Measurement Of Sodium Concentration Research Articles

Quantitative analysis of sodium concentration in condiments, soft drinks and mineral water by external standard 23Na-qNMR.

Sodium is essential for human health, but excessive intake can lead to hypertension. Accurate sodium labeling in foods is critical due to increasing health awareness. This study investigated the use of 23Na nuclear magnetic resonance spectroscopy (NMR) for sodium quantification in condiments, soft drinks and mineral water. In this study, external standard quantitative 23Na-NMR was used to measure sodium concentrations. Key steps included sample preparation, 90° pulse width calibration, and linewidth evaluation. The results showed that 23Na-NMR can accurately quantify sodium concentrations over a wide range, with good agreement with ion electrode methods. The results demonstrated that 23Na-NMR is a reliable method for the quantification of sodium in various liquid foods.

Longitudinal changes in sodium concentration and in clinical outcome in mild traumatic brain injury.

Ionic imbalances and sodium channel dysfunction, well-known sequelae of traumatic brain injury (TBI), promote functional impairment in affected subjects. Therefore, non-invasive measurement of sodium concentrations using 23Na MRI has the potential to detect clinically relevant injury and predict persistent symptoms. Recently, we reported diffusely lower apparent total sodium concentrations (aTSC) in mild TBI patients compared to controls, as well as correlations between lower aTSC and worse clinical outcomes. The main goal of this study was to determine whether these aTSC findings, and their changes over time, predict outcomes at 3- and 12-month from injury. Twenty-seven patients previously studied with 23Na MRI and outcome measures at 22 ± 10 days (average ± standard deviation) after injury (visit-1, v1) were contacted at 3- (visit-2, v2) and 12-month after injury (visit-3, v3) to complete the Rivermead post-concussion symptoms questionnaire (RPQ), the extended Glasgow outcome scale (GOSE), and the brief test of adult cognition by telephone (BTACT). Follow-up 1H and 23Na MRI were additionally scheduled at v2. Linear regression was used to calculate aTSC in global grey and white matters. Six hypotheses were tested in relation to the serial changes in outcome measures and in aTSC, and in relation to the cross-sectional and serial relationships between aTSC and outcome. Twenty patients contributed data at v2 and fifteen at v3. Total RPQ and composite BTACT z-scores differed significantly for v2 and v3 in comparison to v1 (each P < 0.01), reflecting longitudinally reduced symptomatology and improved performance on cognitive testing. No associations between aTSC and outcome were observed at v2. Previously lower grey and white matter aTSC normalized at v2 in comparison to controls, in line with a statistically detectable longitudinal increase in grey matter aTSC between v1 and v2 (P = 0.0004). aTSC values at v1 predicted a subset of future BTACT subtest scores, but not future RPQ scores nor GOSE-defined recovery status. Similarly, aTSC rates of change correlated with BTACT rates of change, but not with those of RPQ. Tissue aTSC, previously shown to be diffusely decreased compared to controls at v1, was no longer reduced by v2, suggesting normalization of the sodium ionic equilibrium. These changes were accompanied by marked improvement in outcome. The results support the notion that early aTSC from 23Na MRI predicts future BTACT, but not RPQ scores, nor future GOSE status.

Evaluation of a wearable fabric-based sensor for accurate sodium determination in sweat during exercise.

Newly developed wearable fabric sensors (WFS) can increase the ease and accuracy of sweat sodium measurements by performing simultaneous sampling and analysis on the body during exercise. Determine the accuracy of a WFS for measurement of sodium concentration in sweat. Subjects wore a WFS prototype and sweat collectors on their forearm during cycle ergometry. Subjects exercised at a moderate intensity (~ 65% heart rate reserve) for 30-60min. Sweat samples were collected and analyzed using a commercial sweat sodium analyzer (SSA) every 10-15min. WFS were adhered with an armband and connected to custom built electronics. Accuracy was determined by comparing predicted WFS concentration to the actual concentration from the commercial SSA and analyzed statistically using ANOVA and Bland-Altman plots. A total of 19 subjects completed the study. The average sweat sodium concentration was 59mM ± 22mM from a SSA compared with 54mM ± 22mM from the WFS. Overall, the average accuracy of the WFS was 88% in comparison to the SSA with p = 0.45. A line of best fit comparing predicted versus actual sweat sodium concentration had a slope of 0.99, intercept of - 4.46, and an r2 of 0.90. Bland-Altman analysis showed the average concentration difference between the WFS and the SSA was 5.35mM, with 99% of data points between ± 1.96 times the standard deviation. The WFS accurately predicted sweat sodium concentration during moderate intensity cycle ergometry. With the need for precise assessment of sodium loss, especially during long duration exercise, this novel analysis method can benefit athletes and coaches. Further research involving longer duration and more intense exercise is warranted.

