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Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is an X-linked disease caused by activating mutations in the arginine vasopressin (AVP) receptor-2 (AVPR2) gene. Affected patients excrete concentrated urine despite very low levels of AVP, and consequently develop euvolemic hyponatremia. Due to its low frequency, patients may be misdiagnosed and treated incorrectly. We report two related male infants with NSIAD that was initially confused with hyporeninemic hypoaldosteronism (HH). First, a 2-month-old male presented with hyponatremia, low plasma osmolality, relatively high urine osmolality, and low plasma renin-aldosterone levels. These clinical and laboratory findings were compatible with syndrome of inappropriate antidiuretic hormone secretion without apparent cause. Consequently,fludrocortisone was initiated with a presumptive diagnosis of HH While correction of hyponatremia, fludrocortisone treatment led to hypertension and discontinued in a short time. The second patient at age of 1 year was admitted with a history of oligohydramnios, four times hospitalizations due to hyponatremia since birth, and a diagnosis of epilepsy. Similarly, the second infant had clinical and laboratory findings compatible with syndrome of inappropriate antidiuretic hormone secretion with no apparent cause. Fluid restriction normalized his serum sodium despite plasma AVP level was undetectable. In both infants, AVPR2 gene analysis revealed a known mutation (c.409C>T; p.R137C) and confirmed the diagnosis of NSIAD. In conclusion, NSIAD should be considered in all patients with unexplained euvolemic hyponatremia despite high urine osmolality. In case of unawareness from NSIAD, plasma renin-aldosterone profile can be confused with HH, especially in the infants. 34645113

Hyponatraemia is the most common electrolyte disturbance observed in hospital inpatients. We report a 90-year-old woman admitted generally unwell following a fall with marked confusion. Examination revealed a tender suprapubic region, and investigations observed elevated inflammatory markers and bacteriuria. Admission investigations demonstrated a serum sodium of 110 mmol/L with associated serum osmolality 236 mmol/kg and urine osmolality 346 mmol/kg. She was treated for hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone (SIADH) and urosepsis. However, her serum sodium failed to normalise despite fluid restriction, necessitating treatment with demeclocycline and hypertonic saline. Despite slow reversal of hyponatraemia over 1 month, the patient developed generalised seizures with pontine and thalamic changes on MRI consistent with osmotic demyelination syndrome (ODS). This case highlights the risk of ODS, a rare but devastating consequence of hyponatraemia treatment, despite cautious sodium correction.

Currently, there are many methods to evaluate the effectiveness of manual lymph drainage in the treatment of lymphedema, that is, limb volume measurement, bio-electrical impedance measurement, computer tomography, and ultrasound imaging. However, it is difficult for these methods to accurately address the lymph flow generated by manual lymph drainage. Therefore, we aimed at developing a concise and accurate method to measure the lymph flow through the thoracic duct in human subjects, which is applicable for evaluating the effectiveness of manual lymph drainage. In the present mini-review, we demonstrate the developed method in detail and its scientific evidence for the effectiveness obtained with animal and human clinical experiments. In rat

Polyuria is a common clinical condition characterized by a urine output that is inappropriately high (more than 3 L in 24 h) for the patient's blood pressure and plasma sodium levels. From a pathophysiological point of view, it is classified into two types: polyuria due to a greater excretion of solutes (urine osmolality300 mOsm/L) or due to an inability to increase solute concentration (urine osmolality150 mOsm/L). Sometimes both mechanisms can coexist (urine osmolality 150-300 mOsm/L). Polyuria is a diagnostic challenge and its proper treatment requires an evaluation of the medical record, determination of urine osmolality, estimation of free water clearance, use of water deprivation tests in aqueous polyuria, and measurement of electrolytes in blood and urine in the case of osmotic polyuria.

Background We examined the link between increased intra-abdominal pressure, intracranial pressure, and vasopressin release as a potential mechanism. Intra-abdominal pressure, produced by abdominal-cavity insufflation with carbon dioxide (CO2) during laparoscopic abdominal procedures to facilitate visualization, is associated with various complications, including arterial hypertension and oliguria. Methods Mean arterial pressure, optic nerve sheath diameter, measured as a proxy for intracranial pressure, plasma vasopressin, serum and urine osmolarity, and urine output were measured 4 times during laparoscopic sleeve gastrectomy in 42 patients: before insufflation with CO2 (T0); after insufflation to 15 cm water (H2O) pressure, with 5 cm H2O positive end-expiratory pressure (T1); after positive end-expiratory pressure was raised to 10 cm H2O (T2); and after a return to the baseline state (T3). Mean values at T0 to T3 and the directional consistency of changes (increase/decrease/ unchanged) were compared among the 4 data-collection points. Results Statistically significant elevations (all P ≤ .001) were noted from T0 to T1 and from T0 to T2 in mean arterial pressure, optic nerve sheath diameter, and vasopressin, followed by decreases at T3. For optic nerve sheath diameter and vasopressin, the increases at T1 and T2 occurred in 98% and 100% of patients, ultimately exceeding normal levels in 88 and 97%, respectively. Conversely, urine output fell from T0 to T1 and T2 by 60.9 and 73.4%, decreasing in 88.1% of patients (all P Conclusion Increased mean arterial pressure, intracranial pressure, and vasopressin release appear to be intermediary steps between increased intra-abdominal pressure and oliguria. Further research is necessary to determine any causative links between these physiological changes.

Objective: Diabetes insipidus (DI) can be classified into 2 types: central/neurogenic DI and nephrogenic DI. Most cases of central DI occur after brain surgery, trauma, tumor, or infection. Here we report a rare case of familial central DI due to a heterozygous AVP gene mutation. Methods: A case of familial neurogenic DI has been described with thorough clinical, laboratory, and genetic workup. PubMed and Google scholar databases were used for literature discussion. Results: A 22-year-old man presented with polyuria and polydipsia. He drank about 4 gallons of water everyday and urinated large volumes very frequently. His physical examination was unremarkable. After 2 hours of water-deprivation, his serum sodium level was 147 mmol/L, serum osmolality was 302 mOsm/kg with concurrent urine osmolality of 78 mOsm/kg, vasopressin level was

Background Lithium is widely used in the treatment of bipolar disorders and may lead to nephrogenic diabetes insipidus (NDI), following long-term treatment. Metformin is considered the preferred initial therapy for patients with type 2 diabetes mellitus (T2D). Objectives To investigate the protective effect of metformin on the kidney damage caused by lithium administration. Material and methods Using an animal model of chronic lithium-induced NDI, rats were divided into 4 groups: sham, metformin, lithium, and lithium + metformin. The effects of these treatments were examined using serum electrolytes, blood and tissue total antioxidant status, total oxidant status, the oxidative stress index, urine and blood osmolality, and tissue aquaporin-2 (AQP2) levels. Additionally, histopathological changes, including congestion, hydropic swelling, tubular necrosis, tubular atrophy, and Bowman's capsule dilatation, were evaluated. The total histopathological score was obtained by summing the scores for each pathological finding. Results In the lithium group, biochemical variables indicating NDI, including sodium, chloride and blood osmolality, increased, and urine osmolality decreased, compared to the sham group. With metformin treatment, the blood osmolality decreased from 328.17 mOsm/kg to 306.33 mOsm/kg, and urine osmolality increased from 349.67 mOsm/kg to 754.50 mOsm/kg (p = 0.004 and p = 0.001, respectively). Tissue AQP2 levels decreased with lithium administration but stabilized with metformin treatment. Additionally, in comparison to the lithium group, the total histopathological score in the metformin group declined from 8.0 to 2.0 (p = 0.002). Conclusions Metformin may help protect the kidneys from lithium-induced NDI through the AQP2 regulating effect and a reduction in oxidative stress.

