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

Association between serum chloride levels and estimated glomerular filtration rate among US adults: evidence from NHANES 1999-2018

PURPOSE

Chloride, the predominant anion in extracellular fluid from humans, is essential to maintaining homeostasis. One important metric for thoroughly assessing kidney function is the estimated glomerular filtration rate (eGFR). However, the relationship between variations in serum chloride concentration and eGFR in general populations has been poorly studied. Therefore, the purpose of this study is to elucidate the correlation between serum chloride levels and eGFR within the United States' adult population.

METHODS

This cohort study was conducted using data from the National Health and Nutrition Examination Survey (NHANES), which covered the years 1999-2018. We employed multiple linear regression analysis and subgroup analysis to evaluate the correlation between serum chloride concentration and eGFR. To examine the nonlinear association between serum chloride levels and eGFR, restricted cubic spline analyses were employed.

RESULTS

Data from 49,008 participants in this cohort study were used for the chloride analysis. In the comprehensively adjusted model, a noteworthy inverse relationship was discovered between chloride plasma concentration and eGFR. Restricted cubic spline analyses revealed a significant nonlinear relationship between chloride levels and eGFR (P for overall < 0.001 and P for nonlinear < 0.001). A significant interaction was observed between eGFR and plasma chloride concentration (all P < 0.001 for interaction) among the subgroups characterized by sex, household income to poverty ratio, BMI, hypertension, and diabetes.

CONCLUSION

Our findings suggest that higher levels of chloride plasma concentration were linked to decreased eGFR. These findings underscore the significance of monitoring chloride plasma concentration as a potential indicator for identifying individuals at risk of developing chronic kidney disease (CKD).

Is there a relationship between hyperchloremia status and the risk of developing acute kidney injury in pediatric patients with diabetic ketoacidosis?

Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes mellitus (T1DM). Prerenal acute kidney injury (AKI) is associated with profound hypovolemia and reduced renal perfusion. Results regarding hyperchloremia-associated AKI in patients with DKA are conflicting; we therefore investigated the potential relationship between hyperchloremia status and the risk of developing AKI. This single-center cohort study included 113 newly diagnosed T1DM patients with DKA admitted to the pediatric intensive care unit. Laboratory parameters, including Na, K, urea, creatinine, and chloride levels, were retrospectively reviewed at the time of presentation and at 12, 24 and 36 h. AKI was defined using the eGFR according to the pediatric RIFLE classification criteria. Twenty-two (19.5%) of the 113 patients were in the AKI group. Two-way repeated-measures ANOVA showed significant (P values ≤ 0.01) time interaction effects within the groups based on the eGFR and the serum chloride, hyperchloremia, and phosphate levels. Serum chloride levels did not differ between the groups during the first 12 h (p > 0.05) but were significantly greater in the AKI group than in the non-AKI group at 24 h and 36 h (p < 0.01). The final DKA resolution time was significantly greater in the AKI group than in the non-AKI group [22.2 (9.5) vs. 17.0 (12.0) h, respectively; p = 0.03]. However, the groups had similar lengths of hospital stay [13.0 (8.0) days vs. 12.0 (4.0) days, respectively; p = 0.17].Conclusions: Hyperchloremia may be iatrogenic rather than causative during treatment. This may worsen renal failure and prolong the recovery and treatment time for DKA patients. What is Known? • Acute kidney injury resulting from severe volume depletion is a common occurrence in diabetic ketoacidosis and typically requires significant volume replacement therapy. • In recent years, hyperchloremia has been associated with increased risks of AKI, morbidity, and mortality in some conditions, such as diabetic ketoacidosis. What is New? • The incidence of hyperchloremia increases over time during the treatment of diabetic ketoacidosis. • Hyperchloremia may be an iatrogenic element rather than a cause of acute kidney injury during the treatment of diabetic ketoacidosis.

The Intersections of COVID-19, HIV, and Race/Ethnicity: Machine Learning Methods to Identify and Model Risk Factors for Severe COVID-19 in a Large U.S. National Dataset

We investigate risk factors for severe COVID-19 in persons living with HIV (PWH), including among racialized PWH, using the U.S. population-sampled National COVID Cohort Collaborative (N3C) data released from January 1, 2020 to October 10, 2022. We defined severe COVID-19 as hospitalized with invasive mechanical ventilation, extracorporeal membrane oxygenation, discharge to hospice or death. We used machine learning methods to identify highly ranked, uncorrelated factors predicting severe COVID-19, and used multivariable logistic regression models to assess the associations of these variables with severe COVID-19 in several models, including race-stratified models. There were 3 241 627 individuals with incident COVID-19 cases and 81 549 (2.5%) with severe COVID-19, of which 17 445 incident COVID-19 and 1 020 (5.8%) severe cases were among PWH. The top highly ranked factors of severe COVID-19 were age, congestive heart failure (CHF), dementia, renal disease, sodium concentration, smoking status, and sex. Among PWH, age and sodium concentration were important predictors of COVID-19 severity, and the effect of sodium concentration was more pronounced in Hispanics (aOR 4.11 compared to aOR range: 1.47-1.88 for Black, White, and Other non-Hispanics). Dementia, CHF, and renal disease was associated with higher odds of severe COVID-19 among Black, Hispanic, and Other non-Hispanics PWH, respectively. Our findings suggest that the impact of factors, especially clinical comorbidities, predictive of severe COVID-19 among PWH varies by racialized groups, highlighting a need to account for race and comorbidity burden when assessing the risk of PWH developing severe COVID-19.

Advancements in Trauma-Induced Acute Kidney Injury: Diagnostic and Therapeutic Innovations

Acute kidney injury following trauma impacts patient recovery critically, necessitating an integrated approach to emergency care and nephrology. This review aims to provide a comprehensive understanding of trauma-induced nephropathy, highlighting recent advancements in pathophysiological insights, diagnostic techniques, and strategic interventions. Our key findings emphasize the role of biomarkers, like Neutrophil Gelatinase-Associated Lipocalin and Liver Fatty Acid-Binding Protein, and imaging techniques, such as contrast-enhanced ultrasound, in early AKI detection. Preventive strategies, including aggressive fluid resuscitation, avoidance of nephrotoxic agents, and hemodynamic optimization, are essential for mitigating AKI progression. Integrating these approaches into trauma care frameworks aims to enhance patient outcomes and set a foundation for future research and clinical improvements.

High versus low chloride load in adult hyperglycemic emergencies with acute kidney injury: a multicenter retrospective cohort study

Hyperglycemic emergencies frequently lead to acute kidney injury (AKI) and require treatment with large amount of intravenous fluids. However, the effects of chloride loading on this population have not yet been investigated. We conducted a multicenter, retrospective, cohort study in 21 acute-care hospitals in Japan. The study included hospitalized adult patients with diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS) who had AKI upon arrival. The patients were classified into high and low chloride groups based on the amount of chloride administered within the first 48 h of their arrival. The primary outcome was recovery from AKI; secondary outcome was major adverse kidney events within 30 days (MAKE30), including mortality and prolonged renal failure. A total of 390 patients with AKI, including 268 (69%) with DKA and 122 (31%) with HHS, were included in the study. Using the criteria of Kidney Disease Improving Global Outcomes, the severity of AKI in the patients was Stage 1 (n = 159, 41%), Stage 2 (n = 121, 31%), and Stage 3 (n = 110, 28%). The analysis showed no significant difference between the two groups in recovery from AKI (adjusted hazard ratio, 0.96; 95% CI 0.72-1.28; P = 0.78) and in MAKE30 (adjusted odds ratio, 0.91; 95% CI 0.45-1.76; P = 0.80). Chloride loading with fluid administration had no significant impact on recovery from AKI in patients with hyperglycemic emergencies.Trial Registration This study was registered in the UMIN clinical trial registration system (UMIN000025393, registered December 23, 2016).

A retrospective study on the relationship between serum electrolyte disorder and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral ischemia (DCI)-induced cerebral infarction is a major cause of adverse neurological outcomes following aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to investigate the relationship between postoperative serum electrolyte levels and DCI in patients with aSAH.

MATERIALS AND METHODS

We analyzed the data of patients with aSAH between 2015 and 2022. The patients were classified into two groups according to whether they experienced DCI. Electrolyte levels were categorized into three groups based on the normal ranges for electrolytes. Logistic regression models were used to study the relationship between electrolyte levels and DCI. Another logistic regression analysis was conducted to explore the relationship between the different severity levels of statistically significant indicators and DCI. A restrictive cubic spline model was adopted to assess the potential linear relationship between electrolytes and DCI. Subsequently, sensitivity analysis was performed to assess the impact of collinearity among ions. Finally, subgroup analysis was performed.

RESULTS

This study included 1,099 patients. Patients with hyperchloremia were more prone to DCI than those with normal chloride levels. Subsequently, excluding the population with hypochloremia, both mild and severe hyperchloremia were found to be associated with an increased risk of DCI compared with normal chloride levels. Within the framework of a restrictive cubic spline, our findings revealed an increased incidence of DCI (P for nonlinear = 0.735) as chloride levels increased. Sensitivity analysis revealed that patients with severe hyperchloremia were more susceptible to DCI.

