Hyperchloremia – Why and how

Chloride ions in health and disease

Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.

Chloride and lactate as prognostic indicators of calf diarrhea from eighty-nine cases

IMPORTANCE

Deaths due to neonatal calf diarrhea are still one of the most critical problems of cattle breeding worldwide. Determining the parameters that can predict diarrhea-related deaths in calves is especially important in terms of prognosis and treatment strategies for the disease.

OBJECTIVE

The primary purpose of this study was to determine mortality rates and durations, survival status, and predictive prognosis parameters based on vital signs, hematology, and blood gas analyses in neonatal diarrheic calves.

METHODS

The hospital automation system retrospectively obtained data from 89 neonatal diarrheic calves.

RESULTS

It was found that 42.7% (38/89) of the calves brought with the complaint of diarrhea died during hospitalization or after discharge. Short-term and long-term fatalities were a median of 9.25 hours and a median of 51.50 hours, respectively. When the data obtained from this study is evaluated, body temperature (°C), pH, base excess (mmol/L), and sodium bicarbonate (mmol/L) parameters were found to be lower, and hemoglobin (g/dL), hematocrit (%), lactate (mmol/L), chloride (mmol/L), sodium (mmol/L) and anion gap (mmol/L) parameters were found to be higher in dead calves compared to survivors. Accordingly, hypothermia, metabolic acidosis, and dehydration findings were seen as clinical conditions that should be considered. Logistic regression analysis showed that lactate (odds ratio, 1.429) and CI- (odds ratio, 1.232) concentration were significant risk factors associated with death in calves with diarrhea.

CONCLUSIONS AND RELEVANCE

According to the findings obtained from this study, the determination of lactate and Cl- levels can be used as an adjunctive supplementary test in distinguishing calves with diarrhea with a good prognosis.

Cullin-3 proteins be a novel biomarkers and therapeutic targets for hyperchloremia induced by oral poisoning

Oral poisoning can trigger diverse physiological reactions, determined by the toxic substance involved. One such consequence is hyperchloremia, characterized by an elevated level of chloride in the blood and leads to kidney damage and impairing chloride ion regulation. Here, we conducted a comprehensive genome-wide analysis to investigate genes or proteins linked to hyperchloremia. Our analysis included functional enrichment, protein-protein interactions, gene expression, exploration of molecular pathways, and the identification of potential shared genetic factors contributing to the development of hyperchloremia. Functional enrichment analysis revealed that oral poisoning owing hyperchloremia is associated with 4 proteins e.g. Kelch-like protein 3, Serine/threonine-protein kinase WNK4, Serine/threonine-protein kinase WNK1 and Cullin-3. The protein-protein interaction network revealed Cullin-3 as an exceptional protein, displaying a maximum connection of 18 nodes. Insufficient data from transcriptomic analysis indicates that there are lack of information having direct associations between these proteins and human-related functions to oral poisoning, hyperchloremia, or metabolic acidosis. The metabolic pathway of Cullin-3 protein revealed that the derivative is Sulfonamide which play role in, increasing urine output, and metabolic acidosis resulted in hypertension. Based on molecular docking results analysis it found that Cullin-3 proteins has the lowest binding energies score and being suitable proteins. Moreover, no major variations were observed in unbound Cullin-3 and all three peptide bound complexes shows that all systems remain compact during 50 ns simulations. The results of our study revealed Cullin-3 proteins be a strong foundation for the development of potential drug targets or biomarker for future studies.

Impact of high Spirulina diet, extruded or supplemented with enzymes, on blood cells, systemic metabolites, and hepatic lipid and mineral profiles of broiler chickens