88 Sodium Concentration Measurements in Prostate Cancer and Normal Tissue Using an External Sodium MRI Butterfly Coil

88 Sodium Concentration Measurements in Prostate Cancer and Normal Tissue Using an External Sodium MRI Butterfly Coil

Accuracy Of Sweat Sodium Concentration Measurements Using A Wearable Fabric Sensor During Cycling

Accuracy Of Sweat Sodium Concentration Measurements Using A Wearable Fabric Sensor During Cycling

Influence of reference tube location on the measured sodium concentrations in calf muscles using a birdcage coil at 3T

To investigate the influence of the sodium (Na) reference tube location in a birdcage coil on the quantification of Na in the calf muscle. Two correction methods were also evaluated. Eight (4 × 20 mM, 4 × 30 mM Na) reference tubes were placed along the inner surface of the coil and one (30 mM Na) tube more centrally near the tibia. In two volunteers, four repeated UTE scans were acquired. In six calf muscles, the Na concentration was calculated based on each reference tube. Flip angle mapping of a homogenous Na phantom was used for correcting intensity values. Alternatively, a normalized intensity map was used for correcting the in vivo signal intensities. Results were given as range or SD of Na concentration measurements over the reference tubes. For calf Na measurements, there was limited space for positioning reference tubes away from coil B1 inhomogeneity. In both volunteers, the Na quantification depended greatly on the reference tube used with a range of up to 10 mM. The central tube location gave a Na quantification close to the mean of the other tubes. The flip angle and normalized signal intensity phantom-based correction methods decreased the quantification variation from 14.9% to 5.0% and 10.4% to 2.7%, respectively. Both correction methods had little influence (< 2.3%) on quantification based on the central tube. Despite use of a birdcage coil, location of the reference tube had a great impact on Na quantification in the calf muscles. Although both correction methods did reduce this variation, placing the reference tube more centrally was found to give the most reliable results.

Performance specifications for sodium should not be based on biological variation

When increasing the quality in clinical laboratories by decreasing measurement uncertainty, reliable methods are needed not only to quantify the performance of measuring systems, but also to set goals for the performance. Sigma metrics used in medical laboratories for documenting and expressing levels of performance, are evidently totally dependent on the “total permissible error” used in the formulas.Although the conventional biological variation (BV) based model for calculation of the permissible (or allowable) total error is commonly used, it has been shown to be flawed. Alternative methods are proposed, mainly also based on the within-subject BV. Measurement uncertainty models might offer an alternative to total error models. Defining the limits for analytical quality still poses a challenge in both models.The aim of the present paper is to critically discuss current methods for establishing performance specifications by using the measurement of sodium concentrations in plasma or serum. Sodium can be measured with high accuracy but fails by far to meet conventional performance specifications based on BV. Since the use of sodium concentrations is well established for supporting clinical care, we question the concept that quality criteria for sodium and similar analytes that are under strict homeostatic control are best set by biology.

Quantitative 23 Na-MRI of the intervertebral disk at 3 T.