CONCLUSIONS

This study found that patients with aSAH and postoperative hyperchloremia are more prone to developing DCI.

5% Dextrose in Ringer's Lactate versus 5% Dextrose Normal Saline as Maintenance Intravenous Fluid Therapy in Children - A Randomised Controlled Trial

OBJECTIVES

To estimate the difference in serum chloride levels between children receiving 5% Dextrose in Ringer's Lactate (RLD5) vs. 5% Dextrose Normal Saline (DNS) and to estimate the incidence of dyselectrolytemia, hyperchloremic metabolic acidosis (HCMA), acute kidney injury (AKI) and all-cause mortality in both groups.

METHODS

A randomised controlled trial was conducted in non-critically ill children aged 6 mo to 14 y, admitted between August 2021 and July 2022, requiring intravenous fluids. A sample size of 140 was estimated and randomised, with controls receiving 5% DNS and the intervention group receiving RLD5. Kidney function tests and blood gas analysis were done at admission, 24 h and 48 h after starting the maintenance IV fluid, and outcomes were analysed at 24 h and 48 h. Data was collected using a pre-designed data collection form that included demographic and clinical profile details, and outcomes were analysed using SPSS Version 20 software.

RESULTS

Seventy-one children per group were enrolled. The mean chloride difference between the two groups at 24 and 48 h were 1.67 (p-value 0.03) and 2.78 (p-value 0.01), respectively. The incidence of AKI at 24 h and 48 h was 1.4% and 2.8% in the RLD5 group and 0% and 1.4% in the DNS group, respectively. At 24 h and 48 h, 2.8% and 2.8% of children had HCMA in the RLD5 group, and 14% and 4.2% had HCMA in the DNS group, respectively. There was no mortality in either group.

CONCLUSIONS

Though clinically insignificant, there was a statistically significant difference in the serum chloride levels between the groups.

The effect of dehydration, hyperchloremia and volume of fluid resuscitation on acute kidney injury in children admitted to hospital with diabetic ketoacidosis

BACKGROUND

Acute kidney injury (AKI) is a recognized comorbidity in pediatric diabetic ketoacidosis (DKA), although the exact etiology is unclear. The unique physiology of DKA makes dehydration assessments challenging, and these patients potentially receive excessive amounts of intravenous fluids (IVF). We hypothesized that dehydration is over-estimated in pediatric DKA, leading to over-administration of IVF and hyperchloremia that worsens AKI.

METHODS

Retrospective cohort of all DKA inpatients at a tertiary pediatric hospital from 2014 to 2019. A total of 145 children were included; reasons for exclusion were pre-existing kidney disease or incomplete medical records. AKI was determined by change in creatinine during admission, and comparison to a calculated baseline value. Linear regression multivariable analysis was used to identify factors associated with AKI. True dehydration was calculated from patients' change in weight, as previously validated. Fluid over-resuscitation was defined as total fluids given above the true dehydration.

RESULTS

A total of 19% of patients met KDIGO serum creatinine criteria for AKI on admission. Only 2% had AKI on hospital discharge. True dehydration and high serum urea levels were associated with high serum creatinine levels on admission (p = 0.042; p < 0.001, respectively). Fluid over-resuscitation and hyperchloremia were associated with delayed kidney recovery (p < 0.001). Severity of initial AKI was associated with cerebral edema (p = 0.018).

CONCLUSIONS

Dehydration was associated with initial AKI in children with DKA. Persistent AKI and delay to recovery was associated with hyperchloremia and over-resuscitation with IVF, potentially modifiable clinical variables for earlier AKI recovery and reduction in long-term morbidity. This highlights the need to re-address fluid protocols in pediatric DKA.

Elevated strong ion gap: A predictor of the initiation of continuous renal replacement therapy in acute kidney injury

BACKGROUND

There is no optimal timing for continuous renal replacement therapy (CRRT) in acute kidney injury (AKI). AKI is a reason for the increased unmeasured anions, which refers to the increased organic acids in the blood, and they can be detected by calculating strong ion gap (SIG). SIG level at the moment of the AKI diagnosis may be a predictor for the initiation of CRRT.

METHODS

Patients who were diagnosed with AKI in the first week of the intensive care unit (ICU) period were included in this prospective observational study. At the moment of the AKI diagnosis, blood gas samples were recorded, and SIG was calculated.

RESULTS

The median level of SIG at the moment of the AKI diagnosis of CRRT (+) patients was significantly higher than CRRT (-) patients (7.4 and 3.2 mmol L-1, respectively). In the multivariate Cox regression analysis, the likelihood of the initiation of CRRT was increased 1.16-fold (1.01-1.33) and 4.0-fold (1.9-8.7) by only 1 mmol L-1 increases in SIG and SIG ≥6 mmol L-1 at the moment of AKI diagnosis, respectively (p = 0.035 and p < 0.001).

CONCLUSIONS

Increased SIG at the moment of the AKI diagnosis in patients with AKI may be a predictive marker to initiate CRRT.

Prediction of adverse events risk in patients with comorbid post-traumatic stress disorder and alcohol use disorder using electronic medical records by deep learning models

BACKGROUND

Identifying co-occurring mental disorders and elevated risk is vital for optimization of healthcare processes. In this study, we will use DeepBiomarker2, an updated version of our deep learning model to predict the adverse events among patients with comorbid post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD), a high-risk population.

METHODS

We analyzed electronic medical records of 5565 patients from University of Pittsburgh Medical Center to predict adverse events (opioid use disorder, suicide related events, depression, and death) within 3 months at any encounter after the diagnosis of PTSD+AUD by using DeepBiomarker2. We integrated multimodal information including: lab tests, medications, co-morbidities, individual and neighborhood level social determinants of health (SDoH), psychotherapy and veteran data.

RESULTS

DeepBiomarker2 achieved an area under the receiver operator curve (AUROC) of 0.94 on the prediction of adverse events among those PTSD+AUD patients. Medications such as vilazodone, dronabinol, tenofovir, suvorexant, modafinil, and lamivudine showed potential for risk reduction. SDoH parameters such as cognitive behavioral therapy and trauma focused psychotherapy lowered risk while active veteran status, income segregation, limited access to parks and greenery, low Gini index, limited English-speaking capacity, and younger patients increased risk.

CONCLUSIONS

Our improved version of DeepBiomarker2 demonstrated its capability of predicting multiple adverse event risk with high accuracy and identifying potential risk and beneficial factors.

Low-Chloride Diet Prevents the Development of Arterial Hypertension and Protects Kidney Function in Angiotensin II-Infused Mice

INTRODUCTION

A comprehensive pathophysiological mechanism to explain the relationship between high-salt intake and hypertension remains undefined. Evidence suggests that chloride, as the accompanying anion of sodium in dietary salt, is necessary to develop hypertension. We evaluated whether reducing dietary Cl- while keeping a standard Na+ intake modified blood pressure, cardiac hypertrophy, renal function, and vascular contractility after angiotensin II (AngII) infusion.

METHODS

C56BL/6J mice fed with standard Cl- diet or a low-Cl- diet (equimolar substitution of Cl- by a mixture of Na+ salts, both diets with standard Na+ content) received AngII (infusion of 1.5 mg/kg/day) or vehicle for 14 days. We measured systolic blood pressure (SBP), glomerular filtration rate (GFR), natriuretic response to acute saline load, and contractility of aortic rings from mice infused with vehicle and AngII, in standard and low-Cl- diet.

RESULTS

The mice fed the standard diet presented increased SBP and cardiac hypertrophy after AngII infusion. In contrast, low-Cl- diet prevented the increase of SBP and cardiac hypertrophy. AngII-infused mice fed a standard diet presented hampered natriuretic response to saline load, meanwhile the low-Cl- diet preserved natriuretic response in AngII-infused mice, without change in GFR. Aortic rings from mice fed with standard diet or low-Cl- diet and infused with AngII presented a similar contractile response.

CONCLUSION

We conclude that the reduction in dietary Cl- as the accompanying anion of sodium in salt is protective from AngII pro-hypertensive actions due to a beneficial effect on kidney function and preserved natriuresis.

A Comparison Between Saline and Balanced Solutions in Kidney Transplants: A Randomized Clinical Trial

Objective This study aimed to investigate the impact of different types of intravenous fluids - normal saline (NS), lactated Ringer's solution (LR), and PlasmaLyte (PL) - on the acid-base balance and electrolyte concentration following kidney transplant, a common procedure for patients with end-stage renal disease (ESRD). Methodology A randomized controlled trial design was employed, wherein the primary parameters analyzed were postoperative pH and serum potassium levels. Postoperative concentrations of serum bicarbonate, sodium, chloride, and creatinine, as well as graft functionality, were assessed as secondary outcomes. These measurements were performed at the start and end of surgery, as well as 24 and 72 hours postoperatively. Results A total of 53 patients were included in the study and randomized into three cohorts: NS, LR, and PL, each of which showed comparability in terms of demographic and transplantation specifics. Notably, patients in the NS group exhibited a more significant decrease in pH (NS group: 7.285 ±0.098, LR group: 7.324 ±0.075, PL group: 7.7338 ±0.059) and bicarbonate levels (17.0 ±4.2, 20.9 ±2.8, 20.0 ±4.5) post 24 hours after the operation and displayed a similar pattern immediately after the surgery. However, there were no discernible differences in potassium (p=0.460), sodium (p=0.681), and chloride (p=0.321) levels across the groups. Furthermore, the study did not observe any significant differences in postoperative graft functionality. Conclusion The use of NS as the intraoperative fluid of choice led to lower pH and bicarbonate levels following kidney transplant, as compared to LR and PL. However, these results did not correlate with improvements in graft functionality.