The impact of 15% dietary inclusion of Spirulina (Arthrospira platensis) in broiler chickens was explored, focusing on blood cellular components, systemic metabolites and hepatic lipid and mineral composition. From days 14 to 35 of age, 120 broiler chickens were divided and allocated into four dietary treatments: a standard corn and soybean meal-based diet (control), a 15% Spirulina diet, a 15% extruded Spirulina diet, and a 15% Spirulina diet super-dosed with an enzyme blend (0.20% porcine pancreatin plus 0.01% lysozyme). The haematological analysis revealed no significant deviations (p > 0.05) in blood cell counts across treatments, suggesting that high Spirulina inclusion maintains haematological balance. The systemic metabolic assessment indicated an enhanced antioxidant capacity in birds on Spirulina diets (p < 0.001), pointing toward a potential reduction in oxidative stress. However, the study noted a detrimental impact on growth performance metrics, such as final body weight and feed conversion ratio (both p < 0.001), in the Spirulina-fed treatments, with the super-dosed enzyme blend supplementation failing to alleviate these effects but with extrusion mitigating them. Regarding hepatic composition, birds on extruded Spirulina and enzyme-supplemented diets showed a notable increase in n-3 fatty acids (EPA, DPA, DHA) (p < 0.001), leading to an improved n-6/n-3 PUFA ratio (p < 0.001). Despite this positive shift, a reduction in total hepatic lipids (p = 0.003) was observed without a significant change in cholesterol levels. Our findings underscore the need for further exploration into the optimal inclusion levels, processing methods and potential enzymatic enhancements of Spirulina in broiler diets. Ultimately, this research aims to strike a balance between promoting health benefits and maintaining optimal growth performance in poultry nutrition.

Hyperchloremic metabolic acidosis after plasma exchange in a patient with renal transplant rejection: A case report

Therapeutic plasma exchange (TPE) is an effective treatment for several renal disorders, including renal transplant rejection. However, repeated plasma exchanges can result in various metabolic disturbances and complications. We present a 61-year old male with a medical history of type 2 diabetes, hypertension, successfully treated multiple myeloma, and a post-mortem kidney transplantation 7 months prior to presentation. The patient was hospitalized with an antibody-mediated transplant rejection for which treatment with methylprednisolone, TPE with a 40 g/L albumin solution as a replacement fluid, and intravenous immunoglobulins was initiated. After four TPE treatments, the patient developed gastrointestinal complaints and muscle weakness. Despite daily oral bicarbonate supplementation, laboratory tests revealed a hyperchloremic metabolic acidosis: bicarbonate 11.7 mmol/L, chloride 111 mmol/L, and sodium 138 mmol/L. Metabolic acidosis due to citrate accumulation was ruled out with a normal total-to-ionized calcium ratio. After treatment with intravenous bicarbonate supplementation, the symptoms disappeared. Analysis of the albumin solution showed a chloride concentration of 132 mmol/L. This is the first case that describes severe metabolic acidosis after multiple sessions of TPE with an albumin solution in a patient with impaired renal function. The hyperchloremic metabolic acidosis is the result of administration of large volumes of an albumin solution with high chloride concentrations. Special attention should be paid to the acid-base balance during TPE in patients with impaired renal function. Future research should investigate the incidence of hyperchloremic metabolic acidosis during TPE in patients with impaired renal function.

Molecular basis for selective uptake and elimination of organic anions in the kidney by OAT1

In mammals, the kidney plays an essential role in maintaining blood homeostasis through the selective uptake, retention or elimination of toxins, drugs and metabolites. Organic anion transporters (OATs) are responsible for the recognition of metabolites and toxins in the nephron and their eventual urinary excretion. Inhibition of OATs is used therapeutically to improve drug efficacy and reduce nephrotoxicity. The founding member of the renal organic anion transporter family, OAT1 (also known as SLC22A6), uses the export of α-ketoglutarate (α-KG), a key intermediate in the Krebs cycle, to drive selective transport and is allosterically regulated by intracellular chloride. However, the mechanisms linking metabolite cycling, drug transport and intracellular chloride remain obscure. Here, we present cryogenic-electron microscopy structures of OAT1 bound to α-KG, the antiviral tenofovir and clinical inhibitor probenecid, used in the treatment of Gout. Complementary in vivo cellular assays explain the molecular basis for α-KG driven drug elimination and the allosteric regulation of organic anion transport in the kidney by chloride.

Dietary Ulva lactuca and CAZyme supplementation improve serum biochemical profile and hepatic composition of weaned piglets

