Fluid balance and mortality in critically ill patients with acute kidney injury: a multicenter prospective epidemiological study

Effects of 24-hour urine-output trajectories on the risk of acute kidney injury in critically ill patients with cirrhosis: a retrospective cohort analysis

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications for critically ill patients with cirrhosis, but it has remained unclear whether urine output fluctuations are associated with the risk of AKI in such patients. Thus, we explored the influence of 24-h urine-output trajectory on AKI in patients with cirrhosis through latent category trajectory modeling.

MATERIALS AND METHODS

This retrospective cohort study examined patients with cirrhosis using the MIMIC-IV database. Changes in the trajectories of urine output within 24 h after admission to the intensive care unit (ICU) were categorized using latent category trajectory modeling. The outcome examined was the occurrence of AKI during ICU hospitalization. The risk of AKI in patients with different trajectory classes was explored using the cumulative incidence function (CIF) and the Fine-Gray model with the sub-distribution hazard ratio (SHR) and the 95% confidence interval (CI) as size effects.

RESULTS

The study included 3,562 critically ill patients with cirrhosis, of which 2,467 (69.26%) developed AKI during ICU hospitalization. The 24-h urine-output trajectories were split into five classes (Classes 1-5). The CIF curves demonstrated that patients with continuously low urine output (Class 2), a rapid decline in urine output after initially high levels (Class 3), and urine output that decreased slowly and then stabilized at a lower level (Class 4) were at higher risk for AKI than those with consistently moderate urine output (Class 1). After fully adjusting for various confounders, Classes 2, 3, and 4 were associated with a higher risk of AKI compared with Class 1, and the respective SHRs (95% CIs) were 2.56 (1.87-3.51), 1.86 (1.34-2.59), and 1.83 1.29-2.59).

CONCLUSIONS

The 24-h urine-output trajectory is significantly associated with the risk of AKI in critically ill patients with cirrhosis. More attention should be paid to the dynamic nature of urine-output changes over time, which may help guide early intervention and improve patients' prognoses.

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

PURPOSE

A positive fluid balance (FB) is associated with harm in intensive care unit (ICU) patients with acute kidney injury (AKI). We aimed to understand how a positive balance develops in such patients.

METHODS

Multinational, retrospective cohort study of critically ill patients with AKI not requiring renal replacement therapy.

RESULTS

AKI occurred at a median of two days after admission in 7894 (17.3%) patients. Cumulative FB became progressively positive, peaking on day three despite only 848 (10.7%) patients receiving fluid resuscitation in the ICU. In those three days, persistent crystalloid use (median:60.0 mL/h; IQR 28.9-89.2), nutritional intake (median:18.2 mL/h; IQR 0.0-45.9) and limited urine output (UO) (median:70.8 mL/h; IQR 49.0-96.7) contributed to a positive FB. Although UO increased each day, it failed to match input, with only 797 (10.1%) patients receiving diuretics in ICU. After adjustment, a positive FB four days after AKI diagnosis was associated with an increased risk of hospital mortality (OR 1.12;95% confidence intervals 1.05-1.19;p-value <0.001).

CONCLUSION

Among ICU patients with AKI, cumulative FB increased after diagnosis and was associated with an increased risk of mortality. Continued crystalloid administration, increased nutritional intake, limited UO, and minimal use of diuretics all contributed to positive FB.

KEY POINTS

Question How does a positive fluid balance develop in critically ill patients with acute kidney injury? Findings Cumulative FB increased after AKI diagnosis and was secondary to persistent crystalloid fluid administration, increasing nutritional fluid intake, and insufficient urine output. Despite the absence of resuscitation fluid and an increasing cumulative FB, there was persistently low diuretics use, ongoing crystalloid use, and a progressive escalation of nutritional fluid therapy. Meaning Current management results in fluid accumulation after diagnosis of AKI, as a result of ongoing crystalloid administration, increasing nutritional fluid, limited urine output and minimal diuretic use.

Associations between serum albumin level trajectories and clinical outcomes in sepsis patients in ICU: insights from longitudinal group trajectory modeling

Background

Sepsis triggers a strong inflammatory response, often leading to organ failure and high mortality. The role of serum albumin levels in sepsis is critical but not fully understood, particularly regarding the significance of albumin level changes over time. This study utilized Group-based Trajectory Modeling (GBTM) to investigate the patterns of serum albumin changes and their impact on sepsis outcomes.

Methods

We conducted a retrospective analysis on ICU patients from West China Hospital (2015-2022), employing GBTM to study serum albumin fluctuations within the first week of ICU admission. The study factored in demographics, clinical parameters, and comorbidities, handling missing data through multiple imputation. Outcomes assessed included 28-day mortality, overall hospital mortality, and secondary complications such as AKI and the need for mechanical ventilation.

Results

Data from 1,950 patients revealed four serum albumin trajectories, showing distinct patterns of consistently low, increasing, moderate, and consistently high levels. These groups differed significantly in mortality, with the consistently low level group experiencing the highest mortality. No significant difference in 28-day mortality was observed among the other groups. Subgroup analysis did not alter these findings.

Conclusion

The study identified four albumin trajectory groups in sepsis patients, highlighting that those with persistently low levels had the worst outcomes, while those with increasing levels had the best. Stable high levels above 30 g/L did not change outcomes significantly. These findings can inform clinical decisions, helping to identify high-risk patients early and tailor treatment approaches.

Association Of Estimated Plasma Volume with New Onset Acute Kidney Injury in Hospitalized COVID-19 Patients

PURPOSE

To explore the association of estimated plasma volume (ePV) and plasma volume status (PVS) as surrogates of volume status with new-onset AKI and in-hospital mortality among hospitalized COVID-19 patients.

MATERIALS AND METHODS

We performed a retrospective multi-center study on COVID-19-related ARDS patients who were admitted to the Mayo Clinic Enterprise health system. Plasma volume was calculated using the formulae for ePV and PVS, and longitudinal analysis was performed to find the association of ePV and PVS with new-onset AKI during hospitalization as the primary outcome and in-hospital mortality as a secondary outcome.

RESULTS

Our analysis included 7616 COVID-19 patients with new-onset AKI occurring in 1365 (17.9%) and a mortality rate of 25.96% among them. A longitudinal multilevel multivariate analysis showed both ePV (OR 1.162; 95% CI 1.048-1.288, p=0.004) and PVS (OR 1.032; 95% CI 1.012-1.050, p=0.001) were independent predictors of new onset AKI. Higher PVS was independently associated with increased in-hospital mortality (OR 1.038, 95% CI 1.007-1.070, p=0.017), but not ePV (OR 0.868, 95% CI 0.740-1.018, p=0.082).

CONCLUSION

A higher PVS correlated with a higher incidence of new-onset AKI and worse outcomes in our cohort of hospitalized COVID-19 patients. Further large-scale and prospective studies are needed to understand its utility.

Association of Postoperative Serum Lactate Levels with Acute Kidney Injury in Mexican Patients Undergoing Cardiac Surgery

Acute kidney injury (AKI) is a highly prevalent and a critical complication of cardiac surgery (CS). Serum lactate (sLac) levels have consistently shown an association with morbimortality after CS. We performed a cross-sectional study including 264 adult patients that had a cardiac surgery between January and December 2020. Logistic regression analysis was performed to determine factors associated with AKI development. We measured the postoperative levels of sLac for all participants immediately after CS (T0) and at 4 h (T4) after the surgical intervention. A linear regression model was used to identify the factors influencing both sLac metrics. We identified four risk predictors of AKI; one was preoperative (atrial fibrillation), one intraoperative (cardiopulmonary bypass time), and two were postoperative (length of hospital stay and postoperative sLac). T0 and T4 sLac levels were higher among CS-AKI patients than in Non-CS-AKI patients. Postoperative sLac levels were significant independent predictors of CSA-AKI, and sLac levels are influenced by length of hospital stay, the number of transfused packed red blood cells, and the use of furosemide in CS-AKI patients. These findings may facilitate the earlier identification of patients susceptible to AKI after CS.

Plasma sodium during the recovery of renal function in critically ill adult patients: Multicenter prospective cohort study

BACKGROUND

Sodium increases during acute kidney injury (AKI) recovery. Both hypernatremia and positive fluid balances are associated with increased mortality. We aimed to evaluate the association between daily fluid balance and daily plasma sodium during the recovery from AKI among critical patients.

METHODS

Adult patients with AKI were enrolled in four ICUs and followed up for four days or until ICU discharge or hemodialysis initiation. Day zero was the peak day of creatinine. The primary outcome was daily plasma sodium; the main exposure was daily fluid balance.

RESULTS

93 patients were included. The median age was 66 years; 68% were male. Plasma sodium increased in 79 patients (85%), and 52% presented hypernatremia. We found no effect of daily fluid balance on plasma sodium (β -0.26, IC95%: -0.63-0.13; p = 0.19). A higher total sodium variation was observed in patients with lower initial plasma sodium (β -0.40, IC95%: -0.53 to -0.27; p < 0.01), higher initial urea (β 0.07, IC95%: 0.04-0.01; p < 0.01), and higher net sodium balance (β 0.002, IC95%: 0.0001-0.01; p = 0.05).

CONCLUSIONS

The increase in plasma sodium is common during AKI recovery and can only partially be attributed to the water and electrolyte balances. The incidence of hypernatremia in this population of patients is higher than in the general critically ill patient population.

Current Fluid Management Practice in Critically Ill Adults on Continuous Renal Replacement Therapy: A Binational, Observational Study

INTRODUCTION

In critically ill patients undergoing continuous renal replacement therapy (CRRT), a positive fluid balance (FB) is associated with adverse outcomes. However, current FB management practices in CRRT patients are poorly understood. We aimed to study FB and its components in British and Australian CRRT patients to inform future trials.

METHODS

We obtained detailed electronic health record data on all fluid-related variables during CRRT and hourly FB for the first 7 days of treatment.