Clinical efficacy of sodium bicarbonate in treating pediatric metabolic acidosis with varying level of acid-base balance parameters: a real-world study

BACKGROUND

Sodium bicarbonate (SB) infusion is commonly used to correct metabolic acidosis, but its clinical efficacy remains controversial. This study aims to investigate whether acid-base balance parameters should be a consideration for administering SB treatment.

METHODS

Children with metabolic acidosis (pH < 7.35 and bicarbonate < 22 mmol/L) who were treated with or without 50 mg/ml SB injection were grouped and extracted from a retrospective cohort database of the Pediatric Intensive Care Unit. The interaction between acid-base balance parameters and SB treatment on mortality was analyzed through mortality curves and cross-effect models. Logistic regression was conducted to estimate the risk of death following SB treatment in the overall children as well as in subgroups, and potential confounding factors were adjusted for. After employing propensity score matching to account for confounding factors, further analysis was performed to evaluate the effectiveness of SB treatment within each chloride subgroup.

RESULTS

A total of 5865 children with metabolic acidosis were enrolled, of which 2462 (42.0%) received SB treatment. In the overall population, it was found that SB treatment did not reduce hospital mortality or 28-day mortality. Interactions between acid-base balance parameters (chloride and anion gap) and SB treatment on mortality were observed. Subgroup analysis clarified that when chloride levels were below 107 mmol/L, children treated with SB had higher in-hospital mortality (29.8% vs 14.9%) and 28-day mortality (26.5% vs 13.4%), with adjusted ORs of 2.065 (95% CI, 1.435-2.97) and 1.947 (95% CI, 1.332-2.846), respectively. In contrast, when chloride levels were greater than or equal to 113 mmol/L, children treated with SB had a shorter stay in the PICU (median: 1.1 days vs 5.1 days, adjusted p = 0.004) and lower in-hospital mortality (4.3% vs 10.3%) and 28-day mortality (4.0% vs 8.4%), with adjusted ORs of 0.515 (95% CI, 0.337-0.788) and 0.614 (95% CI, 0.391-0.965), respectively. After controlling for confounding factors through matching, the impact of SB treatment on the risk of death in each chloride subgroup was consistent with the aforementioned results. However, treatment with SB did not significantly increase the risk of death in newborns or children with moderate to severe metabolic acidosis when chloride levels were below 107 mmol/L (p > 0.05).

CONCLUSIONS

The use of sodium bicarbonate for treating metabolic acidosis has been found to increase mortality in children with low chloride levels but decrease mortality in those with high chloride levels in this study. Further prospective multi-center clinical studies and basic research are needed to validate these findings.

Prediction of Adverse Events Risk in Patients with Comorbid Post- Traumatic Stress Disorder and Alcohol Use Disorder Using Electronic Medical Records by Deep Learning Models

Background

Prediction of high-risk events in mental disorder patients is crucial. In our previous study, we developed a deep learning model: DeepBiomarker by using electronic medical records (EMR) to predict suicide related event (SRE) risk in post-traumatic stress disorder (PTSD) patients.

Methods

We applied DeepBiomarker2 through data integration of multimodal information: lab test, medication, co-morbidities, and social determinants of health. We analyzed EMRs of 5,565 patients from University of Pittsburgh Medical Center with a diagnosis of PTSD and alcohol use disorder (AUD) on risk of developing an adverse event (opioid use disorder, SREs, depression and death).

Results

DeepBiomarker2 predicted whether a PTSD + AUD patient will have a diagnosis of any adverse events (SREs, opioid use disorder, depression, death) within 3 months with area under the receiver operator curve (AUROC) of 0.94. We found piroxicam, vilazodone, dronabinol, tenofovir, suvorexant, empagliflozin, famciclovir, veramyst, amantadine, sulfasalazine, and lamivudine to have potential to reduce risk.

Conclusions

DeepBiomarker2 can predict multiple adverse event risk with high accuracy and identify potential risk and beneficial factors. Our results offer suggestions for personalized interventions in a variety of clinical and diverse populations.

Regional lung perfusion using different indicators in electrical impedance tomography

Management of acute respiratory distress syndrome (ARDS) is classically guided by protecting the injured lung and mitigating damage from mechanical ventilation. Yet the natural history of ARDS is also dictated by disruption in lung perfusion. Unfortunately, diagnosis and treatment are hampered by the lack of bedside perfusion monitoring. Electrical impedance tomography is a portable imaging technique that can estimate regional lung perfusion in experimental settings from the kinetic analysis of a bolus of an indicator with high conductivity. Hypertonic sodium chloride has been the standard indicator. However, hypertonic sodium chloride is often inaccessible in the hospital, limiting practical adoption. We investigated whether regional lung perfusion measured using electrical impedance tomography is comparable between indicators. Using a swine lung injury model, we determined regional lung perfusion (% of total perfusion) in five pigs, comparing 12% sodium chloride to 8.4% sodium bicarbonate across stages of lung injury and experimental conditions (body position, positive end-expiratory pressure). Regional lung perfusion for four lung regions was determined from maximum slope analysis of the indicator-based impedance signal. Estimates of regional lung perfusion between indicators were compared in the lung overall and within four lung regions. Regional lung perfusion estimated with a sodium bicarbonate indicator agreed with a hypertonic sodium chloride indicator overall (mean bias 0%, limits of agreement -8.43%, 8.43%) and within lung quadrants. The difference in regional lung perfusion between indicators did not change across experimental conditions. Sodium bicarbonate may be a comparable indicator to estimate regional lung perfusion using electrical impedance tomography.NEW & NOTEWORTHY Electrical impedance tomography is an emerging tool to measure regional lung perfusion using kinetic analysis of a conductive indicator. Hypertonic sodium chloride is the standard agent used. We measured regional lung perfusion using another indicator, comparing hypertonic sodium chloride to sodium bicarbonate in an experimental swine lung injury model. We found strong agreement between the two indicators. Sodium bicarbonate may be a comparable indicator to measure regional lung perfusion with electrical impedance tomography.

Kidney Dysfunction After Traumatic Brain Injury: Pathophysiology and General Management

Traumatic brain injury (TBI) remains a major cause of mortality and morbidity, and almost half of these patients are admitted to the intensive care unit. Of those, 10% develop acute kidney injury (AKI) and 2% even need kidney replacement therapy (KRT). Although clinical trials in patients with TBI who have AKI are lacking, some general principles in this population may apply. The present review is an overview on the epidemiology and pathophysiology of AKI in patients with TBI admitted to the intensive care unit who are at risk for or who have developed AKI. A cornerstone in severe TBI management is preventing secondary brain damage, in which reducing the intracranial pressure (ICP) and optimizing the cerebral perfusion pressure (CPP) remain important therapeutic targets. To treat episodes of elevated ICP, osmolar agents such as mannitol and hypertonic saline are frequently administered. Although we are currently awaiting the results of a prospective randomized controlled trial that compares both agents, it is important to realize that both agents have been associated with an increased risk of developing AKI which is probably higher for mannitol compared with hypertonic saline. For the brain, as well as for the kidney, targeting an adequate perfusion pressure is important. Hemodynamic management based on the combined use of intravascular fluids and vasopressors is ideally guided by hemodynamic monitoring. Hypotonic albumin or crystalloid resuscitation solutions may increase the risk of brain edema, and saline-based solutions are frequently used but have a risk of hyperchloremia, which might jeopardize kidney function. In patients at risk, frequent assessment of serum chloride might be advised. Maintenance of an adequate CPP involves the optimization of circulating blood volume, often combined with vasopressor agents. Whether individualized CPP targets based on cerebrovascular autoregulation monitoring are beneficial need to be further investigated. Interestingly, such individualized perfusion targets are also under investigation in patients as a strategy to mitigate the risk for AKI in patients with chronic hypertension. In the small proportion of patients with TBI who need KRT, continuous techniques are advised based on pathophysiology and expert opinion. The need for KRT is associated with a higher risk of intracranial hypertension, especially if osmolar clearance occurs fast, which can even occur in continuous techniques. Precise ICP and CPP monitoring is mandatory, especially at the initiation of KRT.

