Development of a new miniaturized system for ultrafiltration

Acute decompensated heart failure and fluid overload are the most common causes of hospitalization in heart failure patients, and often, they contribute to disease progression. Initial treatment encompasses intravenous diuretics although there might be a percentual of patients refractory to this pharmacological approach. New technologies have been developed to perform extracorporeal ultrafiltration in fluid overloaded patients. Current equipment allows to perform ultrafiltration in most hospital and acute care settings. Extracorporeal ultrafiltration is then prescribed and conducted by specialized teams, and fluid removal is planned to restore a status of hydration close to normal. Recent clinical trials and European and North American practice guidelines suggest that ultrafiltration is indicated for patients with refractory congestion not responding to medical therapy. Close interaction between nephrologists and cardiologists may be the key to a collaborative therapeutic effort in heart failure patients. Further studies are today suggesting that wearable technologies might become available soon to treat patients in ambulatory and de-hospitalized settings. These new technologies may help to cope with the increasing demand for the care of chronic heart failure patients. Herein, we provide a state-of-the-art review on extracorporeal ultrafiltration and describe the steps in the development of a new miniaturized system for ultrafiltration, called AD1 (Artificial Diuresis).

Group-Based Trajectory Modeling of Fluid Balance in Elderly Patients with Acute Ischemic Stroke: Analysis from Multicenter ICUs

INTRODUCTION

Acute ischemic stroke (AIS) significantly contributes to severe disability and mortality among the elderly. This study aims to explore the association between longitudinal fluid balance (FB) trajectories and clinical outcomes in elderly patients with AIS. Our hypothesis posits the existence of multiple latent trajectories of FB in patients with AIS during the initial 7 days following ICU admission.

METHODS

Patients (age ≥ 65 years) with AIS and continuous FB records were identified from two large databases. Group-based trajectory modeling identified latent groups with similar 7-day FB trajectories. Subsequently, multivariable logistic and quasi-Poisson regression were employed to evaluate the relationship between trajectory groups and outcomes. Additionally, nonlinear associations between maximum fluid overload (FO) and outcomes were analyzed using restricted cubic spline models. To further validate our findings, subgroup and sensitivity analysis were conducted.

RESULTS

A total of 1146 eligible patients were included in this study, revealing three trajectory patterns were identified: low FB (84.8%), decreasing FB (7.2%), and high FB (7.9%). High FB emerged as an independent risk factor for in-hospital mortality. Compared with those without FO, patients with FO had a 1.57-fold increased risk of hospital mortality (adjusted odd ratio (OR) 1.57, 95% confidence interval (CI) 1.08-2.27), 2.37-fold increased risk of adverse kidney event (adjusted OR 2.37, 95% CI 1.56-3.59), and 1.33-fold increased risk of prolonged ICU stay (adjusted incidence rate ratio (IRR) 1.33, 95% CI 1.19-1.48). The risk of hospital mortality and adverse kidney event increased linearly with rising maximum FO (P for non-linearity = 0.263 and 0.563, respectively).

CONCLUSION

Daily FB trajectories were associated with adverse outcomes in elderly patients with AIS. Regular assessment of daily fluid status and restriction of FO are crucial for the recovery of critically ill patients.

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.

Effect of High Sodium Intake on Gut Tight Junctions' Structure and Permeability to Bacterial Toxins in a Rat Model of Chronic Kidney Disease

INTRODUCTION

Uremic toxicity changes the gut structure and permeability, allowing bacterial toxins to translocate from the lumen to the blood during chronic kidney failure (CKD). Clinical fluid overload and tissue edema without uremia have similar effects but have not been adequately demonstrated and analyzed in CKD.

AIMS

To investigate the effect of sodium intake on the plasma concentration of gut-derived uremic toxins, indoxyl sulfate (IS), and p-cresyl sulfate (pCS) and the expression of genes and proteins of epithelial gut tight junctions in a rat model of CKD.

METHODS

Sham-operated (control group, CG) and five-sixths nephrectomized (5/6Nx) Sprague-Dawley rats were randomly assigned to low (LNa), normal (NNa), or high sodium (HNa) diets., Animals were then sacrificed at 8 and 12 weeks and analyzed for IS and pCS plasma concentrations, as well as for gene and protein expression of thigh junction proteins, and transmission electron microscopy (TEM) in colon fragments.

RESULTS

The HNa 5/6Nx groups had higher concentrations of IS and pCS than CG, NNa, and LNa at eight and twelve weeks. Furthermore, HNa 5/6Nx groups had reduced expression of the claudin-4 gene and protein than CG, NNa, and LNa. HNa had reduced occludin gene expression compared to CG. Occludin protein expression was more reduced in HNa than in CG, NNa, and LNa. The gut epithelial tight junctions appear dilated in HNa compared to NNa and LNa in TEM.

CONCLUSION

Dietary sodium intake and fluid overload have a significant role in gut epithelial permeability in the CKD model.

Loop diuretic down-titration at discharge in patients hospitalized for acute heart failure

AIMS

The current literature provides limited guidance on the best diuretic strategy post-hospitalization for acute heart failure (AHF). It is postulated that the efficacy and safety of the outpatient diuretic regimen may be significantly influenced by the degree of fluid overload (FO) encountered during hospitalization. We hypothesize that in patients with more pronounced FO, reducing their regular oral diuretic dosage might be associated with an elevated risk of unfavourable clinical outcomes.

METHODS AND RESULTS

It was a retrospective observational study of 410 patients hospitalized for AHF in which the dose of furosemide at admission and discharge was collected. Patients were categorized across diuretic dose status into two groups: (i) the down-titration group and (ii) the stable/up-titration group. FO status was evaluated by a clinical congestion score and circulating biomarkers. The endpoint of interest was the composite of time to all-cause death and/or heart failure readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 86 (78-92) years, 256 (62%) were women, and 80% had heart failure with preserved ejection fraction. After multivariate adjustment, the down-titration furosemide equivalent dose remained not associated with the risk of the combined endpoint in the whole sample (hazard ratio 1.34, 95% confidence interval 0.86-2.06, P = 0.184). The risk of the combination of death and/or worsening heart failure associated with the diuretic strategy at discharge was significantly influenced by FO status, including clinical congestion scores and circulating proxies of FO like BNP and cancer antigen 125.

CONCLUSIONS

In patients hospitalized for AHF, furosemide down-titration does not imply an increased risk of mortality and/or heart failure readmission. However, FO status modifies the effect of down-titration on the outcome. In patients with severe congestion or residual congestion at discharge, down-titration was associated with an increased risk of mortality and/or heart failure readmission.

The severity of early fluid overload assessed by bioelectrical vector impedance as an independent risk factor for longer patient care after cardiac surgery

BACKGROUND AND AIMS

Fluid overload is a common postoperative complication in patients undergoing cardiac surgery. Although this condition is notably associated with relevant adverse outcomes, assessment of hydration status in clinical practice is challenging. Bioelectrical impedance vector analysis (BIVA) has emerged as a potentially effective method to monitor hydration changes, but the available evidence in critically ill patients undergoing cardiac surgery is limited and sometimes conflicting. The aim of this study was to explore by mean of BIVA the evolution over time of hydration status and its impact on relevant outcomes.