Monitoring the tissue sodium content (TSC) in the intervertebral disk geometry noninvasively by MRI is a sensitive measure to estimate changes in the proteoglycan content of the intervertebral disk, which is a biomarker of degenerative disk disease (DDD) and of lumbar back pain (LBP). However, application of quantitative sodium concentration measurements in 23Na‐MRI is highly challenging due to the lower in vivo concentrations and smaller gyromagnetic ratio, ultimately yielding much smaller signal relative to 1H‐MRI. Moreover, imaging the intervertebral disk geometry imposes higher demands, mainly because the necessary RF volume coils produce highly inhomogeneous transmit field patterns. For an accurate absolute quantification of TSC in the intervertebral disks, the B1 field variations have to be mitigated. In this study, we report for the first time quantitative sodium concentration in the intervertebral disks at clinical field strengths (3 T) by deploying 23Na‐MRI in healthy human subjects. The sodium B1 maps were calculated by using the double‐angle method and a double‐tuned (1H/23Na) transceive chest coil, and the individual effects of the variation in the B1 field patterns in tissue sodium quantification were calculated. Phantom measurements were conducted to evaluate the quality of the Na‐weighted images and B1 mapping. Depending on the disk position, the sodium concentration was calculated as 161.6 mmol/L–347 mmol/L, and the mean sodium concentration of the intervertebral disks varies between 254.6 ± 54 mmol/L and 290.1 ± 39 mmol/L. A smoothing effect of the B1 correction on the sodium concentration maps was observed, such that the standard deviation of the mean sodium concentration was significantly reduced with B1 mitigation. The results of this work provide an improved integration of quantitative 23Na‐MRI into clinical studies in intervertebral disks such as degenerative disk disease and establish alternative scoring schemes to existing morphological scoring such as the Pfirrmann score.

Reliability of an Ion-Selective Electrode as a Simple Diagnostic Tool for Mastitis.

Developing a simple quantitative tool for mastitis diagnosis is essential. The Ion-Selective Electrode for sodium has been reported to reliably measure sodium concentrations in human milk. To determine whether an Ion-Selective Electrode measurement of sodium:potassium ratios could serve as a diagnostic tool for mastitis and, if so, to determine the diagnostic cut-off value. A total of 107 milk samples, including 55 from milk bank donors and 52 from participants with mastitis, were studied. The sodium:potassium ratios were determined in 33 samples (without mastitis n = 15; with mastitis n = 18) by the Ion-Selective Electrode and ion chromatography. The remaining 74 samples (donor milk n = 40; participants with mastitis n = 34) were analyzed by Ion-Selective Electrode only. Values were averaged over three measurements for each method. The median postpartum months of donors and participants with mastitis were 2 and 3 months, respectively. The mean (SD) sodium:potassium ratios without and with mastitis were 0.5 (0.1) and 1.7 (1.2), respectively. A positive correlation existed between sodium:potassium ratios obtained from the two methods (r = 0.98). Area under the curve values were 0.951 (95% CI [0.904, 0.986]) for the Ion-Selective Electrode (N = 107) and 0.978 (95% CI [0.926, 1.000]) for the ion chromatography (n = 33) methods. The optimal cut-off value for the Ion-Selective Electrode method was 0.60, with 86.5% sensitivity and 92.7% specificity. The Ion-Selective Electrode was sufficiently accurate for the diagnosis of mastitis. Cohort studies are needed to explore the relationship between sodium:potassium ratios and clinical outcomes.

PE-9: Validation of Sodium Concentration in Urine By POCT: Feasibility of the Medimate in Patients with an Ileostomy

Introduction: Excessive loss of water and sodium leading to dehydration is a frequent complication in patients with an ileostomy or those with a (near) short bowel syndrome (1). To maintain electrolyte and fluid balances in these patients, measurement of the sodium concentration in a single portion of urine can be a simple and helpful tool. In general a sodium of over > 20 mmol/L is considered to rule out significant dehydration and/or sodium depletion. A direct measurement of sodium concentration in urine using the new Medimate Minilab enables patients to monitor their own sodium status at home. In this study, the performance characteristics of the Medimate Minilab were evaluated. Method: The Medimate Minilab (Medimate BV) is a self test to measure sodium concentration in urine. The technology is based on microchip capillary electrophoresis combined with conductivity detection, consisting of disposable lab-chips, the Medimate Lab-Chip and a measurement device, the Medimate Multireader ®) (2). For validation, 50 ml of urine was collected and mixed with 5 ml of lithium-containing buffer freshly collected urine was used to determine the limit of quantification (LOQ), imprecision and agreement with the Cobas 8000 ISE Roche system. Results: Imprecision of urine samples was low: a maximum CV of 6,1% was determined in repeated measurements during five days (Table 1). The smallest concentration of sodium that can be reliably measured with an acceptable imprecision was 17 mmol/L (Figure 1). The agreement with Sodium on Cobas 8000 ISE system showed an overall positive bias of 23% (Figure 2, 95 CI of +13% -+33%), with substantial deviation in individual points (R2=0,96).The device was easy to handle, and found to be suitable for patients in a home setting. It is of essential importance that instructions are adequately followed, such as filling the cup to 55 ml of urine, to avoid false low results. Conclusion: Reproducibility of results of individual samples was high. - The stability of the buffer must be optimized - The influence of the expired shelf life of the buffer on the positive bias of sodium in urine should be further investigated - Interferences in individual points must be re-evaluated Figure 1.: LOQ of Sodium in Urine Nine urine samples ranging from 17,7 mmol/l-260 mmol/l were measured in triplo and the average and CV (%) were determined.Figure 2.: Agreement of Sodium in urine Urine samples were measured on 5 consecutive days on both Cobas 8000 system and the Medimate device. Demming regression analysis: y=1,23x-3.5 Note: The buffer solution exceeded the shelf-life. The influence of the buffer on the positive bias will be part of further investigation.