Central metabolites and peripheral parameters associated neuroinflammation in fibromyalgia patients: A preliminary study

To identify central metabolites and peripheral measures associated with neuroinflammation in fibromyalgia (FM), we scanned [11C]-(R)-PK11195 positron emission tomography and magnetic resonance spectroscopy in FM patients. We measured associations between neurometabolite levels measured by magnetic resonance spectroscopy and the extent of neuroinflammation inferred by the distribution volume ratios of [11C]-(R)-PK11195 positron emission tomography in 12 FM patients and 13 healthy controls. We also examined the associations between peripheral parameters, such as creatinine and C-reactive protein, and neuroinflammation. In FM patients, we found negative correlations between neuroinflammation and the creatine (Cr)/total creatine (tCr; Cr + phosphocreatine) ratios in the right (r = -0.708, P = .015) and left thalamus (r = -0.718, P = .008). In FM patients, negative correlations were apparent between neuroinflammation and the glutamate/tCr ratio in the right insula (r = -0.746, P = .005). In FM patients, we found negative correlations between neuroinflammation in the left thalamus (r = -0.601, P = .039) and left insula (r = -0.598, P = .040) and the blood creatinine levels. Additionally, we found significant correlations of other peripheral measures with neuroinflammation in FM patients. Our results suggest that both central metabolites, such as Cr and glutamate, and peripheral creatinine and other parameters are associated with neuroinflammation in patients with FM.

Electrochemical Sensing of Urinary Chloride Ion Concentration for Near Real-Time Monitoring

Urinary chloride concentration is a valuable health metric that can aid in the early detection of serious conditions, such as acid base disorders, acute heart failure, and incidences of acute renal failure in the intensive care unit. Physiologically, urinary chloride levels frequently change and are difficult to measure, involving time-consuming and inconvenient lab testing. Thus, near real-time simple sensors are needed to quickly provide actionable data to inform diagnostic and treatment decisions that affect health outcomes. Here, we introduce a chronopotentiometric sensor that utilizes commercially available screen-printed electrodes to accurately quantify clinically relevant chloride concentrations (5-250 mM) in seconds, with no added reagents or electrode surface modification. Initially, the sensor's performance was optimized through the proper selection of current density at a specific chloride concentration, using electrical response data in conjunction with scanning electron microscopy. We developed a unique swept current density algorithm to resolve the entire clinically relevant chloride concentration range, and the chloride sensors can be reliably reused for chloride concentrations less than 50 mM. Lastly, we explored the impact of pH, temperature, conductivity, and additional ions (i.e., artificial urine) on the sensor signal, in order to determine sensor feasibility in complex biological samples. This study provides a path for further development of a portable, near real-time sensor for the quantification of urinary chloride.

Normal saline versus balanced crystalloids in patients with prerenal acute kidney injury and pre-existing chronic kidney disease

Introduction Normal saline (N/S) and Ringer's-Lactate (L/R), are administered in everyday clinical practice. Despite that, N/S increases the risk of sodium overload and hyperchloremic metabolic acidosis. In contrast, L/R has lower sodium content, significantly less chloride and contains lactates. In this study we compare the efficacy of L/R versus N/S administration in patients with prerenal acute kidney injury (AKI) and pre-established chronic kidney disease (CKD). Methods In this prospective open-label study we included patients with prerenal AKI and previously known CKD stage III-V without need for dialysis. Patients with other forms of AKI, hypervolemia or hyperkalemia were excluded. Patients received either N/S or L/R intravenously at a dose of 20 ml/kg body-weight/day. We studied kidney function at discharge and at 30 days, duration of hospitalization, acid-base balance and the need for dialysis. Results We studied 38 patients and 20 were treated with N/S. Kidney function improvement during hospitalization and at 30 days after discharge, was similar between the two groups. Duration of hospitalization was also similar. Anion-gap improvement as expressed with Δanion-gap between discharge and admission day was higher in those patients that received L/R in comparison to those that received N/S and pH increase (ΔpH) was slightly higher in the L/R group. No patient required dialysis. Conclusions Administration of L/R or N/S to patients with prerenal AKI and pre-established CKD had no significant difference in short or long term kidney function but L/R showed a better profile in acid-base balance improvement and Cl- overload in comparison to N/S.

Patient-Specific Risk Factors Associated With the Development of Hyperchloremia in a Neurocritical Care Intensive Care Unit

BACKGROUND

Hypertonic sodium chloride (HTS) is used in intensive care unit (ICU) settings to manage cerebral edema, intracranial hypertension, and for the treatment of severe hyponatremia. It has been associated with an increased incidence of hyperchloremia; however, there is limited literature focusing on hyperchloremic risk in neurologically injured patients. Objective: The primary objective of this study was to determine risk factors associated with development of hyperchloremia in a neurocritical care (NCC) ICU population.

METHODS

This was a retrospective case-control study performed in an adult NCC ICU and included patients receiving HTS. The primary outcome was to evaluate patient characteristics and treatments associated with hyperchloremia. Secondary outcomes included acute kidney injury and mortality.

RESULTS

Overall, 133 patients were identified; patients who were hyperchloremic were considered cases (n = 100) and patients without hyperchloremia were considered controls (n = 33). Characteristics and treatments were evaluated with univariate analysis and a logistic regression model. In the multivariate model, APACHE II Score, initial serum osmolality, total 3% saline volume, and total 23.4% saline volume were significant predictors for hyperchloremia. In addition, patients with a serum chloride greater than 113.5 mEq/L were found to have a higher risk of acute kidney injury (AKI) (adjusted OR 3.15; 95% CI 1.10-9.04).

CONCLUSIONS

This study demonstrated APACHE II Score, initial serum osmolality, and total 3% and 23.4% saline volumes were associated with developing hyperchloremia in the NCC ICU. In addition, hyperchloremia is associated with an increased risk of AKI.

Association of hyperchloremia and acute kidney injury in pediatric patients with moderate and severe traumatic brain injury

PURPOSE

Acute kidney injury (AKI) is an established complication of adult traumatic brain injury (TBI) and known risk factor for mortality. Evidence demonstrates an association between hyperchloremia and AKI in critically ill adults but studies in children are scarce. Given frequent use of hypertonic saline in the management of pediatric TBI, we believe the incidence of hyperchloremia will be high and hypothesize that it will be associated with development of AKI.

METHODS

Single-center retrospective cohort study was completed at an urban, level 1 pediatric trauma center. Children > 40 weeks corrected gestational age and < 21 years of age with moderate or severe TBI (presenting GCS < 13) admitted between January 2016 and December 2021 were included. Primary study outcome was presence of AKI (defined by pediatric Kidney Disease: Improving Global Outcomes criteria) within 7 days of hospitalization and compared between patients with and without hyperchloremia (serum chloride ≥ 110 mEq/L).

RESULTS

Fifty-two children were included. Mean age was 5.75 (S.D. 5.4) years; 60% were male (31/52); and mean presenting GCS was 6 (S.D. 2.9). Thirty-seven patients (71%) developed hyperchloremia with a mean peak chloride of 125 (S.D. 12.0) mEq/L and mean difference between peak and presenting chloride of 16 (S.D. 12.7) mEq/L. Twenty-three patients (44%) developed AKI; of those with hyperchloremia, 62% (23/37) developed AKI, while among those without hyperchloremia, 0% (0/15) developed AKI (difference 62%, 95% CI 42-82%, p < 0.001). Attributable risk of hyperchloremia leading to AKI was 62.2 (95% CI 46.5-77.8, p = 0.0015).

CONCLUSION

Hyperchloremia is common in the management of pediatric TBI and is associated with development of AKI. Risk appears to be associated with both the height of serum chloride and duration of hyperchloremia.

Hyperchloremia and association with acute kidney injury in critically ill children

BACKGROUND

Hyperchloremia has been associated with acute kidney injury (AKI) in critically ill adult patients. Data is limited in pediatric patients. Our study sought to determine if an association exists between hyperchloremia and AKI in pediatric patients admitted to the intensive care unit (PICU).

METHODS

This is a single-center retrospective cohort study of pediatric patients admitted to the PICU for greater than 24 h and who received intravenous fluids. Patients were excluded if they had a diagnosis of kidney disease or required kidney replacement therapy (KRT) within 6 h of admission. Exposures were hyperchloremia (serum chloride ≥ 110 mmol/L) within the first 7 days of PICU admission. The primary outcome was the development of AKI using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Secondary outcomes included time on mechanical ventilation, new KRT, PICU length of stay, and mortality. Outcomes were analyzed using multivariate logistic regression.

RESULTS

There were 407 patients included in the study, 209 in the hyperchloremic group and 198 in the non-hyperchloremic group. Univariate analysis demonstrated 108 (51.7%) patients in the hyperchloremic group vs. 54 (27.3%) in the non-hyperchloremic group (p =  < .001) with AKI. On multivariate analysis, the odds ratio of AKI with hyperchloremia was 2.24 (95% CI 1.39-3.61) (p = .001). Hyperchloremia was not associated with increased odds of mortality, need for KRT, time on mechanical ventilation, or length of stay.