METHODS

Prospective observational study enrolling 130 patients undergoing cardiac surgery. Height normalized impedance was calculated both before surgery (baseline) and in the first five postoperative days. Relevant clinical and laboratory data were collected daily close to BIVA measurements. Length of mechanical ventilation (MV), intensive care unit (ICU) and hospital stay exceeding the 75th percentile of the study population were considered as study endpoints.

RESULTS

Compared to baseline, a significant reduction in impedance was found at first postoperative day, demonstrating a relevant fluid overload. An adjusted impedance at first postoperative day shorter than the best respective threshold was associated to longer MV (7.4 times), ICU stay (4.7 times) and hospital stay (5.6 times). A significant change in impedance and phase angle was documented throughout the observation days (p < 0.001), without returning to the baseline value. The co-existence of low impedance and high plasma osmolarity increased significantly the risk of incurring the study outcomes.

CONCLUSIONS

In patients with cardiac surgery-induced fluid overload, recovery to baseline conditions occurs slowly. A relevant early fluid overload should be considered predictive for longer time of MV, ICU and total hospital stay.

Consensus on the Approach to Hydrosaline Overload in Acute Heart Failure. SEMI/SEC/S.E.N. Recommendations

Most of the signs and symptoms of heart failure can be explained by fluid overload, which is also related to disease progression. Fluid overload is a complex phenomenon that extends beyond increased intravascular pressures and poses challenges for accurate diagnosis and effective treatment. Current recommendations advise a multiparametric approach, including clinical data (symptoms/signs), imaging tests, and biomarkers. This article proposes a practical therapeutic approach to managing hydrosaline overload in heart failure in both inpatient and outpatient settings. This document is an initiative of the Spanish Society of Internal Medicine in collaboration with the Spanish Society of Cardiology and the Spanish Society of Nephrology. Full English text available from: www.revespcardiol.org/en.

Fluid assessment, fluid balance, and fluid overload in sick children: a report from the Pediatric Acute Disease Quality Initiative (ADQI) conference

BACKGROUND

The impact of disorders of fluid balance, including the pathologic state of fluid overload in sick children has become increasingly apparent. With this understanding, there has been a shift from application of absolute thresholds of fluid accumulation to an appreciation of the intricacies of fluid balance, including the impact of timing, trajectory, and disease pathophysiology.

METHODS

The 26th Acute Disease Quality Initiative was the first to be exclusively dedicated to pediatric and neonatal acute kidney injury (pADQI). As part of the consensus panel, a multidisciplinary working group dedicated to fluid balance, fluid accumulation, and fluid overload was created. Through a search, review, and appraisal of the literature, summative consensus statements, along with identification of knowledge gaps and recommendations for clinical practice and research were developed.

CONCLUSIONS

The 26th pADQI conference proposed harmonized terminology for fluid balance and for describing a pathologic state of fluid overload for clinical practice and research. Recommendations include that the terms daily fluid balance, cumulative fluid balance, and percent cumulative fluid balance be utilized to describe the fluid status of sick children. The term fluid overload is to be preserved for describing a pathologic state of positive fluid balance associated with adverse events. Several recommendations for research were proposed including focused validation of the definition of fluid balance, fluid overload, and proposed methodologic approaches and endpoints for clinical trials.

Early repeat hospitalization for fluid overload in individuals with cardiovascular disease and risks: a retrospective cohort study

AIMS

Fluid overload is a common manifestation of cardiovascular and kidney disease and a leading cause of hospitalizations. To identify patients at risk of recurrent severe fluid overload, we evaluated the incidence and risk factors associated with early repeat hospitalization for fluid overload among individuals with cardiovascular disease and risks.

METHODS

Single-center retrospective cohort study of 3423 consecutive adults with an index hospitalization for fluid overload between January 2015 and December 2017 and had cardiovascular risks (older age, diabetes mellitus, hypertension, dyslipidemia, kidney disease, known cardiovascular disease), but excluded if lost to follow-up or eGFR < 15 ml/min/1.73 m2. The outcome was early repeat hospitalization for fluid overload within 30 days of discharge.

RESULTS

The mean age was 73.9 ± 11.6 years and eGFR was 54.1 ± 24.6 ml/min/1.73 m2 at index hospitalization. Early repeat hospitalization for fluid overload occurred in 291 patients (8.5%). After adjusting for demographics, comorbidities, clinical parameters during index hospitalization and medications at discharge, cardiovascular disease (adjusted odds ratio, OR 1.66, 95% CI 1.27-2.17), prior hospitalization for fluid overload within 3 months (OR 2.52, 95% CI 1.17-5.44), prior hospitalization for any cause in within 6 months (OR 1.33, 95% CI 1.02-1.73) and intravenous furosemide use (OR 1.58, 95% CI 1.10-2.28) were associated with early repeat hospitalization for fluid overload. Higher systolic BP on admission (OR 0.992, 95% 0.986-0.998) and diuretic at discharge (OR 0.50, 95% CI 0.26-0.98) reduced early hospitalization for fluid overload.

CONCLUSION

Patients at-risk of early repeat hospitalization for fluid overload may be identified using these risk factors for targeted interventions.

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.

Pattern of Fluid Overload and its Impact on Mortality Among Mechanically Ventilated Children: Secondary Analysis of the ReLiSCh Trial

OBJECTIVES

To assess the pattern of fluid overload (FO) and its impact on mortality among mechanically ventilated children.

METHODS

In this secondary analysis of an open-label randomized controlled trial (ReLiSCh trial, October 2020-September 2021), hemodynamically stable mechanically ventilated children (n = 100) admitted to a tertiary level pediatric intensive care unit (PICU) in North India were enrolled. The primary outcome was pattern of FO (FO% >10% and cumulative FO% from day 1-7); and secondary outcomes were pattern of FO among survivors and non-survivors, and prescription practices of maintenance fluid.

RESULTS

The median (IQR) age was 3.5 (0.85-7.5) y and 57% were males. Common diagnoses were pneumonia (27%), scrub typhus (14%), Landry-Guillain-Barré syndrome (9%), dengue (8%), central nervous system infections (7%) and staphylococcal sepsis (6%). Common organ dysfunction included acute respiratory distress syndrome (ARDS) (41%), shock (38%), and acute kidney injury (AKI) (9%). The duration PICU stay was 11 (7-17) d and mortality was 12%. The FO% >10% was noted in 19% children; and there was significant increase in cumulative FO% from day 1-7 [1.2 (0.2-2.6)% to 8.5 (1.7-14.3)%, (p = 0.000)]. Among non-survivors, higher proportion had FO% >10% (66.7% vs. 12.5%, p 0.0001); and trend towards higher cumulative FO% on first seven days. From day 1-7, the percentage of maintenance fluid received increased from 60 (50-71)% to 70 (60-77)% (p = 0.691).

CONCLUSIONS

One-fifth of mechanically ventilated children had FO% >10% and there was significant increase in cumulative FO% from day 1-7. Non-survivors had significantly higher degree of FO.

[Application and control of intravenous fluids in German intensive care units : A national survey among critical care physicians]

BACKGROUND

The administration of intravenous fluids includes various indications, e.g., fluid replacement, nutritional therapy or as a solvent for drugs and is a common routine in the intensive care unit (ICU); however, overuse of intravenous fluids can lead to fluid overload, which can be associated with a poorer outcome in critically ill patients.