Electronic control of constant potential capacitive readout of ion-selective electrodes for high precision sensing

Constant potential capacitive readout of ion-selective membranes offers better sensitivity than traditional potentiometry by giving an easily identifiable transient current spike, which can be integrated to give a charge proportional to logarithmic of ion activity. Some concerns of this technique include complex fluidic handling, longer measurement times, baseline drifts and memory effects arising from excess charge accumulation on the capacitor. This work describes an electronic circuit strategy to automate the switching procedure, resulting in rapid and reproducible measurements. In contrast to earlier work, alternating to a reference solution is no longer required for establishing a new current baseline. The open-circuit potential is measured before performing chronoamperometry and its value is applied directly to the sample solution. The intermittent discharging of the capacitor by electronic circuit assures that the potential difference across the capacitor returns again to zero. This electronic capacitive readout system was applied to measure sodium concentration using a 10 μF capacitor to amplify the signal. The precision was found to be improved over direct potentiometry, corresponding to 0.11 mmol L−1 NaCl and 0.13 mmol L−1 NaCl for standard solutions and pooled serum sample, respectively. Using the automated electronic system for ion measurement makes the system more robust while resulting in fast and reliable quantitative measurements.

Pseudohyponatremia and falsely increased serum osmolal gap caused by paraprotein in a patient with severe metabolic acidosis – a case study

Abstract Introduction: The aim of the study is to present a case study of a 63-year-old male with pseudohyponatremia, falsely increased serum osmolal gap and severe metabolic acidosis. Material and Methods: Venous whole blood (direct sodium selective electrode measurement) and serum (indirect sodium selective electrode measurement) were used to measure sodium concentration. Serum cholesterol, triacylglycerides and total protein were measured to confirm pseudohyponatremia. Base excess in extracellular fluid and serum bicarbonate concentrations were employed as markers of metabolic acidosis. Serum protein electrophoresis and free light chain analysis were used for the detection of paraproteins. Results: Venous whole blood acid base analysis showed a pH of 7.171, negative base excess in extracellular fluid of – 18.6 mmol/L and sodium concentration of 140 mmol/L. Serum test measurement revealed serum sodium concentration of 130 mmol/L, osmolal gap of 24 mmol/kg, creatinine concentration of 702 µmol/L, HCO3- concentration of 6.1 mmol/L and total protein concentration of 134.9 g/L. Serum paraprotein IgG kappa with a concentration of 86 g/L and a serum free light chains kappa/lambda ratio of 223.5, along with the final diagnosis of multiple myeloma were detected. Toxic alcohol ingestion was considered, both methanol and ethylene glycol tests were negative. Conclusions: High paraprotein concentrations in serum may lead to pseudohyponatremia when measured by indirect ion selective electrodes. Multiple myeloma frequently leads to renal failure with metabolic acidosis.

COVID-19 and dysnatremia: A comparison between COVID-19 and non-COVID-19 respiratory illness.

