scholarly journals CHANGES IN URINE OSMOLALITY AND URINE FLUORIDE CONCENTRATIONS FOLLOWING METHOXYFLURANE ANAESTHESIA

1974 ◽  
Vol 46 (2) ◽  
pp. 153-158 ◽  
Author(s):  
G.S. ROBERTSON ◽  
W.F.D. HAMILTON
1959 ◽  
Vol XXXII (I) ◽  
pp. 134-141 ◽  
Author(s):  
Niels A. Thorn

ABSTRACT Arginine-, lysine- and leucine-vasopressin, injected i. v. into hydrated rats or dogs caused different patterns of response in that urine osmolality fell much more slowly after the maximum increase following arginine-vasopressin, than after the other two preparations. Using 3 different parameters for antidiuretic response, arginine-vasopressin was somewhat more potent than leucine-vasopressin in both rats and dogs, considerably more potent than lysine-vasopressin in rats, and much more so in dogs.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 250-252
Author(s):  
M Shpoliansky ◽  
B Kamath

Abstract Background True hyponatremia in the setting of cholestatic liver disease may signify cirrhosis with fluid overload, and is therefore an ominous sign of deteriorating liver function. In pediatric liver transplant candidates, it is associated with increased waitlist mortality. Pseudohyponatremia however, is a falsely low measurement of plasma sodium when measured by indirect potentiometry. Pseudohyponatremia secondary to hypercholesterolemia is a phenomenon that occurs due to a reduced aqueous fraction of the plasma when levels of cholesterol or triglycerides are greatly elevated. Severe hypercholesterolemia due to Lipoprotein X accumulation may be the cause of pseudohyponatremia in biliary obstruction or cholestasis. Aims To describe a case of pseudohyponatremia secondary to hypercholesterolemia in an infant with Alagille syndrome (ALGS) and cholestatic liver disease. Methods This 7 month-old male with ALGS (confirmed JAGGED1 mutation) and severe cholestasis, failure to thrive, and pruritus, developed new-onset progressive hyponatremia as low as 121 mmol/L at an outside institution. He was therefore transferred to our center for liver transplant assessment due to concerns of progressive liver dysfunction and for management of the hyponatremia. Results Upon admission, the patient was jaundiced but euvolemic, with no evidence of ascites or peripheral edema. Laboratory work drawn at our institution showed conjugated bilirubin of 180 mmol/L, ALT 300 U/L, AST 250 U/L, and GGT 1200 U/L. INR was 1.1 and albumin of 35 g/L. The cholesterol was elevated above 16.8 mmol/L, with high triglycerides 2.68 mmol/L, and the serum appeared visibly lipemic. The sodium level was 138 mmol/L as measured by direct potentiometry due to the visible lipemia. The osmolality of 288 mmol/kg was normal with a normal osmolar gap. Urine osmolality and sodium were also normal. He underwent routine evaluation and was listed for a liver transplant due to the profound cholestasis and growth failure. Conclusions Pseudohyponatremia is an important entity to recognize when caring for patients with cholestatic liver disease and hyponatremia. Both direct potentiometry and indirect potentiometry are currently used for sodium testing in blood in biochemistry laboratories. These measurement techniques show good agreement as long as protein and lipid concentrations in blood are normal, however, hyperlipidemia is a well-recognized cause for error in sodium estimation. It is therefore imperative to evaluate apparent hyponatremia correctly, especially when the patient appears euvolemic clinically and by normal serum osmolality. In this clinical setting, pseudohyponatremia is the likely cause and a workup should be carried out to identify possible underlying etiologies, the most probable being hypercholesterolemia. Failure to recognize this phenomenon may lead to unnecessary and potentially harmful treatments and interventions. Funding Agencies None


Urolithiasis ◽  
2021 ◽  
Author(s):  
Stavros A. Kavouras ◽  
Hyun-Gyu Suh ◽  
Marion Vallet ◽  
Michel Daudon ◽  
Andy Mauromoustakos ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1757
Author(s):  
Michael R. Szymanski ◽  
Gabrielle E. W. Giersch ◽  
Margaret C. Morrissey ◽  
Courteney L. Benjamin ◽  
Yasuki Sekiguchi ◽  
...  

