Inhibition of pannexin-1 does not restore electrolyte balance in precystic Pkd1 knockout mice.

Mutations in PKD1 and PKD2 cause autosomal dominant polycystic kidney disease (ADPKD), which is characterized by the formation of fluid-filled cysts in the kidney. In a subset of ADPKD patients, reduced blood calcium (Ca2+) and magnesium (Mg2+) concentrations are observed. As cystic fluid contains increased ATP concentrations and purinergic signaling reduces electrolyte reabsorption, we hypothesized that inhibiting ATP release could normalize blood Ca2+ and Mg2+ levels in ADPKD. Inducible kidney-specific Pkd1 knockout mice (iKsp-Pkd1-/-) exhibit hypocalcemia and hypomagnesemia in a precystic stage and show increased expression of the ATP-release channel pannexin-1. Therefore, we administered the pannexin-1 inhibitor brilliant blue-FCF (BB-FCF) every other day from Day 3 to 28 post-induction of Pkd1 gene inactivation. On Day 29, both serum Ca2+ and Mg2+ concentrations were reduced in iKsp-Pkd1-/- mice, while urinary Ca2+ and Mg2+ excretion was similar between the genotypes. However, serum and urinary levels of Ca2+ and Mg2+ were unaltered by BB-FCF treatment, regardless of genotype. BB-FCF did significantly decrease gene expression of the ion channels Trpm6 and Trpv5 in both control and iKsp-Pkd1-/- mice. Finally, no renoprotective effects of BB-FCF treatment were observed in iKsp-Pkd1-/- mice. Thus, administration of BB-FCF failed to normalize serum Ca2+ and Mg2+ levels.

How a positive fluid balance develops in acute kidney injury: A binational, observational study.

PURPOSE: A positive fluid balance (FB) is associated with harm in intensive care unit (ICU) patients with acute kidney injury (AKI). We aimed to understand how a positive balance develops in such patients. METHODS: Multinational, retrospective cohort study of critically ill patients with AKI not requiring renal replacement therapy. RESULTS: AKI occurred at a median of two days after admission in 7894 (17.3%) patients. Cumulative FB became progressively positive, peaking on day three despite only 848 (10.7%) patients receiving fluid resuscitation in the ICU. In those three days, persistent crystalloid use (median:60.0 mL/h; IQR 28.9-89.2), nutritional intake (median:18.2 mL/h; IQR 0.0-45.9) and limited urine output (UO) (median:70.8 mL/h; IQR 49.0-96.7) contributed to a positive FB. Although UO increased each day, it failed to match input, with only 797 (10.1%) patients receiving diuretics in ICU. After adjustment, a positive FB four days after AKI diagnosis was associated with an increased risk of hospital mortality (OR 1.12;95% confidence intervals 1.05-1.19;p-value <0.001). CONCLUSION: Among ICU patients with AKI, cumulative FB increased after diagnosis and was associated with an increased risk of mortality. Continued crystalloid administration, increased nutritional intake, limited UO, and minimal use of diuretics all contributed to positive FB. KEY POINTS: Question How does a positive fluid balance develop in critically ill patients with acute kidney injury? Findings Cumulative FB increased after AKI diagnosis and was secondary to persistent crystalloid fluid administration, increasing nutritional fluid intake, and insufficient urine output. Despite the absence of resuscitation fluid and an increasing cumulative FB, there was persistently low diuretics use, ongoing crystalloid use, and a progressive escalation of nutritional fluid therapy. Meaning Current management results in fluid accumulation after diagnosis of AKI, as a result of ongoing crystalloid administration, increasing nutritional fluid, limited urine output and minimal diuretic use.

Effect of dietary electrolyte balance and arginine to lysine ratio on hematological, antioxidant and immunological traits in dual-purpose breeding hens under cyclic heat stress condition.