CONCLUSION

Hyperchloremia was associated with AKI in critically ill pediatric patients. Further pediatric clinical trials are needed to determine the benefit of a chloride restrictive vs. liberal fluid strategy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Comparing the effect of administering gelatin-low dose albumin versus albumin on renal function in liver transplantation: A randomized clinical trial

BACKGROUND

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) that is independently associated with an increased risk of morbidity and mortality. This study aimed to evaluate the effects of administering gelatin-low dose albumin versus albumin on renal function and other early outcomes in LT.

METHODS

This randomized controlled clinical trial was conducted on 140 patients undergoing LT from brain death donors. Patients were randomly assigned to two groups: albumin or modified gelatin with albumin. Blood samples were collected before (T0) and on the first (T1), second (T2), third (T3), fifth (T4), and last day of hospitalization (T5) after LT for the detection of laboratory parameters, including renal and liver function tests.

RESULTS

The incidence of AKT on the basis of RIFLE criteria was 31.42% in the gelatin group (R: 59.10%, I: 36.40%, and F: 4.50%) and 25.71% in the albumin group (R: 66.70%, I: 27.80%, and F: 5.50%) (p = .845). Two patients in the gelatin and one in the albumin groups required renal replacement therapy (RRT). There was no significant difference between groups when the trends of changes in renal and liver function parameters were assessed during the study period (T0-T5). Furthermore, the incidence of complications was similar across groups.

CONCLUSION

This study showed that modified gelatin could be used without inappropriate outcomes on renal function in patients with normal preoperative kidney function tests undergoing LT.

Early hyperchloremia and outcomes after acute ischemic stroke

OBJECTIVE

Based on the relationship between hyperchloremia and mortality in critically ill patients, we investigated the effect of early hyperchloremia on 90-day outcomes in acute ischemic stroke patients.

MATERIALS AND METHODS

Acute ischemic stroke patients recruited within 5 h of symptom onset were analyzed. Hyperchloremia (defined as 110 mmol/L or greater) at either baseline, or 24, or 48 h after randomization was identified and classified as one occurrence or two or more occurrences. Logistic regression analyses were performed to determine the effects of hyperchloremia on: favorable outcomes (defined by a National Institutes of Health Stroke Scale and/or modified Rankin scale scores of 0-1) at 90-day, death or disability at 90-day, and death within 90-day after accounting for potential confounders.

RESULTS

Among the total of 1275 patients, one and two or more occurrence of hyperchloremia within 48 h were seen in 191 patients and 108 patients, respectively. Compared with patients without hyperchloremia, patients with two or more occurrences of hyperchloremia at significantly higher odds of lack of favorable outcomes (odds ratio 3.0, 95% confidence interval 1.8-5.1) and death or disability (odds ratio 2.6, 95% confidence interval 1.6-4.1) at 90-day after adjustment for age, National Institutes of Health Stroke Scale score strata (6-9, 10-19, ≥ 20), study intervention, initial SBP, and intra-arterial treatment.

CONCLUSIONS

The independent association between sustained hyperchloremia and lack of favorable outcomes at 90-day suggest that avoidance of hyperchloremia may reduce the rate of lack of favorable outcomes and death or disability in patients with acute ischemic stroke.

Early Hyperchloremia is Independently Associated with Death or Disability in Patients with Intracerebral Hemorrhage

BACKGROUND

On the basis of increased mortality associated with hyperchloremia among critically ill patients, we investigated the effect of occurrence of early hyperchloremia on death or disability at 90 days in patients with intracerebral hemorrhage (ICH).

METHODS

We analyzed the data from Antihypertensive Treatment of Cerebral Hemorrhage 2 trial, which recruited patients with spontaneous ICH within 4.5 h of symptom onset. Patients with increased serum chloride levels (110 mmol/L or greater) at either baseline or 24, 48, or 72 h after randomization were identified. We further graded hyperchloremia into one occurrence or two or more occurrences within the first 72 h. Two logistic regression analyses were performed to determine the effects of hyperchloremia on (1) death within 90 days and (2) death or disability at 90 days after adjustment for potential confounders.

RESULTS

Among the total of 1,000 patients analyzed, hyperchloremia within 72 h was seen in 114 patients with one occurrence and in 154 patients with two or more occurrences. Patients with one occurrence of hyperchloremia (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.1-5.5) and those with two or more occurrences (OR 2.6, 95% CI 1.3-5.0) had significantly higher odds of death within 90 days after adjustment for age, race and ethnicity, National Institutes of Health Stroke Scale score strata, hematoma volume, presence or absence of intraventricular hemorrhage, cigarette smoking, previous stroke, and maximum hourly dose of nicardipine. Patients with two or more occurrences of hyperchloremia (OR 3.4, 95% CI 2.1-5.6) had significantly higher odds of death or disability at 90 days compared with patients without hyperchloremia after adjustment for the abovementioned potential confounders.

CONCLUSIONS

The independent association between hyperchloremia and death or disability at 90 days suggests that avoidance of hyperchloremia may reduce the observed death or disability in patients with ICH.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT01176565.

Admission electrolyte and osmotic pressure levels are associated with the incidence of contrast-associated acute kidney injury

This retrospective study aimed to explore the relationships between electrolytes and osmotic pressure homeostasis with contrast-associated acute kidney injury (CA-AKI) risk in patients with percutaneous coronary intervention or coronary angiography. We totally enrolled 4386 hospitalized patients, who were categorized into five groups based on the predetermined cutoff values of electrolytes and osmotic pressure. CA-AKI was defined as an increase in serum creatine by 0.5 mg/dL (44.2 mol/L) or a 25% increase of the highest level post-operation compared to baseline. Multivariable logistic analysis was used to examine the association of CA-AKI incidence with electrolytes and osmotic pressure levels. Piecewise linear regression models and restricted cubic spline analysis were further utilized to determine the nonlinear relationship. The results showed U-shaped relationships between sodium, chloride, magnesium, and osmotic pressure levels and CA-AKI incidence. The lowest incidence was observed in the categories of 139–141.9 mmol/L, 107.0–109.9 mmol/L, 0.91–1.07 mmol/L, and 290.0–299.9 mOsm/kg, respectively. J-shaped associations were observed for potassium and phosphate levels and CA-AKI incidence, with the lowest incidence in the categories of 3.50–4.09 mmol/L and 0.96–1.28 mmol/L, respectively. A negative correlation was observed between calcium level and CA-AKI incidence, with the lowest CA-AKI risk in the category of ≥ 2.58 mmol/L. In conclusion, abnormally higher or lower sodium, chloride, magnesium, phosphate, and osmotic pressure levels on admission were associated with increased risks of CA-AKI. While for potassium and calcium, the status of hyperkalemia and hypocalcemia on admission showed more susceptibility for CA-AKI.

Acute Kidney Injury and Renal Failure in Horses

Nephrotoxic and hemodynamically mediated disorders are the most common causes of acute renal failure (ARF) in horses and foals. Leptospira spp. is the most common infectious cause of ARF. Initial treatments for ARF include elimination of nephrotoxic drugs, correction of predisposing disorders, and fluid therapy to promote diuresis. Horses and foals with polyuric ARF often have a good prognosis, while those with oliguric or anuric ARF have a guarded to poor prognosis. When fluid therapy is unsuccessful in improving urine production, various drugs treatments have been used in an attempt to increase urine production, but none are consistently effective in converting oliguria to polyuria.

Major adverse kidney events within 30 days in patients with acute pancreatitis: a tertiary-center cohort study

BACKGROUND

To evaluate the event rate of major adverse kidney events within 30 days (MAKE30) in acute pancreatitis (AP) and its potential risk factors.

METHODS

A retrospective analysis of a tertiary center data on all AP patients admitted within 72 h after onset of abdominal pain between June 2015 and June 2019 was conducted. MAKE30 - a composite of death, new renal replacement therapy (RRT), or persistent renal dysfunction (PRD) - and its individual components were retrieved at discharge or 30 days. Logistic regression analysis was used to assess the risk factors for MAKE30.

RESULTS

295 patients were enrolled and 16% experienced MAKE30. For individual components, the incidence was 3% for death, 15% for new RRT, and 5% for PRD. In multivariate logistic regression analysis, hyperchloremia at admission [OR = 8.38 (1.07-65.64); P = 0.043] and SOFA score [OR 1.63 (1.18-2.26); P = 0.003] were independent risk factors in predicting MAKE30. Further analysis showed that patients with hyperchloremia had more requirements of RRT (57% vs. 10%, P < 0.001), more PRD (14% vs. 4%, P = 0.034).

CONCLUSION

MAKE30 is a common event in AP patients. Hyperchloremia and SOFA score at admission were two independent risk factors for MAKE30.

Association of hyperchloremia with all-cause mortality in patients admitted to the surgical intensive care unit: a retrospective cohort study

Background

Serum chloride (Cl⁻) is one of the most essential extracellular anions. Based on emerging evidence obtained from patients with kidney or heart disease, hypochloremia has been recognized as an independent predictor of mortality. Nevertheless, excessive Cl⁻ can also cause death in severely ill patients. This study aimed to investigate the relationship between hyperchloremia and high mortality rate in patients admitted to the surgical intensive care unit (SICU).

