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Environmental Research Feb 2023The incorporation of a spacer among membranes has a major influence on fluid dynamics and performance metrics. Spacers create feed channels and operate as turbulence...
The incorporation of a spacer among membranes has a major influence on fluid dynamics and performance metrics. Spacers create feed channels and operate as turbulence promoters to increase mixing and reduce concentration/temperature polarization effects. However, spacer geometry remains unoptimized, and studies continue to investigate a wide range of commercial and custom-made spacer designs. The in-depth discussion of the present systematic review seeks to discover the influence of Reynolds number or solution flowrate on flow hydrodynamics throughout a spacer-filled channel. A fast-flowing solution sweeping one membrane's surface first, then the neighboring membrane's surface produces good mixing action, which does not happen commonly at laminar solution flowrates. A sufficient flowrate can suppress the polarization layer, which may normally require the utilization of a simple feed channel rather than complex spacer configurations. When a recirculation eddy occurs, it disrupts the continuous flow and effectively curves the linear fluid courses. The higher the flowrate, the better the membrane performance, the higher the critical flux (or recovery rate), and the lower the inherent limitations of spacer design, spacer shadow effect, poor channel hydrodynamics, and high concentration polarization. In fact, critical flow achieves an acceptable balance between improving flow dynamics and reducing the related trade-offs, such as pressure losses and the occurrence of concentration polarization throughout the cell. If the necessary technical flowrate is not used, the real concentration potential for transport is relatively limited at low velocities than would be predicted based on bulk concentrations. Electrodialysis stack therefore may suffer from the dissociation of water molecules. Next studies should consider that applying a higher flowrate results in greater process efficiency, increased mass transfer potential at the membrane interface, and reduced stack thermal and electrical resistance, where pressure drop should always be indicated as a consequence of the spacer and circumstances used, rather than a problem.
Topics: Hydrodynamics; Membranes, Artificial; Water Purification; Salinity; Dialysis; Electrochemistry
PubMed: 36574794
DOI: 10.1016/j.envres.2022.115115 -
Environmental Toxicology and Chemistry Dec 2022Industries such as unconventional natural gas have seen increased global expansion to meet the increasing energy needs of our increasing global population.... (Review)
Review
Industries such as unconventional natural gas have seen increased global expansion to meet the increasing energy needs of our increasing global population. Unconventional gas uses hydraulic fracturing that produces significant volumes of produced waters, which can be highly saline and pose a toxic threat to freshwater invertebrates if exposure via discharges, spills, leaks, or runoff were to occur. The primary aim of the present review was to determine the sodium (Na ) and chloride (Cl ) content of these waters as an approximate measure of salinity and how these values compare to the NaCl or synthetic marine salt acute toxicity values of freshwater invertebrate taxa. Shale gas produced waters are much more saline with 78 900 ± 10 200 NaCl mg/L and total dissolved solids (TDS) of 83 200 ± 12 200 mg/L compared to coal bed methane (CBM) produced waters with 4300 ± 1100 NaCl mg/L and TDS of 5900 ± 1300 mg/L and pose a far greater toxicity risk from NaCl to freshwater invertebrates. In addition, the toxicity of other major ions (Ca , K , Mg , , HCO , and ) and their influence on the toxicity of Na and Cl were evaluated. Exposure of untreated and undiluted shale gas produced waters to freshwater invertebrates is likely to result in significant or complete mortality. Shale gas produced waters have higher concentrations of various metals compared with CBM produced waters and are more acidic. We recommend future research to increase the reporting and consistency of water quality parameters, metals, and particularly organics of produced waters to provide a better baseline and help in further investigations. Environ Toxicol Chem 2022;41:2928-2949. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Topics: Animals; Fresh Water; Invertebrates; Natural Gas; Salinity; Sodium Chloride; Water Pollutants, Chemical
PubMed: 36193756
DOI: 10.1002/etc.5492 -
Radiology Nov 2022Background Changing iodinated contrast media (ICM) may reduce the risk of recurrent ICM-induced hypersensitivity reactions in patients with a prior reaction. Purpose To... (Meta-Analysis)
Meta-Analysis