Objective:To investigate the occurrence of disorders of water and sodium balance in COVID-19 in our clinic.Methods:In this retrospective chart review, patients were included if a polymerase chain test result for SARS-CoV-2 was obtained and if at least one plasma sodium concentration measurement was obtained during the period from March to June 2020. The occurrences of hyponatremia and hypernatremia were compared between 193 SARS-CoV-2-positive and 138 SARS-CoV-2-negative patients. A χ² test was used to determine statistical significance, and the corresponding p-values were calculated.Results:Hypernatremia was significantly more frequently observed in COVID-19 patients, in 38% (74 of 193), versus only 8% in SARS-CoV-2-negative patients (11 of 138) (p < 0.01). Hyponatremia was observed in 34% of the included COVID-19 patients (65 of 193) versus 24% of SARS-CoV-2-negative patients (33 of 138). In 12% of all COVID-19 patients (23 of 193), both hyponatremia and hypernatremia were observed at some point during their admission. Among the non-COVID-19 patients, only 4% showed these plasma sodium concentration fluctuations (5 of 138). The mortality rate among the hospitalized COVID-19 patients was 23% (45 of 193). Correcting for double-counting, more than 71% (32 of 45) of the deceased COVID-19 patients developed dysnatremia (hyponatremia, hypernatremia or both) versus 57% (84 out of 148) of the surviving COVID-19 patients.Conclusion:Disorders of water and sodium balance—and especially hypernatremia—seem to be a common occurrence in COVID-19 patients. This has important implications for the treatment of COVID-19 patients.

Sodium distribution in the bovine brain.

Fatal sodium intoxication can occur in many species, including cattle, and postmortem confirmation often includes brain sodium concentration determination. Published information regarding brain sodium distribution in cattle was not found in a literature review. Our study was designed to determine whether sodium is uniformly distributed throughout the bovine brain. Eight whole bovine brains were collected from adult cattle with no neurologic signs or history suggestive of sodium intoxication, and with a non-neurologic cause of death diagnosed on gross examination. Brains were divided mid-sagittally. One hemisphere of each brain was homogenized. Subsamples were obtained from the remaining hemisphere (rostral, caudal, and dorsal cerebral cortices; brainstem, thalamus, and cerebellum). Sodium concentrations of regions and homogenates were measured by inductively coupled plasma-mass spectrometry. Data were analyzed using repeated measures ANOVA with a pairwise post-test to compare mean sodium concentration of each region to mean homogenate sodium concentration. Brain sodium was not uniformly distributed; sodium concentrations in different regions of the same brain varied somewhat unpredictably. Homogenization of an entire brain hemisphere appears to be the ideal method of sample preparation to ensure accurate brain sodium concentration measurement in adult cattle.

Dipodal Molecular Device as Fluorescent Sensor for Na(I) Detection

A novel dipodal fluorescent sensor, N1,N3-bis(2-(2,3,4-trihydroxybenzylidene)amino)ethylmalo namide (MEP), suitable for the practical measurement of sodium concentration has been successfully developed and characterized by several spectroscopic techniques. The design of the dipodal scaffold includes a central unit, spacer, and fluorophore moiety as structural key features. The fluorescence sensor MEP adopts a photoinduced electron transfer mechanism and shows excellent selectivity for Na(I) among other biologically and environmentally important metal ions, viz., Na(I), K(I), Al(III), Cr(III), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) in DMSO by demonstrating a remarkable enhancement in the fluorescence intensity from 345.5 to 705.5 a.u. at λmax = 532.9 nm. The 1:2 binding stoichiometry between the ligand and Na(I) ion was confirmed by Stern–Volmer and Hill plots. The association constant determined for the ligand with the sodium metal ion is found to be very high, 7.7 × 106 M–2, which may be attributed to the trapping of sodium ions into the pseudo cavities of the ligand created by interaction of the ligand and sodium ions. The studies explore potential applications of the ligand for Na(I) ions detection in environmental and industrial applications.

Hyponatraemia despite isotonic maintenance fluid therapy: a time series intervention study

ObjectiveTo examine the prevalence of dysnatraemias among children admitted for paediatric surgery before and after a change from hypotonic to isotonic intravenous maintenance fluid therapy.DesignRetrospective consecutive time series intervention study.SettingPaediatric...