OBJECTIVE

The aim of this survey was to find out the current status of the use and management of intravenous fluids as well as the interprofessional cooperation involving clinical pharmacists on German ICUs.

METHODS

An online survey with 33 questions was developed. The answers of 62 participants from the Scientific Working Group on Intensive Care Medicine of the German Society for Anesthesiology and Intensive Care Medicine were evaluated.

RESULTS

Fluid overload occurs "frequently" in 62.9% (39/62) and "very frequently" in 9.7% (6/62) of the ICUs of respondents. An established standard for an infusion management system is unknown to 71.0% (44/62) of participants and 45.2% of the respondents stated that they did not have a patient data management system. In addition, the participants indicated how they define fluid overload. This was defined by the presence of edema by 50.9% (28/55) and by positive fluid balance by 30.9% (17/55). According to the participants septic patients (38/60; 63.3%) and cardiological/cardiac surgical patients (26/60; 43.3%) are most susceptible to the occurrence of fluid overload. Interprofessional collaboration among intensive care physicians, critical care nurses, and clinical pharmacists to optimize fluid therapy was described as "relevant" by 38.7% (24/62) and "very relevant" by 45.2% (28/62). Participants with clinical pharmacists on the wards (24/62; 38.7%) answered this question more often as "very relevant" with 62.5% (15/24).

CONCLUSION

Fluid overload is a frequent and relevant problem in German intensive care units. Yet there are few established standards in this area. There is also a lack of validated diagnostic parameters and a clear definition of fluid overload. These are required to ensure appropriate and effective treatment that is tailored to the patient and adapted to the respective situation. Intravenous fluids should be considered as drugs that may exert side effects or can be overdosed with severe adverse consequences for the patients. One approach to optimize fluid therapy could be achieved by a fluid stewardship corresponding to comparable established procedures of the antibiotic stewardship. In particular, fluid stewardship will contribute to drug safety of intravenous fluids profiting from joined expertise in a setting of interprofessional collaboration. An important principle of fluid stewardship is to consider intravenous fluids in the same way as medication in terms of their importance. Furthermore, more in-depth studies are needed to investigate the effects of interprofessional fluid stewardship in a prospective and controlled manner.

Using aquapheresis with continuous hematocrit monitoring to guide ultrafiltration

BACKGROUND

Management of edema and volume overload in patients with hypoalbuminemia, either due to nephrotic syndrome or other disease processes, can be extremely challenging.

METHODS

We describe the management of five patients with hypoalbuminemia and severe fluid overload using the Aquadex FlexFlow device with continuous hematocrit monitoring to guide ultrafiltration.

RESULTS

We report five pediatric patients ranging in age from 7 days to 11 years and in size from 2.7 to 65 kg with hypoalbuminemia due to a variety of etiologies treated with slow continuous ultrafiltration with continuous hematocrit monitoring to guide ultrafiltration using the Aquadex device. Treatment allowed successful fluid removal in all cases, without hypotension or other hemodynamic complications.

CONCLUSIONS

In a variety of clinical circumstances and in patients from infants to adolescence, we report that patients with diuretic-resistant fluid overload can be treated with Aquadex using continuous hematocrit monitoring to guide management to allow fluid removal without hemodynamic instability or other complications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Continuous renal replacement therapy in neonates and children: what does the pediatrician need to know? An overview from the Critical Care Nephrology Section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

Continuous renal replacement therapy (CRRT) is the preferred method for renal support in critically ill and hemodynamically unstable children in the pediatric intensive care unit (PICU) as it allows for gentle removal of fluids and solutes. The most frequent indications for CRRT include acute kidney injury (AKI) and fluid overload (FO) as well as non-renal indications such as removal of toxic metabolites in acute liver failure, inborn errors of metabolism, and intoxications and removal of inflammatory mediators in sepsis. AKI and/or FO are common in critically ill children and their presence is associated with worse outcomes. Therefore, early recognition of AKI and FO is important and timely transfer of patients who might require CRRT to a center with institutional expertise should be considered. Although CRRT has been increasingly used in the critical care setting, due to the lack of standardized recommendations, wide practice variations exist regarding the main aspects of CRRT application in critically ill children.     Conclusion: In this review, from the Critical Care Nephrology section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC), we summarize the key aspects of CRRT delivery and highlight the importance of adequate follow up among AKI survivors which might be of relevance for the general pediatric community. What is Known: • CRRT is the preferred method of renal support in critically ill and hemodynamically unstable children in the PICU as it allows for gentle removal of fluids and solutes. • Although CRRT has become an important and integral part of modern pediatric critical care, wide practice variations exist in all aspects of CRRT. What is New: • Given the lack of literature on guidance for a general pediatrician on when to refer a child for CRRT, we recommend timely transfer to a center with institutional expertise in CRRT, as both worsening AKI and FO have been associated with increased mortality. • Adequate follow-up of PICU patients with AKI and CRRT is highlighted as recent findings demonstrate that these children are at increased risk for adverse long-term outcomes.

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

BACKGROUND

The use of peritoneal catheters for prophylactic dialysis or drainage to prevent fluid overload after neonatal cardiac surgery is common in some centres; however, the multi-centre variability and details of peritoneal catheter use are not well described.

METHODS

Twenty-two-centre NEonatal and Pediatric Heart Renal Outcomes Network (NEPHRON) study to describe multi-centre peritoneal catheter use after STAT category 3-5 neonatal cardiac surgery using cardiopulmonary bypass. Patient characteristics and acute kidney injury/fluid outcomes for six post-operative days are described among three cohorts: peritoneal catheter with dialysis, peritoneal catheter with passive drainage, and no peritoneal catheter.

RESULTS

Of 1490 neonates, 471 (32%) had an intraoperative peritoneal catheter placed; 177 (12%) received prophylactic dialysis and 294 (20%) received passive drainage. Sixteen (73%) centres used peritoneal catheter at some frequency, including six centres in >50% of neonates. Four centres utilised prophylactic peritoneal dialysis. Time to post-operative dialysis initiation was 3 hours [1, 5] with the duration of 56 hours [37, 90]; passive drainage cohort drained for 92 hours [64, 163]. Peritoneal catheter were more common among patients receiving pre-operative mechanical ventilation, single ventricle physiology, and higher complexity surgery. There was no association with adverse events. Serum creatinine and daily fluid balance were not clinically different on any post-operative day. Mortality was similar.

CONCLUSIONS

In neonates undergoing complex cardiac surgery, peritoneal catheter use is not rare, with substantial variability among centres. Peritoneal catheters are used more commonly with higher surgical complexity. Adverse event rates, including mortality, are not different with peritoneal catheter use. Fluid overload and creatinine-based acute kidney injury rates are not different in peritoneal catheter cohorts.