PURPOSE: Water needs increase during pregnancy, and proper hydration is critical for maternal and fetal health. This study characterized weekly hydration status changes throughout pregnancy and examined change in response to a randomized, behavioral intervention. An exploratory analysis tested how underhydration during pregnancy was associated with birth outcomes. METHODS: The Healthy Mom Zone Study is a longitudinal, randomized-control trial intervention aiming to regulate gestational weight gain (GWG) in pregnant women with overweight/obesity (n=27). Fourteen women received standard of care; 13 women additionally received weekly guidance on nutrition, physical activity, water intake, and health-promoting behaviors. Hydration status was measured weekly via overnight urine osmolality (Uosm) from ~8–36 weeks gestation; underhydration was dichotomized (Uosm≥500 mOsm/kg). Gestational age- and sex-standardized birth weight and length z scores and percentiles were calculated. We used mixed-effect and linear regression models to test covariate-adjusted relationships. RESULTS: No differences existed in Uosm or other characteristics between control and intervention women at baseline. Significant interactions (p=0.01) between intervention and week of pregnancy on Uosm indicated intervention women maintained lower Uosm, whereas control women had a significant quadratic (inverse-U) relationship and greater Uosm in the second and early third trimesters. Results were consistent across robustness and sensitivity checks. Exploratory analyses suggest underhydration was associated with birth weight, but not length, in opposite ways in the second vs. third trimester. CONCLUSION: A multi-component behavioral intervention helped women with overweight/obesity maintain better hydration throughout pregnancy. Future studies should confirm birth outcome results as they have important implications for early life nutrition. Trial Registration ClinicalTrials.gov Identifier: NCT03945266; registered May 10, 2019 retrospectively

This study aimed to evaluate the protective effects of camel milk (CM) and allopurinol in an adenine-induced acute renal failure (ARF) model in rats. Rats received adenine oral gavage and were treated with either CM (33 mL/kg) or allopurinol (50 mg/kg) for ten consecutive days. Urine and blood samples were collected on the 1st, 5th, and 10th days of the experiment. Renal tissues were collected for oxidative stress and histopathological change analysis. Adenine induced ARF as indicated by a significant decrease in glomerular filtration rate, heavy proteinuria, hyperuricemia, and histological alterations. Serum concentrations of urea, uric acid, serum osmolarity, and urine output were significantly increased, while urine osmolarity was significantly decreased in the adenine-treated rats. Furthermore, in the adenine group, catalase and superoxide dismutase activities and total thiol content were significantly lower, and MDA concentration was significantly higher than the control group. Treatment with CM and allopurinol improved renal function, attenuated structural lesions, and ameliorated oxidative stress in renal tissues. The results indicated that CM and, more effectively, allopurinol were able to protect against adenine-induced kidney injury, possibly by lowering uric acid. Therefore, as a valuable nutrition, CM could be useful in the protection of the kidney against adenine-induced ARF.

We report a 72-year-old woman with Miller-Fisher syndrome (MFS) with syndrome of inappropriate secretion of antidiuretic hormone (SIADH). She developed diplopia and unsteady gait a week after an upper respiratory infection. Neurologic examination revealed ophthalmoplegia, ataxia, symmetrical weakness, numbness, and areflexia. She underwent intravenous immunoglobulin therapy. Her serum sodium concentration decreased to 119 mEq/L on day 12. She had low plasma osmolarity (254 mosm/kg), high urine osmolarity (457 mosm/kg), and high urine sodium level (73 mEq/L), while the blood level of antidiuretic hormone was normal. Anti-GD1b immunoglobulin G (IgG), -GQ1b IgG, -GT1a IgG, and -Gal-C IgM antibodies were positive. We diagnosed her with MFS overlapping with SIADH. Four weeks after onset, her symptoms recovered. The elevation of anti-GD1b, -GQ1b, and -GT1a antibodies that recognize disialosyl residue may be pathologically related to SIADH.

Objective: The common causes of central diabetes insipidus (CDI) include trauma to the pituitary, hypoperfusion, and malignancy. However, CDI can also be transient. An emerging cause of transient diabetes insipidus is through the use and withdrawal of vasopressin. Here, we present a case of transient CDI that developed during an intensive care unit admission. Case report: A Caucasian woman presented to the emergency room after a fall. On presentation, the patient was found to be in shock and was admitted to the surgical intensive care unit. Treatment with norepinephrine, vasopressin, and intravenous antibiotics was started. On day 5 of hospitalization, the patient’s blood pressure improved, and treatment with vasopressin was discontinued. On day 6 of hospitalization, the patient’s urine output increased and serum sodium level was elevated. Despite increasing free water, serum sodium level continued to rise. Endocrinology division was consulted, and urine osmolality was consistent with diabetes insipidus (DI). Urine osmolality at 30 and 60 minutes after desmopressin (1-desamino-8-d-arginine vasopressin [DDAVP]) was consistent with CDI. Magnetic resonance imaging scan of the brain showed no intracranial pathology. Over the next day with scheduled DDAVP, serum sodium level decreased below the goal level. Thus, DDAVP was held. Prior to discharge, the patient did not require additional DDAVP. She was discharged without DDAVP. Discussion: Our patient’s workup was initially consistent with CDI. However, the DI resolved spontaneously, supporting transient CDI secondary to vasopressin infusion. Different theories have emerged about why this occurs with vasopressin. However, further investigation is needed. Conclusion: Although rare, it is important to monitor for DI after vasopressin infusion and have a suspicion that DI may be transient in the absence of a clear cause.

Purpose Growing evidence suggests hydration plays a role in metabolic dysfunction, however data in humans are scarce. This study examined the cross-sectional association between hydration and metabolic dysfunction in a representative sample of the US population. Methods Data from 3961 adult NHANES (National Health and Nutrition Examination Survey) participants (49.8% female; age 46.3 ± 0.5 years) were grouped by quartile of urine specific gravity (USG, 2007–2008 cohort) or urine osmolality (UOsm, 2009–2010 cohort) as measures of hydration. Metabolic dysfunction was assessed by glycemic and insulinemic endpoints and by components of the metabolic syndrome. Multivariate-adjusted linear and logistic regression models were used. Results Increasing quartiles of USG but not UOsm was associated with higher fasting plasma glucose (FPG), glycated hemoglobin (all P P USG but not UOsm had greater risk of metabolic syndrome (Q4 vs. Q1, OR (99% CI): 1.6 (1.0, 2.7), P = 0.01) and diabetes (Q4 vs. Q1, OR: 1.8 (1.0, 3.4), P USG > 1.013 or UOsm > 500 mOsm/kg, common cut-off values for optimal hydration based on retrospective analyses of existing data, had less favorable metabolic markers. In a subset of participants free from diabetes mellitus, impaired kidney function, hypertension and diuretic medication, USG remained positively associated with FPG (P P Conclusion These analyses provide population-based evidence that USG as a proxy for hydration is associated with glucose homeostasis in NHANES 2007–2008. The same association was not significant when UOsm was used as a proxy for hydration in the 2009–2010 wave. Clinical trial registry Not applicable, as this was a reanalysis of existing NHANES data.