Euhydration remains a challenge in children due to lack of access and unpalatability of water and to other reasons. The purpose of this study was to determine if the availability/access to a beverage (Creative Roots®) influences hydration in children and, therefore, sleep quality and mood. Using a crossover investigation, 46 participants were randomly assigned to a control group (CON) or an intervention group and received Creative Roots® (INT) for two-week periods. We recorded daily first morning and afternoon urine color (Ucol), thirst perception, and bodyweight of the two groups. Participants reported to the lab once per week and provided first morning urine samples to assess Ucol, urine specific gravity (USG), and urine osmolality (Uosmo). Participants also completed the questionnaires Profile of Mood States-Adolescents (POMS-a) and Pittsburgh Sleep Quality Index (PSQI). Dependent t-tests were used to assess the effects of the intervention on hydration, mood, and sleep quality. Uosmo was greater and Ucol was darker in the control group (mean ± SD) [Uosmo: INT = 828 ± 177 mOsm·kg−1, CON = 879 ± 184 mOsm·kg−1, (p = 0.037], [Ucol:INT = 5 ± 1, CON = 5 ± 1, p = 0.024]. USG, POMS-a, and PSQI were not significant between the groups. At-home daily afternoon Ucol was darker in the control group [INT = 3 ± 1, CON = 3 ± 1, p = 0.022]. Access to Creative Roots® provides a small, potentially meaningful hydration benefit in children. However, children still demonstrated consistent mild dehydration based on Uosmo, despite consuming the beverage.


Author(s):  
Aaron R. Caldwell ◽  
Megan E. Rosa-Caldwell ◽  
Carson Keeter ◽  
Evan C. Johnson ◽  
François Péronnet ◽  
...  

<b><i>Background:</i></b> Debate continues over whether or not individuals with low total water intake (TWI) are in a chronic fluid deficit (i.e., low total body water) [<xref ref-type="bibr" rid="ref1">1</xref>]. When women with habitually low TWI (1.6 ± 0.5 L/day) increased their fluid intake (3.5 ± 0.1 L/day) for 4 days 24-h urine osmolality decreased, but there was no change in body weight, a proxy for total body water (TBW) [<xref ref-type="bibr" rid="ref2">2</xref>]. In a small (<i>n</i> = 5) study of adult men, there were no observable changes in TBW, as measured by bioelectrical impedance, after increasing TWI for 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>]. However, body weight increased and salivary osmolality decreased indicating that the study may have been underpowered to detect changes in TBW. Further, no studies to date have measured changes in blood volume (BV) when TWI is increased. <b><i>Objectives:</i></b> Therefore, the purpose of this study was to identify individuals with habitually low fluid intake and determine if increasing TWI, for 14 days, resulted in changes in TBW or BV. <b><i>Methods:</i></b> In order to identify individuals with low TWI, 889 healthy adults were screened. Participants with a self-reported TWI less than 1.8 L/day (men) or 1.2 L/day (women), and a 24-h urine osmolality greater than 800 mOsm were included in the intervention phase of the study. For the intervention phase, 15 participants were assigned to the experimental group and 8 participants were assigned to the control group. The intervention period lasted for 14 days and consisted of 2 visits to our laboratory: one before the intervention (baseline) and 14 days into the intervention (14-day follow-up). At these visits, BV was measured using a CO-rebreathe procedure and deuterium oxide (D<sub>2</sub>O) was administered to measure TBW. Urine samples were collected immediately prior, and 3–8 h after the D<sub>2</sub>O dose to allow for equilibration. Prior to each visit, participants collected 24-h urine to measure 24-h hydration status. After the baseline visit, the experimental group increased their TWI to 3.7 L for males and 2.7 L for females in order to meet the current Institute of Medicine recommendations for TWI. <b><i>Results:</i></b> Twenty-four-hour urine osmolality decreased (−438.7 ± 362.1 mOsm; <i>p</i> &#x3c; 0.001) and urine volume increased (1,526 ± 869 mL; <i>p</i> &#x3c; 0.001) in the experimental group from baseline, while there were no differences in osmolality (−74.7 ± 572 mOsm; <i>p</i> = 0.45), or urine volume (−32 ± 1,376 mL; <i>p</i> = 0.89) in the control group. However, there were no changes in BV (Fig. <xref ref-type="fig" rid="f01">1</xref>a) or changes in TBW (Fig. <xref ref-type="fig" rid="f01">1</xref>b) in either group. <b><i>Conclusions:</i></b> Increasing fluid intake in individuals with habitually low TWI increases 24-h urine volume and decreases urine osmolality but does not result in changes in TBW or BV. These findings are in agreement with previous work indicating that TWI interventions lasting 3 days [<xref ref-type="bibr" rid="ref2">2</xref>] to 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>] do not result in changes in TBW. Current evidence would suggest that the benefits of increasing TWI are not related changes in TBW.