Venous Doppler flow patterns, venous congestion, heart disease and renal dysfunction: A complex liaison

The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on. We focused our attention on venous congestion. In intensive care settings, it is now widely accepted that venous congestion is an important clinical feature worthy of investigation. Evaluating venous Doppler profile abnormalities at multiple sites could suggest adequate treatment and monitor its efficacy. Renal dysfunction could trigger or worsen fluid overload in heart disease, and cardio-renal syndrome is a well-characterized spectrum of disorders describing the complex interactions between heart and kidney diseases. Fluid overload and venous congestion, including renal venous hypertension, are major determinants of acute and chronic renal dysfunction arising in heart disease. Organ congestion from venous hypertension could be involved in the development of organ injury in several clinical situations, such as critical diseases, congestive heart failure, and chronic kidney disease. Ultrasonography and abnormal Doppler flow patterns diagnose clinically significant systemic venous congestion. Cardiologists and nephrologists might use this valuable, non-invasive, bedside diagnostic tool to establish fluid status and guide clinical choices.

Improving mixed-integer temporal modeling by generating synthetic data using conditional generative adversarial networks: A case study of fluid overload prediction in the intensive care unit

OBJECTIVE

The challenge of mixed-integer temporal data, which is particularly prominent for medication use in the critically ill, limits the performance of predictive models. The purpose of this evaluation was to pilot test integrating synthetic data within an existing dataset of complex medication data to improve machine learning model prediction of fluid overload.

MATERIALS AND METHODS

This retrospective cohort study evaluated patients admitted to an ICU ≥ 72 h. Four machine learning algorithms to predict fluid overload after 48-72 h of ICU admission were developed using the original dataset. Then, two distinct synthetic data generation methodologies (synthetic minority over-sampling technique (SMOTE) and conditional tabular generative adversarial network (CTGAN)) were used to create synthetic data. Finally, a stacking ensemble technique designed to train a meta-learner was established. Models underwent training in three scenarios of varying qualities and quantities of datasets.

RESULTS

Training machine learning algorithms on the combined synthetic and original dataset overall increased the performance of the predictive models compared to training on the original dataset. The highest performing model was the meta-model trained on the combined dataset with 0.83 AUROC while it managed to significantly enhance the sensitivity across different training scenarios.

DISCUSSION

The integration of synthetically generated data is the first time such methods have been applied to ICU medication data and offers a promising solution to enhance the performance of machine learning models for fluid overload, which may be translated to other ICU outcomes. A meta-learner was able to make a trade-off between different performance metrics and improve the ability to identify the minority class.

Early acute kidney injury and transition to renal replacement therapy in critically ill patients with SARS-CoV-2 requiring veno-venous extracorporeal membrane oxygenation

BACKGROUND

Critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requiring veno-venous extracorporeal membrane oxygenation (vv-ECMO) are at risk for acute kidney injury (AKI). Currently, the incidence of AKI and progression to kidney replacement therapy (RRT) in critically ill patients with vv-ECMO for severe COVID-19 and implications on outcome are still unclear.

METHODS

Retrospective analysis at the University Medical Center Hamburg-Eppendorf (Germany) between March 1st, 2020 and July 31st, 2021. Demographics, clinical parameters, AKI, type of organ support, length of ICU stay, mortality and severity scores were assessed.

RESULTS

Ninety-one critically ill patients with SARS-CoV-2 requiring ECMO were included. The median age of the study population was 57 (IQR 49-64) years and 67% (n = 61) were male. The median SAPS II and SOFA Score on admission were 40 (34-46) and 12 (10-14) points, respectively. We observed that 45% (n = 41) developed early-AKI, 38% (n = 35) late-AKI and 16% (n = 15) no AKI during the ICU stay. Overall, 70% (n = 64) of patients required RRT during the ICU stay, 93% with early-AKI and 74% with late-AKI. Risk factors for early-AKI were younger age (OR 0.94, 95% CI 0.90-0.99, p = 0.02) and SAPS II (OR 1.12, 95% CI 1.06-1.19, p < 0.001). Patients with and without RRT were comparable regarding baseline characteristics. SAPS II (41 vs. 37 points, p < 0.05) and SOFA score (13 vs. 12 points, p < 0.05) on admission were significantly higher in patients receiving RRT. The median duration of ICU (36 vs. 28 days, p = 0.27) stay was longer in patients with RRT. An ICU mortality rate in patients with RRT in 69% (n = 44) and in patients without RRT of 56% (n = 27) was observed (p = 0.23).

CONCLUSION

Critically ill patients with severe SARS-CoV-2 related ARDS requiring vv-ECMO are at high risk of early acute kidney injury. Early-AKI is associated with age and severity of illness, and presents with high need for RRT. Mortality in patients with RRT was comparable to patients without RRT.

An update on the role of fluid overload in the prediction of outcome in acute kidney injury

Over the past two decades, our understanding of the impact of acute kidney injury, disorders of fluid balance, and their interplay have increased significantly. In recent years, the epidemiology and impact of fluid balance, including the pathologic state of fluid overload on outcomes has been studied extensively across multiple pediatric and neonatal populations. A detailed understating of fluid balance has become increasingly important as it is recognized as a target for intervention to continue to work to improve outcomes in these populations. In this review, we provide an update on the epidemiology and outcomes associated with fluid balance disorders and the development of fluid overload in children with acute kidney injury (AKI). This will include a detailed review of consensus definitions of fluid balance, fluid overload, and the methodologies to define them, impact of fluid balance on the diagnosis of AKI and the concept of fluid corrected serum creatinine. This review will also provide detailed descriptions of future directions and the changing paradigms around fluid balance and AKI in critical care nephrology, including the incorporation of the sequential utilization of risk stratification, novel biomarkers, and functional kidney tests (furosemide stress test) into research and ultimately clinical care. Finally, the review will conclude with novel methods currently under study to assess fluid balance and distribution (point of care ultrasound and bioimpedance).

Restricted versus Usual/Liberal Maintenance Fluid Strategy in Mechanically Ventilated Children: An Open-Label Randomized Trial (ReLiSCh Trial)

OBJECTIVES

To assess the impact of restricted vs. usual/liberal maintenance fluid strategy on fluid overload (FO) among mechanically ventilated children.

METHODS

This open-label randomized controlled trial was conducted over a period of 1 y (October 2020-September 2021) in a Pediatric intensive care unit (PICU) in North India. Hemodynamically stable mechanically ventilated children were randomized to 40% (restricted group, n = 50) and 70-80% (usual/liberal group, n = 50) of maintenance fluids. The primary outcome was cumulative fluid overload percentage (FO%) on day 7. Secondary outcomes were FO% >10%; vasoactive inotropic score, sequential organ failure assessment score, pediatric logistic organ dysfunction score and oxygenation index from day 1-7; ventilation free days (VFDs) and PICU free days (PFDs) through day 28; and mortality.

RESULTS

The restricted group had statistically non-significant trend towards lower cumulative FO% at day 7 [7.6 vs. 9.5, p = 0.40]; and proportion of children with FO% >10% (12% vs. 26%, p = 0.21) as compared to usual/liberal group. The increase in FO% from day 1-7 was significant in usual/liberal group as compared to restricted group (p <0.001 and p = 0.134, respectively). Restricted group received significantly lower amount of fluid in the first 5 d; had significantly higher VFDs (23 vs. 17 d, p = 0.008) and PFDs (19 vs. 15 d, p = 0.007); and trend towards lower mortality (8% vs. 16%, p = 0.21).

CONCLUSIONS

Restricted as compared to usual/liberal maintenance fluid strategy among mechanically ventilated children was associated with a trend towards lower rate and severity of FO and mortality; and significantly lower fluid volume received, and higher VFDs and PFDs.