Ulva lactuca is a seaweed with antinutritional cell wall for monogastrics. Carbohydrate-Active enZymes (CAZymes) supplementation can potentially cause its disruption. This study evaluates four diets: Ctrl-control diet; UL-control + 7% U. lactuca (wild caught, powdered form); ULR-UL + 0.005% Rovabio^® Excel AP; ULU-UL + 0.01% ulvan lyase on piglets' haematologic and serologic profiles, hepatic lipids and minerals. White blood cells and lymphocytes reached the highest values in piglets fed UL compared to control, and to control and ULR; respectively (P < 0.05). IgG levels were boosted by seaweed incorporation compared to control (P = 0.015). The glycaemic homeostasis was assured by the seaweed inclusion. Dietary seaweed decreased serum lipids (P < 0.001), with the exception of ULU, due to HDL-cholesterol increase (P < 0.001). Cortisol was decreased in ULR and ULU (P < 0.001). No systemic inflammation was observed (P > 0.05). While hepatic n-3 PUFA increased in piglets fed with seaweed diets due to increment of beneficial 22:5n-3 and 22:6n-3 fatty acids (P < 0.05), the opposite occurred for n-6 PUFA, PUFA/SFA and n-6/n-3 ratios (P < 0.05). Hepatic pigments were unchanged (P > 0.05). ULR reduced α-tocopherol levels (P = 0.036) and increased serum potassium levels (P < 0.001) compared to control. Seaweed contributed to overcome piglets' weaning stress, with some benefits of including CAZyme supplementation.

Effect of Laminaria digitata dietary inclusion and CAZyme supplementation on blood cells, serum metabolites and hepatic lipids and minerals of weaned piglets

Seaweeds, such as Laminaria digitata, are a sustainable alternative to conventional feedstuffs for weaned piglet diets, improving their health and mitigating environmental impacts. L. digitata has a complex cell wall that can be difficult for monogastrics to digest. However, carbohydrate-active enzymes (CAZymes) such as Rovabio® Excel AP and alginate lyase can help break down these polysaccharides and render intracellular nutrients more accessible. This study aimed to evaluate the impact of 10% L. digitata feed inclusion and CAZyme supplementation on piglet blood cells, serum metabolites, liver lipid and mineral profiles. Forty weaned piglets were randomly assigned to one of four diets (n = 10 each): a control diet, 10% L. digitata (LA), 10% L. digitata + 0.005% Rovabio® Excel AP (LAR), and 10% L. digitata + 0.01% alginate lyase (LAL). After two weeks of trial, animals were slaughtered and liver and blood serum samples taken for analysis. The results showed that the LA and LAL diets increased blood lymphocytes, IgG and IgM, and decreased serum lipids, improving both cellular and humoral immune response and cardiovascular health. Dietary CAZymes reversed the anti-inflammatory and hematopoietic effects. Additionally, cortisol levels were reduced with seaweed inclusion compared to the control diet (P < 0.001). In the liver, total n-3 PUFA and n-6/n-3 ratio were increased and decreased, respectively, due to eicosapentaenoic acid and α-linolenic acid accumulation (P < 0.001). However, total liver mineral content was incorporated to a lesser extent with the combined seaweed and enzyme diets (P < 0.001), potentially indicating a negative effect on mineral bioavailability. Overall, results suggest that a 10% L. digitata inclusion can effectively improve piglet health by reducing stress during weaning, without the need for dietary CAZymes.

Radiochemical quality control of the radiopharmaceutical, 89SrCl2 produced in FBTR

⁸⁹SrCl₂ radiopharmaceuticals is mainly used for bone pain palliation in the cancer patients, is being produced in FBTR via ⁸⁹Y(n, p)⁸⁹Sr using yttria target. The irradiated yttria target is chemically processed in high pure quartz distilled nitric acid medium in hot cell facility, to avoid the corrosion of components of hotcell due to chloride ions while using HCl medium. Being ionic species, the purified ⁸⁹Sr(II) cation in aqueous solution containing bulk nitrate and other trace anions, exists as SrX_n species where X: F^-, Cl^-, Br^-, NO₃^-, PO₄^3- and SO₄^2-, n: stoichiometric anion content. The aim of the manuscript is to standardise an efficient ultra-low level anion purification method (ppb range) for the conversion of SrX_n to SrCl₂ and estimate the residual anionic impurities as recommended by the appropriate source specifications for its medical application. Various methods were standardised for the removal of anions in the SrCl₂ source produced by the above process which include evaporation, calcination, anion exchange column, cation exchange column as well as its combination with pre-concentration column of ion chromatography (IC) technique using ⁸⁹Sr tracers as well as FBTR produced ⁸⁹Sr solution. Assay of ⁸⁹Sr and other anions including nitrate for the above study were accomplished using Cerenkov counting and ion chromatography respectively. Thus evaporation-calcination-column chromatography mode was finalised to obtain pure SrCl₂ source free from nitrate and other anionic impurities. This is the first ever systematic study for the Radiochemical quality control of nca ⁸⁹SrCl₂ radiopharmaceutical produced in a fast reactor. This study also finds its application to any analytical lab as well as industry where there is a requirement of anion purification in the ppb level.