1987 ◽  
Vol 252 (2) ◽  
pp. F331-F337 ◽  
Author(s):  
W. Lieberthal ◽  
M. L. Vasilevsky ◽  
C. R. Valeri ◽  
N. G. Levinsky

Interactions between antidiuretic hormone (ADH) and renal prostaglandins in the regulation of sodium reabsorption and urinary concentrating ability were studied in isolated erythrocyte-perfused rat kidneys (IEPK). In this model, hemodynamic characteristics are comparable to those found in vivo, and tubular morphology is preserved throughout the period of perfusion. [Deamino]-D-arginine vasopressin (dDAVP) markedly reduced fractional sodium excretion (FE Na) in the IEPK from 3.5 +/- 0.6 to 0.45 +/- 0.14%. After indomethacin, FE Na fell still further to 0.08 +/- 0.02%. In the absence of dDAVP indomethacin had no effect on sodium excretion; FE Na was 2.4 +/- 0.6% in control and 2.0 +/- 0.4% in indomethacin-treated groups. dDAVP increased urine osmolality in the IEPK to 741 +/- 26 mosmol/kg. When prostaglandin synthesis was blocked with indomethacin, urinary osmolality increased further to 1,180 +/- 94 mosmol/kg. In isolated kidneys perfused without erythrocytes (IPK), dDAVP decreased FENa from 14.5 +/- 1.8% to 9.6 +/- 1.2%; addition of indomethacin had no further effect. dDAVP increased urine osmolality only modestly to 350 +/- 12 mosmol/kg in the IPK and indomethacin did not increase concentrating ability further (342 +/- 7 mosmol/kg). Thus the IEPK (unlike the IPK) can excrete a markedly hypertonic urine in response to ADH. ADH also enhances tubular reabsorption of sodium in the IEPK. Prostaglandins inhibit both these actions of ADH but do not directly affect sodium excretion in the absence of the hormone.


2016 ◽  
Vol 104 (6) ◽  
pp. 1554-1561 ◽  
Author(s):  
Asher Y Rosinger ◽  
Hannah G Lawman ◽  
Lara J Akinbami ◽  
Cynthia L Ogden

2015 ◽  
Vol 41 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Niek F. Casteleijn ◽  
Debbie Zittema ◽  
Stephan J.L. Bakker ◽  
Wendy E. Boertien ◽  
Carlo A. Gaillard ◽  
...  

Background: Vasopressin plays an essential role in osmoregulation, but has deleterious effects in patients with ADPKD. Increased water intake to suppress vasopressin activity has been suggested as a potential renoprotective strategy. This study investigated whether urine and plasma osmolality can be used as reflection of vasopressin activity in ADPKD patients. Methods: We measured urine and plasma osmolality, plasma copeptin concentration, total kidney volume (TKV, by MRI) and GFR (125I-iothalamate). In addition, change in estimated GFR (eGFR) during follow-up was assessed. Results: Ninety-four patients with ADPKD were included (56 males, age 40 ± 10, mGFR 77 ± 32 ml/min/1.73 m2, TKV 1.55 (0.99-2.40) l. Urine osmolality, plasma osmolality and copeptin concentration were 420 ± 195, 289 ± 7 mOsmol/l and 7.3 (3.2-14.6) pmol/l, respectively. Plasma osmolality was associated with copeptin concentration (R = 0.54, p < 0.001), whereas urine osmolality was not (p = 0.4). In addition, urine osmolality was not associated with TKV (p = 0.3), in contrast to plasma osmolality (R = 0.52, p < 0.001) and copeptin concentration (R = 0.61, p < 0.001). Fifty-five patients were followed for 2.8 ± 0.8 years. Baseline plasma and urine osmolality were not associated with change in eGFR (p = 0.6 and p = 0.3, respectively), whereas baseline copeptin concentration did show an association with change in eGFR, in a crude analysis (St. β = -0.41, p = 0.003) and also after adjustment for age, sex and TKV (St. β = -0.23, p = 0.05). Conclusions: These data suggest that neither urine nor plasma osmolality are valid measures to identify ADPKD patients that may benefit from increasing water intake. Copeptin appears a better alternative for this purpose.


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