RESULTS

We studied 1,616 patients from three tertiary intensive care units (ICUs) in two countries. After the start of CRRT, the mean cumulative FB became negative at 31 h and remained negative over 7 days to a mean nadir of -4.1 L (95% confidence interval (CI) of -4.6 to -3.5). The net ultrafiltration (NUF) rate was the dominant fluid variable (-67.7 mL/h; standard deviation (SD): 75.7); however, residual urine output (-34.7 mL/h; SD: 54.5), crystalloid administration (48.1 mL/h; SD: 44.6), and nutritional input (36.4 mL/h; SD: 29.7) significantly contributed to FB. Patients with a positive FB after 72 h of CRRT were more severely ill, required high-dose vasopressors, and had high lactate concentrations (5.0 mmol/L; interquartile range: 2.3-10.5). A positive FB was independently associated with increased hospital mortality (odds ratio: 1.70; 95% CI; p = 0.004).

CONCLUSION

In the study ICUs, most CRRT patients achieved a predominantly NUF-dependent negative FB. Patients with a positive FB at 72 h had greater illness severity and haemodynamic instability. Achieving equipoise for conducting trials that target a negative early FB in such patients may be difficult.

Influence of fluid accumulation on major adverse kidney events in critically ill patients - an observational cohort study

BACKGROUND

Fluid accumulation (FA) is known to be associated with acute kidney injury (AKI) during intensive care unit (ICU) stay but data on mid-term renal outcome is scarce. The aim of this study was to investigate the association between FA at ICU day 3 and major adverse kidney events in the first 30 days after ICU admission (MAKE30).

METHODS

Retrospective, single-center cohort study including adult ICU patients with sufficient data to compute FA and MAKE30. We defined FA as a positive cumulative fluid balance greater than 5% of bodyweight. The association between FA and MAKE30, including its sub-components, as well as the serum creatinine trajectories during ICU stay were examined. In addition, we performed a sensitivity analysis for the stage of AKI and the presence of chronic kidney disease (CKD).

RESULTS

Out of 13,326 included patients, 1,100 (8.3%) met the FA definition. FA at ICU day 3 was significantly associated with MAKE30 (adjusted odds ratio [aOR] 1.96; 95% confidence interval [CI] 1.67-2.30; p < 0.001) and all sub-components: need for renal replacement therapy (aOR 3.83; 95%CI 3.02-4.84), persistent renal dysfunction (aOR 1.72; 95%CI 1.40-2.12), and 30-day mortality (aOR 1.70; 95%CI 1.38-2.09), p all < 0.001. The sensitivity analysis showed an association of FA with MAKE30 independent from a pre-existing CKD, but exclusively in patients with AKI stage 3. Furthermore, FA was independently associated with the creatinine trajectory over the whole observation period.

CONCLUSIONS

Fluid accumulation is significantly associated with MAKE30 in critically ill patients. This association is independent from pre-existing CKD and strongest in patients with AKI stage 3.

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.

Cardiac Surgery Outcomes in Patients Receiving Hemodialysis Versus Peritoneal Dialysis

Rationale & Objective

We sought to compare outcomes of patients receiving dialysis after cardiothoracic surgery on the basis of dialysis modality (intermittent hemodialysis [HD] vs peritoneal dialysis [PD]).

Study Design

This was a retrospective analysis.

Setting & Participants

In total, 590 patients with kidney failure receiving intermittent HD or PD undergoing coronary artery bypass graft and/or valvular cardiac surgery at Cleveland Clinic were included.

Exposure

The patients received PD versus HD (intermittent or continuous).

Outcomes

Our primary outcomes were in-hospital and 30-day mortality. Secondary outcomes were length of stay, days in the intensive care unit, the number of intraoperative blood transfusions, postsurgical pericardial effusion, and sternal wound infection, and a composite of the following 4 in-hospital events: death, cardiac arrest, effusion, and sternal wound infection.

Analytical Approach

We used χ2, Fisher exact, Wilcoxon rank sum, and t tests, Kaplan-Meier survival, and plots for analysis.

Results

Among the 590 patients undergoing cardiac surgery, 62 (11%) were receiving PD, and 528 (89%) were receiving intermittent HD. Notably, 30-day Kaplan-Meier survival was 95.7% (95% CI: 93.9-97.5) for HD and 98.2% (95% CI: 94.7-100) for PD (P = 0.30). In total, 75 patients receiving HD (14.2%) and 1 patient receiving PD (1.6%) had a composite of 4 in-hospital events (death, cardiac arrest, effusion, and sternal wound infection) (P = 0.005). Out of 62 patients receiving PD, 16 (26%) were converted to HD.

Limitations

Retrospective analyses are prone to residual confounding. We lacked details about nutritional data. Intensive care unit length of stay was used as a surrogate for volume status control. Patients have been followed in a single health care system. The HD cohort outnumbered the PD cohort significantly.

Conclusions

When compared with PD, HD does not appear to improve outcomes of patients with kidney failure undergoing cardiothoracic surgery. Patients receiving PD had a lower incidence of a composite outcome of 4 in-hospital events (death, cardiac arrest, pericardial effusion, and sternal wound infections).

Predictors of oliguria in post-traumatic acute kidney injury

BACKGROUND

Acute kidney injury is classified by urine output into non-oliguric and oliguric variants. Non-oliguric acute kidney injury has lower morbidity and mortality and accounts for up to 64% of acute kidney injury in hospitalized patients. However, the incidence of non-oliguric acute kidney injury in the trauma population and whether the 2 variants of acute kidney injury share the same risk factors is unknown. We hypothesized that oliguria would be present in the majority of acute kidney injury in severely injured trauma patients and that unique risk factors would predispose patients to the development of oliguria.

METHODS

Patients admitted to the trauma intensive care unit and diagnosed with an acute kidney injury between 2016 to 2021 were identified. Cases were categorized based on urine output into oliguric (<400 mL per day) and non-oliguric (>400 mL per day) disease. Risk factors, management, and outcomes were compared. Logistic regression was used to identify risk factors associated with oliguria.

RESULTS

A total of 227 patients met inclusion criteria. Non-oliguric acute kidney injury accounted for 74% of all cases and was associated with greater survival (78% vs 35.6%, P < .001). Using logistic regression, female sex, vasopressor use, and a greater net fluid balance at 48 hours were all predictive of oliguria (while controlling for age, race, shock index, massive transfusion, operative intervention, cardiac arrest, and nephrotoxic medication exposure).

CONCLUSION

Non-oliguria accounts for the majority of post-traumatic acute kidney injury and is associated with improved survival. Specific risk factors for the development of oliguric acute kidney injury include female sex, vasopressor use, and a higher net fluid balance at 48 hours.

EARLY TRAJECTORY OF VENOUS EXCESS ULTRASOUND SCORE IS ASSOCIATED WITH CLINICAL OUTCOMES OF GENERAL ICU PATIENTS

ABSTRACT

Background: Systemic venous congestion, assessed by the venous excess ultrasound (VExUS) score, has been associated with adverse effects, including acute kidney injury (AKI), in patients with cardiac disease. In general intensive care unit (ICU) patients, the association between VExUS score and outcomes is understudied. We aimed to investigate the association between the trajectory of VExUS score within the first 3 days of ICU admission and the composite clinical outcome of major adverse kidney events within 30 days (MAKE30). Methods: In this prospective observational study, including patients consecutively admitted to the ICU, VExUS score was calculated within 24 h after ICU admission (day 1) and at 48 to 72 h (day 3). D-VExUS was calculated as the difference between the VExUS score on day 3 minus that on day 1. Development of AKI within 7 days and all-cause mortality within 30 days were recorded. Results: A total of 89 patients (62% men; median age, 62 years; median Acute Physiology and Chronic Health Evaluation II score, 24) were included. Sixty (67%) patients developed AKI within 7 days, and 17 (19%) patients died within 30 days after ICU admission. D-VExUS was associated with MAKE30, even after adjustment for confounders (hazard ratio, 2.07; 95% confidence interval, 1.17-3.66; P = 0.01). VExUS scores on days 1 or 3 were not associated with MAKE30. Also, VExUS scores on day 1 or on day 3 and D-VExUS were not associated with development of AKI or mortality. Conclusions: In a general ICU cohort, early trajectory of VExUS score, but not individual VExUS scores at different time points, was associated with the patient-centered MAKE30 outcome. Dynamic changes rather than snapshot measurements may unmask the adverse effects of systemic venous congestion on important clinical outcomes.

Fluid balance, biomarkers of renal function and mortality in critically ill patients with AKI diagnosed before, or within 24 h of intensive care unit admission: a prospective study

BACKGROUND

To evaluate fluid balance, biomarkers of renal function and its relation to mortality in patients with acute kidney injury (AKI) diagnosed before, or within 24 h of intensive care unit admission.

METHODS

A prospective cohort study considered 773 critically ill patients observed over six years. Pre-intensive care unit-onset AKI was defined as AKI diagnosed before, or within 24 h of intensive care unit admission. Body weight-adjusted fluid balance and fluid balance-adjusted biomarkers of renal function were measured daily for the first three days of intensive care unit admission. Primary outcome was mortality in the intensive care unit.

RESULTS

Prevalence of pre-intensive care unit-onset AKI was 55.1%, of which 55.6% of cases were hospital-acquired and 44.4% were community-acquired. Fluid balance was higher in AKI patients than in non-AKI patients (p < 0.001) and had a negative correlation with urine output (p < 0.01). Positive fluid balance and biomarkers of renal function were independently related to mortality. Multivariate analysis identified the following AKI-related variables associated with increased mortality: (1) In AKI patients: type 1 cardiorenal syndrome (OR 2.00), intra-abdominal hypertension (OR 1.71), AKI stage 3 (OR 2.15) and increase in AKI stage (OR 4.99); 2) In patients with community-acquired AKI: type 1 cardiorenal syndrome (OR 5.16), AKI stage 2 (OR 2.72), AKI stage 3 (OR 4.95) and renal replacement therapy (OR 3.05); and 3) In patients with hospital-acquired AKI: intra-abdominal hypertension (OR 2.31) and increase in AKI stage (OR 4.51).