Increase in chloride from baseline is independently associated with mortality in intracerebral hemorrhage patients admitted to intensive care unit: A retrospective study

Background

Hyperchloremia is associated with increased mortality in critically ill patients. The objective of this study was to investigate the association between increased chloride levels and mortality outcomes in intracerebral hemorrhage (ICH) patients admitted to the intensive care unit (ICU).

Methods

We performed a retrospective study of all patients diagnosed with ICH and included in the Medical Information Mart for Intensive Care (MIMIC-Ⅲ) from 2001 to 2012. Inclusion criteria were the first diagnosis of ICH, ICU length of stay (LOS) over 72 h, and not receiving hypertonic saline treatment. Serum chloride perturbation within 72 h of admission was evaluated as a predictor of outcomes. The increase in chloride from baseline was dichotomized based on an increase in chloride in 72 h (≤5 mmol/L or >5 mmol/L). The primary outcome was 90-day mortality.

Results

A total of 376 patients (54.5% male, median age 70 years, interquartile range:58-79 years) were included. The overall 90-day mortality was 32.2% (n=121), in-hospital mortality was 25.8% (n=97), and Day 2 acute kidney injury (AKI) occurred in 29.0% (n=109) of patients. The prevalence of hyperchloremia on admission, during the first 72 h, and an increase in chloride (>5 mmol/L) were 8.8%, 39.4%, and 42.8%, respectively. After adjusting for confounders, the hazard ratio of increase in chloride (>5 mmol/L) was 1.66 (95% confidence interval:1.05-2.64, P=0.031). An increase in chloride (>5 mmol/L) was associated with a higher odds ratio for 90-day mortality in both the AKI and non-AKI groups.

Conclusions

An increase in chloride from baseline is common in adult patients with ICH admitted to ICU. The increase is significantly associated with elevated mortality. These results support the significance of diligently monitoring chloride levels in these patients.

Relationships of hyperchloremia with hypertension and proteinuria in patients with chronic kidney disease

BACKGROUND

A few previous clinical studies have shown that chloride (Cl) contributes to the progression and development of hypertension or proteinuria. Therefore, we aimed to determine whether hyperchloremia is associated with hypertension or proteinuria in patients with chronic kidney disease (CKD) and to define the relationships between the reduction in serum Cl concentration associated with CKD treatment and improvements in hypertension and/or proteinuria.

METHODS

We performed a retrospective observational study of new or referred patients with CKD who had hyperchloremia, moderate proteinuria, renal dysfunction, and hypertension. Patients taking medication for metabolic acidosis or with a history of dialysis were excluded. The participants' systolic and diastolic blood pressure (BP), serum sodium (Na) and Cl concentrations, and urinary protein (UP) concentration were measured at baseline and after 1 month of CKD treatment.

RESULTS

Fifty-one patients with CKD were included in the study. Their serum Cl concentration independently correlated with sBP and UP at baseline (P = 0.022 and P = 0.033, respectively). After 1 month's CKD treatment, their serum Na and Cl concentrations, sBP, and UP were significantly lower. The change in sBP during the month (ΔsBP) correlated with the change in serum Cl (ΔCl) (P = 0.012) but not with the change in serum Na. Multivariate analysis showed that ΔsBP was independently associated with ΔCl (P = 0.029).

CONCLUSIONS

Hyperchloremia is an independent predictor of hypertension and proteinuria for patients with CKD.

Hypothetical Mechanism of Skin Argyria

Introduction. Argyria is an acquired skin condition that appears after the exposure or consumption of silver, leading to blue or grey coloration of the skin and mucosa. The aim of the present work was to draw researchers’ attention to two aspects of the argyria that until now have not received enough consideration. They are: (1) the process of delivering silver compound from the gastrointestinal tract to the skin and (2) the possibility for silver chloride to participate in this process along with the silver proteinates. Methodology. Illustrative experiments included the observation of color change (visual and using UV-Vis spectrometry) under different light exposure conditions of silver chloride sol in a sweat-simulating solution, in vials and under pig skin (in direct contact). Results and Discussion. A hypothetical mechanism based on a perspiration system for delivering the silver compounds from the gastrointestinal tract to the skin for argyria was proposed. It was also proposed not to completely exclude the partial participation of silver chloride along with the silver proteinates in this process.