Methods

We enrolled 2131 patients from the Multiparameter Intelligent Monitoring in Intensive Care III database version 1.4 (MIMIC-III v1.4) from 2001 to 2012. Selected SICU patients were more than 18 years old and survived more than 72 h. A serum Cl⁻ level ≥ 108 mEq/L was defined as hyperchloremia. Clinical and laboratory variables were compared between hyperchloremia (n = 664) at 72 h post-ICU admission and no hyperchloremia (n = 1467). The Locally Weighted Scatterplot Smoothing (Lowess) approach was utilized to investigate the correlation between serum Cl- and the thirty-day mortality rate. The Cox proportional-hazards model was employed to investigate whether serum chlorine at 72 h post-ICU admission was independently related to in-hospital, thirty-day and ninety-day mortality from all causes. Kaplan-Meier curve of thirty-day and ninety-day mortality and serum Cl⁻ at 72 h post-ICU admission was further constructed. Furthermore, we performed subgroup analyses to investigate the relationship between serum Cl⁻ at 72 h post-ICU admission and the thirty-day mortality from all causes.

Results

A J-shaped correlation was observed, indicating that hyperchloremia was linked to an elevated risk of thirty-day mortality from all causes. In the multivariate analyses, it was established that hyperchloremia remained a valuable predictor of in-hospital, thirty-day and ninety-day mortality from all causes; with adjusted hazard ratios (95% CIs) for hyperchloremia of 1.35 (1.02 ~ 1.77), 1.67 (1.28 ~ 2.19), and 1.39 (1.12 ~ 1.73), respectively. In subgroup analysis, we observed hyperchloremia had a significant interaction with AKI (P for interaction: 0.017), but there were no interactions with coronary heart disease, hypertension, and diabetes mellitus (P for interaction: 0.418, 0.157, 0.103, respectively).

Conclusion

Hyperchloremia at 72 h post-ICU admission and increasing serum Cl⁻ were associated with elevated mortality risk from all causes in severely ill SICU patients.

DNA repair factor KAT5 prevents ischemic acute kidney injury through glomerular filtration regulation

The “preconditioning effect” in AKI is a phenomenon in which an episode of ischemia-reperfusion results in tolerance to subsequent ischemia-reperfusion injury. However, its relationship between DNA damage repair has not been elucidated. Here, we show the role of KAT5 in the preconditioning effect. Preconditioning attenuated DNA damage in proximal tubular cells with elevated KAT5 expression. Ischemia-reperfusion (IR) injuries were exacerbated, and preconditioning effect vanished in proximal tubular-cell-specific KAT5 knockout mice. Investigation of tubuloglomerular feedback (TGF) by MALDI-IMS and urinary adenosine revealed that preconditioning caused attenuated TGF at least in part via KAT5. In addition, K-Cl cotransporter 3 (KCC3) expression decreased in damaged proximal tubular cells, which may be involved in accelerated TGF following IR. Furthermore, KAT5 induced KCC3 expression by maintaining chromatin accessibility and binding to the KCC3 promoter. These results suggest a novel mechanism of the preconditioning effect mediated by the promotion of DNA repair and attenuation of TGF through KAT5.

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KAT5-mediated DNA damage repair acts against ischemia-reperfusion (IR) injuries

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K-Cl cotransporter3 (KCC3) expression is decreased in damaged proximal tubular cells

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Decreased KCC3 may lead to AKI via acceleration of tubuloglomerular feedback

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KAT5 induces KCC3 expression through an epigenetic mechanism

High salt exacerbates acute kidney injury by disturbing the activation of CD5L/apoptosis inhibitor of macrophage (AIM) protein

The influence of excess salt intake on acute kidney injury (AKI) has not been examined precisely except for some clinical data, unlike in chronic kidney disease. Here, we addressed the influence of high salt (HS) on AKI and its underlying mechanisms in terms of the activity of circulating apoptosis inhibitor of macrophage (AIM, also called CD5L) protein, a facilitator of AKI repair. HS loading in mice subjected to ischemia/reperfusion (IR) resulted in high mortality with advanced renal tubular obstruction and marked exacerbation in biomarkers of proximal renal tubular damage. This AKI exacerbation appeared to be caused mainly by the reduced AIM dissociation from IgM pentamer in serum, as IgM-free AIM is indispensable for the removal of intratubular debris to facilitate AKI repair. Injection of recombinant AIM (rAIM) ameliorated the AKI induced by IR/HS, dramatically improving the tubular damage and mouse survival. The repair of lethal AKI by AIM was dependent on AIM/ kidney injury molecule-1 (KIM-1) axis, as rAIM injection was not effective in KIM-1 deficient mice. Our results demonstrate that the inhibition of AIM dissociation from IgM is an important reason for the exacerbation of AKI by HS, that AIM is a strong therapeutic tool for severe AKI.

Hypernatremia subgroups among hospitalized patients by machine learning consensus clustering with different patient survival

BACKGROUND

The objective of this study was to characterize hypernatremia patients at hospital admission into clusters using an unsupervised machine learning approach and to evaluate the mortality risk among these distinct clusters.

METHODS

We performed consensus cluster analysis based on demographic information, principal diagnoses, comorbidities, and laboratory data among 922 hospitalized adult patients with admission serum sodium of > 145 mEq/L. We calculated the standardized difference of each variable to identify each cluster's key features. We assessed the association of each hypernatremia cluster with hospital and 1-year mortality.

RESULTS

There were three distinct clusters of patients with hypernatremia on admission: 318 (34%) patients in cluster 1, 339 (37%) patients in cluster 2, and 265 (29%) patients in cluster 3. Cluster 1 consisted of more critically ill patients with more severe hypernatremia and hypokalemic hyperchloremic metabolic acidosis. Cluster 2 consisted of older patients with more comorbidity burden, body mass index, and metabolic alkalosis. Cluster 3 consisted of younger patients with less comorbidity burden, higher baseline eGFR, hemoglobin, and serum albumin. Compared to cluster 3, odds ratios for hospital mortality were 15.74 (95% CI 3.75-66.18) for cluster 1, and 6.51 (95% CI 1.48-28.59) for cluster 2, whereas hazard ratios for 1-year mortality were 6.25 (95% CI 3.69-11.46) for cluster 1 and 4.66 (95% CI 2.73-8.59) for cluster 2.

CONCLUSION

Our cluster analysis identified three clinically distinct phenotypes with differing mortality risk in patients hospitalized with hypernatremia.

Intra-operative intravascular effect of the difference in colloid solutions during acute normovolemic hemodilution

Background

Acute normovolemic hemodilution (ANH) is used to reduce the risk of peri-operative allogeneic blood transfusion. Although crystalloid and/or colloid solutions have been used for volume replacement during ANH, no studies have examined the differences among solutions on the volume status, electrolytes, acid-base balance, and hemodynamic status during surgery with ANH.

Methods

We retrospectively compared the effect of Ringer’s lactate with 3% dextran-40 (Saviosol®, DEX group) and 6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride (Voluven®, HES group) on blood hemoglobin serum electrolytes and estimated blood volume before induction of anesthesia (baseline), after ANH and after blood transfusion following surgery in patients undergoing open gynecological surgery (n = 111 and 67, respectively). The primary outcomes were the changes in hemoglobin and electrolytes after ANH.

Results

There were no differences in hemoglobin or electrolytes between the two groups at baseline. Postoperative hemoglobin was significantly higher (11.0 ± 1.5 g/dL vs 9.9 ± 1.3 g/dL) (mean ± SD) in the DEX group than in the HES group (p = 0.03). Postoperative potassium was significantly decreased from the baseline both in the DEX group (137.9 ± 2.5 mmol/L vs 136.3 ± 2.7 mmol/L) and in the HES group (138.3 ± 2.0 mmol/L vs 137.8 ± 2.5 mmol/L) (p < 0.001 for both); however, it was significantly higher than in the DEX group after surgery (p < 0.001). Estimated blood volume after surgery was significantly increased after ANH in both groups; however, it was larger in the HES group than in the DEX group.

Conclusions

Postoperative hemoglobin and potassium were significantly higher, and estimated blood volume was significantly smaller in the DEX than in the HES group.

Clinical differentiation between acute renal infarction and acute ureteral stone in the emergency department: A single-center retrospective case-control study

BACKGROUND

Few studies have compared renal infarction (RI) and ureteral stone (US), so there is insufficient evidence for emergency clinicians (ECs) to quickly suspect RI during the first assessment. Therefore, we compared the initial clinical presentation and laboratory findings of these diseases in the emergency department (ED) to determine a factor that may indicate RI.

METHODS

This single-center retrospective case-control study included 42 patients with acute RI and 210 with US who visited the ED from 2014 to 2020. Medical record data from first ED arrival were investigated, and clinical presentations, blood and urine test results obtained in the ED were compared and analyzed using logistic regression analysis.

