Establishment and validation of a predictive nomogram for polyuria during general anesthesia in thoracic surgery.

BACKGROUND: To develop and evaluate a predictive nomogram for polyuria during general anesthesia in thoracic surgery. METHODS: A retrospective study was designed and performed. The whole dataset was used to develop the predictive nomogram and used a stepwise algorithm to screen variables. The stepwise algorithm was based on Akaike's information criterion (AIC). Multivariable logistic regression analysis was used to develop the nomogram. The receiver operating characteristic (ROC) curve was used to evaluate the model's discrimination ability. The Hosmer-Lemeshow (HL) test was performed to check if the model was well calibrated. Decision curve analysis (DCA) was performed to measure the nomogram's clinical usefulness and net benefits. P < 0.05 was considered to indicate statistical significance. RESULTS: The sample included 529 subjects who had undergone thoracic surgery. Fentanyl use, gender, the difference between mean arterial pressure at admission and before the operation, operation type, total amount of fluids and blood products transfused, blood loss, vasopressor, and cisatracurium use were identified as predictors and incorporated into the nomogram. The nomogram showed good discrimination ability on the receiver operating characteristic curve (0.6937) and is well calibrated using the Hosmer-Lemeshow test. Decision curve analysis demonstrated that the nomogram was clinically useful. CONCLUSIONS: Individualized and precise prediction of intraoperative polyuria allows for better anesthesia management and early prevention optimization.

Salt-losing nephropathy associated with supraventricular arrhythmia.

We present a case of a young man with a new-onset supraventricular arrhythmia accompanied by polyuria and natriuresis with subsequent renal salt-wasting causing hypovolemic hyponatremia. Resolution of the electrolyte imbalance occurred only after successful atrial flutter ablation.

Arginine vasopressin deficiency: diagnosis, management and the relevance of oxytocin deficiency.

Polyuria-polydipsia syndrome can be caused by central diabetes insipidus, nephrogenic diabetes insipidus or primary polydipsia. To avoid confusion with diabetes mellitus, the name 'central diabetes insipidus' was changed in 2022 to arginine vasopressin (AVP) deficiency and 'nephrogenic diabetes insipidus' was renamed as AVP resistance. To differentiate the three entities, various osmotic and non-osmotic copeptin-based stimulation tests have been introduced in the past decade. The hypertonic saline test plus plasma copeptin measurement emerged as the test with highest diagnostic accuracy, replacing the water deprivation test as the gold standard in differential diagnosis of the polyuria-polydipsia syndrome. The mainstay of treatment for AVP deficiency is AVP replacement with desmopressin, a synthetic analogue of AVP specific for AVP receptor 2 (AVPR2), which usually leads to rapid improvements in polyuria and polydipsia. The main adverse effect of desmopressin is dilutional hyponatraemia, which can be reduced by regularly performing the so-called desmopressin escape method. Evidence from the past few years suggests an additional oxytocin deficiency in patients with AVP deficiency. This potential deficiency should be further evaluated in future studies, including feasible provocation tests for clinical practice and interventional trials with oxytocin substitution.

The relation between autophagy modulation by intermittent fasting and aquaporin 2 expression in experimentally induced diabetic nephropathy in albino rat.

Polyuria is an early sign of diabetic nephropathy (DN) that produces dehydration in diabetic patients. This could be caused by alteration of renal aquaporin 2 (AQP2) expression. This study aimed to describe the relation between autophagy modulation via intermittent fasting (IF) and renal AQP2 expression and polyuria in case of DN. We divided the rats into control, DN and IF groups. After 2 and 4 weeks of diabetes induction, blood glucose (BG), serum creatinine (Scr), urine volume, and 24 hours urine protein (UP) were examined. Diabetic nephropathy histopathological index (DNHI) was calculated to evaluate histopathological changes. Immunohistochemistry and real-time PCR were performed to measure the levels of AQP2 and the autophagy marker; LC3 in kidney tissue. DNHI was correlated to the PCR and immunoexpression of AQP2 and LC3. Intermittent fasting significantly decreased the BG, Scr, urine volume, 24 hours UP, and DNHI as compared diabetes. Diabetes significantly elevated the immunoreactivity and mRNA expression levels of AQP2 and LC3 as compared to the control. However, the IF decreased AQP2 and stimulated autophagy in cyclic fashion. Our data revealed significant positive correlations between AQP2 and LC3 at the level of immunoexpression and mRNA at 2nd weeks. Taken together, these data showed that autophagy stimulation didn't regulate AQP2 expression in case of diabetic nephropathy, however IF decreased polyuria through improvement of glycemic state.