Fluid Management during Continuous Renal Replacement Therapy: A Case-Based Approach

Continuous renal replacement therapy (CRRT) is frequently used for fluid management of critically ill patients with acute or chronic kidney failure. There is significant practice variation worldwide in fluid management during CRRT. Multiple clinical studies have suggested that both the magnitude and duration of fluid overload are associated with morbidity and mortality in critically ill patients. Therefore, timely and effective fluid management with CRRT is paramount in managing critically ill patients with fluid overload. While the optimal method of fluid management during CRRT is still unclear and warrants further investigation, observational data have suggested a U-shape relationship between net ultrafiltration rate and mortality. Furthermore, recent clinical data have underpinned a significant gap in prescribed versus achieved fluid balance during CRRT, which is also associated with mortality. This review uses a case-based approach to discuss two fluid management strategies based on net ultrafiltration rate and fluid balance goals during CRRT and harmonizes operational definitions.

Substitution of calcineurin inhibitors with corticosteroids after allogeneic hematopoietic cell transplantation

Combination of calcineurin inhibitors (CIs) with short-term methotrexate is a standard prophylactic regimen for graft-versus-host disease (GVHD). However, it is sometimes difficult to continue CIs due to adverse effects, such as renal impairment and fluid overload. In such cases, we replace CIs with corticosteroids, considering that full dose of CIs is equivalent to prednisolone (PSL) at 1 mg/kg. We retrospectively evaluated the clinical significance of replacement of CIs with corticosteroids after allogeneic hematopoietic cell transplantation (HCT). We evaluated 42 patients switched from CIs to corticosteroids within 90 days among the 479 patients who underwent allogeneic HCT at our center between 2007 and 2019. Renal impairment (n = 33), fluid overload (n = 13), and thrombotic microangiopathy (n = 3) were the main reasons for switching. Although creatinine and body weight returned to baseline at 4 weeks after switching, 100-day non-relapse mortality was high (57.1%). Grade II-IV acute GVHD was seen in 10 (24.4%) patients who did not have it before switching treatment (n = 41). In conclusion, CIs were switched to corticosteroids in patients with severe clinical conditions. The incidence of acute GVHD was acceptable. Although the short-term mortality rate was high, improvement of renal function or fluid overload was observed in a certain proportion of the patients.

Loop diuretics improve conditions of dialysis inception in advanced CKD: an observational cohort study

BACKGROUND

Diuretics can reduce fluid overload but their effects on conditions of dialysis start remain elusive. We aimed to determine whether loop diuretics exposure in the year before inception can delay the need for dialysis, affect the conditions of dialysis start, and cause early mortality three months after initiation in pre-dialysis patients.

METHODS

All adult patients starting dialysis from 2009 to 2015 in the REIN registry were included. Three subgroups were defined according to diuretics exposure: "continuous", "stopped", or "no diuretics" over the year before inception and compared for pre-dialysis hospitalization rates, and 3-month mortality after dialysis.

RESULTS

Among 59,302 patients, we found fewer emergency initiations of dialysis in the continuous diuretics group than in the stopped diuretics and no diuretics groups: 9492 (27.5%) vs 1905 (32.3%) and 5226 (35.0%), respectively; p < 0.0001. In the continuous diuretics group, there were fewer starts on central venous catheters than in the stopped diuretics and no diuretics groups: 16,677 (49.4%) vs. 3246 (56.0%) vs. 8,639 (58.4%); p < 0.0001. Patients with continuous diuretic exposure had a lower hospitalization rate than the stopped diuretics group in the year prior to dialysis, except for heart failure. The unadjusted 3-month hazard ratio of mortality after dialysis inception was significantly higher in the "no diuretics" or "stopped diuretics" groups compared with "continuous diuretics", but the excess of risk was blunted after adjustment for emergency start and pre-dialysis visits to a nephrologist.

CONCLUSION

Continuous loop diuretics exposure in the year before dialysis was associated with better conditions of dialysis inception, and possibly lower mortality rates in the three months after inception.

Early postoperative weight-based fluid overload is associated with worse outcomes after neonatal cardiac surgery

OBJECTIVES

Evaluate the association of postoperative day (POD) 2 weight-based fluid balance (FB-W) > 10% with outcomes after neonatal cardiac surgery.

METHODS

Retrospective cohort study of 22 hospitals in the NEonatal and Pediatric Heart and Renal Outcomes Network (NEPHRON) registry from September 2015 to January 2018. Of 2240 eligible patients, 997 neonates (cardiopulmonary bypass (CPB) n = 658, non-CPB n = 339) were weighed on POD2 and included.

RESULTS

Forty-five percent (n = 444) of patients had FB-W > 10%. Patients with POD2 FB-W > 10% had higher acuity of illness and worse outcomes. Hospital mortality was 2.8% (n = 28) and not independently associated with POD2 FB-W > 10% (OR 1.04; 95% CI 0.29-3.68). POD2 FB-W > 10% was associated with all utilization outcomes, including duration of mechanical ventilation (multiplicative rate of 1.19; 95% CI 1.04-1.36), respiratory support (1.28; 95% CI 1.07-1.54), inotropic support (1.38; 95% CI 1.10-1.73), and postoperative hospital length of stay (LOS 1.15; 95% CI 1.03-1.27). In secondary analyses, POD2 FB-W as a continuous variable demonstrated association with prolonged durations of mechanical ventilation (OR 1.04; 95% CI 1.02-1.06], respiratory support (1.03; 95% CI 1.01-1.05), inotropic support (1.03; 95% CI 1.00-1.05), and postoperative hospital LOS (1.02; 95% CI 1.00-1.04). POD2 intake-output based fluid balance (FB-IO) was not associated with any outcome.

CONCLUSIONS

POD2 weight-based fluid balance > 10% occurs frequently after neonatal cardiac surgery and is associated with longer cardiorespiratory support and postoperative hospital LOS. However, POD2 FB-IO was not associated with clinical outcomes. Mitigating early postoperative fluid accumulation may improve outcomes but requires safely weighing neonates in the early postoperative period. A higher resolution version of the Graphical abstract is available as Supplementary information.

Personalized Management of Sodium and Volume Imbalance in Hemodialysis to Mitigate High Costs of Hospitalization

The primary objective of hemodialysis (HD) is lowering concentrations of organic uremic toxins that accumulate in blood in end-stage kidney disease (ESKD) and redress imbalances of inorganic compounds in particular sodium and water. Removal by ultrafiltration of excess fluid that has accumulated during the dialysis-free interval is a vital aspect of each HD session. Most HD patients are volume overloaded, with ∼25% of patients having severe (&gt;2.5 L) fluid overload (FO). The potentially serious complications of FO contribute to the high cardiovascular morbidity and mortality observed in the HD population. Weekly cycles imposed by the schedule of HD treatments create a deleterious and unphysiological "tide phenomenon" marked by sodium-volume overload (loading) and depletion (unloading). Fluid overload-related hospitalizations are frequent and costly, with average cost estimates of $ 6,372 per episode, amounting to some $ 266 million total costs over a 2-year period in a US dialysis population. Various strategies (e.g., dry weight management or use of fluids with different sodium concentrations) have been attempted to rectify FO in HD patients but have met with limited success largely due to imprecise and cumbersome, or costly, approaches. In recent years, conductivity-based technologies have been refined to actively restore sodium and fluid imbalance and maintain the predialysis plasma sodium set point (plasma tonicity) of each patient. By automatically controlling the dialysate-plasma sodium gradient based on the specific patient needs throughout a session, an individualized sodium dialysate prescription can be delivered. Maintaining precise sodium mass balance helps better control of blood pressure, reduces FO, and thus tends to prevent hospitalization for congestive heart failure. We present the case for personalized salt and fluid management via a machine-integrated sodium management tool. Results from proof-of-principle clinical trials indicate that the tool enables individualized sodium-fluid volume control during each HD session. Its application in routine clinical practice has the potential to mitigate the substantial economic burden of hospitalizations attributed to volume overload complications in HD. Additionally, such a tool would contribute toward reduced symptomology and dialysis-induced multiorgan damage in HD patients and to improving their treatment perception and quality of life which matters most to patients.