Optimization of the compositions of polyanionic sodium-ion battery cathode NaFe2−xVx(PO4)(SO4)2

Sodium (Na) super ionic conductor (NASICON) polyanionic compounds have recently attracted much attention from the battery community because of their electroactive properties and reasonably high ionic conductivities, leading to their use as a cathode in sodium-ion batteries. This article describes the compositional optimizations, crystallographic evaluations, and electrochemical behavior of a new mixed NASICON polyanionic compound, NaFe2−xVx(PO4)(SO4)2. By doping the characteristic Fe3+ sites of the FeO6 octahedrons with varying amounts of V3+, the electrochemical stability and charge transport in NaFe2(PO4)(SO4)2 were enhanced. The resulting best composition, with crystal structure NaFe1.4V0.6(PO4)(SO4)2 resolved through the Rietveld method, exhibited a stable capacity compared with the other synthesized compositions. In situ powder x-ray diffraction measurements, a single-phase intercalation/deintercalation mechanism of the NASICON structure in the measured sodium concentration window was observed with no impurity phase formation. Further electrochemical assessments revealed the interfacial charge transfer kinetics to be the rate-limiting step in the sodium concentration window. Also, the measured sodium-ion diffusivity values in the range of 6 × 10−11 to 7 × 10−11 cm2/s in the measured sodium concentration range. The results reported here highlight the potential of compositionally and morphologically optimized NaFe1.4V0.6(PO4)(SO4)2 with higher particle surface areas as a cathode material for high-performance sodium-ion batteries.

Assessing the variability of 23 Na MRI in skeletal muscle tissue: Reproducibility and repeatability of tissue sodium concentration measurements in the lower leg at 3 T.

The goal of this study was to evaluate the reproducibility and repeatability of tissue sodium concentration (TSC) measurements using 23 Na MRI in skeletal muscle tissue. 23 Na MRI was performed at 3 T on the right lower leg of eight healthy volunteers (aged 28 ± 4 years). The examinations were repeated at the same site after ~ 22 weeks to assess the variability over a medium-term period. Additionally, they were scanned at a second site shortly before or shortly after the first visit (within 3 weeks) to evaluate the inter-site reproducibility. Moreover, we analysed the effect of B0 correction on the variability. Coefficients of variations (CVs) from mean TSC values as well as Bland-Altman plots were used to assess intra-site repeatability and inter-site reproducibility. In phantom measurements, the B0 correction improved the quantitative accuracy. We observed differences of up to 4.9 mmol/L between the first and second visit and a difference of up to 3.7 mmol/L between the two different sites. The CV for the medium-term repeatability was 15% and the reproducibility CV was 9%. The Bland-Altman plots indicated high agreement between the visits in all muscle regions. The systematic bias of -0.68 mmol/L between site X and Y (P = 0.03) was slightly reduced to -0.64 mmol/L after B0 correction (P = 0.04). This work shows that TSC measurements in healthy skeletal muscle tissue can be performed with good repeatability and reproducibility, which is of importance for future longitudinal or multicentre studies.

Impact of fractional excretion of sodium on a single morning void urine collection as an estimate of 24-hour urine sodium.

The standard for assessing dietary sodium intake is to measure 24-hour urine sodium. On average, 93% of daily sodium intake is excreted over24-hours. Expense and difficulties in obtaining complete 24-hour collections have led to the measurement of sodium concentration in spot and single-void urine samples, using predictive equations to estimate 24-hour urine sodium. Although multiple predictive equations have been developed, in addition to having anaverage bias, all the equations overestimate 24-hour sodium at lower levels of 24-hour sodium and underestimate 24-hour urine sodium at higher levels of24-hour sodium. One of the least biased estimating equations is the INTERSALT equation, which incorporates a spot urine creatinine concentration. The authors hypothesized that differential fractional excretion of sodium (FeNa)(derived from a morning void collection) relative to creatinine would impacton the accuracy of the INTERSALT equation in estimating 24-hour urine sodium. In a prospective study of 139 adults aged 65years and over, three sequential morning void and 24-hour urine samples were examined. There was a significant correlation between increasing FENa and the difference between estimated and measured 24-hours urine sodium (r=0.358, P<.01). In the lowest quartile of FENa, the INTERSALT equation overestimated 24-hour urine sodium, but underestimated 24-hour urine sodium with greater magnitude in each of the subsequent quartiles of FENa. Differential excretion of sodium relative to creatinine, potentially impacted by renal blood flow and hydration, among other factors, affected the accuracy of the INTERSALT equation. Additional research may refine the INTERSALT and other predictive equations to increase their accuracy.

Hypotonic and isotonic intravenous maintenance fluids in hospitalised paediatric patients: a randomised controlled trial

ObjectiveTo compare the changes in serum sodium and acid/base status in patients receiving hypotonic and isotonic solutions.DesignA randomised, controlled and double-blind clinical trial.SettingDepartment of Paediatrics in a tertiary general hospital...