A total of 245 hens and 35 cocks (32 weeks age) were assigned to seven treatment groups (five replicates with seven hens and one cock) to investigate the effect of dietary electrolyte balance (DEB) and arginine to lysine ratio (Arg/Lys) on birds' physiological and biochemical traits under cyclic heat stress (CHS) condition. Birds were housed in an environmentally controlled facility having four sectors. The first group (positive control, PC) was kept under thermoneutral conditions and fed diet with DEB of 180 mEq and Arg/Lys of 1.25, whereas the other six treatments were kept in the second sector under CHS and fed diet with DEB and Arg/Lys equal to: 180 mEq and 1.25 (negative control, NC); 250 mEq and 1.25; 320 mEq and 1.25; 180 mEq and 1.37; 250 mEq and 1.37; 320 mEq and 1.37, respectively. Hens on NC group had significantly decreased red blood cells (RBCs), white blood cells (WBCs) and its fractions. The groups fed different DEB and Arg/Lys in diet significantly enhanced the blood parameters and plasma lipid profile compared NC group. Hens under CHS fed on 250 and 320 DEB with 1.37 Arg/Lys recorded the lowest concentration of low-density lipoprotein (LDL) compared with the other groups. Triiodothyronine (T3) activity was not differed among groups, while T4 activity in layer exposed to CHS (NC group) recorded the highest activity compared to PC. From findings, it can be concluded that laying hens fed a diet having DEB 250 mEq with 1.37 Arg/Lys could be successfully applied to counteract the adverse effect of CHS and to improve blood hematological and biochemical traits, antioxidants, and immunity response.

Managing fluid balance and nutritional status in a short bowel syndrome patient awaiting intestinal transplant: a case report.

BACKGROUND: Despite being a long-term therapy for patients with short bowel syndrome (SBS), subcutaneous injections of teduglutide promote the regeneration of the gastrointestinal tract. Such cases are particularly concerning for patients with residual small bowel. METHODS: In this report, we present a case of an SBS patient with only 5 cm of remaining small bowel and a high-output duodenal stoma, who was treated with teduglutide. RESULTS: The initiation of teduglutide injections in our patient resulted in a reduction of stoma output, improvement in the patient's nutritional status, regulation of fluid balance, and stabilization of their clinical condition. CONCLUSIONS: This case suggests that subcutaneous injections of teduglutide, when combined with appropriate nutritional care, can effectively treat high-output stomas, even in cases where the small bowel is nearly absent.

Association between the intraoperative fluid balance during cardiac surgery and postoperative sequential organ failure assessment score: a post hoc analysis of the BROTHER study, a retrospective multicenter cohort study.

Although intraoperative intravenous fluids are commonly administered to reverse intraoperative hypotension during cardiac surgery, the appropriate volume remains unclear. This study aimed to evaluate the relationship between the intraoperative fluid balance and sequential organ failure assessment (SOFA) score in patients undergoing cardiac surgery to determine the impact of intraoperative intravenous fluids on their organs. This was a post hoc analysis using data from a multicenter, retrospective, observational study across 14 intensive care units (ICUs) in Japan. Adult patients admitted to ICUs after elective coronary artery bypass grafting or valve surgery from January 1 to December 31, 2018 were enrolled. We compared patients with intraoperative fluid balance < 20 ml/kg to those with fluid balance ≥ 20 ml/kg and conducted a multiple regression analysis for the SOFA score within 24 h of ICU admission. Of the 1567 included patients, 870 met the eligibility criteria. A total of 725 patients (83%) had an intraoperative fluid balance of ≥ 20 ml/kg. In the univariate analysis, the SOFA score (interquartile range) was 7 (6-8) and 7 (6-9) in the intraoperative fluid balance < 20 ml/kg and ≥ 20 ml/kg groups, respectively (p = 0.017). Multiple regression analysis showed a positive association between intraoperative fluid balance and SOFA score within 24 h of ICU admission [standardized coefficient 0.0065 (95% confidence interval 0.0036-0.0095), p < 0.001]. Intraoperative fluid balance in patients undergoing cardiac surgery was significantly associated with higher SOFA scores within 24 h of ICU admission.

Hydration and Performance in Young Triathletes During a Competition in Tropical Climate.