Long-term safety of desmopressin orally disintegrating tablets in men with nocturia due to nocturnal polyuria: Interim results of a specified drug use-results survey in Japan.

OBJECTIVES: This interim report presents the 12-week results of a post-marketing surveillance evaluating the safety of desmopressin orally disintegrating tablets 25 and 50 µg in Japanese men with nocturia due to nocturnal polyuria. METHODS: Of the planned study population of 1000 Japanese men receiving desmopressin for the first time for nocturia due to nocturnal polyuria, 971 cases were enrolled. In this interim analysis, 9 cases, including 6 registry violations and 3 cases of unconfirmed desmopressin dosing, were excluded from the 354 case report forms collected and fixed by the end of December 2021, and data up to 12 weeks after administration in 345 cases were defined as the safety analysis set. RESULTS: The mean age was 74.5 ± 9.9 years and 88.7% of the survey participants were aged ≥65 years. Desmopressin was started at a dose of 25 µg in 153 cases (44.3%). There were 102 adverse drug reactions (ADRs) reported in 71 cases, including 6 serious ADRs in 3 cases (0.9%). The most common ADR was hyponatremia occurring in 29 cases (8.4%). Eight of the hyponatremic cases were asymptomatic. Symptoms were resolved or slightly improved within 4 weeks of onset in 13 of 29 cases of hyponatremia. In addition, hyponatremia occurred in 11 of 217 cases (5.1%), with a serum sodium level before the administration of desmopressin of ≥140 mmol/L, and in 13 of 87 cases (14.9%), with a level of 135-139 mmol/L, and was not measured in 5 hyponatremia cases. Patient characteristics that showed significant differences in the occurrence of hyponatremia included body weight, body mass index, renal function, and pretreatment serum sodium level. Regular monitoring of serum sodium is necessary for early detection of hyponatremia. CONCLUSIONS: Hyponatremia was the most common ADR when desmopressin orally disintegrating tablets were used to treat nocturia due to nocturnal polyuria over a 12-week period.

Successful Treatment of Lithium-Induced Nephrogenic Diabetes Insipidus with Celecoxib: A Promising Therapeutic Option.

BACKGROUND Nephrogenic diabetic insipidus (NDI) poses a challenge in clinical management, particularly when associated with lithium ingestion. Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) have been widely used for the treatment of numerous diseases worldwide, including NDI. However, many studies have reported the diverse adverse effects of long-term use of non-selective NSAIDs. Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is a better drug to relieve pain and inflammation in terms of long-term safety and efficacy than non-selective NSAIDs. Nevertheless, there are few reports describing the effectiveness of celecoxib in treating NDI. CASE REPORT We report a case of a 46-year-old woman with schizophrenia who presented with severe hypernatremia and refractory polyuria due to lithium-induced NDI. Cessation of lithium ingestion and traditional treatments, including trichlormethiazide and desmopressin, yielded minimal improvement in her hypernatremia and polyuria. Her sodium level needed to be strictly controlled with the infusion of dextrose 5% in water. Given the safety of celecoxib, we decided to initiate celecoxib as the treatment of lithium-induced NDI instead of indomethacin. Notably, the introduction of celecoxib led to a substantial and sustained amelioration of polyuria and hypernatremia without any celecoxib-associated adverse effects. Even after transfer to another hospital, stability in serum sodium levels persisted with celecoxib. CONCLUSIONS We presented a case of lithium-induced NDI successfully treated with celecoxib, a selective COX-2 inhibitor. To the best of our knowledge, this is the first reported case of successful treatment of lithium-induced NDI with celecoxib, and suggests celecoxib is a viable therapeutic option warranting further exploration. Physicians should consider its use when faced with the challenging management of lithium-induced NDI.