Testosterone esters are hormones commonly used for affirming gender identity in transmen. The present study evaluates the effect of testosterone on renal morphology and function in an animal model submitted to cross-sex hormone therapy used for transmen. Two-month-old Wistar rats were divided into three groups: male control (MC), female control (FC), and female on testosterone therapy (FTT). The FTT group received testosterone cypionate (3.0 mg/kg, i.m.), and the MC and MF groups received vehicle oil every 10 days for 4 months. Renal function and indirect systolic blood pressure (SBP) measurements were evaluated at 6 months of age. Plasma and urine concentrations of urea, creatinine, sodium, potassium, osmolality, and glomerular filtration rate (GFR) were measured. The kidneys were weighed, paraffin-embedded, and histological sections were prepared to evaluate the glomerular area. We verified that the FTT group, in comparison to FC, had increased kidney weight [MC, 3.2 ± 0.05; FC, 1.8 ± 0.04; FTT, 2.2 ± 0.06; g], decreased urine osmolarity [MC, 486.9 ± 18.3; FC, 1012.0 ± 5.4; FTT, 768.2 ± 40.3 mOsm/L/g kw], reduced GFR [MC, 0.77 ± 0.04; FC, 0.78 ± 0.02; FTT, 0.67 ± 0.03; mL/min/g kw], larger glomerular area [MC, 9334 ± 120.8; FC, 7884 ± 112.8; FTT, 9078 ± 133.4 µm2 ], and higher SBP [MC, 126 ± 3.4; FC, 119 ± 1.0; FTT, 131 ± 1.4; mmHg]. Sodium excretion was higher in FC and FTT in comparison to MC [MC, 0.34 ± 0.05; FC, 0.56 ± 0.06; FTT, 0.54 ± 0.04; mEq/24 h/g kw]. Cross-sex hormone therapy with testosterone in female rats induces renal morphofunctional changes and may underlie increased systolic pressure, suggesting an adaptation similar to what is observed in transmen on long-term testosterone therapy.

Introduction. Recurrent vomiting is a commonly overlooked debilitating symptom which causes significant impact on the quality of life. There are several causes for vomiting, ranging from commonly known causes to rare causes. Nonfunctioning pituitary macroadenomas generally present with visual disturbances, headache, and symptoms due to anterior pituitary hormone deficiencies. This case report is about an atypical presentation of a nonfunctioning pituitary macroadenoma in which the patient presented with cyclical vomiting with severe hyponatremia. Case Report. A 23-year-old girl presented with four to five episodes of vomiting per day for two days duration. She had a history of similar episodes of vomiting since 2016, with each episode generally lasting for 4-5 days and occurring in every four to six months. All episodes exhibited similar symptomatology and she was free of symptoms in-between. Generalized body weakness, postural dizziness, reduced appetite, and secondary amenorrhea were other symptoms she has had since 2016. Examination findings showed a low body mass index (BMI) (16 kg/m2) with normal system examination. Investigations showed severe hyponatremia (110 mmol/L) with hypokalemia (3.2 mmol/L) and hypochloremia (74 mmol/L). Her urinary excretion of potassium, sodium, and serum osmolality was low. Urine osmolality was mildly elevated compared to serum osmolality. Blood urea was normal. Severe hyponatremia with minimal hyponatremic symptoms was suggestive of chronic hyponatremia, which was accentuated by ongoing vomiting and possible reduced intake of salt. Further investigations showed evidence of secondary hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, and mild hyperprolactinemia. Magnetic resonance imaging (MRI) revealed a pituitary macroadenoma with mass effect on the optic chiasma. Hydrocortisone and levothyroxine were started, and she underwent transsphenoidal resection of the pituitary tumor. She recovered from cyclical vomiting. Conclusion. There can be multiple overlapping aetiologies for every observed symptom, sign, and abnormal investigation finding. Therefore, aetiological diagnosis is challenging, especially in the presence of an atypical clinical presentation. Cyclical vomiting and severe hyponatremia are atypical presentations of nonfunctioning pituitary macroadenomas.

Purpose To determine the association between urine osmolality (Uosm) in patients with primary monosymptomatic enuresis (PMNE) and response to desmopressin (dDAVP) lyophilisate. Methods This was a prospective cohort study that included 419 children with enuresis seen in outpatient clinic between October 2017 and October 2019. Patient workup included symptom checklist, 48 h frequency/volume chart, kidney and bladder ultrasound, uroflow, urinalysis and culture, spot urine Ca/creatinine, and first-morning Uosm. Patients < 5 years, with secondary enuresis, or loss of follow-up were excluded. Oral dDAVP lyophilisate was recommended to all with PMNE and normal bladder capacity. After 1 month of therapy, initial success was assessed according to ICCS. Significant predictor variables for complete response were identified and analyzed using correlation coefficients and binary logistic regression. Results There were 48 patients with PMNE who received dDAVP and were followed for treatment success. Partial and complete responses were achieved for 14 (29.2%) and 20 cases (41.7%), respectively. Older age and lower Uosm were found to be significantly in favor of complete response to dDAVP lyophilisate, P = 0.007 and 0.033, respectively. ROC analysis determined the Uosm of 814 mOsm/kg) might be suggestive of an alternative treatment to dDAVP lyophilisate in PMNE because of the higher risk of treatment failure.

If the gut of Octopus vulgaris is ligated at both ends, the animal loses weight at about 10% per day at 21°C, dying after about 48 h. Ligation of the ducts to the midgut gland has the same effect. If one or both ducts are cannulated and led to the exterior with a sufficient length of duct remaining, sea water is taken up by peristalsis and there is little or no weight loss. As body weight falls, blood and urine osmolality remain unchanged, but blood conductivity falls and blood copper concentration rises, indicating a loss of salts as well as water. Muscle dry weight, as a percentage of muscle wet weight, increases as body weight falls. Octopus is hyperosmotic compared with sea water and the rate of ultrafiltration through the branchial heart appendages into the kidney sacs is estimated to be sufficient to account for the observed body weight losses. Each side of the midgut gland, connected to the gut by a digestive duct, includes two distinct structures. One, the digestive gland, produces enzymes and is also concerned with absorption of the fluid and paniculate products of digestion. The other, the digestive gland appendage (the so-called ‘pancreas9), is composed of cells with characteristics that strongly indicate bulk fluid transport; it seems likely that this is the principal site of the fluid uptake. This evidently includes salts as well as water, since sea water taken into the gut (notably by rectal pumping) is not concentrated as fluid is withdrawn.

Abstract We found an experimental solution to the paradox when the reabsorption of solute-free water increases with a simultaneous increase in diuresis and saluresis in the rat kidney under the oxytocin action. Injection of oxytocin to rats (0.25 nmol/100 g of body weight) increases diuresis from 0.16 ± 0.03 to 0.26 ± 0.02 mL/h, the excretion of solutes from 134 ± 13.7 to 300 ± 16.3 μOsm/h, and the reabsorption of solute-free water, which correlates with the renal excretion of oxytocin (p < 0.001). The mechanism of the effect is that oxytocin decreases the reabsorption of ultrafiltrate in the proximal tubule (the clearance of lithium increases) and increases the fluid flow through the distal segment of the nephron. In vivarium rats, urine osmolality (1010 ± 137 mOsm/kg H2O) and the concentration of vasopressin are high, this causes an increase in the reabsorption of solute-free water. Thus, oxytocin increases saluresis, which, against the background of a high level of endogenous vasopressin, increases the water reabsorption in the collecting ducts.

COVID-19, also known as SARS-CoV-2, which originated in China in late 2019, has spread rapidly resulting in a global pandemic. COVID-19 has been linked to many different clinical manifestations, including hyponatremia. The cause of hyponatremia in acute COVID-19 infection is speculated to be multifactorial, including syndrome of inappropriate antidiuretic hormone secretion (SIADH), thought to be a result of inflammatory cytokines (Interleukin-6) and/or related to the gastrointestinal symptoms of this infection. SIADH in the setting of COVID-19 pneumonia is an established complication of this disease. This is the case of an 81-year-old woman with a history of hypertension, on thiazide diuretic, initially presented after a fall in the setting of COVID-19 pneumonia. She was treated with remdesivir and dexamethasone and then discharged to a rehab facility with normal labwork, including a sodium of 137 mmol/L. Two weeks later, routine labwork identified hyponatremia of 111 mmol/L. Her vital signs were normal, she was euvolemic on exam and alert/oriented with no complaints. Investigations into the etiology of her hyponatremia included a urine sodium of 72 mmol/L, serum osmolality of 231 mOsm/kg, urine osmolality of 454 mOsm/kg. We diagnosed hypo-osmolar hyponatremia due to SIADH. Management included fluid restriction and then tolvaptan, which ultimately corrected the serum sodium to 134 mmol/L. As COVID-19 is a new infection, little is known regarding its impact on electrolyte imbalances. Our patient recovered from pneumonia, then later developed severe hyponatremia possibly secondary to the lasting effects of inflammation in her lungs.