PURPOSE: We examined fluid intake, the relation between body mass (BM) loss and performance, and core temperature in young triathletes during a competition in tropical climate. METHODS: Fluid intake and pre and post BM were measured in 35 adolescent athletes, and core temperature was measured in one female and one male. RESULTS: Mean urine specific gravity (1.024 [0.007]) indicated that athletes were in suboptimal state of hydration upon waking. Race time was 73.2 (8.0) minutes. BM decreased by 0.6 (0.3) kg (P < .05). Fluid intake (528.5 [221.6] mL) replaced 47% of the fluid loss (1184.9 [256.4] mL) and was higher during run (11.5 [6.6] mL·min-1) compared to bike (7.3 [3.1] mL·min-1), P < .01. Loss in BM was ≥1.0% in 66% and ≥1.5% in 29% of the athletes. Males showed a moderate association between percentage loss in BM and finishing time (r = -.52), higher sweat rates (1.0 [0.3] L·h-1), and faster times (69.4 [7.5] min; P < .05). Core temperature rose to 40.1 °C in the female and 39.6 °C in the male. CONCLUSION: Young triathletes competing in a hot/humid climate became mildly to moderately dehydrated and hyperthermic even when water and sports drinks were available but did not show symptoms of heat illness.

Peritoneal catheters in neonates undergoing complex cardiac surgery: a multi-centre descriptive study.

BACKGROUND: The use of peritoneal catheters for prophylactic dialysis or drainage to prevent fluid overload after neonatal cardiac surgery is common in some centres; however, the multi-centre variability and details of peritoneal catheter use are not well described. METHODS: Twenty-two-centre NEonatal and Pediatric Heart Renal Outcomes Network (NEPHRON) study to describe multi-centre peritoneal catheter use after STAT category 3-5 neonatal cardiac surgery using cardiopulmonary bypass. Patient characteristics and acute kidney injury/fluid outcomes for six post-operative days are described among three cohorts: peritoneal catheter with dialysis, peritoneal catheter with passive drainage, and no peritoneal catheter. RESULTS: Of 1490 neonates, 471 (32%) had an intraoperative peritoneal catheter placed; 177 (12%) received prophylactic dialysis and 294 (20%) received passive drainage. Sixteen (73%) centres used peritoneal catheter at some frequency, including six centres in >50% of neonates. Four centres utilised prophylactic peritoneal dialysis. Time to post-operative dialysis initiation was 3 hours [1, 5] with the duration of 56 hours [37, 90]; passive drainage cohort drained for 92 hours [64, 163]. Peritoneal catheter were more common among patients receiving pre-operative mechanical ventilation, single ventricle physiology, and higher complexity surgery. There was no association with adverse events. Serum creatinine and daily fluid balance were not clinically different on any post-operative day. Mortality was similar. CONCLUSIONS: In neonates undergoing complex cardiac surgery, peritoneal catheter use is not rare, with substantial variability among centres. Peritoneal catheters are used more commonly with higher surgical complexity. Adverse event rates, including mortality, are not different with peritoneal catheter use. Fluid overload and creatinine-based acute kidney injury rates are not different in peritoneal catheter cohorts.

Safety and Efficacy of Albumin for Pump Priming in Cardiac Surgery: A Meta-Analysis.

OBJECTIVES: To assess the efficacy and safety of albumin as pump priming fluid in cardiac surgery. DESIGN: Meta-analysis of randomized controlled trials. SETTING: Each study was conducted in a surgical center or intensive care unit. PARTICIPANTS: Adult and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass who received circuit priming fluids. INTERVENTIONS: Extracorporeal circuit priming with either albumin or crystalloid. MEASUREMENTS AND RESULTS: Fourteen eligible randomized controlled trials with 741 patients were included in the present meta-analysis. Albumin prime had lower bleeding (CI -202.20 to -142.88 mL, p < 0.00001) and showed a greater advantage in preserving platelet counts (CI 14.85-21.48 × 103 mm-3, p < 0.00001), maintaining colloid osmotic pressure and sustaining negative fluid balance. No significant differences were found in the remaining study outcomes. CONCLUSIONS: Albumin was shown to be safe and efficacious in extracorporeal circulation perfusion. However, its clinical advantages were not clearly highlighted, as there were no significant differences in the number of deaths, length of hospital stay, or intensive care unit duration. The results should be interpreted cautiously, as most included studies were small in scale, and the total number of participants was limited.

Effect of Personalized Sodium Replacement on Fluid and Sodium Balance and Thermophysiological Strain During and After Ultraendurance Running in the Heat.