Biological Variation Estimates for Plasma Copeptin and Clinical Implications.

BACKGROUND: Plasma copeptin measurement is useful for the differential diagnoses of polyuria-polydipsia syndrome. It has also been proposed as a prognostic marker for cardiovascular diseases. However, limited information is available about the within- (CVI) and between-subject (CVG) biological variation (BV). This study presents BV estimates for copeptin in healthy individuals. METHODS: Samples were collected weekly from 41 healthy subjects over 5 weeks and analyzed using the BRAHMS Copeptin proAVP KRYPTOR assay after at least 8 h of food and fluid abstinence. Outlier detection, variance homogeneity, and trend analysis were performed followed by CV-ANOVA for BV and analytical variation (CVA) estimation with 95% confidence intervals. Reference change values (RCVs), index of individuality (II), and analytical performance specification (APS) were also calculated. RESULTS: The analysis included 178 results from 20 males and 202 values from 21 females. Copeptin concentrations were significantly higher in males than in females (mean 8.5 vs 5.2 pmol/L, P < 0.0001). CVI estimates were 18.0% (95% CI, 15.4%-21.6%) and 19.0% (95% CI, 16.4%-22.6%), for males and females, respectively; RCVs were -35% (decreasing value) and 54% (increasing value). There was marked individuality for copeptin. No result exceeded the diagnostic threshold (>21.4 pmol/L) for arginine vasopressin resistance. CONCLUSIONS: The availability of BV data allows for refined APS and associated II, and RCVs applicable as aids in the serial monitoring of patients with specific diseases such as heart failure. The BV estimates are only applicable in subjects who abstained from oral intake due to the rapid and marked effects of fluids on copeptin physiology.

Un mecanismo nefrogénico subyace a la poliuria inducida por dexmedetomidina: informe de un caso / Nephrogenic mechanism underlies dexmedetomidine-induced polyuria: A case report

La dexmedetomidina, agonista del adrenorreceptor α, se utiliza cada vez más como agente sedativo-hipnótico y analgésico, aunque su popularidad suscita preocupación acerca de los efectos secundarios de dicho fármaco.La bradicardia y la hipotensión son efectos adversos comunes, pero también existen diversos informes de gasto urinario excesivo, posiblemente debido a la secreción de vasopresina y a la permeabilidad de los conductos colectores.La poliuria se resuelve normalmente con la discontinuación del fármaco, no habiéndose reportado morbilidad significativa. La identificación temprana, la eliminación del agente y el tratamiento son imperativos para minimizar las complicaciones, principalmente natremia y síntomas neurológicos.Este informe de caso describe la poliuria relacionada con dexmedetomidina durante la anestesia general libre de opioides para cirugía mayor de cabeza y cuello. Nuestra hipótesis de etiología nefrogénica se ve reforzada por los datos analíticos obtenidos. También describimos cómo abordar la poliuria intraoperatoria. (AU)

Dexmedetomidine's α-adrenoreceptor agonism has been gaining popularity in the anesthetic room as a sedative-hypnotic and analgesic agent, and with extensive perioperative use rising concern about side effects is necessary.Bradycardia and hypotension are common but excessive urine output is increasingly reported, suggested mechanisms being vasopressin secretion and increasing permeability of the collecting ducts.Polyuria usually resolves with discontinuation of the drug and significant morbidity has not been reported. Early identification, removal of agent and treatment are imperative to minimize complications, mainly associated with natremia levels and neurological symptoms.This case report describes a dexmedetomidine-related polyuric syndrome during opioid-free general anesthesia for major head and neck surgery. A nephrogenic mechanism for the clinical effect is proposed and reinforced by analytical data obtained. An intra-operative polyuria approach is also delineated. (AU)

Antidiuretic hormone deficiency secondary to inactive hydrocephalus: a case report.