RESULTS

ECs never suspected the initial diagnosis of RI as RI. The most common initial diagnosis was US (40.5%). Among patients with US, 150 patients (71.4%) were suspected of having US (p < 0.001). Abdominal pain (61.9%) was the most common chief complaint in the RI group, and flank pain (73.8%) was the most common in the US group (p < 0.001). 27 factors showed significant differences between the groups. Among those, age ≥ 70 years (odds ratio [OR]: 311.2, 95% confidence interval [CI]: 2.0-47,833.1), history of A-fib (OR: 149872.8, 95% CI: 289.4-7.8E+07), fever ≥37.5 °C (OR: 297.3, 95% CI: 3.3-27,117.8), Cl^- ≤ 103 mEq/L (OR: 9.0, 95% CI: 1.0-80.1), albumin ≤4.3 g/dL (OR: 26.6, 95% CI: 2.1-330.3), LDH ≥500 IU/L (OR: 17.9, 95% CI: 1.8-182.5), and CRP ≥0.23 mg/dL (OR: 7.5, 95% CI: 1.1-52.3) showed significantly high ORs, whereas urine RBCs (OR: 0, 95% CI: 0-0.02) showed a low OR (p < 0.05). The regression model showed good calibration (chi-square: 6.531, p = 0.588) and good discrimination (area under the curve = 0.9913).

CONCLUSIONS

When differentiating acute RI from US in the ED, age ≥ 70 years, history of A-fib, fever ≥37.5 °C, LDH ≥500 IU/L, Cl^- ≤ 103 mEq/L, albumin ≤4.3 g/dL, CRP ≥0.23 mg/dL and negative urine RBC result suggest the possibility of RI.

Intraoperative crystalloid utilization variability and association with postoperative outcomes: A post hoc analysis of two multicenter prospective cohort studies

BACKGROUND

The optimal regimen for intravenous administration of intraoperative fluids remains unclear. Our goal was to analyze intraoperative crystalloid volume administration practices and their association with postoperative outcomes.

METHODS

We extracted clinical data from two multicenter observational studies including adult patients undergoing colorectal surgery and total hip (THA) and knee arthroplasty (TKA). We analyzed the distribution of intraoperative fluid administration. Regression was performed using a general linear model to determine factors predictive of fluid administration. Patient outcomes and intraoperative crystalloid utilization were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low intraoperative crystalloid with the likelihood of increased postoperative complications, mainly acute kidney injury (AKI) and hospital length of stay (LOS).

RESULTS

7580 patients were included. The average adjusted intraoperative crystalloid infusion rate across all surgeries was to 7.9 (SD 4) mL/kg/h. The regression model strongly favored the type of surgery over other patient predictors. We found that high fluid volume was associated with 40% greater odds ratio (OR 1.40; 95% confidence interval 1.01-1.95, p = 0.044) of postoperative complications in patients undergoing THA, while we found no associations for the other types of surgeries, AKI and LOS CONCLUSIONS: A wide variability was observed in intraoperative crystalloid volume administration; however, this did not affect postoperative outcomes.

The effects of 0.9% saline versus Plasma-Lyte 148 on renal function as assessed by creatinine concentration in patients undergoing major surgery: A single-centre double-blinded cluster crossover trial

OBJECTIVES

Saline and Plasma-Lyte have different physiochemical contents; consequently, they may differently affect patients' renal function. We compared the effects of fluid therapy with 0.9% saline and with Plasma-Lyte 148 on renal function as assessed by creatinine concentration among patients undergoing major surgery.

METHODS

We conducted a prospective, double-blinded cluster crossover trial comparing the effects of the two fluids on major surgery patients. The primary aim was to establish the pilot feasibility, safety and preliminary efficacy evidence base for a large interventional trial to establish whether saline or Plasma-Lyte is the preferred crystalloid fluid for managing major surgery patients. The primary efficacy outcome was the proportion of patients with changes in renal function as assessed by creatinine concentration during their index hospital admission. We used changes in creatinine to define acute kidney injury (AKI) according to the RIFLE criteria.

RESULTS

The study was feasible with 100% patient and clinician acceptance. There were no deviations from the trial protocol. After screening, we allocated 602 patients to saline and 458 to Plasma-Lyte. The median (IQR) volume of intraoperative fluid received was 2000 mL (1000:2000) in both groups. Forty-nine saline patients (8.1%) and 49 Plasma-Lyte patients (10.7%) developed a postoperative AKI (adjusted incidence rate ratio [aIRR]: 1.34; 95% CI: 0.93-1.95; p = 0.120). No differences were observed in the development of postoperative complications (aIRR: 0.98; 95% CI: 0.89-1.08) or the severity of the worst complication (aIRR: 1.00; 95% CI: 0.78-1.30). The median (IQR) length of hospital stay was six days (3:11) for the saline group and five days (3:10) for the Plasma-Lyte group (aIRR: 0.85; 95% CI: 0.73-0.98). There were no serious adverse events relating to the trial fluids, nor were there fluid crossover or contamination events.

CONCLUSIONS

The study design was feasible to support a future follow-up larger clinical trial. Patients treated with saline did not demonstrate an increased incidence of postoperative AKI (defined as changes in creatinine) compared to those treated with Plasma-Lyte. Our findings imply that clinicians can reasonably use either solution intraoperatively for adult patients undergoing major surgery.

TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; ACTRN12613001042730; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364988.

Safety analysis regarding acute kidney injuries for chloride-restrictive intravenous fluid administration against that of chloride-liberal for patients admitted in the medical intensive care unit: A non-randomised retrospective (chrachl-mic) study

BACKGROUND

Acute kidney injuries are common in the medical intensive care unit. Generally, intravenous normal saline is administered in critically ill patients but it is associated with acute kidney injury. Current knowledge of chloride and its effect on the physiological functions of the kidney is limited. The objectives of the study were to compare the safety of chloride-restrictive intravenous fluid administration against that of chloride-liberal regarding acute kidney injuries.

METHODS

Data regarding RIFLE (risk, injury, failure, loss, and end-stage renal failure) categories, Kidney Disease: Improved Global Outcomes (KDIGO) stage, Δ creatinine, and requirements of renal replacement therapy of 285 patients admitted to medical intensive care unit for critical illness during 4-months from the hospitalisation were retrospectively collected and analysed. Patients received chloride-liberal intravenous fluid (CL cohort, n = 163) or that of chloride-restrictive (CR cohort, n = 122) during bundle-of-care.

RESULTS

Patients with risk (P = .039) and injury (P = .041) categories of RIFLE, high Δ creatinine (0.22 ± 0.02 mg/dL/patient vs 0.18 ± 0.02 mg/dL/patient, P < .0001), and patients with KDIGO stage 1 (P = .023) and stage 2 (P = .048) were reported significantly higher in the CL cohort than the CR cohort. The higher numbers of patients were put on renal replacement therapy in the CL cohort than those of the CR cohort (16 vs 3, P = .014).

CONCLUSION

The chloride-restrictive intravenous fluid administration has reduced the chances of acute kidney injuries in the intensive medical care unit.

A Post Hoc Analysis of Osmotherapy Use in the Erythropoietin in Traumatic Brain Injury Study-Associations With Acute Kidney Injury and Mortality

OBJECTIVES

Mannitol and hypertonic saline are used to treat raised intracerebral pressure in patients with traumatic brain injury, but their possible effects on kidney function and mortality are unknown.

DESIGN

A post hoc analysis of the erythropoietin trial in traumatic brain injury (ClinicalTrials.gov NCT00987454) including daily data on mannitol and hypertonic saline use.

SETTING

Twenty-nine university-affiliated teaching hospitals in seven countries.

PATIENTS

A total of 568 patients treated in the ICU for 48 hours without acute kidney injury of whom 43 (7%) received mannitol and 170 (29%) hypertonic saline.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We categorized acute kidney injury stage according to the Kidney Disease Improving Global Outcome classification and defined acute kidney injury as any Kidney Disease Improving Global Outcome stage-based changes from the admission creatinine. We tested associations between early (first 2 d) mannitol and hypertonic saline and time to acute kidney injury up to ICU discharge and death up to 180 days with Cox regression analysis. Subsequently, acute kidney injury developed more often in patients receiving mannitol (35% vs 10%; p < 0.001) and hypertonic saline (23% vs 10%; p < 0.001). On competing risk analysis including factors associated with acute kidney injury, mannitol (hazard ratio, 2.3; 95% CI, 1.2-4.3; p = 0.01), but not hypertonic saline (hazard ratio, 1.6; 95% CI, 0.9-2.8; p = 0.08), was independently associated with time to acute kidney injury. In a Cox model for predicting time to death, both the use of mannitol (hazard ratio, 2.1; 95% CI, 1.1-4.1; p = 0.03) and hypertonic saline (hazard ratio, 1.8; 95% CI, 1.02-3.2; p = 0.04) were associated with time to death.

CONCLUSIONS

In this post hoc analysis of a randomized controlled trial, the early use of mannitol, but not hypertonic saline, was independently associated with an increase in acute kidney injury. Our findings suggest the need to further evaluate the use and choice of osmotherapy in traumatic brain injury.

Intraoperative crystalloid utilization variability and association with postoperative outcomes: A post hoc analysis of two multicenter prospective cohort studies

BACKGROUND

The optimal regimen for intravenous administration of intraoperative fluids remains unclear. Our goal was to analyze intraoperative crystalloid volume administration practices and their association with postoperative outcomes.