Background The Syndrome of Inappropriate Antidiuresis (SIADH) has been described to be associated with a multitude of conditions and medications, including the severe acute respiratory syndrome coronavirus 2. We describe the case of a patient with newly diagnosed and symptomatic SIADH after receiving the second COVID-19 vaccination not explained otherwise. Case presentation A 79-year-old male person was admitted to the emergency department due to a worsening of his general health state expressed by weakness, fatigue and anorexia. Vital signs and clinical findings were normal, in particular the patient was considered to be euvolemic. Laboratory investigations revealed a serum sodium of 117 mmol/L, a serum osmolality of 241 mosm/kg and a urea of 1.2 mmol/L with creatinine within normal range. Urine chemistry showed a urine osmolality of 412 mosm/kg and urine sodium of 110 mmol/L. TSH, C-reactive protein, and basal cortisol levels were normal. Under therapy with balanced crystalloid fluids, hyponatremia worsened and in absence of diuretic medications, diagnosis of SIADH was made. Since fluid restriction was not sufficiently effective, oral urea was administered. Under this therapy regimen hyponatremia resolved. Conclusions Local as well as systemic reactions have been described for the new mRNA-based vaccines including pain and fever. Therefore, it is imaginable that the vaccine might trigger SIADH in some patients.

Disorders of water and sodium homeostasis in the human body—or dysnatraemias—are frequently encountered in clinical practice, but their analysis is often complex and their management is often troublesome. For many clinicians, it remains challenging to correctly interpret all relevant biochemical parameters involved in the analysis of dysnatraemia, especially when a rapid ‘bedside’ evaluation is required to initiate treatment. By mathematically deriving the relationship between plasma osmolality and urine osmolality under physiological circumstances, we were able to propose a novel and clinically useful nomogram for the rapid evaluation of disorders of plasma osmolality. We believe that the presented osmolality nomogram could be a transparent and clinically useful tool for the quick evaluation of disorders of the water and sodium balance in patients.

We discuss the use of urine electrolytes and urine osmolality in the clinical diagnosis of patients with fluid, electrolytes, and acid-base disorders, emphasizing their physiological basis, their utility, and the caveats and limitations in their use. While our focus is on information obtained from measurements in the urine, clinical diagnosis in these patients must integrate information obtained from the history, the physical examination, and other laboratory data.

Syndrome of inappropriate antidiuretic hormone (SIADH) is a disorder of fluid and sodium balance characterized by hypotonic hyponatremia, low plasma osmolality, and increased urine osmolality caused by excessive release of antidiuretic hormone (ADH). Malignancy is one of the most common causes of SIADH, but SIADH in esophageal carcinoma is very rarely reported. In this case report, a 74-year-old male patient of moderate differentiation of squamous cell esophageal carcinoma had a recurrent electrolyte balance disorder despite repeated corrections. The patient experienced improvement after fluid restriction and drug administration.

To test the diagnostic ability of two combined practical markers for elevated urine osmolality (underhydration) in free-living adults and children. One hundred and one healthy adults (females n = 52, 40 ± 14 y, 1.70 ± 0.95 m, 76.7 ± 17.4 kg, 26.5 ± 5.5 kg/m2) and 210 children (females = 105, 1.49 ± 0.13 m, 43.4 ± 12.6 kg, 19.2 ± 3.2 kg m−2) collected urine for 24-h. Urine was analyzed for urine osmolality (UOsm), color (UC), while the number of voids (void) was also recorded. Receiver Operating Characteristic (ROC) analysis was performed for UC, void, and combination of UC and void, to determine markers’ diagnostic ability for detecting underhydration based on elevated UOsm (UOsm ≥ 800 mmol kg−1). Linear regression analysis revealed that UC was significantly associated with UOsm in both adults (R2 = 0.38; P 3 and void 3 and void

To provide a new and efficient at-the-toilet-bowl method of self-assessing urine concentration via urine color (Uc) to identify hypohydration. A large athletic population (n = 189) delivered a urine sample, then chose a color panel that was displayed on the back wall of the lavatory stall. Selection was based on duration of urine voiding time, so that for a short-duration, the lighter panel was selected; for a mid-duration, the mid color panel; and for a longer-void-duration, the darker panel was selected. Then, subjects noted if their urine was lighter than, similar to, or darker than the selected color panel. Trained investigators also rated subjects’ urine samples. To assess validity of Uc classification, the outcome was compared with a urine concentration (urine specific gravity, USG, and urine osmolality) threshold indicating hypohydration. Urine color was scored similarly by subjects and investigators (P = 0.99). Based on receiver operating curves (ROC), the method scored fair, i.e., the area under the curve ranging 0.73–0.82, with an accuracy of participants and investigators correctly classifying 72% and 75% urine samples compared to a USG threshold of 1.020, respectively, and 62% and 70% compared to a urine osmolality threshold of 836 mmol·kg−1, respectively. This new lavatory urine color (LUC) method of scoring Uc levels to assess potential hypohydration gives results similar to those of traditional urine color charts, but it has the advantage of an immediate assessment of hydration status based on scoring urine color directly from the toilet bowl.

Objective The challenge of finding patients with the rare conditon of diabetes insipidus in need of vasopressin treatment is demanding. The guidelines for performing the fluid deprivation test and interpreting the results are abundant. We evaluated the discriminative capacity of the fluid deprivation test in patients with polyuria to define a cut off for a more effective discrimination between diabetes insipidus and other polyuria syndromes. Research design and methods Retrospective review and data collection of all ambulatory fluid deprivation tests, of patients with mild polyuria and polydipsia ( Results The study group consisted of 153 patients, 123 were diagnosed with non-diabetes insipidus and 30 with diabetes insipidus. After 12 h fasting (baseline) median duration of the fluid deprivation test was 5 h (fasting range: 12–21 h). At baseline, there was a significant difference between median serum and urine osmolality between the groups (P < 0.05). The best cut-off for the diagnosis of diabetes insipidus, was the combination of 302 mosmol/kg in serum. With this cut-off a sensitivity of 90% and specificity of 98% was achieved. Conclusion After 12 h fasting our proposed cut off clearly differentiated between diabetes insipidus, and non-diabetes insipidus suggesting a possibility to considerably reduce the duration of the fluid deprivation test.

IntroductionDiabetes insipidus (DI) is characterized by the excretion of large volumes of hypotonic urine and thirst due to an impaired ability to concentrate urine, leading to uncontrolled diuresis, which may cause life-threatening dehydration and electrolyte imbalances. Central DI is caused by the deficient secretion of the posterior pituitary antidiuretic hormone arginine vasopressin (AVP). Desmopressin (Deamino-8-D-AVP, the synthetic analogue of AVP, Minirinmelt®) is generally used to treat central DI. Desmopressin orally disintegrating tablets are recently administered to male patients with nocturia. We herein attempted to select male patients with an elevated nocturnal urinary frequency possibly due to a shortage of AVP. These patients may be good candidates for low-dose oral desmopressin administration.Patients and methodsSerum and spot urine osmolality, electrolytes, serum creatinine, casual blood glucose, plasma brain natriuretic polypeptide (BNP), and plasma AVP were measured at the same time in 97 elderly male patients with urinary symptoms under free water drinking. The International Prostate Symptom Score, Overactive Bladder Symptom Score, and frequency-volume charts at least twice were also evaluated.ResultsA binary plot of plasma AVP and serum osmolality indicated a region at which patients had relatively lower AVP considering higher serum osmolality. It was tentatively named the Desmopressin region. Twenty out of 97 (20.6 %) patients were in the Desmopressin region.No significant differences were observed in the frequency of administered urinary drugs or existing co-morbidities between patients in the Desmopressin and non-Desmopressin regions. Daily urine output did not exceed 3 L in any patient. Plasma AVP was lower, while serum osmolality and serum sodium were higher in patients in the Desmopressin region than in those in non-Desmopressin region. Furthermore, urine osmolality was slightly lower in patients in the Desmopressin region. No significant differences were observed in urine volume, urinary frequency, or urination questionnaire scores between both groups.ConclusionAVP-shortage patients may be selected for treatment with oral desmopressin based on measurements of serum osmolality and plasma AVP. After the exclusion of patients with marked hyperglycemia, decreased cardiac, or renal function, low-dose oral desmopressin may be administered to patients with an increased urine output, nocturia, elevated plasma osmolality, and relatively low plasma AVP.