Early Postoperative Volume Overload is a Predictor of 1-Year Post-Transplant Mortality in Pediatric Heart Transplant Recipients

Fluid restriction and diuretic management are mainstays in the postoperative management of cardiac patients, at risk of volume overload and its deleterious effects on primary cardiac function and multi-organ systems. The importance of fluid homeostasis is further emphasized among orthotopic heart transplant recipients (OHT). We sought to investigate the relationship between postoperative volume overload, mortality, and allograft dysfunction among pediatric OHT recipients within 1-year of transplantation. This is a retrospective cohort study from a single pediatric OHT center. Children under 21 years undergoing cardiac transplantation between 2010 and 2018 were included. Cumulative fluid overload (cFO) was assessed as percent fluid accumulation adjusted for preoperative body weight. Greater than 10% cFO defined those with postoperative cFO and a comparison of postoperative cFO vs. no postoperative cFO (< 5%) is reported. 102 pediatric OHT recipients were included. Early cFO at 72 h post-OHT occurred in 14% and overall cFO at 1-week post-OHT occurred in 23% of patients. Risk factors for cFO included younger age, lower weight, and postoperative ECMO. Early cFO was associated with postoperative mortality at 1-year, OR 8.6 (95% CI 1.4, 51.6), p = 0.04, independent of age and weight. There was no significant relationship between cFO and allograft dysfunction, measured by rates of clinical rejection and cardiopulmonary filling pressures within 1-year of transplant. Early postoperative volume overload is prevalent and associated with increased risk of death at 1-year among pediatric OHT recipients. It may be an important postoperative marker of transplant survival, and this relationship warrants further clinical investigation.

Extracorporeal veno-venous ultrafiltration in congestive heart failure: What’s the state of the art? A mini-review

Hospitalizations for heart failure exceed 1 million per year in both the United States and Europe and more than 90% are due to symptoms and signs of fluid overload. Rates of rehospitalizations or emergency department visit at 60 days are remarkable regardless of whether loop diuretics were administered at low vs high doses or by bolus injection vs continuous infusion. Ultrafiltration (UF) has been considered a promising alternative to stepped diuretic therapy and it consists in the mechanical, adjustable removal of iso-tonic plasma water across a semipermeable membrane with the application of hydrostatic pressure gradient generated by a pump. Fluid removal with ultrafiltration presents several advantages such as elimination of higher amount of sodium with less neurohormonal activation. However, the conflicting results from UF studies highlight that patient selection and fluid removal targets are not completely understood. The best way to assess fluid status and therefore establish the fluid removal target is also still a matter of debate. Herein, we provide an up-to-date systematic review about the role of ultrafiltration among patients with fluid overload and its gaps in daily practice.

New Miniaturized System for Ultrafiltration: Rationale and Design of a Single-Center, Crossover, Randomized, Open-Label, Pilot Study Protocol

INTRODUCTION

Fluid overload and congestion are common features in patients with heart failure and are associated with negative clinical outcomes. Therapies for these conditions are diuretic-centered but frequently fail to achieve patient-adequate hydration status, prompting the use of extracorporeal ultrafiltration. Artificial Diuresis 1 (AD1) is a miniaturized, portable, and wearable system designed to deliver isolated ultrafiltration with the finest degree of simplicity and practicality.

METHODS/DESIGN

Single-center, crossover, randomized, open-label pilot study to investigate the safety and the efficacy (concerning ultrafiltration accuracy) of extracorporeal ultrafiltration with the device AD1 in comparison to isolated ultrafiltration with a traditional machine (PrisMaX). Patients with chronic kidney disease stage 5D (on hemodialysis) or intensive care patients presenting acute kidney injury stage 3D (requiring hemodialysis) will carry out a single session of isolated ultrafiltration with each of the machines. The safety primary outcomes will be the occurrence of adverse events. The efficacy primary outcome will be the accuracy of ultrafiltration rate (delivered/prescribed) on each of the devices.

CONCLUSION

AD1 is a novel miniaturized device for extracorporeal ultrafiltration. This study will be the first-in-human use of AD1 in patients with fluid overload.

Fluid Overload and AKI After the Norwood Operation: The Correlation and Characterization of Routine Clinical Markers

The purpose of this study was to determine the correlation of different methods of assessing fluid overload and determine which metrics are associated with development of acute kidney injury (AKI) in the period immediately following Norwood palliation. This was a retrospective single-center study of Norwood patients from January 2011 through January 2021. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO). Patients were separated into two groups: those with AKI and those without. A logistic regression analysis was conducted with AKI at any point in the study period as the dependent variable and clinical and laboratory data as independent variables. Analysis was conducted as a stepwise regression. The coefficients from the logistic regression were then used to develop a cumulative AKI risk score. Spearman correlations were conducted to analyze the correlation of fluid markers. 116 patients were included, and 49 (42.4%) developed AKI. The duration of open chest, duration of mechanical ventilation, need for dialysis, need for extracorporeal membrane oxygenation, and inpatient mortality were associated with AKI (p ≤ 0.05). Stepwise logistic regression demonstrated the following significant independent associations AKI: age at Norwood in days (p < 0.01), blood urea nitrogen (p < 0.01), central venous pressure (p = 0.04), and renal oxygen extraction ratio (p < 0.01). The area under the receiver operating characteristic curve for the logistic regression was 0.74. The fluid markers had weak R-value. Urea, central venous pressure, and renal oxygen extraction ratio are associated with AKI after the Norwood operation. Common clinical metrics used to assess fluid overload are poorly correlated with each other for postoperative Norwood patients.

Fluid balance in critically ill children with lower respiratory tract viral infection: a cohort study

BACKGROUND

Increasing evidence has associated positive fluid balance of critically ill patients with poor outcomes. The aim of this study was to explore the pattern of daily fluid balances and their association with outcomes in critically ill children with lower respiratory tract viral infection.

METHODS

A retrospective single-center study was conducted, in children supported with high-flow nasal cannula, non-invasive ventilation, or invasive ventilation. Median (interquartile range) daily fluid balances, cumulative fluid overload (FO) and peak FO variation, indexed as the % of admission body weight, over the first week of Pediatric Intensive Care Unit admission, and their association with the duration of respiratory support were assessed.