PURPOSE: To investigate the effect of personalized sweat sodium replacement on drinking behavior, sodium and water balance, and thermophysiological responses during and after ultraendurance running in hot conditions. METHODS: Nine participants (7 male, 2 female) completed two 5-hour treadmill runs (60% maximum oxygen uptake, 30°C ambient temperature), in a double-blind randomized crossover design, consuming sodium chloride (SODIUM) capsules to replace 100% of previously assessed losses or placebo (PLACEBO). Fluid was consumed ad libitum. RESULTS: No effect of SODIUM was observed for ad libitum fluid intake or net fluid balance (P > .05). Plasma sodium concentration increased in both trials, but to a greater extent in SODIUM at 2.5 hours (mean [SD]: 4 [4] mmol·L-1 vs 1 [5] mmol·L-1; P < .05) and postexercise (4 [3] mmol·L-1 vs 1 [5] mmol·L-1; P < .05). Plasma volume change was not different between trials (P > .05) but was strongly correlated with sodium balance in SODIUM (r = .880, P < .01). No effect of sodium replacement was observed for heart rate, rectal temperature, thermal comfort, perceived exertion, or physiological strain index. During the 24 hours postexercise, ad libitum fluid intake was greater following SODIUM (2541 [711] mL vs 1998 [727] mL; P = .04), as was urinary sodium excretion (NaCl: 66 [35] mmol, Pl: 21 [12] mmol; P < .01). CONCLUSIONS: Personalized sweat sodium replacement during ultraendurance running in hot conditions, with ad libitum fluid intake, exacerbated the rise in plasma sodium concentration compared to no sodium replacement but did not substantially influence overall body-water balance or thermophysiological strain. A large sodium deficit incurred during exercise leads to substantial renal sodium conservation postexercise.

The impact of intraoperative and postoperative fluid balance on complications for transthoracic esophagectomy: a retrospective analysis.

OBJECTIVE: Transthoracic esophagectomy is associated with significant morbidity and mortality. Therefore, it is imperative to optimize perioperative management and minimize complications. In this retrospective analysis, we evaluated the association between fluid balance and esophagectomy complications at a tertiary hospital in Melbourne, Australia, with a particular focus on respiratory morbidity and anastomotic leaks. Cumulative fluid balance was calculated intraoperatively, postoperatively in recovery postoperative day (POD) 0, and on POD 1 and 2. High and low fluid balance was defined as greater than or less than the median fluid balance, respectively, and postoperative surgical complications were graded using the Clavien-Dindo classification. RESULTS: In total, 109 patients, with an average age of 64 years, were included in this study. High fluid balance on POD 0, POD1 and POD 2 was associated with a higher incidence of anastomotic leak (OR 8.59; 95%CI: 2.64-39.0). High fluid balance on POD 2 was associated with more severe complications (of any type) (OR 3.33; 95%CI: 1.4-8.26) and severe pulmonary complications (OR 3.04; 95%CI: 1.27-7.67). For every 1 L extra cumulative fluid balance in POD 1, the odds of a major complication increase by 15%, while controlling for body mass index (BMI) and American Society of Anaesthesiologists (ASA) class. The results show that higher cumulative fluid balance is associated with worsening postoperative outcomes in patients undergoing transthoracic esophagectomy. Restricted fluid balance, especially postoperatively, may mitigate the risk of postoperative complications - however prospective trials are required to establish this definitively.

[Time-related association between fluid balance and prognosis in sepsis patients: a cohort study based on MIMIC-IV database].