SARS-CoV-2-induced ARDS is a new entity that should be characterized as it appears to be different from standard ARDS. Hypernatremia is a biological alteration that seems to occur very often in this population without any clear cause. The present study aims to clarify the possible causes of hypernatremia and evaluate its impact on patient outcome. We conducted a retrospective one-day prevalence study in 2 intensive care units, which only treated COVID-19 patients with moderate to severe ARDS. We measured blood and urine electrolytes in all the patients. Patients with chronic renal failure or renal replacement therapy were excluded from the study. Hypernatremia was defined as plasma sodium levels above 145 mmol/L. Inclusion criteria were met in 17 out of 24 patients. Hypernatremia was present in 52% patients. All had a natriuresis higher than 20 mmol/L and a urine osmolality above 600 mOsm/L. Hypernatremia was acquired in ICU as all the patients had a normal serum sodium level at admission. The incidence of hypernatremia was elevated and appears to be linked to significant insensible water losses. This should trigger us to optimize the maintenance fluid therapy in critically ill patients with SARS-CoV-2-induced ARDS., SCOPUS: ar.j, info:eu-repo/semantics/published

Renal water conservation after an overnight fast mirrors the habitual intake of liquid. The hypothesis in the present study was that water conservation influences the diuretic response to infusion of two types of crystalloid fluid. Twenty‐three elderly male patients (mean age 72 years) underwent a total of 46 intravenous infusions of 1.0 or 1.5 L of either hypotonic non‐electrolyte fluid (glycine 1.5%) or isotonic electrolyte fluid (Ringer's acetate or 0.9% saline). Urine osmolality (used to indicate renal water conservation) and plasma creatinine were measured before the infusions started. A two‐volume model was fitted to repeated measurements of the blood haemoglobin concentration and the urinary excretion, using mixed‐effects modelling software. Urine osmolality was examined as a potential covariate to the fixed kinetic parameters. The results show that distribution and redistribution of infused fluid occurred twice as fast for the non‐electrolyte fluids as for the electrolyte‐containing fluids, while the urine flow showed less difference. For both types of fluid, high urine osmolality served as a statistically significant covariate to the rate constant describing urinary excretion. Simulations showed that a high pre‐infusion urine osmolality doubled the time required for the kidneys to excrete 50% of a 30‐minute infusion. High plasma creatinine independently prolonged the elimination of non‐electrolyte fluid. The use of 0.9% saline instead of Ringer's prolonged the excretion of electrolyte‐containing fluid. In conclusion, renal water conservation is a determinant of the diuretic response to crystalloid fluid, regardless of whether the fluid contains electrolytes, and it should be considered in fluid balance studies., Studies of infusion fluids usually do not consider that the kidneys may be set to conserve or excrete the infused volume before fluid is administered. The present retrospective analysis of the kinetics of electrolyte‐free and electrolyte‐containing fluids showed that the excretion of both types of fluid were mathematically dependent on the urinary osmolality measured just before the study was initiated

Objectives Clinical and laboratory data of reset osmostat (RO) and cerebral/renal salt wasting (C/RSW) mimic syndrome of inappropriate antidiuretic hormone (SIADH) and can pose diagnostic challenges because of significant overlapping between clinical and laboratory findings. Failure to correctly diagnose hyponatremia may result in increased mortality risk, longer hospital stay, and is cost-effective. We aim to illustrate clinical and laboratory similarities and difference among patients with hyponatremic disorders and discuss the diagnostic value of factional uprate excretion (FEurate) to differentiate SIADH from RO and C/RSW. Case presentations We report the use of FEurate in the evaluation of three patients with hyponatremia and elevated urine osmolality in the absence of edema or clinical evidence of dehydration to differentiate SIADH from RO and C/RSW. Conclusions Measurement of FEurate may offset in part the diagnostic confusion imparted by the diagnoses of SIADH, RO, and C/RSW.

Purpose: Examine changes from 90-minutes of competitive match-play in countermovement jump (CMJ), creatine kinase (CK) and urine osmolality (Uosm) in elite football players over a season and their ...

Summary Severe hyponatremia and osmotic demyelination syndrome (ODS) are opposite ends of a spectrum of emergency disorders related to sodium concentrations. Management of severe hyponatremia is challenging because of the difficulty in balancing the risk of overcorrection leading to ODS as well as under-correction causing cerebral oedema, particularly in a patient with chronic hypocortisolism and hypothyroidism. We report a case of a patient with Noonan syndrome and untreated anterior hypopituitarism who presented with symptomatic hyponatremia and developed transient ODS. Learning points: Patients with severe anterior hypopituitarism with severe hyponatremia are susceptible to the rapid rise of sodium level with a small amount of fluid and hydrocortisone. These patients with chronic anterior hypopituitarism are at high risk of developing ODS and therefore, care should be taken to avoid a rise of more than 4–6 mmol/L per day. Early recognition and rescue desmopressin and i.v. dextrose 5% fluids to reduce serum sodium concentration may be helpful in treating acute ODS.

Acute CNS illness comprising of Acute CNS infections along with Traumatic head Injury is an important cause for significant morbidity and mortality in Pediatric Intensive Care units across the world. Osmolar changes in the blood correlate well with CNS status. Acute BM is still a meaningful, host-pathogen interaction responsible for bacterial invasion of the CNS Osmolality in children with CNS illness is a good indicator of assessing neurological Morbidity and Mortality. A complex neuroendocrine system is involved in the maintenance of sodium and water homeostasis. Bacterial Meningitis (BM) is an acute purulent infection of the meninges. It is the most common bacterial infection of the CNS& it’s the medical emergency that still has high mortality and morbidity. Blood-Brain Barrier is relatively impermeable to sodium, but water crosses freely. Variety of result in sodium dysregulation such as Traumatic Brain Injury, pyogenic meningitis, viral encephalitis, which is associated with significant Mortality and Morbidity. The objective of our study is to determine the incidence and outcome of Serum Osmolar change in children presenting with acute neurological illness. A prospective observational study was carried out between Jan 6th2020-March 6 th2020 enrolling children between ages of 1 month to 15 years, admitted to the PICU of SMCH with Acute onset neurological illness. Among 40 children, 20 children with hyponatremia have 50% of neurological deficit, Children with hypernatremia 50% had Neurological deficit, which is not statistically significant at P value0.083. Among the 40 children 40% had low Osmolality, 25% have high Osmolality& 35% had normal range, which is not statistically significant at P value 0.199

Recommendations for composition of oral rehydration solutions (ORS) for calves, particularly concerning Na+, glucose, and their combined effect on tonicity, are not in line with guidelines for humans. Thus, this study aimed to determine the effect of ORS tonicity on water, mineral and acid–base balance. Seventy‐two calves were selected based on the severity of dehydration and blood base excess (BE) on day 0. Five calves that did not develop diarrhoea were removed post‐inclusion from the study. Calves were allocated to blocks of four animals based on blood BE on day 1. Within each block, calves were randomly assigned to one of four treatments: (a) hypotonic ORS with low Na+ and lactose (HYPO); (b) isotonic ORS with low Na+and glucose (ISO); (c) hypertonic ORS with high Na+ and glucose (HYPER); and (d) control consisting of warm water including 5 g/L of whey powder (CON). Treatments were administered twice daily over a 3‐day period, in which calves were offered 2.0 L of treatment at 1300 and 2100 hr. Calves were fed 2.5 L of milk replacer at 0700 and 1630 hr from day 1 to 3 and 3.0 L from day 4 to 5, and had access to water. Calves were monitored for 5 days in which measurements included intakes, BW, blood sampling and collection of faeces on day 1 and urine from day 1 to 3. All ORS treatments maintained normal serum Na+, whereas CON did not. Calves in the HYPER group had lower blood pH and greater faecal Na+ losses than HYPO and ISO. Plasma expansion relative to baseline was higher in low tonicity ORS (+4.8%) when compared with CON (+1.0%). Urine osmolality was 30% higher in HYPER calves. In this experiment, low tonicity ORS were more effective at restoring water, mineral and acid–base balance than the hypertonic ORS.