CONCLUSIONS

In patients with pre-intensive care unit-onset AKI, positive fluid balance is associated with worse renal outcomes. Positive fluid balance and decline in biomarkers of renal function are related to increased mortality, thus in this subpopulation of critically ill patients, positive fluid balance is not recommended and renal function must be closely monitored.

The role of peritoneal dialysis in the treatment of acute kidney injury in neurocritical patients: a retrospective Brazilian study

BACKGROUND

Acute kidney injury (AKI) occurs frequently in the neurocritical intensive care unit and is associated with greater morbidity and mortality. AKI and its treatment, including acute kidney replacement therapy, can expose patients to a secondary greater brain injury. This study aimed to explore the role of peritoneal dialysis (PD) in neurocritical AKI patients in relation to metabolic and fluid control, complications related to PD and outcome.

METHODS

Neurocritical AKI patients were treated by PD (prescribed Kt/V = 0.40/session) using a flexible catheter and a cycler and lactate as a buffer.

RESULTS

A total of 58 patients were included. The mean age was 61.8 ± 13.2 years, 65.5% were in the intensive care unit, 68.5% needed intravenous inotropic agents, 72.4% were on mechanical ventilation, APACHE II was 16 ± 6.67 and the main neurological diagnoses were stroke (25.9%) and intracerebral haemorrhage (31%). Ischaemic acute tubular necrosis (iATN) was the most common cause of AKI (51.7%), followed by nephrotoxic ATN AKI (25.8%). The main dialysis indications were uraemia and hypervolemia. Blood urea and creatinine levels stabilised after four sessions at around 48 ± 11 mg/dL and 2.9 ± 0.4 mg/dL, respectively. Negative fluid balance and ultrafiltration increased progressively and stabilised around 2.1 ± 0.4 L /day. Weekly delivered Kt/V was 2.6 ± 0.31. The median number of high-volume PD sessions was 6 (4-10). Peritonitis and mechanical complications were not frequent (8.6% and 10.3%, respectively). Mortality rate was 58.6%. Logistic regression identified as factors associated with death in neurocritical AKI patients: age (odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.78, 95% CI = 0.69- 0.95, p = 0.03), mechanical ventilation (OR = 1.54, 95% CI = 1.17-2.46, p = 0.01), intracerebral haemorrhage as main neurological diagnoses (OR = 1.15, 95% CI = 1.09-2.11, p = 0.03) and negative fluid balance after two PD sessions (OR = 0.94, 95% CI = 0.74-0.97, p = 0.009).

CONCLUSION

Our study suggests that careful prescription may contribute to providing adequate treatment for most neurocritical AKI patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious, mechanical and metabolic complications. Mechanical ventilation, positive fluid balance and intracerebral haemorrhage were factors associated with mortality, while patients with nephrotoxic AKI had lower odds of mortality compared to those with septic and ischaemic AKI. Further studies are needed to investigate better the role of PD in neurocritical patients with AKI.

Capillary leak and endothelial permeability in critically ill patients: a current overview

Capillary leak syndrome (CLS) represents a phenotype of increased fluid extravasation, resulting in intravascular hypovolemia, extravascular edema formation and ultimately hypoperfusion. While endothelial permeability is an evolutionary preserved physiological process needed to sustain life, excessive fluid leak-often caused by systemic inflammation-can have detrimental effects on patients' outcomes. This article delves into the current understanding of CLS pathophysiology, diagnosis and potential treatments. Systemic inflammation leading to a compromise of endothelial cell interactions through various signaling cues (e.g., the angiopoietin-Tie2 pathway), and shedding of the glycocalyx collectively contribute to the manifestation of CLS. Capillary permeability subsequently leads to the seepage of protein-rich fluid into the interstitial space. Recent insights into the importance of the sub-glycocalyx space and preserving lymphatic flow are highlighted for an in-depth understanding. While no established diagnostic criteria exist and CLS is frequently diagnosed by clinical characteristics only, we highlight more objective serological and (non)-invasive measurements that hint towards a CLS phenotype. While currently available treatment options are limited, we further review understanding of fluid resuscitation and experimental approaches to target endothelial permeability. Despite the improved understanding of CLS pathophysiology, efforts are needed to develop uniform diagnostic criteria, associate clinical consequences to these criteria, and delineate treatment options.

A Systematic Bibliometric Analysis of High-Impact Articles in Critical Care Nephrology

INTRODUCTION

Critical care nephrology is a subspecialty that merges critical care and nephrology in response to shared pathobiology, clinical care, and technological innovations. To date, there has been no description of the highest impact articles. Accordingly, we systematically identified high impact articles in critical care nephrology.

METHODS

This was a bibliometric analysis. The search was developed by a research librarian. Web of Science was searched for articles published between January 1, 2000 and December 31, 2020. Articles required a minimum of 30 citations, publication in English language, and reporting of primary (or secondary) original data. Articles were screened by two reviewers for eligibility and further adjudicated by three experts. The "Top 100" articles were hierarchically ranked by adjudication, citations in the 2 years following publication and journal impact factor (IF). For each article, we extracted detailed bibliometric data. Risk of bias was assessed for randomized trials by the Cochrane Risk of Bias tool. Analyses were descriptive.

RESULTS

The search yielded 2,805 articles. Following initial screening, 307 articles were selected for full review and adjudication. The Top 100 articles were published across 20 journals (median [IQR] IF 10.6 [8.9-56.3]), 38% were published in the 5 years ending in 2020 and 62% were open access. The agreement between adjudicators was excellent (intraclass correlation, 0.96; 95% CI, 0.84-0.99). Of the Top 100, 44% were randomized trials, 35% were observational, 14% were systematic reviews, 6% were nonrandomized interventional studies and one article was a consensus document. The risk of bias among randomized trials was low. Common subgroup themes were RRT (42%), AKI (30%), fluids/resuscitation (14%), pediatrics (10%), interventions (8%), and perioperative care (6%). The citations for the Top 100 articles were 175 (95-393) and 9 were cited >1,000 times.

CONCLUSION

Critical care nephrology has matured as an important subspecialty of critical care and nephrology. These high impact papers have focused largely on original studies, mostly clinical trials, within a few core themes. This list can be leveraged for curricula development, to stimulate research, and for quality assurance.

The "CHEOPS" bundle for the management of Left Ventricular Diastolic Dysfunction in critically ill patients: an experts' opinion

The impact of left ventricular (LV) diastolic dysfunction (DD) on the outcome of patients with heart failure was established over three decades ago. Nevertheless, the relevance of LVDD for critically ill patients admitted to the intensive care unit has seen growing interest recently, and LVDD is associated with poor prognosis. Whilst an assessment of LV diastolic function is desirable in critically ill patients, treatment options for LVDD are very limited, and pharmacological possibilities to rapidly optimize diastolic function have not been found yet. Hence, a proactive approach might have a substantial role in improving the outcomes of these patients. Recalling historical Egyptian parallelism suggesting that Doppler echocardiography has been the "Rosetta stone" to decipher the study of LV diastolic function, we developed a potentially useful acronym for physicians at the bedside to optimize the management of critically ill patients with LVDD with the application of the bundle. We summarized the bundle under the acronym of the famous ancient Egyptian pharaoh CHEOPS: Chest Ultrasound, combining information from echocardiography and lung ultrasound; HEmodynamics assessment, with careful evaluation of heart rate and rhythm, as well as afterload and vasoactive drugs; OPtimization of mechanical ventilation and pulmonary circulation, considering the effects of positive end-expiratory pressure on both right and left heart function; Stabilization, with cautious fluid administration and prompt fluid removal whenever judged safe and valuable. Notably, the CHEOPS bundle represents experts' opinion and are not targeted at the initial resuscitation phase but rather for the optimization and subsequent period of critical illness.

The effects of timing onset and progression of AKI on the clinical outcomes in AKI patients with sepsis: a prospective multicenter cohort study

BACKGROUND

Limited studies are available concerning on the earlier identification of AKI with sepsis. The aim of the study was to identify the risk factors of AKI early which depended on the timing onset and progression of AKI and investigate the effects of timing onset and progression of AKI on clinical outcomes.

METHODS

Patients who developed sepsis during their first 48-h admission to ICU were included. The primary outcome was major adverse kidney events (MAKE) consisted of all-cause mortality, RRT-dependence, or an inability to recover to 1.5 times of the baseline creatinine value up to 30 days. We determined MAKE and in-hospital mortality by multivariable logistic regression and explored the risk factors of early persistent-AKI. C statistics were used to evaluate model fit.

RESULTS

58.7% sepsis patients developed AKI. According to the timing onset and progression of AKI, Early transient-AKI, early persistent-AKI, late transient-AKI, late persistent-AKI were identified. Clinical outcomes were quite different among subgroups. Early persistent-AKI had 3.0-fold (OR 3.04, 95% CI 1.61 - 4.62) risk of MAKE and 2.6-fold (OR 2.60, 95%CI 1.72 - 3.76) risk of in-hospital mortality increased compared with the late transients-AKI. Older age, underweight, obese, faster heart rate, lower MAP, platelet, hematocrit, pH and energy intake during the first 24 h on ICU admission could well predict the early persistent-AKI in patients with sepsis.

CONCLUSION

Four AKI subphenotypes were identified based on the timing onset and progression of AKI. Early persistent-AKI showed higher risk of major adverse kidney events and in-hospital mortality.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trials Registry (www.chictr.org/cn) under registration number ChiCTR-ECH-13003934.

Fluid balance control in critically ill patients: results from as-treated analyses of POINCARE-2 randomized trial

BACKGROUND

Intention-to-treat analyses of POINCARE-2 trial led to inconclusive results regarding the effect of a conservative fluid balance strategy on mortality in critically ill patients. The present as-treated analysis aimed to assess the effectiveness of actual exposure to POINCARE-2 strategy on 60-day mortality in critically ill patients.