RESULTS

Overall, 94 patients with a median age of 6.9 (1.9-18) months, and a respiratory support duration of 4 (2-7) days, showed a median (interquartile range) daily fluid balance of 18 (4.5-19.5) ml/kg at day 1, which decreased up to day 3 to 5.9 (- 14 to 24.9) ml/kg and increased to 13 (- 11 to 29.9) ml/kg at day 7 (p = 0.001). Median cumulative FO% was 4.6 (- 0.8 to 11) and peak FO% was 5.7 (1.9-12.4). Daily fluid balances, once patients were stratified according to the respiratory support, were significantly lower in those requiring mechanical ventilation (p = 0.003). No correlation was found between all examined fluid balances and respiratory support duration or oxygen saturation, even after subgroup analysis of patients with invasive mechanical ventilation, or respiratory comorbidities, or bacterial coinfection, or of patients under 1 year old.

CONCLUSIONS

In a cohort of children with bronchiolitis, fluid balance was not associated with duration of respiratory support or other parameters of pulmonary function.

Risk factors for severe acute kidney injury after pediatric hematopoietic cell transplantation

BACKGROUND

Acute kidney injury (AKI) is common after hematopoietic cell transplantation (HCT) and is associated with poorer outcomes. Risk factors for AKI after pediatric HCT are not fully understood. The study objective was to assess unique risk factors for AKI in the HCT population and evaluate post-HCT AKI patterns.

METHODS

We conducted a retrospective cohort study of patients < 21 years of age who underwent HCT at Seattle Children's Hospital/Fred Hutchinson Cancer Center from September 2008 to July 2017 (n = 484). We defined AKI using KDIGO criteria. We collected demographics, baseline HCT characteristics, post-HCT complications, and mortality. Multinomial logistic regression was used to estimate association between AKI and potential risk factors. We used adjusted Cox proportional hazard ratios to evaluate differences in mortality.

RESULTS

One hundred and eighty-six patients (38%) developed AKI. Seventy-nine (42%) had severe AKI and 27 (15%) required kidney replacement therapy. Fluid overload was common in all groups and 67% of those with severe AKI had > 10% fluid overload. Nephrology was consulted in less than 50% of those with severe AKI. In multivariable analysis, risk of severe AKI was lower in those taking a calcineurin inhibitor (CNI). Risk of death was higher in severe AKI compared to no AKI (RR 4.6, 95% CI 2.6-8.1).

CONCLUSIONS

AKI and fluid overload are common in pediatric patients after HCT. Severe AKI occurred less often with CNI use and was associated with higher mortality. Future interventions to reduce AKI and its associated complications such as fluid overload are approaches to reducing morbidity and mortality after HCT. A higher resolution version of the Graphical abstract is available as Supplementary information.

Assessment of fluid balance after neonatal cardiac surgery: a description of intake/output vs. weight-based methods

BACKGROUND

Fluid overload associates with poor outcomes after neonatal cardiac surgery, but consensus does not exist for the most clinically relevant method of measuring fluid balance (FB). While weight change-based FB (FB-W) is standard in neonatal intensive care units, weighing infants after cardiac surgery may be challenging. We aimed to identify characteristics associated with obtaining weights and to understand how intake/output-based FB (FB-IO) and FB-W compare in the early postoperative period in this population.

METHODS

Observational retrospective study of 2235 neonates undergoing cardiac surgery from 22 hospitals comprising the NEonatal and Pediatric Heart and Renal Outcomes Network (NEPHRON) database.

RESULTS

Forty-five percent (n = 998) of patients were weighed on postoperative day (POD) 2, varying from 2 to 98% among centers. Odds of being weighed were lower for STAT categories 4 and 5 (OR 0.72; 95% CI 0.53-0.98), cardiopulmonary bypass (0.59; 0.42-0.83), delayed sternal closure (0.27; 0.19-0.38), prophylactic peritoneal dialysis use (0.58; 0.34-0.99), and mechanical ventilation on POD 2 (0.23; 0.16-0.33). Correlation between FB-IO and FB-W was weak for every POD 1-6 and within the entire cohort (correlation coefficient 0.15; 95% CI 0.12-0.17). FB-W measured higher than paired FB-IO (mean bias 12.5%; 95% CI 11.6-13.4%) with wide 95% limits of agreement (- 15.4-40.4%).

CONCLUSIONS

Weighing neonates early after cardiac surgery is uncommon, with significant practice variation among centers. Patients with increased severity of illness are less likely to be weighed. FB-W and FB-IO have weak correlation, and further study is needed to determine which cumulative FB metric most associates with adverse outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Bioimpedance spectroscopy fluid analysis in acute high-risk abdominal surgery, a prospective clinician-blinded observational feasibility study

Objective assessment of fluid status in critical surgical care may help optimize perioperative fluid administration and prevent postoperative fluid retention. We evaluated the feasibility of hydration status and fluid distribution assessment by Bioimpedance spectroscopy Analysis (BIA) in patients undergoing acute high-risk abdominal (AHA) surgery. This observational study included 73 patients undergoing AHA surgery. During the observational period (0-120 h), we registered BIA calculated absolute fluid overload (AFO) and relative fluid overload (RFO), defined as AFO/extracellular water ratio, as well as cumulative fluid balance and weight. Based on RFO values, hydration status was classified into three categories: dehydrated (RFO <  - 10%), normohydrated (- 10% ≤ RFO ≤  + 15%), overhydrated RFO > 15%. We performed a total of 365 BIA measurements. Preoperative overhydration was found in 16% of patients, increasing to 66% by postoperative day five. The changes in BIA measured AFO correlated with the cumulative fluid balance (r2 = 0.44, p < .001), and change in weight (r2 = 0.55, p < .0001). Perioperative overhydration measured with BIA was associated with worse outcome compared to patients with normo- or dehydration. We have demonstrated the feasibility of obtaining perioperative bedside BIA measurements in patients undergoing AHA surgery. BIA measurements correlated with fluid balance, weight changes, and postoperative clinical complications. BIA-assessed fluid status might add helpful information to guide fluid management in patients undergoing AHA surgery.

Bioelectrical impedance analysis during deresuscitation: correlation and agreement with cumulative fluid balance in ICU patients

Bioelectrical impedance analysis (BIA) is a promising tool to evaluate the body composition of critically-ill patients. The present study aimed to assess its value as a fluid management monitoring tool during standardized deresuscitation strategy. A historical cohort of critically-ill adult patients with fluid overload and continuous renal replacement therapy was used to explore both relationship and agreement between changes in cumulative fluid balance and BIA-derived hydration variables within the 5 days following initiation of deresuscitation strategy using net ultrafiltration. Correlations were described using Spearman's rank correlation coefficient, and agreement using Bland-Altman analysis for repeated measurements. Sixty-one couples of fluid shift measurements from 30 patients were analyzed. The deresuscitation strategy induced a negative mean (± SD) cumulative fluid balance (- 4.2 ± 3.8 L) and a significant decrease in extra- and intracellular water (P < 0.001). Decreases in extra- and intracellular water were independent of weight variations inputted in the BIA device. Total body water (rho = 0.63), extracellular water (rho = 0.68), and intracellular water (rho = 0.67) were significantly correlated with cumulative fluid balance (all P values < 0.001). The limits of agreement did not allow interchangeability for a delta of 2L between cumulative fluid balance and BIA-derived hydration variables (P > 0.05). BIA hydration-derived variables are significantly correlated with cumulative fluid balance but the large limits of agreements exclude interchangeability of the measures.