International audience; Background: Properly replacing energy and fluids is a challenge for 24-h ultramarathoners because such unusually high intake may induce adverse effects (gastrointestinal symptoms [GIS] and exercise-associated hyponatremia [EAH]). We analyzed such intake for 12 twelve elite athletes (6 males and 6 females; age: 46 ± 7 years, height: 170 ± 9 cm, weight: 61.1 ± 9.6 kg, total distance run: 193-272 km) during the 2019 24-h World Championships and compared it to the latest nutritional recommendations described by the International Society of Sports Nutrition in 2019. We hypothesized that these elite athletes would easily comply these recommendations without exhibiting detrimental adverse symptoms. Methods: Ad libitum food and fluid intake was recorded in real-time and energy, macronutrient, sodium, and caffeine intake then calculated using a spreadsheet in which the nutritional composition of each item was previously recorded. GIS, markers of dehydration (body mass modifications, plasma and urine osmolality, and plasma volume; samples obtained 26 h before and just after the race) and EAH (plasma and urine sodium concentrations) were also assessed. Results: Fluid, energy, and carbohydrate intake of the 11 finishers was 16.4 ± 6.9 L, 35.1 ± 15.7 MJ, and 1.49 ± 0.71 kg, respectively. Individual analyses showed that all but one (for fluid intake) or two (for energy and carbohydrate intake) consumed more than the minimum recommendations. The calculated energy balance remained, however, largely negative (− 29.5 ± 16.1 MJ). Such unusually high intake was not accompanied by detrimental GIS (recorded in 75%, but only transiently [3.0 ± 0.9 h]) or EAH (0%). The athletes were not dehydrated, shown by the absence of significant body mass loss (− 0.92 ± 2.13%) and modifications of plasma osmolality and an increase in plasma volume (+ 19.5 ± 15.8%). Performance (distance ran) positively correlated with energy intake (ρ = 0.674, p = 0.023) and negatively (ρ = − 0.776, p = 0.005) with fluid intake. Conclusions: Overall, almost all of these elite 24-h ultramarathoners surpassed the nutritional recommendations without encountering significant or the usual adverse effects.

Background Patients with nocturnal polyuria (NP) experience a unique surge in nocturnal diuresis rate during the early hours of sleep. Objective To determine the diagnostic utility of the volume and osmolality of a single early nocturnal urine sample in detecting NP. Design, setting, and participants Analysis of 1 am urine samples obtained from two prospective observational studies at Ghent University Hospital involving participants recruited from a urology ambulatory care unit and those who consulted a continence clinic. Nocturic participants (one or more nocturnal void[s]; n = 176) were stratified based on the presence (n = 87) or absence (n = 89) of NP (>90 ml/h). Outcome measurements and statistical analysis Receiver operating characteristic curves with Youden’s Index were used to determine cutoff values for urine volume and urine osmolality (Uosm). Results and limitations Individuals with NP demonstrated higher 1 am volume (400 [interquartile range 300–515] vs 210 [160–300] ml, area under the curve [AUC] = 0.843, p am volume ≥350 ml or Uosm ≤314 mOsm/kg H2O were 85% sensitive and 75% specific for NP, while criteria of both 1 am volume ≥350 ml and Uosm ≤314 mOsm/kg H2O were 60% sensitive and 92% specific for NP. Comparable AUC values, sensitivities, and specificities were observed in both men and women. Limitations include post hoc design and a relatively small study sample. Conclusions Individuals with NP are more likely than those without NP to produce a higher volume of more dilute urine (ie, “aquaresis”) in the early hours of sleep. Analysis of easily measurable parameters of the first nocturnal void (for which 1 am values serve as a surrogate) in men and women with nocturia can predict a diagnosis of NP with a reasonably high degree of sensitivity and specificity. Patient summary Urologists often try to understand the specific reason why people wake up to urinate at night by asking them to record the amount of urine they make every time they go to the bathroom (also known as a “voiding diary”) during the nighttime as well as the daytime—typically for a total of 1–3 days. In this study, we showed that an analysis of the composition of the urine that people produce when they first wake up to urinate at night might be sufficient to determine whether their symptoms are caused by excessive urine production or something else, and some people might find this urine study easier than keeping a voiding diary.

Urea transporters are a family of urea-selective channel proteins expressed in multiple tissues that play an important role in the urine-concentrating mechanism of the mammalian kidney. Previous studies have shown that knockout of urea transporter (UT)-B, UT-A1/A3, or all UTs leads to urea-selective diuresis, indicating that urea transporters have important roles in urine concentration. Here, we sought to determine the role of UT-A1 in the urine-concentrating mechanism in a newly developed UT-A1–knockout mouse model. Phenotypically, daily urine output in UT-A1–knockout mice was nearly 3-fold that of WT mice and 82% of all-UT–knockout mice, and the UT-A1–knockout mice had significantly lower urine osmolality than WT mice. After 24-h water restriction, acute urea loading, or high-protein (40%) intake, UT-A1–knockout mice were unable to increase urine-concentrating ability. Compared with all-UT–knockout mice, the UT-A1–knockout mice exhibited similarly elevated daily urine output and decreased urine osmolality, indicating impaired urea-selective urine concentration. Our experimental findings reveal that UT-A1 has a predominant role in urea-dependent urine-concentrating mechanisms, suggesting that UT-A1 represents a promising diuretic target.

Summary The etiology of hyponatremia is assessed based on urine osmolality and sodium. We herein describe a 35-year-old Asian man with pulmonary tuberculosis and perforated duodenal ulcer who presented with hyponatremia with hourly fluctuating urine osmolality ranging from 100 to 600 mosmol/kg, which resembled urine osmolality observed in typical polydipsia and SIADH simultaneously. Further review revealed correlation of body temperature and urine osmolality. Since fever is a known non-osmotic stimulus of ADH secretion, we theorized that hyponatremia in this patient was due to transient ADH secretion due to fever. In our case, empiric exogenous glucocorticoid suppressed transient non-osmotic ADH secretion and urine osmolality showed highly variable concentrations. Transient ADH secretion-related hyponatremia may be underrecognized due to occasional empiric glucocorticoid administration in patients with critical illnesses. Repeatedly monitoring of urine chemistries and interpretation of urine chemistries with careful review of non-osmotic stimuli of ADH including fever is crucial in recognition of this etiology. Learning points: Hourly fluctuations in urine osmolality can be observed in patients with fever, which is a non-osmotic stimulant of ADH secretion. Repeated monitoring of urine chemistries aids in the diagnosis of the etiology underlying hyponatremia, including fever, in patients with transient ADH secretion. Glucocorticoid administration suppresses ADH secretion and improves hyponatremia even in the absence of adrenal insufficiency; the etiology of hyponatremia should be determined carefully in these patients.