Background Changing iodinated contrast media (ICM) may reduce the risk of recurrent ICM-induced hypersensitivity reactions in patients with a prior reaction. Purpose To perform a systematic review on the effectiveness of ICM change in comparison with no change to prevent recurrent ICM immediate hypersensitivity reactions. Materials and methods Multiple data bases were searched without language restriction between January 1990 and August 2021 to identify comparative studies of any design that included patients with a prior ICM hypersensitivity reaction to low-osmolality ICM and re-exposure to intravascular ICM. The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, and random-effects meta-analysis. The primary outcome was the incidence of all-grade immediate recurrent hypersensitivity reactions. Secondary outcomes were the incidence of severe immediate recurrent hypersensitivity reactions and other adverse events associated with ICM change. Results Six retrospective observational studies at moderate to severe risk of bias assessed 7155 adult patients (4329 in the ICM change group and 2826 in the no-change group). Studies adopted nonstandardized switching methods, and the proportions of the ICM change group ranged between 19% (five of 27 examinations) and 80% (3104 of 3880 examinations). A Bayesian meta-analysis revealed that changing ICM was associated with a reduced risk of recurrent hypersensitivity reaction by 61% (risk ratio = 0.39; 95% credible interval [CrI]: 0.24, 0.58). The wide-ranging estimates of risk reduction were not explained by the risk of bias ratings, the event rates in the no-change group, the index-reaction severity, or the co-administered nonstandard premedication. Rare severe recurrent reactions (five studies with five events) precluded a conclusion (risk ratio = 0.34, favoring ICM change; CrI: 0.01, 3.74). Adverse events associated with ICM change were not reported. Conclusion In observational evidence of limited quality, iodinated contrast media (ICM)-change was associated with a reduced risk of recurrent immediate hypersensitivity reaction in patients with a prior ICM-induced hypersensitivity reaction. © RSNA, 2022 See also the editorial by McDonald in this issue.
Topics: Adult; Humans; Contrast Media; Retrospective Studies; Bayes Theorem; Iodine Compounds; Hypersensitivity, Immediate; Hypersensitivity
PubMed: 35852428
DOI: 10.1148/radiol.220370 -
World Neurosurgery Jun 2022Hypertonic saline (HTS) is a widely used adjunct in the treatment of traumatic brain injury (TBI). However, there is significant variability in practice patterns. Toward... (Review)
Review
Hypertonic saline (HTS) is a widely used adjunct in the treatment of traumatic brain injury (TBI). However, there is significant variability in practice patterns. Toward the goal of optimality and standardization in the use of HTS in TBI, we performed a comprehensive review of clinical protocols reported in the neurosurgical and neurocritical care literature. PubMed, Web of Science, Cochrane, Scopus, and Embase were independently queried between October and November 2021. The PRISMA guidelines were used throughout the screening process. We identified 15 high-quality studies representing data from 535 patients. We extracted patient demographics, Glasgow Coma Scale (GCS) score, mechanism of injury, HTS dosage, and rate of administration. Various HTS concentrations including 3%, 5%, 7.2%, 7.5%, and 20% were used. Modes of HTS administration included bolus (n = 125) and infusion (n = 376). Average length of stay was 22.4 days. Patient GCS score on initiation of HTS was depressed (average mean, 7.15; average median, 4.25 for studies reporting mean and median GCS, respectively). Excluding 2 studies with ambiguous doses, the mean HTS dosage was 2.7 × 10 mL across 8 studies and 2.5 mL/kg across 5 (with average post-HTS osmolality level of 304.6 mOsm/L reported in 3 studies). Infusions of 3% and 7.5% HTS are the most used concentrations given their efficacy in reducing intracranial pressure (ICP) and improving GCS score. In addition, lower HTS concentrations strongly correlated with greater ICP reduction. Therefore, lower concentrations of HTS may be practical therapeutic agents for patients with TBI given their efficacy in ICP reduction and safer complication profile compared with greater HTS concentrations. Evidence-based parametric use of HTS stands to improve patient outcomes by standardization of varied clinical practice.
Topics: Brain Injuries, Traumatic; Glasgow Coma Scale; Humans; Intracranial Hypertension; Intracranial Pressure; Retrospective Studies; Saline Solution, Hypertonic
PubMed: 35318155
DOI: 10.1016/j.wneu.2022.03.056 -
Medicine Feb 2022Rapid-onset, acute hypernatremia caused by sodium overload is a rare, life-threatening condition. Although experts recommend rapid correction of sodium concentration...
BACKGROUND
Rapid-onset, acute hypernatremia caused by sodium overload is a rare, life-threatening condition. Although experts recommend rapid correction of sodium concentration [Na] based on pathophysiological theories, only a few reports have documented the specific details of sodium correction methods. The objective of this study was to systematically review the reported treatment regimens, achieved [Na] correction rates, and treatment outcomes.
METHODS
PubMed, Ichushi-database, and references without language restrictions, from inception to January 2021, were searched for studies that described ≥1 adult (aged ≥18 years) patients with rapid-onset hypernatremia caused by sodium overload, whose treatment was initiated ≤12 hours from the onset. The primary outcome of interest was the [Na] correction rate associated with mortality.
