/mL/hr) and elevated aldosterone-renin ratio (100 ng/dL per ng/mL/hr, n ≤ 30 ng/dL per ng/mL/hr). As renin was very low despite mild hypokalemia and active Losartan use at the time of testing, these findings were suggestive of primary aldosteronism. In-hospital 24-hour urine aldosterone collection showed urine aldosterone of 29.3 mcg/24 h (n 5-19 mcg/24 h) with urine sodium of 93 mmol/ 24 h (n 40-220 mmol/24 h). Oxcarbazepine was subsequently tapered off; Spironolactone was intermittently held until complete discontinuation. Fluid restriction and oral salt repletion were started and the patient’s sodium ultimately normalized. Outpatient saline suppression testing and adrenal vein sampling were scheduled. Conclusion: Oxcarbazepine was likely causing high ADH release but co-occurring untreated hyperaldosteronism inhibited natriuresis. Use of Spironolactone unmasked natriuresis by blocking aldosterone activity on the intercalated cells of the renal nephron. Stopping Oxcarbazepine ultimately resulted in hyponatremia resolution. Presentation Date: 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

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.

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.

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.