Summary Primary adrenal lymphoma (PAL) is a rare cause of adrenal insufficiency. More than 90% is of B-cell origin. The condition is bilateral in up to 75% of cases, with adrenal insufficiency in two of three patients. We report two cases of adrenal insufficiency presenting at the age of 70 and 79 years, respectively. Both patients had negative 21-hydroxylase antibodies with bilateral adrenal lesions on CT. Biopsy showed B-cell lymphoma. One of the patients experienced intermittent disease regression on replacement dosage of glucocorticoids. Learning points: Primary adrenal lymphoma (PAL) is a rare cause of adrenal insufficiency. Bilateral adrenal masses of unknown origin or in individuals with suspected extra-adrenal malignancy should be biopsied quickly when pheochromocytoma is excluded biochemically. Steroid treatment before biopsy may affect diagnosis. Adrenal insufficiency with negative 21-hydroxylase antibodies should be evaluated radiologically.

Introduction: There is much debate about whether idiopathic hypercalciuria (IH) affects kidney water management. For the first time in the literature, we carried out a longitudinal study of kidney water management (KWM) in patients diagnosed with IH in childhood and followed-up until adulthood (mean follow-up 17.7 ± 1.4 years). Methods: Twenty-nine patients (7 M, 22 F) over the age of 24 years (mean 28.2 ± 2.9 years, range: 24.1–35.9) who were diagnosed with IH in childhood (mean 7.6 ± 3.2 years, range: 1–14) were included. Maximum urine osmolality (UO) and/or urine volume adjusted for 100 ml of glomerular filtration rate (V/GFR) in both age groups (pediatric and adult) were determined. Moreover, whenever possible, in both age groups plasma creatinine levels, plasma sodium levels, uric acid levels, the citrate/creatinine ratio and the calcium/citrate ratio were recorded and a renal and bladder ultrasound was performed. Results: In the pediatric age group, KWM was altered in 9/29 cases (31%) (4 with reduced maximum UO and 5 with elevated V/GFR). In adulthood, KWM was found to be affected in 7/29 cases (24.1%) (6 with reduced UO and one with elevated V/GFR). Compared to the pediatric age group, adult patients had lower V/GFR, calcium/creatinine and citrate/creatinine values, as well as higher plasma creatinine, uric acid and calcium/citrate. There were no differences in the maximum UO in both age groups. However, UO in adulthood was significantly lower in subjects who had renal colic compared to those who did not (p = .04). Conclusions: KWM was affected in approximately one third of patients with IH, which persisted 20 years after diagnosis. We think that these results may be due to adherence to the recommended protective diet and to the pharmacological treatment administered at the diagnosis of IH during childhood. Resumen: Existe controversia si la hipercalciuria idiopática (HI) produce alteraciones en el manejo renal del agua. Por primera vez en la literatura, llevamos a cabo un estudio longitudinal del manejo renal del agua (MRA) en pacientes diagnosticados de HI en edad pediátrica y con seguimiento hasta la edad adulta (media de seguimiento de 17,7 ± 1,4 años). Métodos: Veintinueve pacientes (7 M, 22 F) mayores de 24 años (media 28,2 ± 2,9 años, rango: 24,1-35,9) que fueron diagnosticados de HI en la edad pediátrica (media 7,6 ± 3,2 años, rango: 1-14) fueron incluidos. Se determinaron la osmolaridad urinaria máxima (OsU) y/o el volumen urinario ajustado para 100 ml de tasa de filtrado glomerular (V/TFG) en ambos tiempos (pediátrico y adulto). Además, siempre que fue posible, en ambas edades se recogieron los niveles plasmáticos de creatinina, sodio plasmático, ácido úrico, cociente citrato/creatinina y calcio/citrato y, además, se realizó una ecografía renovesical. Resultados: El MRA estuvo alterado en edad pediátrica en 9/29 casos (31%) (4 con OsU máxima reducida y 5 con V/TFG elevado). En la edad adulta, 7/29 (24,1%) presentaron alteración del MRA (6 OsU reducidos y uno con V/TFG elevado). En comparación con el grupo de edad pediátrica, los pacientes adultos mostraron valores reducidos de V/TFG, cociente calcio/creatinina y citrato/creatinina, así como aumento de creatinina plasmática, ácido úrico y del cociente calcio/citrato. No hubo diferencias en la OsU máxima en ambos tiempos. Sin embargo, la OsU en la edad adulta fue significativamente menor en aquellos que tenían cólicos renales comparado con aquellos que no los tuvieron (p = 0,04). Conclusiones: La alteración del MRA ocurrió en aproximadamente un tercio de los pacientes con HI, y no se alteró tras 20 años después de su diagnóstico. Nosotros pensamos que estos resultados pueden ser debido a un cierto cumplimiento de la dieta protectora recomendada y al tratamiento farmacológico administrado en el diagnóstico de HI en la edad pediátrica.

Purpose Elevated plasma concentration of the vasopressin marker copeptin and low water intake are associated with elevated blood glucose and diabetes risk at a population level. Moreover, in individuals with low urine volume and high urine osmolality (u-Osm), water supplementation reduced fasting plasma (fp) copeptin and fp-glucose. In this observational study, we investigated if low total water intake or high u-Osm correlated with high fp-copeptin and components of the metabolic syndrome at the population level. Methods In the population-based Malmö Offspring Study (MOS, n = 2599), fp-copeptin and u-Osm from morning urine samples were measured, and diet and total water intake (from beverages and food moisture) was assessed by a 4-day web-based record. Results Increasing water intake by tertile was after adjustment for age and sex associated with low fp-triglycerides (p = 0.002) and high fp-HDL (p = 0.004), whereas there was no association with the other investigated metabolic traits (HbA1c, fp-glucose, BMI or waist circumference). Increasing u-Osm by tertile was, after adjustment for age and sex, associated with high fp-glucose (p = 0.007), and borderline significantly associated with high HbA1c (p = 0.053), but no association was observed with fp-HDL, fp-triglycerides, BMI or waist circumference. Fp-copeptin concentration correlated significantly with water intake (r = − 0.13, p r = 0.27, p p Conclusion Low concentrations of the vasopressin marker copeptin is linked to high water intake, low u-Osm, and a favorable metabolic profile, suggesting that vasopressin lowering lifestyle interventions, such as increased water intake, may promote metabolic health.

In this study, the risk factors associated with sodium overcorrection were investigated with an optimal cutoff for baseline serum sodium for use in daily clinical practice. Electronic medical records of patients who received tolvaptan for non-hypovolemic hyponatremia were reviewed. Demographic and clinical data including age, sex, weight, height, comorbidity, cause of hyponatremia, hypertonic saline use, and comedication were collected. Baseline laboratory parameters measured included serum sodium, serum potassium, serum creatinine, blood urea nitrogen, serum tonicity, ALT, AST, and urine osmolality. The primary outcome was the overcorrection of serum sodium, which was defined as an increase in serum sodium by more than 10 mmol/L in 24 h. From a total of 77 patients included in the analysis, 24 (31.2%) showed sodium overcorrection (> 10 mmol/L/24 h); 2 (2.6%) in heart failure cohort, 17 (22.1%) in SIADH cohort, and 5 (6.5%) in unknown cause cohort. More than half of patients (51.9%) were administered hypertonic saline prior to tolvaptan. Hypertension, cancer, diuretics, baseline serum sodium, and SIADH were associated with the risk of overcorrection in the univariable analysis. Significant factors for the overcorrection from multivariable analysis were lower body mass index, presence of cancer (adjusted odds ratio, 10.87; 95% CI, 1.23–96.44), and lower serum sodium at baseline (adjusted odds ratio, 0.76 for every 1 mEq/L increase; 95% CI, 0.61–0.94). The overcorrection of hyponatremia in non-hypovolemic patients treated with tolvaptan was significantly associated with lower body mass index, presence of cancer, and lower serum sodium at baseline. In subgroup analysis using SIADH patients, baseline sodium and cancer were found to be significant factors of overcorrection.