METHODS

POINCARE‑2 was a stepped wedge randomized controlled trial. Eligible patients were ≥ 18 years old, under mechanical ventilation and had an expected length of stay in ICU > 24 h. POINCARE-2 strategy consisted of daily weighing over 14 days, and subsequent restriction of fluid intake, administration of diuretics, and/or ultrafiltration. We computed a score of exposure to the strategy based on deviations from the strategy algorithm. We considered patients with a score ≥ 75 as exposed to the strategy. We used logistic regression adjusted for confounders (ALR) or for an instrumental variable (IVLR). We handled missing data using multiple imputations.

RESULTS

A total of 1361 patients were included. Overall, 24.8% of patients in the control group and 69.4% of patients in the strategy group had a score of exposure ≥ 75. Exposure to the POINCARE-2 strategy was not associated with 60-day all-cause mortality (ALR: OR 1.2, 95% CI 0.85-1.55; IVLR: OR 1.0, 95% CI 0.76-1.33).

CONCLUSION

Actual exposure to POINCARE-2 conservative strategy was not associated with reduced mortality in critically ill patients. Trial registration POINCARE-2 trial is registered at ClinicalTrials.gov (NCT02765009). Registered 29 April 2016.

Associations between fluid overload and outcomes in critically ill patients with acute kidney injury: a retrospective observational study

Increased fluid overload (FO) is associated with poor outcomes in critically ill patients, especially in acute kidney injury (AKI). However, the exact timing from when FO influences outcomes remains unclear. We retrospectively screened intensive care unit (ICU) admitted patients with AKI between January 2011 and December 2015. Logistic or linear regression analyses were performed to determine when hourly %FO was significant on 90-day in-hospital mortality (primary outcome) or ventilator-free days (VFDs). In total, 1120 patients were enrolled in this study. Univariate analysis showed that a higher %FO was significantly associated with higher mortality from the first hour of ICU admission (odds ratio 1.34, 95% confidence interval 1.15-1.56, P < 0.001), whereas multivariate analysis adjusted with age, sex, APACHE II score, and sepsis etiology showed the association was significant from the 27th hour. Both univariate and multivariate analyses showed that a higher %FO was significantly associated with shorter VFDs from the 1st hour. The significant associations were retained during all following observation periods after they showed significance. In patients with AKI, a higher %FO was associated with higher mortality and shorter VFDs from the early phase after ICU admission. FO should be administered with a physiological target or goal in place from the initial phase of critical illness.

Current management of fluid balance in critically ill patients with acute kidney injury: A scoping review

Objective

The overall objective of this scoping review is to assess the extent of the literature related to the fluid management of critically ill patients with acute kidney injury (AKI).

Introduction

AKI is common in critically ill patients where fluid therapy is a mainstay of treatment. An association between fluid balance (FB) and adverse patient-centred outcomes in critically ill patients with AKI regardless of severity has been demonstrated. The evidence for the prospective intervention of FB and its impact on outcomes is unknown.

Inclusion criteria

All studies investigating FB in patients with AKI admitted to an intensive care unit were included. Literature not related to FB in the critically ill patient with AKI population was excluded.

Methods

We searched MEDLINE, EMBASE, and CINAHL from January 1st, 2012, onwards. We included primary research studies, experimental and observational, recruiting adult participants admitted to an intensive care unit who had an AKI. We extracted data on study and patient characteristics, as well as FB, renal-based outcomes, and patient-centred outcomes. Two reviewers independently screened citations for eligible studies and performed data extraction.

Results

Of the 13,767 studies reviewed, 22 met the inclusion criteria. Two studies examined manipulation of fluid input, 18 studies assessed enhancing fluid removal, and two studies applied a restrictive fluid protocol. Sixteen studies examined patients receiving renal replacement therapy, five studies included non-renal replacement therapy patients, and one study included both. Current evidence is broad with varied approaches to managing fluid input and fluid removal. The studies did not demonstrate a consensus approach for any aspect of the fluid management of critically ill patients. There was a limited application of a restrictive fluid protocol with no conclusions possible.

Conclusions

The current body of evidence for the management of FB in critically ill patients with AKI is limited in nature. The current quality of evidence is unable to guide current clinical practice. The key outcome of this review is to highlight areas for future research.

Predictors of fluid responsiveness in the operating room: a narrative review

Prediction of fluid responsiveness has been considered an essential tool for modern fluid management. However, most studies in this field have focused on patients in intensive care unit despite numerous research throughout several decades. Therefore, the present narrative review aims to show the representative method's feasibility, advantages, and limitations in predicting fluid responsiveness, focusing on the operating room environments. Firstly, we described the predictors of fluid responsiveness based on heart-lung interaction, including pulse pressure and stroke volume variations, the measurement of respiratory variations of inferior vena cava diameter, and the end-expiratory occlusion test and addressed their limitations. Subsequently, the passive leg raising test and mini-fluid challenge tests were also mentioned, which assess fluid responsiveness by mimicking a classic fluid challenge. In the last part of this review, we pointed out the pitfalls of fluid management based on fluid responsiveness prediction, which emphasized the importance of individualized decision-making. Understanding the available representative methods to predict fluid responsiveness and their associated benefits and drawbacks through this review will aid anesthesiologists in choosing the most reliable methods for optimal fluid administration in each patient during anesthesia in the operating room.

Relationship between the rate of fluid resuscitation and acute kidney injury: A retrospective cohort study

Background

Septic shock is the leading cause of acute kidney injury (AKI) in critically ill patients. The foundation of early septic shock management includes early fluid resuscitation, but the association between fluid resuscitation rates and kidney outcomes remains unclear. This investigation examines the association between fluid resuscitation rate and AKI recovery.

Methods

In the medical intensive care unit of Mayo Clinic Rochester, adult patients with AKI and septic shock were retrospectively studied from January 1, 2006 to May 31, 2018. The surviving sepsis campaign recommends an initial fluid bolus of 30 ml/kg for sepsis resuscitation. The cohort of patients was divided into three groups based on the average fluid resuscitation time (<1 h, 1.1-3 h, >3 h) and the corresponding fluid rate ≥0.5, 0.17-0.49, and <0.17 ml/kg/min, respectively. The primary outcome was the recovery of AKI on day 7. To account for potential confounders, multivariable regression analyses were conducted.

Results

After meeting the eligibility, 597 patients were included in the analysis. The AKI recovery was considerably different among the groups (P = 0.006). Patients in group 1 who received fluid resuscitation faster had a higher rate of AKI recovery (53%) compared to group 2 and group 3 (50% and 37.8%).

Conclusion

In septic shock patients with AKI, a higher fluid resuscitation rate of 30 ml/kg IV fluids within the 1st-h sepsis diagnosis (i.e., >0.50 ml/kg/min) lead to higher AKI recovery compared with slower infusion rates.

Real-World Use of AKI Biomarkers: A Quality Improvement Project Using Urinary Tissue Inhibitor Metalloprotease-2 and Insulin-Like Growth Factor Binding Protein 7 ([TIMP-2]*[IGFBP7])

INTRODUCTION

Novel urinary biomarkers, including tissue inhibitor metalloprotease-2 and insulin-like growth factor binding protein 7 ([TIMP-2]*[IGFBP7]), have been developed to identify patients at risk for acute kidney injury (AKI). We investigated the "real-world" clinical utility of [TIMP-2]*[IGFBP7] in preventing AKI.

METHODS

We performed a before and after single-center quality improvement study of intensive care unit (ICU) patients at risk for severe (KDIGO stage 2 or 3) AKI. In the prospective cohort, ICU providers were allowed to order [TIMP-2]*[IGFBP7] for patients at their discretion, then offered AKI practice recommendations based on the results. Outcomes were compared to a historical cohort in which biomarker values were not reported to clinical teams.

RESULTS

There was no difference in 7-day progression to severe AKI between the prospective (n = 116) and historical cohorts (n = 63) when [TIMP-2]*[IGFBP7] ≥0.3 (24 [28%] versus 8 [21%], p = 0.38) despite more stage 1 AKI at time of biomarker measurement in the prospective cohort (58 [67%] versus 9 [23%], p < 0.001). In the prospective cohort, patients with higher [TIMP-2]*[IGFBP7] values were more likely to receive a nephrology consult. Early consultation (within 24 h of biomarker measurement, n = 20) had a nonsignificant trend toward net negative volume balance (-1,787 mL [6,716 mL] versus + 4,974 mL [15,540 mL]) and more diuretic use (19 [95%] versus 8 [80%]) and was associated with less severe AKI (9 [45%] versus 10 [100%], p = 0.004) and inpatient dialysis (2 [10%] versus 7 [70%], p = 0.002) compared to delayed consultation (n = 10).

CONCLUSIONS

Despite the prospective cohort having more preexisting stage 1 AKI, there were equal rates of progression to severe AKI in the prospective and historical cohorts. In the setting of [TIMP-2]*[IGFBP7] reporting, there were more nephrology consults in response to elevated biomarker levels. Early nephrology consultation resulted in improved volume balance and favorable outcomes compared to delayed consultation.

Fluid Management for Critically Ill Patients with Acute Kidney Injury Receiving Kidney Replacement Therapy: An International Survey

BACKGROUND

In critically ill patients receiving KRT, high ultrafiltration rates and persistent fluid accumulation are associated with adverse outcomes. The purpose of this international survey was to evaluate current practices and evidence gaps related to fluid removal with KRT in critically ill patients.

METHODS

This was a multinational, web-based survey distributed by seven networks comprising nephrologists and intensivists. Physicians involved in the care of critically ill patients were invited to complete a 39-question survey about fluid management practices on KRT. The survey was distributed from September 2021 to December 2021.

RESULTS

There were 757 respondents from 96 countries (response rate of 65%). Most respondents practiced adult medicine (89%) and worked in an academic center (69%). The majority (91%) reported aiming for a 0.5- to 2-L negative fluid balance per day when fluid removal is indicated, although there was important variability in what respondents considered a safe maximal target. Intensivists were more likely than nephrologists to use adjunct volume status assessment methods ( i.e. , ultrasound, hemodynamic markers, and intra-abdominal pressure), while nephrologists were more likely to deploy cointerventions aimed at improving tolerance to fluid removal ( i.e. , osmotic agents and low-temperature dialysate). There was a broad consensus that rapid decongestion should be prioritized when fluid accumulation is present, but the prevention of hypotension was also reported as a competing priority. A majority (77%) agreed that performing trials that compare fluid management strategies would be ethical and clinically relevant.