BACKGROUND: Diabetes insipidus is a syndrome characterized by polyuria, which is almost always associated with polydipsia. The most frequent cause is central diabetes insipidus, which is the result of an inadequate secretion of the antidiuretic hormone, and diagnosis involves differentiating it from other causes of polyuria and polydipsia. CASE PRESENTATION: Here, we present a clinical case of a previously healthy 13-year-old Nepali boy, who, in December 2022, was found to have intense polydipsia accompanied by polyuria. He had bilateral lower limb weakness at the time of presentation. Biochemical evaluation demonstrated raised serum sodium (181 mEq/L), serum creatinine (78 µmol/L), and serum uric acid (560 µmol/L) with suppressed serum potassium (2.7 mEq/L), which was the major concern to the clinicians. Further laboratory workup revealed an increased serum osmolarity (393.6 mOsm/kg) with reduced urine osmolarity (222.7 mOsm/kg). On contrast magnetic resonance imaging of the brain, a thick-walled third ventricular cyst with bilateral foramen obstruction, thin membrane-like structure at top of aqueduct of Sylvius with gross obstructive hydrocephalus (inactive), and compressed and thinned pituitary gland with no bright spot was observed. The laboratory findings, radiological findings, and case presentation provided the provisional diagnosis of diabetes insipidus due to hydrocephalus and third ventricular cyst. CONCLUSIONS: Central diabetes insipidus due to hydrocephalus, though rare, can have serious complications including the predilection to develop a deficit of other pituitary hormones. Thus, even if hydrocephalus is dormant with normal intracranial pressure, it must be addressed during investigations of central diabetes insipidus.

Coexistence of type 2 diabetes mellitus, arginine vasopressin deficiency, and Marfan syndrome: A case report.

Diabetes mellitus (DM) and arginine vasopressin deficiency (AVP-D) are characterized by polyuria. Marfan syndrome is an autosomal dominant disorder caused by pathogenetic variants in FBN1. Here, we report a patient with type 2 diabetes mellitus, AVP-D, and Marfan syndrome. Although the coexistence of type 2 diabetes mellitus and AVP-D is rare, for those patients with type 2 diabetes mellitus, the existence of AVP-D should be considered when polyuria is not in accordance with the blood glucose levels, especially for those with a low urine specific gravity. Specific symptoms or signs help to identify Marfan syndrome early, and genetic testing of the FBN1 pathogenetic variant helps to make a definitive diagnosis.

The diagnostic performance of copeptin in clinical practice: A prospective study.

OBJECTIVE: Plasma copeptin is a relatively new biomarker for evaluation of arginine vasopressin (AVP) secretion. The aim of this study was to test the diagnostic performance of copeptin in patients with polyuria-polydipsia syndrome. DESIGN, PATIENTS AND MEASUREMENTS: This was a prospective study where 88 patients with polyuria-polydipsia syndrome were evaluated with a water deprivation test (WDT). Weight, urine osmolality, urine specific gravity, and plasma copeptin were collected at baseline, after 8 h, and at termination of the WDT when one of the following had been reached: (i) >3% weight reduction, (ii) urine specific gravity >1.017 or urine osmolality >600 mOsm/kg, or (iii) intolerable adverse symptoms. RESULTS: Of 88 patients (57 women), 21 (24%) were diagnosed with central diabetes insipidus (cDI), 5 (6%) with nephrogenic DI (nDI), and 62 (71%) with primary polydipsia (PP). Median (interquartile range) copeptin at baseline was 1.7 (1.4-2.5) pmol/L in cDI, 22 (18-65) pmol/L in nDI, and 2.7 (2-4) pmol/L in PP. After 8 h of WDT, the highest copeptin in patients with cDI was 4.0 pmol/L. In patients with PP: (i) 41 had urine osmolality <600 mOsm/kg, 7 (17%) of these had copeptin >4.0 pmol/L, (ii) 21 had urine osmolality ≥600 mOsm/kg, 14 (67%) of these had copeptin >4.0 pmol/L. CONCLUSIONS: Copeptin >4.0 pmol/L after an overnight WDT can be used to rule out cDI and copeptin ≥21 pmol/L at baseline to diagnose nDI. The diagnostic performance of copeptin in the context of the WDT is otherwise limited in the diagnostic work-up of patients with polyuria-polydipsia syndrome.