OBJECTIVE: To investigate time-related association between fluid balance and prognosis in sepsis patients. METHODS: A retrospective cohort study was conducted based on the data of sepsis patients in the Medical Information Database for Intensive Care-IV 2.0 (MIMIC-IV 2.0) from 2008 to 2019. Sepsis patients aged ≥ 18 years who were admitted to intensive care unit (ICU) for at least 2 days were included. The daily fluid balance and cumulative fluid balance (CFB) were calculated from days 1 to 7 after ICU admission. According to CFB,the patients were divided into negative fluid balance group (CFB% < 0%), fluid balance group (0% ≤ CFB% ≤ 10%), and fluid overload group (CFB% > 10%). In-hospital mortality was the primary outcome. Multifactorial Logistic regression was used to analyze time-related association between different CFB and the risk of in-hospital mortality in patients with sepsis during 7 days after ICU admission. In addition, subgroup analysis was performed on patients with septic shock and patients with sepsis who stayed in the ICU for 7 days or longer. RESULTS: A total of 11 437 patients with sepsis were included, of which 6 595 were male and 4 842 were female. The mean age was (64.4±16.4) years. A total of 10 253 patients (89.6%) survived and 1 184 patients (10.4%) died during hospitalization. Compared with the survival group, patients in the death group were older, lighter, had higher sequential organ failure assessment (SOFA), simplified acute physiology score II (SAPS II), longer ICU stay, higher incidence of septic shock, and higher proportion of invasive mechanical ventilation, renal replacement therapy (RRT) and vasoactive drugs. In terms of comorbidities, congestive heart failure, renal disease, liver disease, and malignancy were more common in the death group. The death group had a higher daily fluid balance than the survival group during 7 days after ICU admission, the CFB in the two groups gradually increased with length of ICU stay. After adjusting variables such as age, gender, race, SOFA score, SAPS II score, comorbidities, and the use of invasive mechanical ventilation, RRT and vasoactive drugs, multivariate Logistic regression analysis showed that fluid overload on day 1 after ICU admission was a protective factor for the reduced risk of in-hospital mortality in sepsis patients [odds ratio (OR) = 0.74, 95% confidence interval (95%CI) was 0.64-0.86, P = 0.001]. However, fluid overload on day 3 was a risk factor for in-hospital mortality in sepsis patients (OR = 1.70, 95%CI was 1.47-1.97, P < 0.001) and the risk of in-hospital mortality was significantly increased from day 4 to day 7. Furthermore, the same results were obtained in patients with septic shock and sepsis patients who stayed in the ICU for 7 days or longer. CONCLUSIONS: Fluid overload on day 1 was associated with reduced in-hospital mortality. However, from the third day, fluid overload increases the risk of in-hospital mortality. Thus, managing fluid balance at different times may improve prognosis.

The impact of intra- and postoperative fluid balance in pancreatic surgery - A retrospective cohort study.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate the impact of perioperative fluid administration in pancreatic surgery. METHODS: Patients who underwent pancreatic resections were identified from our institution's prospectively maintained database. Fluid balances were recorded intraoperatively and at 24hr postoperatively. Patients were stratified into tertiles of fluid administration (low, medium, high). Adjusted multivariable analysis was performed and outcome measures were postoperative complications. RESULTS: A total of 211 patients were included from 2012 to 2017. Complication rates were POPF(B/C) 19.4%, DGE(B/C) 14.7%, PPH(C) 10.0% and CDC ≥ IIIb 26.1%. In multivariable analysis, high perioperative fluid balance was an independent risk factor associated with POPF (OR = 10.5, 95%CI 2.7-40.7, p = .001), CDC (OR = 2.5, 95%CI 1.2-5.3, p < .002), DGE (OR = 2.3, 95%CI 1.0-5.2, p = .017), PPH (OR = 6.7 95%CI 2.2-20.0, p = .038) and reoperation (OR = 3.1, 95%CI 1.6-6.2, p = .006). In multivariable analysis with intraoperative and postoperative fluid balances as separate predictors, intraoperative (OR = 2,5, 95%CI 1.2-5.5, p = .04) and postoperative fluid balance (OR = 2.5, 95%CI 1.2-5.5, p = .02) were predictors of POPF. Postoperative fluid balance was the only predictor for mortality (OR = 4.5, 95%CI 1.0-18.9, p = .041) and predictor for CDC (OR = 2.0, 95%CI 1.0-4.0, p = .043) and OHS days (OR = 6.9, 95%CI 0.03-13.7, p = .038). CONCLUSIONS: High postoperative fluid balance in particular is associated with postoperative morbidity. Maintaining a fluid-restrictive strategy postoperatively should be recommended for patients undergoing pancreatic surgery.

Perioperative Fluid Balance and the Risk of Postoperative Pancreatic Fistula After Pancreaticoduodenectomy: A Propensity Score-adjusted Analysis.