CONCLUSIONS

We have identified multiple areas of variability in current practice of fluid management for patients receiving KRT. Most nephrologists and intensivists agreed that several knowledge gaps related to fluid removal strategies should be investigated in future randomized controlled trials.

Chloride, Sodium and Calcium Intake Are Associated with Mortality and Follow-Up Kidney Function in Critically Ill Patients Receiving Continuous Veno-Venous Hemodialysis-A Retrospective Study

BACKGROUND

Studies on the association between solute, nutrition and fluid intakes and mortality and later kidney function in critically ill acute kidney injury (AKI) patients receiving continuous veno-venous hemodialysis (CVVHD) are scarce.

METHODS

Altogether, 471 consecutive critically ill AKI patients receiving CVVHD in the research intensive care unit (ICU) were recruited in this single-center, retrospective study.

RESULTS

The median age was 66 (58-74) years, and 138 (29.3%) were female. The 90-day and one-year mortalities were 221 (46.9%) and 251 (53.3%), respectively. After adjusting for age, sex, Acute Physiology and Chronic Health Evaluation II (APACHE) score, coronary artery disease, immunosuppression, ICU care duration, mechanical ventilation requirement, vasopressor requirement and study time period, the cumulative daily intake of potassium, chloride, sodium, phosphate, calcium, glucose, lipids and water was associated with one-year mortality in separate multivariable cox proportional hazards models. In a sensitivity analysis excluding patients who died within the first three days of ICU care, the daily intake of chloride (hazard ratio (HR) 1.001, confidence interval (CI) 95% 1.000-1.003, p = 0.032), sodium (HR 1.001, CI 95% 1.000-1.002, p = 0.031) and calcium (HR 1.129, CI 95% 1.025-1.243, p = 0.014) remained independently associated with mortality within one-year in the respective, similarly adjusted multivariable cox analyses. The cumulative daily intake of chloride, sodium, calcium and water was independently associated with the estimated glomerular filtration rate (eGFR) at 90 days follow-up in separate substantially adjusted multivariable cox proportional hazards models.

CONCLUSION

The cumulative daily intake of chloride, sodium and calcium is associated with mortality and daily chloride, sodium, calcium and water intake is associated with follow-up eGFR in critically ill patients with CVVHD-treated AKI.

Risk factors of serious postoperative outcomes in patients aged ≥90 years undergoing surgical intervention

Objective

We aimed to identify preoperative and intraoperative factors associated with serious postoperative outcomes, which may help patients and clinicians make better-informed decisions.

Methods

We conducted a retrospective study including all patients aged ≥90 years who underwent surgery between January 1, 2011, and January 1, 2021, at Chongqing University Central Hospital. We assessed 30 pre- and intraoperative demographic and clinical variables. Logistic regression was used to identify the independent risk factors for serious postoperative outcomes in patients aged ≥90 years.

Results

A total of 428 patients were included in our analysis. The mean age was 92.6 years (SD ± 2.6). There were 240 (56.1%) females and 188 (43.9%) males. The most common comorbidities were hypertension (44.9%) and arrhythmias (34.8%). The 30-day hospital mortality was 5.6%, and severe morbidity was 33.2%. Based on the multivariate logistic regression classification analysis of the American Society of Anesthesiologists (ASA)≥ Ⅳ [odds ratio (OR), 5.39, 95% confidence interval (CI), 2.06-14.16, P = .001], emergency surgery (OR, 5.02, 95% CI, 2.85-15.98, P = .001) and chronic heart failure (OR, 6.11, 95% CI, 1.93-13.06, P = .001) were identified as independent risk factors for 30-day hospital mortality, and ASA≥ Ⅳ (OR, 4.56, 95%CI, 2.56-8.15, P < .001), Barthel index (BI) < 35 (OR, 2.28, 95%CI, 1.30-3.98, P = .001), chronic heart failure (OR, 3.67, 95%CI, 1.62-8.31, P = .002), chronic kidney disease (OR, 4.24, 95%CI, 1.99-9.05, P < .001), general anesthesia (OR, 3.31, 95%CI, 1.91-5.76, P < .001), emergency surgery (OR, 3.72, 95%CI, 1.98-6.99, P < .001), and major surgery (OR, 3.44, 95%CI, 1.90-6.22, P < .001) were identified as independent risk factors for serious postoperative complications.

Conclusions

Patients aged ≥90 years with ASA≥ Ⅳ, BI < 35, combined with chronic heart failure or chronic kidney disease, undergoing emergency surgery, major surgery or general anesthesia have a higher risk of serious postoperative outcomes. Identifying these risk factors in an early stage may contribute to our clinical decision-making and improve the quality of treatments.

Perioperative changes in fluid distribution and haemodynamics in acute high-risk abdominal surgery

BACKGROUND

Understanding the pathophysiology of fluid distribution in acute high-risk abdominal (AHA) surgery is essential in optimizing fluid management. There is currently no data on the time course and haemodynamic implications of fluid distribution in the perioperative period and the differences between the surgical pathologies.

METHODS

Seventy-three patients undergoing surgery for intestinal obstruction, perforated viscus, and anastomotic leakage within a well-defined perioperative regime, including intraoperative goal-directed therapy, were included in this prospective, observational study. From 0 to 120 h, we measured body fluid volumes and hydration status by bioimpedance spectroscopy (BIA), fluid balance (input vs. output), preload dependency defined as a > 10% increase in stroke volume after preoperative fluid challenge, and post-operatively evaluated by passive leg raise.

RESULTS

We observed a progressive increase in fluid balance and extracellular volume throughout the study, irrespective of surgical diagnosis. BIA measured variables indicated post-operative overhydration in 36% of the patients, increasing to 50% on the 5th post-operative day, coinciding with a progressive increase of preload dependency, from 12% immediately post-operatively to 58% on the 5th post-operative day and irrespective of surgical diagnosis. Patients with overhydration were less haemodynamically stable than those with normo- or dehydration.

CONCLUSION

Despite increased fluid balance and extracellular volumes, preload dependency increased progressively during the post-operative period. Our observations indicate a post-operative physiological incoherence between changes in the extracellular volume compartment and inadequate physiological preload control in patients undergoing AHA surgery. Considering the increasing overhydration during the observational period, our findings show that an indiscriminate correction of preload dependency with intravenous fluid bolus could lead to overhydration. Trial registration clinicaltrials.gov. (NCT03997721), Registered 23 May 2019, first participant enrolled 01 June 2019.

Diuretics and Ultrafiltration in Heart Failure

Fluid overload is a risk factor for increased morbidity and mortality, especially in patients with heart disease. The treatment options are limited to diuretics and mechanical fluid removal using ultrafiltration or renal replacement therapy. This paper provides an overview of the challenges of managing fluid overload, outlines the risks and benefits of different pharmacological options and extracorporeal techniques, and provides guidance for clinical practice.

A Machine Learning Model to Predict Diuretic Resistance

BACKGROUND

Volume overload is a common complication encountered in hospitalized patients, and the mainstay of therapy is diuresis. Unfortunately, the diuretic response in some individuals is inadequate despite a typical dose of loop diuretics, a phenomenon called diuretic resistance. An accurate prediction model that predicts diuretic resistance using predosing variables could inform the right diuretic dose for a prospective patient.

METHODS

Two large, deidentified, publicly available, and independent intensive care unit (ICU) databases from the United States were used-the Medical Information Mart for Intensive Care III (MIMIC) and the Philips eICU databases. Loop diuretic resistance was defined as <1400 ml of urine per 40 mg of diuretic dose in 24 hours. Using 24-hour windows throughout admission, commonly accessible variables were obtained and incorporated into the model. Data imputation was performed using a highly accurate machine learning method. Using XGBoost, several models were created using train and test datasets from the eICU database. These were then combined into an ensemble model optimized for increased specificity and then externally validated on the MIMIC database.

RESULTS

The final ensemble model was composed of four separate models, each using 21 commonly available variables. The ensemble model outperformed individual models during validation. Higher serum creatinine, lower systolic blood pressure, lower serum chloride, higher age, and female sex were the most important predictors of diuretic resistance (in that order). The specificity of the model on external validation was 92%, yielding a positive likelihood ratio of 3.46 while maintaining overall discrimination (C-statistic 0.69).

CONCLUSIONS

A diuretic resistance prediction model was created using machine learning and was externally validated in ICU populations. The model is easy to use, would provide actionable information at the bedside, and would be ready for implementation in existing electronic medical records. This study also provides a framework for the development of future machine learning models.

Non-interventional follow-up versus fluid bolus in RESPONSE to oliguria in hemodynamically stable critically ill patients: a randomized controlled pilot trial

BACKGROUND

Fluid bolus therapy is a common intervention to improve urine output. Data concerning the effect of a fluid bolus on oliguria originate mainly from observational studies and remain controversial regarding the actual benefit of such therapy. We compared the effect of a follow-up approach without fluid bolus to a 500 mL fluid bolus on urine output in hemodynamically stable critically ill patients with oliguria at least for 2 h (urine output < 0.5 mL/kg/h) in randomized setting.

METHODS

We randomized 130 patients in 1:1 fashion to receive either (1) non-interventional follow-up (FU) for 2 h or (2) 500 mL crystalloid fluid bolus (FB) administered over 30 min. The primary outcome was the proportion of patients who doubled their urine output, defined as 2-h urine output post-randomization divided by urine output 2 h pre-randomization. The outcomes were adjusted for the stratification variables (presence of sepsis or AKI) using two-tailed regression. Obtained odds ratios were converted to risk ratios (RR) with 95% confidence intervals (CI). The between-group difference in the continuous variables was compared using mean or median regression and expressed with 95% CIs.