The laboratory investigation of diabetes insipidus: A review.

Diabetes insipidus (DI) is a group of disorders that lead to inappropriate production of large volumes of dilute urine. The three main forms are central DI (CDI), nephrogenic DI (NDI) and primary polydipsia (PP). Differentiating CDI/NDI from PP is important as patients with true DI are at risk of severe dehydration without treatment. Biochemical testing is key in the diagnosis of DI. The indirect water deprivation test (WDT) is commonly used in the investigation of DI but has drawbacks including being cumbersome and sometimes producing equivocal results. Direct measurement of AVP has theoretical advantages but has generally only been used in specialist centres. Disadvantages include the requirement to measure AVP under hypertonic stimulation and pre-analytical/analytical challenges. Copeptin (CT-proAVP) is a proxy marker for AVP that is more stable, easier to measure and has been studied more widely in recent years. Historically, the evidence supporting the diagnostic performance of these tests has been relatively poor, being based on a few small, usually single-centre studies. However more recent, well-designed prospective studies are improving the evidence base for investigation of DI. These studies have focused on the utility of copeptin measurements during stimulation tests. There is evidence that measurement of copeptin under stimulation offers improved diagnostic performance compared to the WDT. There is currently a lack of systematic, evidence-based guidelines on the diagnosis of DI, but as the quality of the evidence defining the diagnostic performance of tests for DI continues to improve, a clearer consensus on the optimal approach should become achievable.

Effects of salt and protein intake on polyuria in V2RA-treated ADPKD patients.

BACKGROUND: The only treatment proven to be renoprotective in autosomal dominant polycystic kidney disease (ADPKD) is a vasopressin V2-receptor antagonist (V2RA). However, aquaresis-associated side effects limit tolerability. We investigated whether salt and/or protein intake influences urine volume and related endpoints in V2RA-treated ADPKD patients. METHODS: In this randomized, controlled, double-blind, crossover trial, ADPKD patients treated with maximally tolerated dose of a V2RA were included. While on a low salt and low protein diet, patients were given additional salt and protein to mimic regular intake, which was subsequently replaced by placebo in random order during four 2-week periods. Primary endpoint was change in 24-h urine volume. Secondary endpoints were change in quality of life, measured glomerular filtration rate (mGFR), blood pressure and copeptin level. RESULTS: Twelve patients (49 ± 8 years, 25.0% male) were included. Baseline salt and protein intake were 10.8 ± 1.3 g/24-h and 1.2 ± 0.2 g/kg/24-h, respectively. During the low salt and low protein treatment periods, intake decreased to 5.8 ± 1.6 g/24-h and 0.8 ± 0.1 g/kg/24-h, respectively. Baseline 24-h urine volume (5.9 ± 1.2 L) decreased to 5.2 ± 1.1 L (-11%, P = .004) on low salt and low protein, and to 5.4 ± 0.9 L (-8%, P = .04) on low salt. Reduction in 24-h urine volume was two times greater in patients with lower urine osmolality (-16% vs -7%). Polyuria quality of life scores improved in concordance with changes in urine volume. mGFR decreased during the low salt and low protein, while mean arterial pressure did not change during study periods. Plasma copeptin decreased significantly during low salt and low protein periods. CONCLUSION: Lowering dietary salt and protein intake has a minor effect on urine volume in V2RA-treated ADPKD patients. Reduced intake of osmoles decreased copeptin concentrations and might thus increase the renoprotective effect of a V2RA in ADPKD patients.