Subtyping Hyperchloremia among Hospitalized Patients by Machine Learning Consensus Clustering

Background and Objectives: Despite the association between hyperchloremia and adverse outcomes, mortality risks among patients with hyperchloremia have not consistently been observed among all studies with different patient populations with hyperchloremia. The objective of this study was to characterize hyperchloremic patients at hospital admission into clusters using an unsupervised machine learning approach and to evaluate the mortality risk among these distinct clusters. Materials and Methods: We performed consensus cluster analysis based on demographic information, principal diagnoses, comorbidities, and laboratory data among 11,394 hospitalized adult patients with admission serum chloride of >108 mEq/L. We calculated the standardized mean difference of each variable to identify each cluster's key features. We assessed the association of each hyperchloremia cluster with hospital and one-year mortality. Results: There were three distinct clusters of patients with admission hyperchloremia: 3237 (28%), 4059 (36%), and 4098 (36%) patients in clusters 1 through 3, respectively. Cluster 1 was characterized by higher serum chloride but lower serum sodium, bicarbonate, hemoglobin, and albumin. Cluster 2 was characterized by younger age, lower comorbidity score, lower serum chloride, and higher estimated glomerular filtration (eGFR), hemoglobin, and albumin. Cluster 3 was characterized by older age, higher comorbidity score, higher serum sodium, potassium, and lower eGFR. Compared with cluster 2, odds ratios for hospital mortality were 3.60 (95% CI 2.33-5.56) for cluster 1, and 4.83 (95% CI 3.21-7.28) for cluster 3, whereas hazard ratios for one-year mortality were 4.49 (95% CI 3.53-5.70) for cluster 1 and 6.96 (95% CI 5.56-8.72) for cluster 3. Conclusions: Our cluster analysis identified three clinically distinct phenotypes with differing mortality risks in hospitalized patients with admission hyperchloremia.

Stability of Whole Blood Electrolyte Specimens at Room Temperature vs. Slushed Ice Conditions

BACKGROUND

Data on the stability of whole blood electrolytes is limited to small sample sizes. We sought to determine the stability of whole blood electrolytes under room temperature and slushed iced conditions in human patients at a major hospital center.

METHODS

Whole blood samples were obtained from 203 patients hospitalized for various pathophysiological conditions. Electrolyte concentrations of sodium, potassium [K+], ionized calcium, and chloride were measured at 5 different timepoints spanning 3 h. Samples were stored at room temperature (22-24 °C) or under slushed ice conditions (0.1-0.2 °C) before analysis.

RESULTS

Under both conditions, sodium, ionized calcium, and chloride did not show a measurable change up to 109 min compared to baseline; however, the mean increase in [K+] over 138 min of storage in slushed ice was 0.0032 (0.0021 [5th percentile] to 0.0047 [95th percentile]) mmol/L/min (adjusted R2 = 0.62, P < 0.001). Five percent of the specimens demonstrated a ≥0.3 mmol/L change in [K+] from baseline after 67 min of storage in slushed ice. In contrast, 1% of the specimens stored at room temperature showed the same change at the same timepoint.

CONCLUSIONS

Whole blood sodium, [K+], ionized calcium, and chloride concentrations remain stable for at least 109 min at room temperature. However, whole blood specimens stored in slushed ice for not more than 67 min exhibit a 5% probability that the [K+] concentration will increase by at least 0.3 mmol/L compared to baseline. The other analytes do not destabilize for up to 178 min of slushed ice storage.

Crystalloid and Colloid Compositions and Their Impact

This manuscript will review crystalloid (hypo-, iso-, and hyper-tonic) and colloid (synthetic and natural) fluids that are available for intravenous administration with a focus on their electrolyte, acid-base, colligative, and rheological effects as they relate to each solution's efficacy and safety. The goal is for the reader to better understand the differences between each fluid and the influence on plasma composition, key organ systems, and their implications when used therapeutically in animals with critical illness.