RESULTS

Altogether 10 (15.9%) of 63 patients in the FU group and 22 (32.8%) of 67 patients in FB group doubled their urine output during the 2-h period, RR (95% CI) 0.49 (0.23-0.71), P = 0.026. Median [IQR] change in individual urine output 2 h post-randomization compared to 2 h pre-randomization was - 7 [- 19 to 17] mL in the FU group and 19[0-53] mL in the FB group, median difference (95% CI) - 23 (- 36 to - 10) mL, P = 0.001. Median [IQR] duration of oliguria in the FU group was 4 [2-8] h and in the FB group 2 [0-6] h, median difference (95%CI) 2 (0-4) h, P = 0.038. Median [IQR] cumulative fluid balance on study day was lower in the FU group compared to FB group, 678 [518-1029] mL versus 1071 [822-1505] mL, respectively, median difference (95%CI) - 387 (- 635 to - 213) mL, P < 0.001.

CONCLUSIONS

Follow-up approach to oliguria compared to administering a fluid bolus of 500 mL crystalloid in oliguric patients improved urine output less frequently but lead to lower cumulative fluid balance. Trial registration clinical.

TRIALS

gov, NCT02860572. Registered 9 August 2016.

Sodium flux during hemodialysis and hemodiafiltration treatment of acute kidney injury: Effects of dialysate and infusate sodium concentration at 140 and 145 mmol/L

BACKGROUND

A higher sodium (Na) dialysate concentration is recommended during renal replacement therapy (RRT) of acute kidney injury (AKI) to improve intradialytic hemodynamic tolerance, but it may lead to Na loading to the patient. We aimed to evaluate Na flux according to Na dialysate and infusate concentrations at 140 and 145 mmol/L during hemodialysis (HD) and hemodiafiltration (HDF).

METHODS

Fourteen AKI patients that underwent consecutive HD or HDF sessions with Na dialysate/infusate at 140 and 145 mmol/L were included. Per-dialytic flux of Na was estimated using mean sodium logarithmic concentration including diffusive and convective influx. We compared the flux of sodium between HD140 and 145, and between HDF140 and 145.

RESULTS

Nine HD140, ten HDF140, nine HD145, and 11 HDF145 sessions were analyzed. A Na gradient from the dialysate/replacement fluid to the patient was observed with dialysate/infusate Na at 145 mmol/L in both HD and HDF (p = 0.01). The comparison of HD145 to HD140 showed that higher Na dialysate induced a diffusive Na gradient to the patient (163 mmol vs. -25 mmol, p = 0.004) and that of HDF145 to -140 (211 vs. 36 mmol, p = 0.03) as well. Intradialytic hemodynamic tolerance was similar across all RRT sessions.

CONCLUSIONS

During both HD and HDF, a substantial Na loading occurred with a Na dialysate and infusate at 145 mmol/L. This Na loading is smaller in HDF with Na dialysate and infusate concentration at 140 mmol/L and inversed with HD140. Clinical and intradialytic hemodynamic tolerance was fair regardless of Na dialysate and infusate.

Comparing the associations of central venous pressure and pulmonary artery pulsatility index with postoperative renal injury

Objective

Cardiac surgery-associated acute kidney injury (CS-AKI) is associated with significant morbidity and mortality. We investigated the association of postoperative central venous pressure (CVP) and pulmonary artery pulsatility index (PAPi) with the development of CS-AKI.

Methods

This was a single-center, retrospective cohort study of patients undergoing cardiac surgery. CVP and PAPi were acquired hourly postoperatively and averaged for up to 48 h. PAPi was calculated as [(Pulmonary Artery Systolic Pressure–Pulmonary Artery Diastolic Pressure) / CVP]. The primary aim was CS-AKI. Secondary aims were need for renal replacement therapy (RRT), hospital and 30-day mortality, total ventilator and intensive care unit hours, and hospital length of stay. Logistic regression was used to calculate odds of development of renal injury and need for RRT.

Results

One thousand two hundred eighty-eight patients were included. The average postoperative CVP was 10.3 mmHg and average postoperative PAPi was 2.01. Patients who developed CS-AKI (n = 384) had lower PAPi (1.79 vs. 2.11, p < 0.01) and higher CVP (11.5 vs. 9.7 mmHg, p < 0.01) than those who did not. Lower PAPi and higher CVP were also associated with each secondary aim. A standardized unit decrease in PAPi was associated with increased odds of CS-AKI (OR 1.39, p < 0.01) while each unit increase in CVP was associated with both increased odds of CS-AKI (OR 1.56, p < 0.01) and postoperative RRT (OR 1.49, p = 0.02).

Conclusions

Both lower PAPi and higher CVP values postoperatively were associated with the development of CS-AKI but only higher CVP was associated with postoperative RRT use. When differences in values are standardized, CVP may be more associated with development of CS-AKI when compared to PAPi.

Association between predialysis creatinine and mortality in acute kidney injury patients requiring dialysis

Background

Creatinine is widely used to estimate renal function, but this is not practical in critical illness. Low creatinine has been associated with mortality in many clinical settings. However, the associations between predialysis creatinine level, Sepsis-related Organ Failure Assessment (SOFA) score, fluid overload, and mortality in acute kidney injury patients receiving dialysis therapy (AKI-D) has not been fully addressed.

Methods

We extracted data for AKI-D patients in the eICU and MIMIC databases. We conducted a retrospective observational cohort study using the eICU dataset. The study cohort was divided into the high-creatine group and the low-creatinine group by the median value (4 mg/dL). The baseline patient information included demographic data, laboratory tests, medications, and comorbid conditions. The independent association of creatinine level with 30-day mortality was examined using multivariate logistic regression analysis. In sensitivity analyses, the associations between creatinine, SOFA score, and mortality were analyzed in patients with or without fluid overload. We also carried out an external validity using the MIMIC dataset.

Results

In all 1,600 eICU participants, the 30-day mortality rate was 34.2%. The crude overall mortality rate in the low-creatinine group (44.9%) was significantly higher than that in the high-creatinine group (21.9%; P < 0.001). In the fully adjusted models, the low-creatinine group was associated with a higher risk of 30-day mortality (odds ratio, 1.77; 95% confidence interval, 1.29–2.42; P < 0.001) compared with the high-creatinine group. The low-creatinine group had higher SOFA and nonrenal SOFA scores. In sensitivity analyses, the low-creatinine group had a higher 30-day mortality rate with regard to the BMI or albumin level. Fluid overloaded patients were associated with a significantly worse survival in the low-creatinine group. The results were consistent when assessing the external validity using the MIMIC dataset.

Conclusions

In patients with AKI-D, lower predialysis creatinine was associated with increased mortality risk. Moreover, the mortality rate was substantially higher in patients with lower predialysis creatinine with concomitant elevation of fluid overload status.

Incremental value of preoperative right ventricular function in predicting moderate to severe acute kidney injury after heart transplantation

Background

Acute kidney injury (AKI) commonly occurs after heart transplantation (HTx), but its association with preoperative right ventricular (RV) function remains unknown. Consequently, we aimed to determine the predictive value of preoperative RV function for moderate to severe AKI after HTx.

Materials and methods

From 1 January 2016 to 31 December 2019, all the consecutive HTx recipients in our center were enrolled and analyzed for the occurrence of postoperative AKI staged by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Conventional RV function parameters, including RV fractional area change (RVFAC) and tricuspid annular plane systolic excursion (TAPSE), were obtained. The primary endpoint was moderate to severe AKI (the KDIGO stage 2 or 3). The secondary endpoints included the impact of AKI on intensive care unit (ICU) mortality, in-hospital mortality, and 1-year mortality.

Results

A total of 273 HTx recipients were included in the study. Postoperative AKI occurred in 209 (77%) patients, including 122 (45%) patients in stage 1 AKI, 49 (18%) patients in stage 2 AKI, and 38 (14%) patients in stage 3 AKI. Patients with higher AKI stage had lower baseline estimated glomerular filtration rate (eGFR), more frequent diabetes, higher right atrial pressure (RAP), longer cardiopulmonary bypass (CPB) duration, more perioperative red blood cell (RBC) transfusions, and worse preoperative RV function. A multivariate logistic regression model incorporating previous diabetes mellitus [odds ratio (OR): 2.21; 95% CI: 1.06–4.61; P = 0.035], baseline eGFR (OR: 0.99; 95% CI: 0.97–0.10; P = 0.037), RAP (OR: 1.05; 95% CI: 1.00–1.10; P = 0.041), perioperative RBC (OR: 1.18; 95% CI: 1.08–1.28; P < 0.001), and TAPSE (OR: 0.84; 95% CI: 0.79–0.91; P < 0.001) was established to diagnose moderate to severe AKI more accurately [the area under the curve (AUC) = 79.8%; Akaike information criterion: 274].

Conclusion

Preoperative RV function parameters provide additional predicting value over clinical and hemodynamic parameters, which are imperative for risk stratification in patients with HTx at higher risk of AKI.

Early echocardiographic assessment of cardiac function may be prognostically informative in unresuscitated patients with sepsis: A prospective observational study

Purpose

The goal of this study was to explore the association cardiac function at Emergency Department (ED) presentation prior to the initiation of resuscitation, and its change at 3-hours, with adverse outcomes in patients with sepsis.

Methods

This was a prospective observational study of patients presenting to an urban ED with suspected sepsis. Patients had a point-of-care echocardiogram performed prior to initiation of resuscitation and again 3 hours later. Left-ventricular (LV) parameters recorded included e’, and E/e’, and ejection fraction (EF); right-ventricular (RV) function was evaluated using tricuspid annular plane systolic excursion (TAPSE). Logistic and generalized linear regression were used to assess the association of echocardiographic parameters and ≥ 2-point increase in SOFA score at 24 hours (primary outcome) and 24-hours SOFA score and in-hospital mortality (secondary outcomes).

Results

For ΔSOFA ≥ 2 and 24-hour SOFA score, declining LVEF was associated with better outcomes in patients with greater baseline SOFA scores, but worse outcomes in patients with lower baseline scores. A similar relationship was found for ΔTAPSE at 3 hours. Reduced LVEF at presentation was associated with increased mortality after adjusting for ED SOFA score (odds-ratio (OR) 0.76 (CI 0.60–0.96). No relationship between diastolic parameters and outcomes was found. IVF administration was similar across ΔLVEF/TAPSE sub-groups.