RESULTS
Eighteen case reports (18 patients; median [Na], 180.5 mEq/L) were included. The cause of sodium overload was self-ingestion in 8 patients and iatrogenic sodium gain in 10 patients; baseline [Na] and symptoms at presentation were comparable for both groups. Individualized rapid infusion of dextrose-based solutions was the most commonly adopted fluid therapy, whereas hemodialysis was also used for patients already treated with hemodialysis. The correction rates were more rapid in 13 successfully treated patients than in 5 fatal patients. The successfully treated patients typically achieved [Na] ≤160 within 8 hours, [Na] ≤150 within 24 hours, and [Na] ≤145 within 48 hours. Hyperglycemia was a commonly observed treatment-related adverse event.
CONCLUSION
The limited empirical evidence derived from case reports appears to endorse the recommended, rapid, and aggressive sodium correction using dextrose-based hypotonic solutions.
Topics: Adolescent; Adult; Fluid Therapy; Glucose; Humans; Hypernatremia; Infusions, Intravenous; Osmolar Concentration; Sodium; Sodium, Dietary; Soy Foods; Treatment Outcome
PubMed: 35212303
DOI: 10.1097/MD.0000000000028945 -
Clinical Nutrition ESPEN Feb 2022Advice to drink plenty of fluid is common in respiratory infections. We assessed whether low fluid intake (dehydration) altered outcomes in adults with pneumonia. (Meta-Analysis)
Meta-Analysis
BACKGROUND AND AIMS
Advice to drink plenty of fluid is common in respiratory infections. We assessed whether low fluid intake (dehydration) altered outcomes in adults with pneumonia.
METHODS
We systematically reviewed trials increasing fluid intake and well-adjusted, well-powered observational studies assessing associations between markers of low-intake dehydration (fluid intake, serum osmolality, urea or blood urea nitrogen, urinary output, signs of dehydration) and mortality in adult pneumonia patients (with any type of pneumonia, including community acquired, health-care acquired, aspiration, COVID-19 and mixed types). Medline, Embase, CENTRAL, references of reviews and included studies were searched to 30/10/2020. Studies were assessed for inclusion, risk of bias and data extracted independently in duplicate. We employed random-effects meta-analysis, sensitivity analyses, subgrouping and GRADE assessment. Prospero registration: CRD42020182599.
RESULTS
We identified one trial, 20 well-adjusted cohort studies and one case-control study. None suggested that more fluid (hydration) was associated with harm. Ten of 13 well-powered observational studies found statistically significant positive associations in adjusted analyses between dehydration and medium-term mortality. The other three studies found no significant effect. Meta-analysis suggested doubled odds of medium-term mortality in dehydrated (compared to hydrated) pneumonia patients (GRADE moderate-quality evidence, OR 2.3, 95% CI 1.8 to 2.8, 8619 deaths in 128,319 participants). Heterogeneity was explained by a dose effect (greater dehydration increased risk of mortality further), and the effect was consistent across types of pneumonia (including community-acquired, hospital-acquired, aspiration, nursing and health-care associated, and mixed pneumonia), age and setting (community or hospital). The single trial found that educating pneumonia patients to drink ≥1.5 L fluid/d alongside lifestyle advice increased fluid intake and reduced subsequent healthcare use. No studies in COVID-19 pneumonia met the inclusion criteria, but 70% of those hospitalised with COVID-19 have pneumonia. Smaller COVID-19 studies suggested that hydration is as important in COVID-19 pneumonia mortality as in other pneumonias.
CONCLUSIONS
We found consistent moderate-quality evidence mainly from observational studies that improving hydration reduces the risk of medium-term mortality in all types of pneumonia. It is remarkable that while many studies included dehydration as a potential confounder, and major pneumonia risk scores include measures of hydration, optimal fluid volume and the effect of supporting hydration have not been assessed in randomised controlled trials of people with pneumonia. Such trials, are needed as potential benefits may be large, rapid and implemented at low cost. Supporting hydration and reversing dehydration has the potential to have rapid positive impacts on pneumonia outcomes, and perhaps also COVID-19 pneumonia outcomes, in older adults.
Topics: Aged; COVID-19; Case-Control Studies; Drinking; Humans; Pneumonia; SARS-CoV-2
PubMed: 35063249
DOI: 10.1016/j.clnesp.2021.11.021 -
Archives of Gynecology and Obstetrics Sep 2022Acute Sheehan's syndrome is a rare, but potentially life-threatening, obstetric event that can be complicated by diabetes insipidus. Little information on the diagnosis...