METHODS

We extracted clinical data from two multicenter observational studies including adult patients undergoing colorectal surgery and total hip (THA) and knee arthroplasty (TKA). We analyzed the distribution of intraoperative fluid administration. Regression was performed using a general linear model to determine factors predictive of fluid administration. Patient outcomes and intraoperative crystalloid utilization were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low intraoperative crystalloid with the likelihood of increased postoperative complications, mainly acute kidney injury (AKI) and hospital length of stay (LOS).

RESULTS

7,580 patients were included. The average adjusted intraoperative crystalloid infusion rate across all surgeries was to 7.9 (SD 4) mL/kg/h. The regression model strongly favored the type of surgery over other patient predictors. We found that high fluid volume was associated with 40% greater odds ratio (OR 1.40; 95% confidence interval1.01-1.95, p = 0.044) of postoperative complications in patients undergoing THA, while we found no associations for the other types of surgeries, AKI and LOS CONCLUSIONS: A wide variability was observed in intraoperative crystalloid volume administration; however, this did not affect postoperative outcomes.

Hypochloremia Secondary to Diuretics in Preterm Infants: Should Clinicians Pay Close Attention?

Diuretic therapy, commonly used in the newborn intensive care unit, is associated with a variety of electrolyte abnormalities such as hyponatremia, hypokalemia, and hypochloremia. Hypochloremia, often ignored, is associated with significant morbidities and increased mortality in infants and adults. Clinicians respond in a reflex manner to hyponatremia than to hypochloremia. Hypochloremia is associated with nephrocalcinosis, hypochloremic alkalosis, and poor growth. Besides, the diuretic resistance associated with hypochloremia makes maintaining chloride levels in the physiological range even more logical. Since sodium supplementation counters the renal absorption of calcium and lack of evidence for spironolactone role in diuretic therapy for bronchopulmonary dysplasia (BPD), alternate chloride supplements such as potassium or arginine chloride may need to be considered in the management of hypochloremia due to diuretic therapy. In this review, we have summarized the current literature on hypochloremia secondary to diuretics and suggested a pragmatic approach to hypochloremia in preterm infants.

Association of Hyperchloremia and Acute Kidney Injury in Patients With Traumatic Brain Injury

Introduction:

Hypertonic saline is often used to treat patients with traumatic brain injury. It carries the undesired side effect of hyperchloremia, which has been linked to acute kidney injury (AKI). We sought to evaluate the relationship of hyperchloremia and AKI in this population and whether the absolute exposure to hyperchloremia, including maximal hyperchloremia and duration of hyperchloremia were associated with AKI.

Methods:

A retrospective study of severe traumatic brain injury patients who received hypertonic saline at a single academic institution. Demographics, head abbreviated injury scale, development of hyperchloremia (Cl ≥ 115), duration of hyperchloremia, highest chloride level, duration of hypertonic saline use, admission GFR, and administration of nephrotoxic medications were abstracted. The outcome of interest was the association between renal function and hyperchloremia.

Results:

A total of 123 patients were included in the study. Multivariable logistic regression analysis demonstrated that only duration of hyperchloremia ( p = 0.014) and GFR on admission ( p = 0.004) were independently associated with development of AKI. The number of days of hypertonic saline infusion ( p = 0.79) without the persistence of hyperchloremia and highest serum chloride levels ( p = 0.23) were not predictive of AKI development.

Discussion:

In patients with traumatic brain injury, admission GFR and prolonged hyperchloremia rather than the highest chloride level or the duration of hypertonic saline infusion were associated with the development of AKI.

The association between serum chloride levels and chronic kidney disease progression: a cohort study

Background

Limited data suggest serum chloride levels associate with mortality in heart failure, chronic kidney disease (CKD), and pulmonary arterial hypertension. Randomized trials have also shown that administration of crystalloid intravenous fluids with lower chloride concentration may have better renal outcomes. However, chloride has not been studied longitudinally for CKD progression.

Methods

We used a prospective cohort of subjects with stage 3 and 4 CKD recruited from a nephrology clinic at a single medical center. Linear regression, linear regression with generalized estimating equations, and Cox proportional hazards models were created for outcomes of overall change in estimated glomerular filtration rate (eGFR), longitudinal changes in eGFR, and time to > 30% decline in eGFR, respectively. Baseline chloride was modeled continuously and categorically, and models were adjusted for potential confounders.

Results

Median follow-up was 1.7 years. Baseline median age was 72 years and median eGFR was 35.7 mL/min/1.73m². In multivariable analysis, higher serum chloride associated with worsened eGFR decline. Every 1 mEq/L increase in chloride associated with an overall eGFR decline of 0.32 mL/min/1.73m² (p = 0.003), while the difference in eGFR decline in the highest quartile of chloride was 3.4 mL/min/1.73m² compared to the lowest quartile (p = 0.004). No association between serum chloride and time to 30% decline in eGFR was observed in multivariable analysis (hazard ratio 1.05 per 1 mEq/L increase in serum chloride, p = 0.103).

Conclusions

In CKD patients, higher serum chloride associated with a modestly steeper rate of eGFR decline, and may be a useful biomarker to predict CKD progression. Further studies are needed to determine causality.

Effect of mannitol plus hypertonic saline combination versus hypertonic saline monotherapy on acute kidney injury after traumatic brain injury

PURPOSE

To compare the effect of mannitol plus hypertonic saline combination (MHS) versus hypertonic saline monotherapy (HS) on renal function in patients with traumatic brain injury (TBI).

MATERIALS AND METHODS

This was a secondary analysis of data from the Resuscitation Outcomes Consortium Hypertonic Saline Trial Shock Study and Traumatic Brain Injury Study. The study cohort included a propensity matched subset of patients with TBI who received MHS or HS. The primary outcome measure was the maximum serum creatinine value during critical illness.

RESULTS

The cohort consisted of 163 patients in the MHS group and 163 patients in the HS group (n = 326). The maximum serum creatinine value during hospitalization was 82 ± 47 μmol/L (0.86 ± 0.26 mg/dL) in the MHS group and 76 ± 23 μmol/L (0.92 ± 0.53 mg/dL) in the HS group (difference -6 μmol/L, 95% CI -14 to 2 μmol/L, p = .151). The lowest eGFR during hospitalization was 108 ± 25 mL/min in the MHS group and 112 ± 24 mL/min in the HS group (difference -4 mL/min, 95% CI -1 to 9 mLmin, p = .150).

CONCLUSIONS

The addition of mannitol to HS did not increase the risk of renal dysfunction compared to HS alone in patients with TBI.

The Many Faces of Calcineurin Inhibitor Toxicity-What the FK?

Calcineurin inhibitors (CNIs) are both the savior and Achilles' heel of kidney transplantation. Although CNIs have significantly reduced rates of acute rejection, their numerous toxicities can plague kidney transplant recipients. By 10 years, virtually all allografts will have evidence of CNI nephrotoxicity. CNIs have been strongly associated with hypertension, dyslipidemia, and new onset of diabetes after transplantation-significantly contributing to cardiovascular risk in the kidney transplant recipient. Multiple electrolyte derangements including hyperkalemia, hypomagnesemia, hypercalciuria, metabolic acidosis, and hyperuricemia may be challenging to manage for the clinician. Finally, CNI-associated tremor, gingival hyperplasia, and defects in hair growth can have a significant impact on the transplant recipient's quality of life. In this review, the authors briefly discuss the pharmacokinetics of CNI and discuss the numerous clinically relevant toxicities of commonly used CNIs, cyclosporine and tacrolimus.

Urinary chloride concentration as a prognostic marker in critically ill patients

AIM

Associations have been reported among serum chloride concentration, mortality and incidence of acute kidney injury (AKI) in intensive care units (ICU). This study aimed to examine associations among urinary chloride, mortality, and AKI incidence in ICU patients.

METHODS

A retrospective observational study was conducted among medical-surgical ICU in a tertiary hospital wherein 170 consecutive ICU patients were evaluated from October 2015 to March 2016 and 116 patients were enrolled. Serial data of serum and urine electrolytes from day 1 to day 4 of ICU admission were examined. The primary and secondary outcomes were ICU mortality and incidence of AKI in the ICU, respectively.

RESULTS

Among the 116 enrolled patients, 15 (13%) died during their ICU stay. Although serum and urinary sodium and potassium on day 1 did not significantly differ between ICU survivors and non-survivors, urinary chloride concentration on day 1 was significantly lower in non-survivors. Receiver operating characteristic analysis showed that the cutoff value of day 1 urinary chloride concentration for prediction of ICU mortality was 53 mEq/L. The lower urinary chloride concentration group on day 1 showed a significantly lower survival rate, even in long-term follow-up, compared with the higher urinary chloride group. Addition of day 1 urinary chloride concentration improved prediction of AKI incidence in the ICU by Sequential Organ Failure Assessment score alone.

CONCLUSION

Lower urinary chloride concentration was associated with increased mortality and incidence of AKI in the ICU. Further investigation is necessary to clarify the mechanism of urinary chloride regulation.