Conclusions

Our results suggest that early change in LV and RV systolic function are independently prognostic of sepsis illness severity at 24-hours. Further study is needed to determine if this information can be used to guide treatment and improve outcomes.

Loop diuretics in adult intensive care patients with fluid overload: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

BACKGROUND

Fluid overload is a risk factor for organ dysfunction and death in intensive care unit (ICU) patients, but no guidelines exist for its management. We systematically reviewed benefits and harms of a single loop diuretic, the predominant treatment used for fluid overload in these patients.

METHODS

We conducted a systematic review with meta-analysis and Trial Sequential Analysis (TSA) of a single loop diuretic vs. other interventions reported in randomised clinical trials, adhering to our published protocol, the Cochrane Handbook, and PRISMA statement. We assessed the risks of bias with the ROB2-tool and certainty of evidence with GRADE. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020184799).

RESULTS

We included 10 trials (804 participants), all at overall high risk of bias. For loop diuretics vs. placebo/no intervention, we found no difference in all-cause mortality (relative risk (RR) 0.72, 95% confidence interval (CI) 0.49-1.06; 4 trials; 359 participants; I2 = 0%; TSA-adjusted CI 0.15-3.48; very low certainty of evidence). Fewer serious adverse events were registered in the group treated with loop diuretics (RR 0.81, 95% CI 0.66-0.99; 6 trials; 476 participants; I2 = 0%; very low certainty of evidence), though contested by TSA (TSA-adjusted CI 0.55-1.20).

CONCLUSIONS

The evidence is very uncertain about the effect of loop diuretics on mortality and serious adverse events in adult ICU patients with fluid overload. Loop diuretics may reduce the occurrence of these outcomes, but large randomised placebo-controlled trials at low risk of bias are needed.

Association between fluid overload and mortality in newborns: a systematic review and meta-analysis

Fluid overload (FO) is associated with higher rates of mortality and morbidity in pediatric and adult populations. The aim of this systematic review and meta-analysis was to investigate the association between FO and mortality in critically ill neonates. Systematic search of Ovid MEDLINE, EMBASE, Cochrane Library, trial registries, and gray literature from inception to January 2021. We included all studies that examined neonates admitted to neonatal intensive care units and described FO and outcomes of interest. We identified 17 observational studies with a total of 4772 critically ill neonates who met the inclusion criteria. FO was associated with higher mortality (OR, 4.95 [95% CI, 2.26-10.87]), and survivors had a lower percentage of FO compared with nonsurvivors (WMD, - 4.33 [95% CI, - 8.34 to - 0.32]). Neonates who did not develop acute kidney injury (AKI) had lower FO compared with AKI patients (WMD, - 2.29 [95% CI, - 4.47 to - 0.10]). Neonates who did not require mechanical ventilation on postnatal day 7 had lower fluid balance (WMD, - 1.54 [95% CI, - 2.21 to - 0.88]). FO is associated with higher mortality, AKI, and need for mechanical ventilation in critically ill neonates in the intensive care unit. Strict control of fluid balance to prevent FO is essential. A higher resolution version of the Graphical abstract is available as Supplementary information.

A Positive Fluid Balance in the First Week Was Associated With Increased Long-Term Mortality in Critically Ill Patients: A Retrospective Cohort Study

Introduction

Early fluid balance has been found to affect short-term mortality in critically ill patients; however, there is little knowledge regarding the association between early cumulative fluid balance (CFB) and long-term mortality. This study aims to determine the distinct association between CFB day 1-3 (CFB 1-3) and day 4-7 (CFB 4-7) and long-term mortality in critically ill patients.

Patients and Methods

This study was conducted at Taichung Veterans General Hospital, a tertiary care referral center in central Taiwan, by linking the hospital critical care data warehouse 2015-2019 and death registry data of the Taiwanese National Health Research Database. The patients followed up until deceased or the end of the study on 31 December 2019. We use the log-rank test to examine the association between CFB 1-3 and CFB 4-7 with long-term mortality and multivariable Cox regression to identify independent predictors during index admission for long-term mortality in critically ill patients.

Results

A total of 4,610 patients were evaluated. The mean age was 66.4 ± 16.4 years, where 63.8% were men. In patients without shock, a positive CFB 4-7, but not CFB 1-3, was associated with 1-year mortality, while a positive CFB 1-3 and CFB 4-7 had a consistent and excess hazard of 1-year mortality among critically ill patients with shock. The multivariate Cox proportional hazard regression model identified that CFB 1-3 and CFB 4-7 (with per 1-liter increment, HR: 1.047 and 1.094; 95% CI 1.037-1.058 and 1.080-1.108, respectively) were independently associated with high long-term mortality in critically ill patients after adjustment of relevant covariates, including disease severity and the presence of shock.

Conclusions

We found that the fluid balance in the first week, especially on days 4-7, appears to be an early predictor for long-term mortality in critically ill patients. More studies are needed to validate our findings and elucidate underlying mechanisms.

Association between Latent Trajectories of Fluid Balance and Clinical Outcomes in Critically Ill Patients with Acute Kidney Injury: A Prospective Multicenter Observational Study

INTRODUCTION

We aimed to identify different trajectories of fluid balance (FB) and investigate the effect of FB trajectories on clinical outcomes in intensive care unit (ICU) patients with acute kidney injury (AKI) and the dose-response association between fluid overload (FO) and mortality.

METHODS

We derived data from the Beijing Acute Kidney Injury Trial (BAKIT). A total of 1,529 critically ill patients with AKI were included. The primary outcome was 28-day mortality, and hospital mortality, ICU mortality and AKI stage were the secondary outcomes. A group-based trajectory model was used to identify the trajectory of FB during the first 7 days. Multivariable logistic regression was performed to examine the relationship between FB trajectories and clinical outcomes. A logistic regression model with restricted cubic splines was used to examine the dose relationship between FO and 28-day mortality.

RESULTS

Three distinct trajectories of FB were identified: low FB (1,316, 86.1%), decreasing FB (120, 7.8%), and high FB (93, 6.1%). Compared with low FB, high FB was associated with increased 28-day mortality (odds ratio [OR] 1.94, 95% confidence interval [CI] 1.17-3.19) and AKI stage (OR 2.04, 95% CI 1.23-3.37), whereas decreasing FB was associated with a reduction in 28-day mortality by approximately half (OR 0.53, 95% CI 0.32-0.87). Similar results were found for the outcomes of ICU mortality and hospital mortality. We observed a J-shaped relationship between maximum FO and 28-day mortality, with the lowest risk at a maximum FO of 2.8% L/kg.

CONCLUSION

Different trajectories of FB in critically ill patients with AKI were associated with clinical outcomes. An FB above or below a certain range was associated with an increased risk of mortality. Further studies should explore this relationship and search for the optimal fluid management strategies for critically ill patients with AKI.

Do septic patients with reduced left ventricular ejection fraction require a low-volume resuscitative strategy?

BACKGROUND

Many clinicians are wary of administering 30 cc/kg of intravenous fluid (IVF) to septic patients with reduced left-ventricular ejection fraction (rLVEF), fearing volume overload. Prior studies have used history of heart failure, rather than LVEF measured at presentation, thereby potentially distorting the relationship between rLVEF, IVF, and adverse outcomes. Our goal was to assess the relationship between IVF volume and outcomes in patients with, versus without, rLVEF.

METHODS

This was a prospective observational study performed at an urban Emergency Department (ED). Included patients were adults with suspected sepsis, defined as being treated for infection plus either systolic blood pressure <90 mm/Hg or lactate >2 mmol/L. All patients had LVEF assessed by ED echocardiogram, prior to receipt of >1 l IVF.

MEASUREMENTS AND MAIN RESULTS

We enrolled 73 patients, of whom 33 had rLVEF, defined as <40%. Patients with rLVEF were older, had greater initial lactate, more ICU admission, and more vasopressor use. IVF volume was similar between LVEF groups at 3-h (2.2 (IQR 0.8) vs 2.0 (IQR 2.4) liters) while patients with rLVEF were more likely to achieve 30 cc/kg (61% (CI 44-75) vs 45% (CI 31-60). In the reduced versus not-reduced LVEF groups, hospital days, ICU days, and ventilator days were similar: 8 (IQR 7) vs 6.5 (8.5) days, 7 (IQR 7) vs 5 (4) days, and 4 (IQR 8) vs. 5 (10) days, respectively.

CONCLUSIONS

Septic patients with rLVEF at presentation received similar volume of IVF as those without rLVEF, without an increase in adverse outcomes attributable to volume overload. While validation is needed, our results suggest that limiting IVF administration in the setting of rLVEF is not necessary.

[Acute kidney injury in intensive care unit: A review]

Acute kidney injury is a common complication in intensive care unit. Its incidence is variable according to the studies. It is considered to occur in more than 50 % of patients. Acute kidney injury is responsible for an increase in morbidity (length of hospitalization, renal replacement therapy) but also for excess mortality. The commonly accepted definition of acute kidney injury comes from the collaborative workgroup named Kidney Disease: Improving Global Outcomes (KDIGO). It made it possible to standardize practices and raise awareness among practitioners about monitoring plasma creatinine and also diuresis. Acute kidney injury in intensive care unit is a systemic disease including circulatory, endothelial, epithelial and cellular function involvement and an acute kidney injury is not accompanied by ad integrum repair. After prolonged injury, inadequate repair begins with a fibrotic process. Several mechanisms are involved (cell cycle arrest, epithelial-mesenchymal transition, mitochondrial dysfunction) and result in improper repair. A continuum exists between acute kidney disease and chronic kidney disease, characterized by different renal recovery phenotypes. Thus, preventive measures to prevent the occurrence of kidney damage play a major role in management. The nephrologist must be involved at every stage, from the prevention of the first acute kidney injury (upon arrival in intensive care unit) to long-term follow-up and the care of a chronic kidney disease.