Relationship Between Serum Total Carbon Dioxide Concentration and Bicarbonate Concentration in Patients Undergoing Peritoneal Dialysis

Background

Few studies have assessed the relationship between serum total carbon dioxide (CO₂) and bicarbonate ion (HCO₃⁻) concentration in patients undergoing peritoneal dialysis. We determined the agreement between serum total CO₂ and HCO₃⁻ concentration and the diagnostic accuracy of serum total CO₂ for the prediction of low (HCO₃⁻ <24 mEq/L) and high (HCO₃⁻ ≥24 mEq/L) bicarbonate concentrations in patients on peritoneal dialysis.

Methods

We collected 245 samples of venous blood from 51 patients on peritoneal dialysis. Independent factors that correlated with the HCO₃⁻ concentration were analyzed using multiple linear regression analysis. The diagnostic accuracy of serum total CO₂ was evaluated by receiver operating characteristic (ROC) curve analysis and a 2×2 table. Agreement between serum total CO₂ and HCO₃⁻ concentration was assessed by Bland-Altman analysis.

Results

Serum total CO₂ was independently correlated with HCO₃⁻ concentration (β = 0.354, p < 0.001). The area under the curve of serum total CO₂ for the identification of low and high bicarbonate concentrations was 0.909. The diagnostic accuracy of serum total CO₂ for the prediction of low and high bicarbonate concentrations was: sensitivity, 91.5%; specificity, 74.7%; positive predictive value, 53.5%; negative predictive value, 96.5%; and accuracy, 78.8%. Bland-Altman analysis showed a moderate agreement between serum total CO₂ and HCO₃⁻ concentration.

Conclusion

Serum total CO₂ correlated closely with the HCO₃⁻ concentration in patients undergoing peritoneal dialysis. Serum total CO₂ might be useful for predicting low and high bicarbonate in peritoneal dialysis patients.

Relationship between serum total carbon dioxide concentration and bicarbonate concentration in patients undergoing hemodialysis

Background

Few studies have investigated the relationship between serum total carbon dioxide (CO₂) concentration and bicarbonate ion (HCO₃^-) concentration in patients undergoing hemodialysis. We determined the agreement and discrepancy between serum total CO₂ and HCO₃^- concentrations and the diagnostic accuracy of serum total CO₂ for the prediction of low (HCO₃^- < 24 mEq/L) and high (HCO₃^- ≥ 24 mEq/L) bicarbonate concentrations in hemodialysis patients.

Methods

One hundred forty-nine arteriovenous blood samples from 84 hemodialysis patients were studied. Multiple linear regression analysis was used to determine factors correlated with HCO₃^- concentration. Diagnostic accuracy of serum total CO₂ was evaluated using receiver operating characteristic curve analysis and a 2 × 2 table. Agreement between serum total CO₂ and HCO₃^- concentrations was assessed using Bland-Altman analysis.

Results

Serum total CO₂ concentration was closely correlated with HCO₃^- concentration (β = 0.858, P < 0.001). Area under the curve of serum total CO₂ for the identification of low and high bicarbonate concentrations was 0.989. Use of serum total CO₂ to predict low and high bicarbonate concentrations had a sensitivity of 100%, specificity of 50.0%, positive predictive value of 96.5%, negative predictive value of 100%, and accuracy of 96.6%. Bland-Altman analysis showed moderate agreement between serum total CO₂ and HCO₃^- concentrations. Discrepancies between HCO₃^- and serum total CO₂ concentrations (serum total CO₂ - HCO₃^- ≤ -1) were observed in 89 samples.

Conclusion

Serum total CO₂ concentration is closely correlated with HCO₃^- concentration in hemodialysis patients. However, there is a non-negligible discrepancy between serum total CO₂ and HCO₃^- concentrations.

Abnormal Basic Metabolic Panel Findings: Implications for Nursing

In this article, the second in a new series designed to improve acute care nurses' understanding of laboratory abnormalities, the author continues her discussion of important values in the basic metabolic panel (see Back to Basics, January, for a discussion of sodium and fluid balance). Here she addresses the electrolytes potassium and chloride as well as blood urea nitrogen and creatinine, four values that are best considered together because they both reflect and impact renal function as well as acid-base homeostasis. Important etiology, clinical manifestations, and treatment concerns are also presented. Three case studies are used to integrate select laboratory diagnostic tests with history and physical examination findings, allowing nurses to develop a thorough, focused plan of care for electrolyte abnormalities and kidney disorders commonly encountered in the medical-surgical setting.

Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort

Objective:

To evaluate the association between dysnatremias or dyschloremias and mortality during hospitalization in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) undergoing acute hemodialysis.