BACKGROUND/AIM: The impact of perioperative fluid management on postoperative morbidity after pancreaticoduodenectomy (PD) remains uncertain. This study aimed to investigate the independent association between perioperative fluid balance (FB) and clinically relevant postoperative pancreatic fistula (POPF) in PD patients. PATIENTS AND METHODS: A total of 243 consecutive open PD patients were included. Intra- and postoperative FB until postoperative day 3 were calculated, and their predictive performance for POPF was assessed using receiver operating characteristic (ROC) analysis. Propensity score (PS) was estimated as the probability of having higher FB, and factors associated with POPF were identified using crude and PS-adjusted logistic regression models. RESULTS: POPF occurred in 60 patients (24.7%). ROC analysis showed the highest predictive value for total FB on postoperative days 1 and 2, with a cut-off value of 1,585 ml (area under the ROC curve=0.74). Patients with FB ≥1,585 ml had a significantly higher POPF rate (48.3%) compared to those with lower FB (11.0%, PS-adjusted p<0.001). Male sex, body mass index ≥25 kg/m2, non-pancreatic ductal adenocarcinoma, biliary drainage, main pancreatic duct diameter <3 mm, and higher FB showed significant associations with POPF in crude univariate analysis. Higher FB remained a significant factor in both crude multivariate and PS-adjusted analysis [crude multivariate: odds ratio (OR)=8.0; PS-adjusted univariate: OR=4.2; PS-adjusted multivariate: OR=6.1, all p<0.001]. CONCLUSION: Higher early postoperative FB, a potentially modifiable factor, may be independently associated with increased risk of POPF in PD patients.

Effect of fluid replacement with green tea on body fluid balance and renal responses under mild thermal hypohydration: a randomized crossover study.

PURPOSE: Maintaining an appropriate hydration level by ingesting fluid in a hot environment is a measure to prevent heat-related illness. Caffeine-containing beverages, including green tea (GT), have been avoided as inappropriate rehydration beverages to prevent heat-related illness because caffeine has been assumed to exert diuretic/natriuretic action. However, the influence of caffeine intake on urine output in dehydrated individuals is not well documented. The aim of the present study was to examine the effect of fluid replacement with GT on body fluid balance and renal water and electrolyte handling in mildly dehydrated individuals. METHODS: Subjects were dehydrated by performing three bouts of stepping exercise for 20 min separated by 10 min of rest. They were asked to ingest an amount of water (H2O), GT, or caffeinated H2O (20 mg/100 ml; Caf-H2O) that was equal to the volume of fluid loss during the dehydration protocol; fluid balance was measured for 2 h after fluid ingestion. RESULTS: The dehydration protocol induced hypohydration by ~ 10 g/kg body weight (~ 1% of body weight). Fluid balance 2 h after fluid ingestion was significantly less negative in all trials, and the fluid retention ratio was 52.2 ± 4.2% with H2O, 51.0 ± 5.0% with GT, and 47.9 ± 6.2% with Caf-H2O; those values did not differ among the trials. After rehydration, urine output, urine osmolality, and urinary excretions of osmotically active substances, sodium, potassium and chloride were not different among the trials. CONCLUSION: The data indicate that ingestion of GT or an equivalent caffeine amount does not worsen the hydration level 2 h after ingestion and can be effective in reducing the negative fluid balance for acute recovery from mild hypohydration. TRIAL REGISTRATION: ISRCTN53057185; retrospectively registered.

The effects of betaine supplementation on fluid balance and heat tolerance during passive heat stress in men.

INTRODUCTION: Consuming intracellular osmolytes, like betaine (BET), may attenuate symptoms of heat stress. The purpose of this study was to examine the effects of BET supplementation on fluid balance and heat tolerance after a 7-day loading period and during passive heat exposure. METHODS: A double-blind, placebo controlled, crossover study compared BET or placebo consumption (50 mg·kg-1 , twice daily) for 7 days in young, recreationally active men (N = 11). RESULTS: During the loading period, no significant interactions were found for any marker of fluid balance between or within conditions. During heat exposure, significant time effects but no condition x time interactions, were found for plasma characteristics (i.e., volume, osmolality, sodium, albumin, and total protein). Plasma volume was significantly increased by min 30 in both conditions (PLA: +6.9. ± 5.0%, BET: +10.2 ± 7.4%) and remained elevated for the remainder of the experimental trial, but was not significantly different between conditions. After 60 min of passive heat exposure, both conditions experienced a similar increase in core temperature (PLA: +0.32 ± 0.22°C, BET: +0.31 ± 0.21°C; p = 0.912). CONCLUSIONS: Supplemental BET did not improve markers of fluid balance or heat tolerance during 7 days of loading or during passive heat exposure.