Very elevated serum copeptin concentrations occur in a subset of healthy children in the minutes after phlebotomy.

OBJECTIVES: Although AVP and its surrogate, copeptin, are mainly regulated by osmotic and volume stimuli, their secretion is also elicited by stress and growth hormone (GH) stimulating agents. The aim of this report is to describe unusual patterns of copeptin response in a subset of children undergoing GH stimulation tests (GH-ST). METHODS: We conducted a secondary analysis of a cohort of 93 healthy short children with no polydipsia, polyuria or fluid/electrolyte abnormalities, undergoing GH-ST with intravenous arginine, insulin, oral clonidine, or L-Dopa/carbidopa in various combinations. Serum copeptin concentrations were measured 1-3 min after phlebotomy (0 min) and at 60, 90, 120 min during GH-ST. RESULTS: In 85 subjects (normal response group, NRG) serum copeptin concentrations increased from a 0 min median of 9 pmol/L (IQR 6, 11.5) (all values ≤21) to a median peak between 60 and 120 min of 22 (IQR15, 38) pmol/L, which varied depending on the stimulating agent. Conversely, in the eight outliers, copeptin concentrations decreased gradually from a median of 154 (IQR 61, 439) pmol/L (all ≥40 pmol/L) to values as low as 14 % of the basal value, by 120 min. Test-associated anxiety was described in 17 subjects in the NRG (20 %) and five of the outliers (63 %). CONCLUSIONS: A distinctive pattern of very elevated serum copeptin concentrations occurred in 9 % of children undergoing GH-ST, similar to reports in previous pediatric studies. Etiology may include pain or stress of phlebotomy. This phenomenon should be recognized for proper interpretation of copeptin values in children.

Association between nocturnal polyuria and 24-h blood pressure fluctuations in males with lower urinary tract symptoms: A multicenter prospective study.

OBJECTIVES: Nocturnal polyuria (NP) is one of the causes of nocturia that impairs quality of life. It is necessary to consider that NP is latent when the initial treatment for nocturia is unsatisfactory. Therefore, it is important to establish a treatment for NP based on the pathophysiology. We have previously reported the relationship between NP and fluctuation in blood pressure. The present study aimed to investigate the association between NP and 24-h blood pressure fluctuations in a multicenter prospective study. METHODS: This study included male patients with lower urinary tract symptoms. We categorized the patients into the nonnocturnal polyuria (non-NP) group (≤0.33) and the NP group (>0.33) based on the nocturnal polyuria index from the frequency volume chart. We measured the 24-h diurnal blood pressure and compared the two groups. RESULTS: Among 90 patients, 46 in the non-NP group and 44 in the NP group were included. There was no significant difference in the systolic and diastolic blood pressure during waking time between the two groups; however, the degree of systolic blood pressure reduction during sleep time in the NP group was significantly less than that in the non-NP group (p = 0.039). In the multivariate analysis, systolic BP during sleep was significantly associated with NP (OR 0.970, p = 0.028). CONCLUSION: NP is associated with inadequate nocturnal blood pressure reduction in males, suggesting that reduction in nocturnal blood pressure may lead to improvement in nocturia.

An exceptional cause of polyuria-polydipsia syndrome in a 10-year-old boy.

Polyuria-polydipsia syndrome is a frequent symptom in pediatrics, primarily attributed to diabetes mellitus. In the context of diabetes insipidus, this syndrome can stem from central or nephrogenic factors. Sjögren's syndrome, an uncommon autoimmune disease in children, can affect multiple organs. Kidney involvement as described in adults is usually related to glomerular or tubular impairment, often linked to distal tubular acidosis. As a kidney involvement during childhood, Sjögren's syndrome has rarely been reported. Hereby, we present the case of Sjögren's syndrome revealed by polyuria-polydipsia syndrome in a 10-year-old boy.