Methods:

We carried out a retrospective cohort study on adult patients undergoing acute hemodialysis with AKI or CKD diagnosis at a public hospital in Lima, Peru. Dysnatremias were categorized as hyponatremia (Na < 135mmol/L) or hypernatremia (Na > 145mmol/L), and dyschloremias were defined as hypochloremia (Cl < 98 mmol/L) or hyperchloremia (Cl > 109mmol/L). The outcome of interest was mortality during hospitalization. We performed generalized lineal Poisson family models with bias-corrected and accelerated non-parametric bootstrap to estimate the risk ratios at crude (RR) and adjusted analysis (aRR) by gender, age, HCO3 (for all patients) and Liaño score (only for AKI) with CI95%.

Results:

We included 263 patients (mean age: 54.3 years, females: 43%): 191 with CKD and 72 with AKI. Mortality was higher in patients with AKI (59.7%) than in patients with CKD (14.1%). In overall, patients with hypernatremia had a higher mortality during hospitalization compared to those who had normal sodium values (aRR: 1.82, 95% CI: 1.17-2.83); patients with hyponatremia did not have different mortality (aRR: 0.19, 95% CI: 0.69-2.04). We also found that hyperchloremia (aRR: 1.35, 95% CI: 0.83-2.18) or hypochloremia (aRR: 0.66, 95% CI: 0.30-14.78) did not increase mortality in comparison to normal chloride values. No association between dysnatremias or dyschloremias and mortality during hospitalization was found in CKD and AKI subgroups.

Conclusions:

In our exploratory analysis, only hypernatremia was associated with mortality during hospitalization among patients with AKI or CKD undergoing acute hemodialysis.

Biochemical recovery from exertional heat stroke follows a 16-day time course

BACKGROUND

The aim of this study was to characterize the time-resolved progression of clinical laboratory disturbances days-following an exertional heat stroke (EHS). Currently, normalization of organ injury clinical biomarker values is the primary indicator of EHS recovery. However, an archetypical biochemical recovery profile following EHS has not been established.

METHODS

We performed a retrospective analysis of EHS patient records in US military personnel from 2008-2014 using the Military Health System Data Repository (MDR). We focused on commonly reported clinical laboratory analytes measured on the day of injury and all proceeding follow-up visits.

RESULTS

Over the prescribed period, there were 2,529 EHS episodes treated at 250 unique treatment locations. Laboratory results, including a standardized set of blood, serum and urine assays, were analyzed from 0-340 days following the initial injury. Indicators of acute kidney injury, including serum electrolyte disturbances and abnormal urinalysis findings, were most prevalent on the day of the injury but normalized within 24-48hours (creatinine, blood urea nitrogen, and blood and protein in urine). Muscle damage and liver function-associated markers peaked 0-4 days after injury and persisted outside their respective reference ranges for 2-16 days (alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, myoglobin, prothrombin time).

CONCLUSION

Biochemical recovery from EHS spans a 16-day time course, and markers of end-organ damage exhibit distinct patterns over this period. This analysis underscores the prognostic value of each clinical laboratory analyte and will assist in evaluating EHS patient presentation, injury severity and physiological recovery.

Fluctuations in Serum Chloride and Acute Kidney Injury among Critically Ill Patients: A Retrospective Association Study

Exposure to dyschloremia among critically ill patients is associated with an increased risk of acute kidney injury (AKI). We aimed to investigate how fluctuations in serum chloride (Cl⁻) are associated with the development of AKI in critically ill patients. We retrospectively analyzed medical records of adult patients admitted to the intensive care unit (ICU) between January 2012 and December 2017. Positive and negative fluctuations in Cl⁻ were defined as the difference between the baseline Cl- and maximum Cl- levels and the difference between the baseline Cl⁻ and minimum Cl⁻ levels measured within 72 h after ICU admission, respectively. In total, 19,707 patients were included. The odds of developing AKI increased 1.06-fold for every 1 mmol L⁻¹ increase in the positive fluctuations in Cl⁻ (odds ratio: 1.06; 95% confidence interval: 1.04 to 1.08; p < 0.001) and 1.04-fold for every 1 mmol L⁻¹ increase in the negative fluctuations in Cl⁻ (odds ratio: 1.04; 95% confidence interval: 1.02 to 1.06; p < 0.001). Increases in both the positive and negative fluctuations in Cl- after ICU admission were associated with an increased risk of AKI. Furthermore, these associations differed based on the functional status of the kidneys at ICU admission or postoperative ICU admission.