Background Abdominal compartment syndrome has been linked to detrimental hemodynamic side effects that include increased intracranial pressure and diminished renal function, but the mechanisms behind this continue to be elucidated. In this study, we sought to investigate any direct association between acute elevations in intra-abdominal pressure and intracranial hypertension during experimentally induced abdominal compartment syndrome and between acutely elevated intracranial pressure and the hemodynamic response that might be elicited by a vasopressin-induced Cushing reflex affecting urine osmolality and urine output. The aim of this study is to explain the Cushing reflex and the vasopressin-mediated hemodynamic response to intracranial pressure during acute elevations in intra-abdominal pressure. Methods We measured intra-abdominal pressure, intrathoracic pressure, optic nerve sheath diameter as an indirect sign of intracranial pressure, vasopressin levels in blood, urine osmolality, and urine output at 4 time points during surgery in 16 patients undergoing sleeve gastrectomy for morbid obesity. Values for the 4 time points were compared by repeated-measures analysis of variance. Results More than 50-fold elevations in serum vasopressin paralleled increases in optic nerve sheath diameter, rising throughout prepneumoperitoneum and tapering off afterward, in conjunction with a marked decrease in urine but not serum osmolality. Mean arterial pressure rose transiently during pneumoperitoneum without elevated positive end-expiratory pressure but was not significantly elevated thereafter. Conclusions These findings support our hypothesis that the oliguric response observed in abdominal compartment syndrome might be the result of the acutely elevated intra-abdominal pressure triggering increased intrathoracic pressure, decreased venous outflow from the central nervous system, increased intracranial pressure, and resultant vasopressin release via a Cushing reflex.

Background: Extracellular fluid retained in the lungs lead to respiratory distress in both late preterm (LP) and term neonates. The relationship between urine parameters toward the diuresis and the duration of ventilation postnatally is unknown. To find the correlation between the diuretic phase with urine parameters in the first 4 days after birth and the duration of non-invasive ventilation (NIV). Methods: Serial measurements of urine osmolality (Uosm), urine sodium (UNa), and urine output (U/O) in neonates were collected at 5 time periods (T1:0–12 postnatal hours, T2:12–24 postnatal hours, T3:24–48 postnatal hours, T4:48–72 postnatal hours, T5:72–96 postnatal hours) were recorded. The correlations were analyzed in late preterm and term neonates. Results: Ninety-seven neonates were included. Negative correlation between Uosm and U/O were observed. LP neonates (n=26) and term neonates (n=71) had differences with Uosm at T2, UNa at T4, T5, and U/O at T2, T3. Factors of U/O < 1 ml/kg/hr at T1 (odds ratio (OR) = 20.0; 95% confidence interval (CI) 1.796-222.776; p = 0.015) or Uosm > 273 mOsm/L at T1 (OR = 9.0; 95% CI 1.031-78.574; p = 0.047) in LP neonates and UNa > 26.5 mEq/L at T5 (OR = 23.625; 95% CI 2.683-79.276; p < 0.01) in term neonates were associated with prolonged NIV use (> 120 hours). Conclusion: We speculate the significant correlation between Uosm/UNa and the diuretic phase. The LP neonates acquire earlier diuretic phase than the term neonates. The Uosm/UNa in the first few postnatal days had the correlation with the duration of NIV support. Keywords: Diuretic phase, Neonate, Non-invasive ventilation, Urine osmolality, Urine sodium

Living kidney donation is safe and established but can lead to short- and long-term complications. Hyponatremia is the most common disorder of body fluid and electrolyte balance in clinical practice, associated with increased morbidity, mortality, and the length of hospital stay. A correct diagnosis of the etiology of hyponatremia is critical, both to determine correct management and prognosis. Here, we present a case of a severe hyponatremia following left- sided donor nephrectomy with a physical examination suggestive of mild hypovolemia. Laboratory tests revealed high urine osmolality and sodium concentration mimicking syndrome of inappropriate antidiuretic hormone secretion (SIADH), in the setting of abnormally blunted response to Synacthen. The patient responded well to hydrocortisone replacement. Differentiating between primary adrenal insufficiency and SIADH as a cause of severe hyponatremia was the key to successfully treating this patient. Hyponatremia following donor nephrectomy is unusual and could be explained in this case by hypocortisolism.

BACKGROUND: In patients receiving total parenteral nutrition (TPN), the frequency of hyponatraemia is high. However, the causes of hyponatraemia in TPN have not been elucidated, although diagnosis is required for appropriate therapy. The aim of this study is to describe the aetiology of hyponatraemia in non-critical hospitalised patients receiving TPN. METHODS: Prospective multicentre study in 19 Spanish hospitals. Non-critically hyponatraemic patients receiving TPN and presenting hyponatraemia over a 9-month period were studied. Data collected included sex, age, previous comorbidities, and serum sodium levels (SNa) before and following TPN initiation. Parameters for study of hyponatraemia were also included: clinical volaemia, the presence of pain, nausea, gastrointestinal losses, diuretic use, oedema, renal function, plasma and urine osmolality, urinary electrolytes, cortisolaemia, and thyroid stimulating hormone. RESULTS: 162 patients were included, 53.7% males, age 66.4 (SD13.8) years. Volume status was evaluated in 142 (88%): 21 (14.8%) were hypovolaemic, 96 (67.6%) euvolaemic and 25 (17.6%) hypervolaemic. In 111/142 patients the analytical assessment of hyponatraemia was completed. Hypovolaemic hyponatraemia was secondary to GI losses in 10/111 (9%), and to diuretics in 3/111 (2.7%). Euvolaemic hyponatraemia was due to Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) in 47/111 (42.4%), and to physiological stimuli of Arginine Vasopressin (AVP) secretion in 28/111 (25.2%). Hypervolaemic hyponatraemia was induced by heart failure in 19/111 (17.1%), cirrhosis of the liver in 4/111 (3.6%). CONCLUSIONS: SIADH was the most frequent cause of hyponatraemia in patients receiving TPN. The second most frequent cause was physiological stimuli of AVP secretion induced by pain/nausea.

This study aimed to elucidate the clinical features of water-electrolyte disturbance (WED) as a sequela of hemispherotomy.We performed a retrospective chart review to identify the clinical features of diabetes insipidus (DI) as a complication in 12-month-old patients who underwent hemispherectomy or hemispherotomy for severe epilepsy between 2007 and 2018. Central DI was diagnosed if a patient developed polyuria (urine output 5 mL/kg/h), abnormally high serum osmolality ( 300 mOsm/kg), high serum sodium level ( 150 mEq/L), either abnormally low urine specific gravity ( 1.005) or low urine osmolality ( 300 mOsm/kg) or both, and effective control of polyuria with arginine vasopressin (AVP). The clinical course of post-hemispherotomy WED, complications other than WED, and seizure outcomes were analyzed.The review identified that 3 of 23 infants developed WED. All patients developed polyuria within 2 days after surgery, with high serum osmolality and hypotonic urine; AVP was effective in treating these symptoms. The clinical course was compatible with central DI. Two patients subsequently developed hyponatremia in a biphasic or triphasic manner. All patients had multiple seizures that were probably related to WED. Two patients developed asymptomatic cerebral sinovenous thrombosis, possibly because of the surgical procedure and dehydration; anticoagulant treatment was provided. All patients were treated for WED for up to 2 months and had no residual pituitary dysfunction.Systemic complications other than intracranial ones can occur in patients who have undergone hemispherotomy. Perioperative systemic management of young infants undergoing this procedure should include careful water and electrolyte balance monitoring.

BACKGROUND AND OBJECTIVES: Metabolic acidosis is a frequent manifestation of sickle cell disease but the mechanisms and determinants of this disorder are unknown. Our aim was to characterize urinary acidification capacity in adults with sickle cell disease and to identify potential factors associated with decreased capacity to acidify urine. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Among 25 adults with sickle cell disease and an eGFR of ≥60 ml/min per 1.73 m(2) from a single center in France, we performed an acute acidification test after simultaneous administration of furosemide and fludrocortisone. A normal response was defined as a decrease in urinary pH