Fluid overload and acute kidney injury in children with tumor lysis syndrome

AIM

Tumor lysis syndrome (TLS) is a common oncologic emergency among patients with pediatric hematologic malignancies. The mainstay of TLS management is aggressive intravenous hydration. However, the epidemiology of fluid overload (FO) and acute kidney injury (AKI) in this population is understudied. In this study, we aimed to describe the incidence, severity, and complications of FO and AKI among pediatric patients with TLS.

METHODS

We completed a single-center retrospective cohort study of pediatric patients with a new diagnosis of hematologic malignancy over a 10-year period. Patients with TLS were analyzed in two groups based on the severity of AKI and FO. Charts were reviewed for complications associated with AKI and FO including hypoxemia, mechanical ventilation, hyponatremia, pulmonary edema, pediatric intensive care (PICU) admission, and need for renal replacement therapy (RRT).

RESULTS

We analyzed 56 patients with TLS for FO and AKI. We found severe FO (≥10%) occurred in 35.7% (n = 20). PICU admission occurred in 35% of patients with severe FO compared to 8.3% in those with mild/moderate FO <10% (p = .013). Complications of hypoxemia (30% vs. 5.6%, p = .012) and pulmonary edema (25% vs. 2.8%, p = .010) were more common among those with severe FO. AKI occurred in 37.5% (n = 21) patients and resulted in a significant increase in PICU admission and requirement for RRT (p = .001 and <.001, respectively).

CONCLUSION

Our results show FO and AKI are common, and often unrecognized complications of TLS associated with increased morbidity. Prospective, multicenter studies are needed to further dissect the burden of FO and AKI within this vulnerable population.

Management of Acute Kidney Injury/Renal Replacement Therapy in the Intensive Care Unit

Common causes of acute kidney injury (AKI) in the ICU setting include acute tubular necrosis (due to shock, hemolysis, rhabdomyolysis, or procedures that compromise renal perfusion), abdominal compartment syndrome, urinary retention, and interstitial nephritis. Treatment is geared toward addressing the underlying cause. Dialysis may be required if renal injury does not resolve. Early initiation of dialysis based on the stage of AKI alone has not been shown to provide a mortality benefit. Dialysis modalities are based on the dialysis indication and the patient's clinical status. Providers should pay close attention to nutritional requirements and medication dosing according to renal function and dialysis modality.

The lymphatics in kidney health and disease

The mammalian vascular system consists of two networks: the blood vascular system and the lymphatic vascular system. Throughout the body, the lymphatic system contributes to homeostatic mechanisms by draining extravasated interstitial fluid and facilitating the trafficking and activation of immune cells. In the kidney, lymphatic vessels exist mainly in the kidney cortex. In the medulla, the ascending vasa recta represent a hybrid lymphatic-like vessel that performs lymphatic-like roles in interstitial fluid reabsorption. Although the lymphatic network is mainly derived from the venous system, evidence supports the existence of lymphatic beds that are of non-venous origin. Following their development and maturation, lymphatic vessel density remains relatively stable; however, these vessels undergo dynamic functional changes to meet tissue demands. Additionally, new lymphatic growth, or lymphangiogenesis, can be induced by pathological conditions such as tissue injury, interstitial fluid overload, hyperglycaemia and inflammation. Lymphangiogenesis is also associated with conditions such as polycystic kidney disease, hypertension, ultrafiltration failure and transplant rejection. Although lymphangiogenesis has protective functions in clearing accumulated fluid and immune cells, the kidney lymphatics may also propagate an inflammatory feedback loop, exacerbating inflammation and fibrosis. Greater understanding of lymphatic biology, including the developmental origin and function of the lymphatics and their response to pathogenic stimuli, may aid the development of new therapeutic agents that target the lymphatic system.

Effect of half-molar sodium lactate infusion on biochemical parameters in critically ill patients

OBJECTIVE

To evaluate the impact of the infusion of sodium lactate 500ml upon different biochemical variables and intracranial pressure in patients admitted to the intensive care unit.

DESIGN

A prospective experimental single cohort study was carried out.

SCOPE

Polyvalent intensive care unit of a university hospital.

PATIENTS

Critical patients with shock and intracranial hypertension.

PROCEDURE

A 500ml sodium lactate bolus was infused in 15min. Plasma levels of sodium, potassium, magnesium, calcium, chloride, lactate, bicarbonate, PaCO₂, pH, phosphate and albumin were recorded at 3 timepoints: T0 pre-infusion; T1 at 30min, and T2 at 60min post-infusion. Mean arterial pressure and intracranial pressure were measured at T0 and T2.

RESULTS

Forty-one patients received sodium lactate: 19 as an osmotically active agent and 22 as a volume expander. Metabolic alkalosis was observed: T0 vs. T1 (p=0.007); T1 vs. T2 (p=0.003). Sodium increased at the 3 timepoints (T0 vs. T1, p<0.0001; T1 vs. T2, p=0.0001). In addition, sodium lactate decreased intracranial pressure (T0: 24.83±5.4 vs. T2: 15.06±5.8; p<0.001). Likewise, plasma lactate showed a biphasic effect, with a rapid decrease at T2 (p<0.0001), including in those with previous hyperlactatemia (p=0.002).

CONCLUSIONS

The infusion of sodium lactate is associated to metabolic alkalosis, hypernatremia, reduced chloremia, and a biphasic change in plasma lactate levels. Moreover, a decrease in intracranial pressure was observed in patients with acute brain injury.

The Role of Peritoneal Dialysis in the Treatment of Acute Kidney Injury in Patients With Acute-on-Chronic Liver Failure: A Prospective Brazilian Study

This study aimed to explore the role of peritoneal dialysis (PD) in acute-on-chronic liver disease (ACLD) in relation to metabolic and fluid control and outcome. Fifty-three patients were treated by PD (prescribed Kt/V = 0.40/session), with a flexible catheter, tidal modality, using a cycler and lactate as a buffer. The mean age was 64.8 ± 13.4 years, model of end stage liver disease (MELD) was 31 ± 6, 58.5% were in the intensive care unit, 58.5% needed intravenous inotropic agents including terlipressin, 69.5% were on mechanical ventilation, alcoholic liver disease was the main cause of cirrhosis and the main dialysis indications were uremia and hypervolemia. Blood urea and creatinine levels stabilized after four sessions at around 50 and 2.5 mg/dL, respectively. Negative fluid balance (FB) and ultrafiltration (UF) increased progressively and stabilized around 3.0 L and -2.7 L/day, respectively. Weekly-delivered Kt/V was 2.7 ± 0.37, and 71.7% of patients died. Five factors met the criteria for inclusion in the multivariable analysis. Logistic regression identified as risk factors associated with Acute Kidney Injury (AKI) in ACLD patients: MELD (OR = 1.14, CI 95% = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.79, CI 95% = 0.61-0.93, p = 0.02), mechanical ventilation (OR = 1.49, CI 95% = 1.14-2.97, p < 0.001), and positive fluid balance (FB) after two PD sessions (OR = 1.08, CI 95% = 1.03-1.91, p = 0.007). These factors were significantly associated with death. In conclusion, our study suggests that careful prescription may contribute to providing adequate treatment for most Acute-on-Chronic Liver Failure (ACLF) patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious or mechanical complications. MELD, mechanical complications and FB were factors associated with mortality, while nephrotoxic AKI was a protective factor. Further studies are needed to better investigate the role of PD in ACLF patients with AKI.

Fluid overload and renal function in children after living-donor renal transplantation: a single-center retrospective analysis

BACKGROUND

We aimed to compare renal function after kidney transplantation in children who were treated with higher vs. lower fluid volumes.

METHODS

A retrospective analysis of 81 living-donor renal transplantation pediatric patients was performed between the years 2007 and 2018. We analyzed associations of the decrease in serum creatinine (delta creatinine) with fluid balance, central venous pressure (CVP), pulmonary congestion, mean arterial pressure (MAP), and MAP-CVP percentiles in the first 3 postoperative days. After correcting creatinine for fluid overload, we also assessed associations of these variables with the above parameters. Finally, we evaluated the association between delta creatinine and estimated glomerular filtration rate (eGFR) at 3 months follow-up.

RESULTS

Both delta creatinine and delta-corrected creatinine were found to be associated with pulmonary congestion on the second and third postoperative days (p < 0.02). In addition, trends for positive correlations were found of delta creatinine with fluid balance/kg (p = 0.07), and of delta-corrected creatinine with fluid balance/kg and CVP (p = 0.06-0.07) on the second postoperative day. An association was also demonstrated between the accumulated fluid balance of the first 2 days and eGFR at 3 months after transplantation (p = 0.03).

CONCLUSIONS

An association was demonstrated between indices of fluid overload, >80 ml/kg, and greater improvement in renal function.

IMPACT

There is no consensus regarding the optimal fluid treatment after pediatric renal transplantation. In our cohort, indices of fluid overload were associated with better renal function immediately after the transplantation and 3 months thereafter. Fluid overload after living-donor renal transplantation in children may have short- and long-term benefits on renal function.

Increased 28-day mortality due to fluid overload prior to continuous renal replacement in sepsis associated acute kidney injury

Patients with sepsis are prone to fluid overload (FO) due to fluid resuscitation, irrespective of stage of acute kidney injury (AKI). The aim of our study was to analyze the association between FO at continuous renal replacement therapy (CRRT) initiation and 28-day mortality in patients with sepsis associated AKI (S-AKI). In this retrospective study, data for patient characteristics were collected and 28-day mortality were studied. We also analyze association of variables, including FO degrees with 28-day mortality. Earlier commencement of CRRT showed better outcome. Non-survivors had higher FO than survivor (9.17% vs. 5.20%; p = 0.016). Survival in patients with FO > 10% over 28 days was significantly worse compared to those with FO ≤ 10% (p = 0.006). Multivariate analysis showed, FO > 10% (95%CI [1.721, 17.195], p = 0.004) was significantly associated with increased 28-day mortality. In S-AKI requiring CRRT, FO > 10% at CRRT initiation was independently associated with 28-day mortality.