"I don't get no respect": the role of chloride in acute kidney injury

Acute kidney injury (AKI) is a major public health problem that complicates 10-40% of hospital admissions. Importantly, AKI is independently associated with increased risk of progression to chronic kidney disease, end-stage renal disease, cardiovascular events, and increased risk of in-hospital and long-term mortality. The chloride content of intravenous fluid has garnered much attention over the last decade, as well as its association with excess use and adverse outcomes, including AKI. Numerous studies show that changes in serum chloride concentration, independent of serum sodium and bicarbonate, are associated with increased risk of AKI, morbidity, and mortality. This comprehensive review details the complex renal physiology regarding the role of chloride in regulating renal blood flow, glomerular filtration rate, tubuloglomerular feedback, and tubular injury, as well as the findings of clinical research related to the chloride content of intravenous fluids, changes in serum chloride concentration, and AKI. Chloride is underappreciated in both physiology and pathophysiology. Although the exact mechanism is debated, avoidance of excessive chloride administration is a reasonable treatment option for all patients and especially in those at risk for AKI. Therefore, high-risk patients and those with "incipient" AKI should receive balanced solutions rather than normal saline to minimize the risk of AKI.

Development of a selective chloride sensing platform using a screen-printed platinum electrode

A new and selective voltammetric method for chloride determination is proposed, based on platinum and chloride interactions. A screen-printed platinum electrode (SPPtE) functions as a sensing platform, which promotes the formation of chloro-adsorbed species on the electrode surface, acting as an effective means of anion-determination in several matrices. The pretreatment of the SPPtE and careful control of the cathodic stripping voltammetric parameters yielded a well-defined electrochemical signal. This cathodic peak was due to the adsorption of chlorine, which had previously been oxidized from chloride anions in the initial anodic deposition step. It offers a simple, low-cost, fast, reproducible (RSD < 6%) and precise method for selective chloride determination, with limit of detection of 0.76 mM, and a sensitivity of - 24.147 µA mM ^-1 for a broad determination range of up to 150 mM. Chloride determination was correctly performed with single drops of environmental, pharmaceutical and food samples. In addition, the sensor was successfully adapted as a flexible screen-printed platinum electrode sensor using Gore-Tex^® as support for printing.

Biosafety evaluation of Janus Fe3O4-TiO2 nanoparticles in Sprague Dawley rats after intravenous injection

Introduction

Newly synthesized Janus-structured Fe₃O₄-TiO₂ nanoparticles (NPs) appear to be a promising candidate for the diagnosis and therapy of cancer. Although the toxicity of individual Fe₃O₄ or TiO₂ NPs has been studied extensively, the toxicity of Janus Fe₃O₄-TiO₂ NPs is not clear.

Methods

In this study, the biosafety of both Janus Fe₃O₄-TiO₂ NPs (20–25 nm) and the maternal material TiO₂ NPs (7–10 nm) were evaluated in Sprague Dawley rats after one intravenous injection into the tail vein. Healthy rats were randomly divided into one control group and six experimental groups. Thirty days after treatment, rats were killed, then blood and tissue samples were collected for hematological, biochemical, element-content, histopathological, and Western blot analysis.

Results

The results show that only a slight Ti element accumulation in the heart, spleen, and liver could be found in the Janus Fe₃O₄-TiO₂ NP groups (P>0.05 compared with control). However, significant Ti element accumulation in the spleen, lungs, and liver was found in the TiO₂ NP-treated rats. Both Fe₃O₄-TiO₂ NPs and TiO₂ NPs could induce certain histopathological abnormalities. Western blot analysis showed that both NPs could induce certain apoptotic or inflammatory-related molecular protein upregulation in rat livers. A certain degree of alterations in liver function and electrolyte and lipid parameters was also observed in rats treated with both materials. However, compared to Janus structure Fe₃O₄-TiO₂ NP-treated groups, TiO₂ NPs at 30 mg/kg showed more severe adverse effects.

Conclusion

Our results showed that under a low dose (5 mg/kg), both NP types had no significant toxicity in rats. Janus NPs certainly seem less toxic than TiO₂ NPs in rats at 30 mg/kg. To ensure safe use of these newly developed Janus NPs in cancer diagnosis and therapy, further animal studies are needed to evaluate long-term bioeffects.