The association between increasing fluid balance, acute kidney injury and mortality in patients with sepsis and septic shock: A retrospective single center audit.

PURPOSE: To determine whether a positive fluid balance is associated with AKI and mortality in sepsis and septic shock patients. METHODS: A retrospective chart review of 482 patients treated for sepsis or septic shock. Patients were stratified according to quartiles of cumulative fluid balance on days 1 and 3. Logistic models were built to explore the association between fluid balance, AKI, and ICU mortality. RESULTS: During the first days of ICU admission, fluid input did not differ between survivors and non-survivors, yet a significant difference in output resulted in a more positive fluid balance in non-survivors on day 1 (37.24 ± 31.98 ml/kg vs. 24.97 ± 23.76 ml/kg, p < 0.001) and day 3 (83.33 ± 70.86 ml/kg vs. 62.20 ± 45.90 ml/kg, P = 0.005). Using a logistic regression model, a positive fluid balance on day three was independently associated with higher ICU mortality (odds ratio 1.007 for every one ml/kg, P = 0038) and AKIN stage III (odds ratio 1.006 for every one ml/kg, p = 0.031). CONCLUSION: In patients with sepsis and septic shock, a more positive fluid balance is associated with an increased incidence of acute kidney injury and death after correction for possible confounders.

Osmoregulatory Performance among Prickly Sculpin (Cottus asper) Living in Contrasting Osmotic Habitats.

AbstractDuring the colonization of freshwater by marine fish, adaptation to hypoosmotic conditions may impact their ability to osmoregulate in seawater. The prickly sculpin (Cottus asper) is a euryhaline fish with marine ancestors that postglacially colonized many freshwater habitats. Previous work on C. asper suggested that isolation in freshwater habitats has resulted in putative adaptations that improve ion regulation in freshwater populations compared with populations with current access to estuaries. To determine whether long-term colonization of freshwater is associated with a reduced ability to ion regulate in seawater, we acclimated C. asper populations from three habitat types that vary in the extent to which they are isolated from marine habitats and compared their seawater osmoregulation. Seawater acclimation revealed that lake populations exhibited a reduced capacity to osmoregulate in seawater compared with coastal river populations with ongoing access to estuaries. In particular, when acclimated to seawater for several weeks, lake populations had lower gill Na+/K+-ATPase activity and lower intestinal H+-ATPase activity than coastal river populations. Lake populations also had a reduced ability to maintain plasma ion concentrations, and they produced lower quantities of intestinal carbonate precipitates in seawater than coastal river populations. Furthermore, there was a positive relationship between the anterior intestinal Na+/K+-ATPase activity and the amount of precipitate produced by the intestine, which suggests that the anterior intestine plays a role in seawater osmoregulation. Our results suggest that the extent of isolation from the sea could, in part, explain the reduced osmoregulation in seawater in postglacial freshwater populations of C. asper.

Toxic copper level increases erythrocyte glycolytic rate, glutathione production and alters electrolyte balance in male Wistar rats.