Efficacy and safety of desmopressin in nocturia and nocturnal polyuria control of neurological patients: A systematic review and meta-analysis.

PURPOSE: Evidence on the efficacy of desmopressin in nocturia in patients with neurological diseases is still very limited except for multiple sclerosis (MS). Our aim was to evaluate the efficacy and safety of desmopressin treatment on nocturia in patients with underlying neurological diseases. METHODS: Studies were identified by electronic search of PubMed, Embase, Cochrane, CINAHL, and Google Scholar databases. Studies were considered if they provided information on the effectiveness and safety of desmopressin (1-desamino-8-d-arginine vasopressin, or DDAVP) in the treatment of nocturia and their participants had acquired neurological pathology. Two researchers independently extracted the articles using specified datasets, such as quality-of-study indicators. Statistical meta-analysis was carried out using Review Manager (RevMan) 5.4 statistical software (Cochrane Collaboration). RESULTS: Of a total of 1042 articles in the initial search, 14 studies were included. Most of the published papers were related to MS (n = 7), two were on spinal cord injury, and other conditions were neural tube defect, myelodysplasia, Parkinson's disease, stroke, and multiple system atrophy. Overall, a total of 200 patients (mostly females) were enrolled. Thirteen studies evaluated the intranasal formulation of desmopressin and one study evaluated oral desmopressin. A significant decrease in nocturia episodes was reported in seven studies evaluating this topic. An increase in the maximum hours of uninterrupted sleep was reported in the three studies in which this outcome was assessed. A significant reduction in the volume of nocturnal incontinence was found in one study. Three studies were eligible to include in the meta-analysis. The results showed that desmopressin compared to placebo, significantly reduced nighttime urination (mean difference: -0.75, 95% CI: -1.10 to -0.41; p < 0.00001). The rate of adverse events ranged from 0% to 68.42%. The critical appraisal results for all trials showed that most of the studies had low or moderate quality. CONCLUSIONS: Our results emphasized desmopressin's safety and efficacy in reducing nocturia episodes, with transient adverse effects on neurological patients. However, the data were achieved from low or medium-quality trials, and further well-designed randomized controlled trials are needed.

Urine concentration impairment in sickle cell anemia: genuine nephrogenic diabetes insipidus or osmotic diuresis?

The urine concentration impairment responsible for hyposthenuria in sickle cell nephropathy is currently thought to be a consequence of renal medulla lesions, which lead to nephrogenic diabetes insipidus. The objective of the present study was to investigate the mechanism of hyposthenuria in patients with sickle cell anemia. We performed an observational study of patients with homozygous SS sickle cell anemia and data available on the fasting plasma antidiuretic hormone (ADH) concentration. A total of 55 patients were analyzed. The fasting plasma ADH values ranged from 1.2 to 15.4 pg/mL, and 82% of the patients had elevated ADH values and low fasting urine osmolality (<505 mosmol/kgH2O). Plasma ADH was positively associated with plasma tonicity and natremia (P < 0.001). None of the patients experienced polyuria and fasting free water clearance was negative in all cases, thus, ruling out nephrogenic diabetes insipidus. The tertile groups did not differ with regard to fasting urine osmolality, plasma renin level, mGFR, or several hemolysis biomarkers. The negative fasting free water clearance in all cases and the strong association between 24-h osmolal clearance and 24-h diuresis favors the diagnosis of osmotic diuresis due to an impaired medullary gradient, rather than lesions to collecting tubule.NEW & NOTEWORTHY The urine concentration impairment in sickle cell anemia is an osmotic diuresis related to an impaired renal medullary gradient leading to an ADH plateau effect. The fasting plasma ADH was high in the context of a basic state of close-to-maximal urine concentration probably driven by short nephrons maintaining a cortex-outer medullary gradient (about 400 milliosmoles). The patients had a low daily osmoles intake without evidence of thirst dysregulation so no one experienced polyuria.