PURPOSE
Acute Sheehan's syndrome is a rare, but potentially life-threatening, obstetric event that can be complicated by diabetes insipidus. Little information on the diagnosis and treatment of Sheehan's syndrome with diabetes insipidus is available. We report on a 28-year-old patient who developed acute Sheehan's syndrome with diabetes insipidus after giving birth, and on a systematic review of similar cases.
METHODS
We performed a systematic review of the literature cataloged in PubMed and Google Scholar using the keywords "Sheehan syndrome" OR "Sheehan's syndrome" AND "diabetes insipidus" to identify relevant case reports published between 1990 and 2021. Eight Reports met the inclusion criteria (English-language abstracts available, onset in the puerperium, information about the day of the onset).
RESULTS
In the present case, postpartum curettage was necessary to remove the residual placenta. The total amount of blood loss was severe (2500 ml). On the second day postpartal, the patient developed polyuria. Laboratory analysis revealed hypernatremia with increased serum osmolality and decreased urinary osmolality. Hormone analysis showed partial hypopituitarism involving the thyroid, corticotropic, and gonadotropic axes. The prolactin level was elevated. Brain magnetic resonance imaging showed pituitary gland infarction. Desmopressin therapy was initiated and resolved the polyuria. Hormone replacement therapy was administered. Four months later, the patient was well, with partial diabetes insipidus. The literature review indicated that this case was typical in terms of symptoms and disease onset. Most reported cases involve hypotension and peripartum hemorrhage, but some patients without hemorrhage also develop Sheehan's syndrome. Elevated prolactin levels are uncommon and associated with poor prognosis in patients with Sheehan's syndrome.
CONCLUSION
Acute Sheehan's syndrome with diabetes insipidus involves nearly all pituitary hormone axes, indicating severe disease. Prolactin elevation could suggest that a case of Sheehan's syndrome is severe.
Topics: Adult; Diabetes Mellitus; Female; Humans; Hypopituitarism; Polyuria; Postpartum Hemorrhage; Postpartum Period; Pregnancy; Prolactin
PubMed: 34779875
DOI: 10.1007/s00404-021-06294-2 -
Frontiers in Pediatrics 2021Wolfram Syndrome is a rare autosomal recessive disease characterized by early-onset diabetes mellitus, neurodegeneration, and psychological disorders. Mutations in the...
Wolfram Syndrome is a rare autosomal recessive disease characterized by early-onset diabetes mellitus, neurodegeneration, and psychological disorders. Mutations in the gene , coding for the protein wolframin, cause Wolfram Syndrome and are associated with bipolar disorder and schizophrenia. This report aims to connect mutations to their impact on protein expression and structure, which ultimately translates to altered cell function and behavioral alterations of an individual. Published data were used to compile mutations associated with psychiatric symptoms, both in homozygous patients and heterozygous carriers of mutations. These mutations were evaluated using SNAP2, PolyPhen-2, and PROVEAN to predict the effects of sequence variants. Statistical analysis was performed to assess the correlation between the locations of the mutations and the damage prediction scores. Several mutations, clustering in the center and C-terminus of the polypeptide, such as A559T and R558C, are found in individuals with psychiatric diseases and appear particularly impactful on protein structure. Our analysis showed that mutations in all regions of wolframin were present in patients with schizophrenia whereas only cytoplasmic and ER luminal mutations were reported in patients with manic episodes and bipolar disorders. According to Poly-Phen-2 predictions, 82.4% of the ER lumen mutations and 85.7% of the membrane mutations are damaging. We propose mood disorders in Wolfram Syndrome and heterozygous carriers of mutations are the consequence of specific mutations in that alter the structure of wolframin, resulting in intracellular calcium dysregulations and impaired cell signaling, Understanding the effect of mutations on bipolar disorder and schizoprenia is integral to designing clinically targeted treatments for both diseases, which need more specialized treatments.
PubMed: 34746052
DOI: 10.3389/fped.2021.718132 -
Sports Medicine (Auckland, N.Z.) Feb 2022Body-fluid loss during prolonged continuous exercise can impair cardiovascular function, harming performance. Delta percent plasma volume (dPV) represents the change in... (Meta-Analysis)
Meta-Analysis
The Hydrating Effects of Hypertonic, Isotonic and Hypotonic Sports Drinks and Waters on Central Hydration During Continuous Exercise: A Systematic Meta-Analysis and Perspective.
BACKGROUND
Body-fluid loss during prolonged continuous exercise can impair cardiovascular function, harming performance. Delta percent plasma volume (dPV) represents the change in central and circulatory body-water volume and therefore hydration during exercise; however, the effect of carbohydrate-electrolyte drinks and water on the dPV response is unclear.