BACKGROUND: Copper is a micronutrient vital to several cellular energy metabolic processes and drives erythropoiesis. However, it disrupts cellular biological activities and causes oxidative damage when in excess of cellular needs. This study investigated the effects of copper toxicity on erythrocyte energy metabolism in male Wistar rats. METHODS: Ten Wistar rats (150-170 g) were randomly divided into 2 groups: control (given 0.1 ml distilled water) and copper toxic (given 100 mg/kg copper sulphate). Rats were orally treated for 30 days. Blood, collected retro-orbitally after sodium thiopentone anaesthesia (50 mg/kg i.p.) into fluoride oxalate and EDTA bottles, was subjected to blood lactate assay and extraction of red blood cell respectively. Red blood cell nitric oxide (RBC NO), glutathione (RBC GSH), adenosine triphosphate (RBC ATP) levels, RBC hexokinase, glucose-6-phosphate (RBC G6P), glucose-6-phosphate dehydrogenase (RBC G6PDH), and lactate dehydrogenase (RBC LDH) activity was estimated spectrophotometrically. Values (Mean±SEM, n = 5) were compared by Student's unpaired T-test at p < 0.05. RESULTS AND CONCLUSION: Copper toxicity significantly increased RBC hexokinase (23.41 ± 2.80 µM), G6P (0.48 ± 0.03 µM), G6PDH (71.03 ± 4.76nmol/min/ml) activities, ATP (624.70 ± 57.36 µmol/gHb) and GSH (3.08 ± 0.37 µM) level compared to control (15.28 ± 1.37 µM, 0.35 ± 0.02 µM, 330.30 ± 49.58 µmol/gHb, 54.41 ± 3.01nmol/min/ml and 2.05 ± 0.14 µM respectively, p < 0.05). Also, RBC LDH activity (145.00 ± 19.88mU/ml), NO (3.45 ± 0.25 µM) and blood lactate (31.64 ± 0.91 mg/dl) level were lowered significantly compared to control (467.90 ± 94.23mU/ml, 4.48 ± 0.18 µM and 36.12 ± 1.06 mg/dl respectively). This study shows that copper toxicity increases erythrocyte glycolytic rate and glutathione production. This increase could be connected to a compensatory mechanism for cellular hypoxia and increased free radical generation.

A randomised trial to assess fluid and electrolyte balance responses following ingestion of different beverages in young and older men.

BACKGROUND: Older adults are susceptible to dehydration and fluid overload due to a reduced ability to maintain homeostatic control of fluid and electrolyte balance. PURPOSE: To assess fluid and electrolyte balance responses in young and older men following ingestion of commonly consumed beverages differing in composition. METHODS: 12 young and 11 older men were recruited. Euhydrated body mass was recorded. Participants consumed 1L (250 ml every 15 min) of water, fruit juice, a sports drink or low-fat milk in a randomized cross-over design. Urine and blood samples were obtained before and after the drinking period and every hour thereafter for 3-h. Samples were used to determine osmolality, electrolytes (Na+ and K+), water clearance, and glomerular filtration rate. RESULTS: Free water clearance was significantly higher in Young than Older at 1 and 2 h after the ingestion of W and S (p < 0.05). Net Na+ and K+ balance were not different between Young and Older (p = 0.91 and p = 0.65) adults, respectively. At 3 h Na+ balance was negative after ingesting water and fruit juice, but neutral after sport drink and milk. Net K+ balance was neutral at 3 h after ingesting milk, but negative after water, fruit juice and sport drink. CONCLUSIONS: Milk was retained longer than other beverages in Young, but not in Older, despite similar net electrolyte balance responses. Older had higher fluid retention in the first 2 h after the ingestion of all beverages, except for milk when compared to Young, indicating an age-related loss of ability to regulate fluid balance under current study conditions.

Exposure to silver impairs the osmoregulatory capability of euryhaline medaka (Oryzias latipes) subjected to salinity changes.

The widespread use of silver in nanomaterials has led to increases in environmental contamination, which poses a threat to aquatic animals. Euryhaline fish, which live in environments with fluctuating salinity levels, have strong osmotic regulatory abilities to cope with such changes. This study attempted to investigate how silver affects the osmoregulatory capabilities of euryhaline fish, using medaka (Oryzias latipes) embryos as a model. The embryos were exposed to AgNO3 for 7 d in either fresh water (FW) or seawater (SW), and their mortality, heart rate, morphology, and ionocytes were examined. Results showed that the toxicity of AgNO3 was higher in FW than in SW (50% lethal concentrations (LC50) were 0.17 vs. 1.01 ppm). Although AgNO3 (0.05 and 0.1 ppm) did not significantly change the morphology of embryos, it impaired ionocytes and elevated heart rates in FW. While, AgNO3 (0.1 and 0.5 ppm) did not affect the morphology, ionocytes, or heart rate in SW, it impaired the hypo-osmoregulatory capability and elevated the mortality of embryos that were transferred from FW to SW. At 12 h after SW transfer, ionocytes were severely impaired, and water-drinking behavior was suppressed, resulting in body dehydration and sodium overload. In contrast, AgNO3 did not elevate the mortality of embryos that were transferred from SW to FW. To sum up, the presence of silver in FW during the developmental stage of euryhaline fish could potentially endanger their survival during SW adaptation.