The diagnostic role of arginine-stimulated copeptin in the differential diagnosis of polyuria-polydipsia syndrome (PPS) in pediatric age.

PURPOSE: In recent years, copeptin stimulation through arginine administration has been evaluated as a new potential tool in the differential diagnosis of polyuria-polydipsia syndrome (PPS) in adults; to date very few data, all retrospective, exist in pediatric age. The aim of this prospective study is to evaluate the diagnostic performance of the arginine-stimulation test for copeptin in a cohort of pediatric patients affected by PPS. METHODS: All children (<18 years) referred to the Department of Pediatric Endocrinology of the Regina Margherita Children Hospital for polyuria-polydipsia in the period January 2021-June 2023 were enrolled. The Arginine-stimulation test for copeptin was performed in all patients presenting PPS after water deprivation test (WDT). Patients with polyuria-polydipsia were then classified as having primary polyuria (PP), complete and partial central diabetes insipidus (CDI), according to the standardized interpretation. Arginine-stimulation test for copeptin was also performed in a control cohort. RESULTS: A significant difference in arginine-stimulated copeptin values was observed at baseline (p = 0.005), at 60 min (p = 0.01), and at 90 min (p = 0.005) in 7 subjects presenting PP, 6 patients affected by CDI and 50 subjects of the control cohort. Plasma osmolality values remained stable at all measurements. The arginine-stimulated copeptin test demonstrated sensitivity and specificity of 100%, whereas the sensitivity of the WDT test was 83.3% and the specificity was 85.7%. CONCLUSION: Given the reliability and the minor adverse effects and costs, the copeptin level after arginine administration could replace the WDT in the diagnostic workup of these in pediatric age.

Uso de ibuprofeno en el tratamiento de pacientes pediátricos con poliuria y disnatremia. Reporte de una serie de casos / Ibuprofen use for the treatment of pediatric patients with polyuria and dysnatremia. A case series report

Los niños con lesiones selares y/o supraselares pueden presentar diabetes insípida central con posterior secreción inadecuada de hormona antidiurética. Nosotros observamos, en algunos casos, aumento de la incidencia de poliuria, natriuresis e hiponatremia, tríada diagnóstica del síndrome cerebral perdedor de sal. Aquí comunicamos la evolución de 7 pacientes con antecedentes de daño agudo del sistema nervioso central y diabetes insípida central seguida por síndrome cerebral perdedor de sal. Como tratamiento aportamos secuencialmente fluidos salinos parenterales, cloruro de sodio oral, desmopresina, mineralocorticoides e incluso tiazidas. Ante la persistencia de poliuria con hiponatremia, agregamos ibuprofeno. Como resultado de este esquema terapéutico secuencial, este grupo redujo significativamente los valores de diuresis diaria de 10 ml/kg/h a 2 ml/kg/h en un tiempo promedio de 5 días, normalizando también las natremias (de 161 mEq/L a 143 mEq/L) en un tiempo promedio de 9 días. En ningún caso observamos efectos adversos asociados al tratamiento.

Children with sellar and/or suprasellar lesions may develop central diabetes insipidus with subsequent inappropriate antidiuretic hormone secretion. An increased incidence of polyuria, natriuresis, and hyponatremia has been reported in some cases, which make up the diagnostic triad of cerebral salt wasting syndrome. Here we report the clinical course of 7 patients with a history of acute central nervous system injury and central diabetes insipidus followed by cerebral salt wasting syndrome. Treatment included the sequential use of parenteral saline solution, oral sodium chloride, desmopressin, mineralocorticoids, and even thiazides. Due to persistent polyuria and hyponatremia, ibuprofen was added. As a result of this sequential therapeutic regimen, daily urine output reduced significantly from 10 mL/ kg/h to 2 mL/kg/h over an average period of 5 days, together with a normalization of natremia (from 161 mEq/L to 143 mEq/L) over an average period of 9 days. No treatment-related adverse effects were observed in any case.