OBJECTIVE
To determine by meta-analysis the effects of ingested hypertonic (> 300 mOsmol kg), isotonic (275-300 mOsmol kg) and hypotonic (< 275 mOsmol kg) drinks containing carbohydrate and electrolyte ([Na] < 50 mmol L), and non-carbohydrate drinks/water (< 40 mOsmol kg) on dPV during continuous exercise.
METHODS
A systematic review produced 28 qualifying studies and 68 drink treatment effects. Random-effects meta-analyses with repeated measures provided estimates of effects and probability of superiority (p) during 0-180 min of exercise, adjusted for drink osmolality, ingestion rate, metabolic rate and a weakly informative Bayesian prior.
RESULTS
Mean drink effects on dPV were: hypertonic - 7.4% [90% compatibility limits (CL) - 8.5, - 6.3], isotonic - 8.7% (90% CL - 10.1, - 7.4), hypotonic - 6.3% (90% CL - 7.4, - 5.3) and water - 7.5% (90% CL - 8.5, - 6.4). Posterior contrast estimates relative to the smallest important effect (dPV = 0.75%) were: hypertonic-isotonic 1.2% (90% CL - 0.1, 2.6; p = 0.74), hypotonic-isotonic 2.3% (90% CL 1.1, 3.5; p = 0.984), water-isotonic 1.3% (90% CL 0.0, 2.5; p = 0.76), hypotonic-hypertonic 1.1% (90% CL 0.1, 2.1; p = 0.71), hypertonic-water 0.1% (90% CL - 0.8, 1.0; p = 0.12) and hypotonic-water 1.1% (90% CL 0.1, 2.0; p = 0.72). Thus, hypotonic drinks were very likely superior to isotonic and likely superior to hypertonic and water. Metabolic rate, ingestion rate, carbohydrate characteristics and electrolyte concentration were generally substantial modifiers of dPV.
CONCLUSION
Hypotonic carbohydrate-electrolyte drinks ingested continuously during exercise provide the greatest benefit to hydration.
Topics: Bayes Theorem; Dehydration; Exercise; Humans; Osmolar Concentration; Sodium; Water-Electrolyte Balance
PubMed: 34716905
DOI: 10.1007/s40279-021-01558-y -
Children (Basel, Switzerland) Sep 2021Hyponatraemia is a known complication in hospitalised children receiving maintenance intravenous fluid. Several studies have been published to investigate the efficacy...
Efficacy and Safety of Isotonic and Hypotonic Intravenous Maintenance Fluids in Hospitalised Children: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
Hyponatraemia is a known complication in hospitalised children receiving maintenance intravenous fluid. Several studies have been published to investigate the efficacy and safety of intravenous fluids in children. However, there is still an ongoing debate regarding the ideal solution to be used in the paediatric population. Therefore, the aim of this meta-analysis was to investigate the safety and efficacy of administering isotonic versus hypotonic intravenous maintenance fluid in hospitalised children. An extensive search was undertaken on PubMed, Web of Science, Scopus, ScienceDirect, Google Scholar and Cochrane Library on 28 December 2020. Only randomised controlled trials (RCTs) were included. We used the random-effects model for all analyses. Risk ratio (RR) and mean difference with 95% confidence intervals (CIs) were used for dichotomous and continuous outcomes, respectively. The quality of each study was assessed using the Joanna Briggs Institute critical appraisal tool for RCTs. This study is registered with PROSPERO (CRD42021229067). Twenty-two RCTs with a total of 3795 participants were included. The studies encompassed surgical and medical patients admitted to intensive care unit as well as to general wards. We found that hypotonic fluid significantly increases the risk of hyponatremia at both ≤24 h (RR 0.34; 95% CI: 0.26-0.43, < 0.00001) and >24 h (RR 0.48; 95% CI: 0.36-0.64, < 0.00001). Isotonic fluid increases the risk of hypernatraemia at ≤24 h (RR 2.15; 95% CI: 1.24-3.73, = 0.006). The prevalence of hyponatraemia was also higher in the hypotonic group at both ≤24 h (5.7% vs. 23.3%) and >24 h (6.0% vs. 26.3%). There was no statistically significant difference in the risk of developing adverse outcomes between the two groups. Mean serum and urine sodium as well as serum osmolality/osmolarity was lower in the hypotonic group. Isotonic solution is protective against the development of hyponatraemia while hypotonic solution increases the risk of hyponatraemia.
PubMed: 34572217
DOI: 10.3390/children8090785