Artificial Diuresis: Animal Studies on Efficacy and Safety of a New Miniaturized Device for Extracorporeal Ultrafiltration

INTRODUCTION

We have recently developed a new miniaturized device for extracorporeal ultrafiltration (UF) to be used in patients with fluid overload: Artificial Diuresis-1 (AD1) (Medica S.p.A., Medolla, Italy). The device has a reduced priming volume, operates at very low pressures and flow regimes, and is designed to perform extracorporeal UF at bedside. After accurate experiments were carried out in vitro, we report in this paper the results of in vivo UF sessions carried out in selected animals according to veterinary best practice.

MATERIALS AND METHODS

The AD1 kit is pre-filled with sterile isotonic solution and operates with a polysulfone mini-filter, MediSulfone (polysulfone at 50,000 Dalton). A collection bag with a volumetric scale is connected to the UF line, and the ultrafiltrate is obtained by gravity based on the height at which the ultrafiltrate collection bag is placed. Animals were prepared and anesthetized. The jugular vein was cannulated with a double-lumen catheter. Three 6-h sessions of UF were scheduled with a target fluid removal of 1,500 mL. Heparin was used as anticoagulant.

RESULTS

In all treatments, the target value of UF was obtained in the absence of major clinical or technical problems with a maximum deviation from the scheduled UF rate lower than 10%. The device resulted to be safe, reliable, accurate, and easily usable thanks to a user-friendly interface and its very small dimensions.

CONCLUSIONS

This study opens the way for clinical trials in different settings including departments with low intensity of care and even in ambulatory centers or patient's home.

Active fluid de-resuscitation in critically ill patients with septic shock: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of active fluid de-resuscitation on mortality in critically ill patients with septic shock.

METHODS

A systematic search was performed on PubMed, EmBase, and the Cochrane Library databases. Trials investigating active fluid de-resuscitation and reporting data on mortality in patients with septic shock were eligible. The primary objective was the impact of active de-resuscitation in patients with septic shock on short-term mortality. Secondary outcomes were whether de-resuscitation lead to a fluid separation, and the impact of de-resuscitation on patient-centred outcomes.

RESULTS

Thirteen trials (8,030 patients) were included in the systematic review, whereof 5 randomised-controlled trials (RCTs) were included in the meta-analysis. None of the RCTs showed a reduction in mortality with active de-resuscitation measures (relative risk (RR) 1.12 [95%-CI 0.84 - 1.48]). Fluid separation was achieved by two RCTs. Evidence from non-randomised trials suggests a mortality benefit with de-resuscitation strategies and indicates a trend towards a more negative fluid balance. Patient-centred outcomes were not influenced in the RCTs, and only one non-randomised trial revealed an impact on the duration of mechanical ventilation and renal replacement requirement (RRT).

CONCLUSION

We found no evidence for superiority of active fluid de-resuscitation compared to usual care regarding mortality, fluid balance or patient-centred outcomes in patients with septic shock. Current evidence is limited by the lack of high-quality RCTs in patients with septic shock, the small sample sizes and the heterogeneity of the applied de-resuscitation techniques. In addition, validity of the majority of RCTs is compromised by their inability to achieve fluid separation.

Nephrologist-performed point-of-care venous excess Doppler ultrasound (VExUS) in the management of acute kidney injury

Acute kidney injury (AKI) is frequently associated with alterations in fluid balance making accurate assessment of hemodynamics a vital component of patient management. Unfortunately, conventional parameters such as history, physical examination, vital signs, weight, natriuretic peptides have limitations in this regard. Point of care ultrasonography (POCUS) is a clinician-performed limited ultrasound study intended to answer focused clinical questions at the bedside. In the past several years, it has evolved as an extension of physical examination in various medical specialties. Herein, we describe a case of AKI where nephrologist-performed multi-organ POCUS aided in accurate diagnosis of fluid overload state. In addition, we describe how venous Doppler (VExUS) evaluation can be used to monitor the efficacy of decongestive therapy in real-time. Nephrologists should adopt a multi-parametric approach integrating all the pieces of hemodynamic puzzle when evaluating patients with AKI and fluid/electrolyte disorders.

The Science of Extracorporeal Ultrafiltration: Introducing a Novel Miniaturized Device

INTRODUCTION

Fluid overload has been associated with untoward outcomes in a variety of clinical settings. Isolated extracorporeal ultrafiltration (UF) allows for mechanical extraction of excess fluid and optimization of volume status without the established risks associated with use of high-dose diuretics. Conventional machines for renal replacement therapy can be used to perform isolated UF. However, they typically need high blood flow rates with high circuit volumes and the therapy has to be performed by trained nurses. Herein, we describe a novel device, the Artificial Diuresis-1, or AD 1 (Medica S.p.A., Medolla, Italy), which is a portable technology designed to perform extracorporeal UF at bedside.

MATERIALS AND METHODS

The AD 1 uses a polysulfone mini-filter to generate ultrafiltrate with the help of two forces: blood flow (Qb) and gravity (based on the height at which the ultrafiltrate collection bag is placed). In vitro experiments were performed using human blood to evaluate vascular access pressures and ultrafiltrate volumes using various central venous catheters (CVCs; 12 Fr bilume, 10 Fr with 2 separate lumens, pediatric catheter 7 Fr). A variety of combinations were tested with Qb of 20, 35, 50 mL/min and collection bag height at 20, 40, 60 cm, measuring the UF rate per minute while monitoring the pressures in the venous and arterial lines and filtration fraction.

RESULTS

The device's performance was as expected. Regarding the pediatric CVC, it was possible to perform measurements only with a Qb of 20 mL/min due to increased venous pressure. UF rates when lines were directly connected to the blood container as well as for CVC Tesio ranged from 3.7 to 11 mL/min, for the CVC Niagara™ from 4.5 to 12.5 mL/min, and for the CVC 7 Fr from 8.5 to 10 mL/min. The pressures of the vascular accesses were kept within a range of -5/-40 mm Hg for the artery and +10/+70 mm Hg for the vein. The highest venous pressure values were found with the CVC 7 Fr (+80/+100 mm Hg).

CONCLUSIONS

This novel device allows to treat patients with fluid overload in a variety of settings, from low-intensity department such as long-term care facilities to the intensive care unit. The device is small and portable, has a simple design, and is user friendly. Future studies will be needed to evaluate whether gentle UF and treatment of volume overload will translate into improvement in clinical outcomes such as a reduction in congestion-related hospital admissions.

Effect of a standardized fluid management algorithm on acute kidney injury and mortality in pediatric patients on extracorporeal support

Acute kidney injury (AKI), fluid overload (FO), and mortality are common in pediatric patients supported by extracorporeal membrane oxygenation (ECMO). The aim of this study is to evaluate if using a fluid management algorithm reduced AKI and mortality in children supported by ECMO. We performed a retrospective study of pediatric patients aged birth to 25 years requiring ECMO at a quaternary level children's hospital from 2007 to 2019 In October 2017, a fluid management algorithm was implemented for protocolized fluid removal after deriving a daily fluid goal using a combination of diuretics and ultrafiltration. Daily algorithm compliance was defined as ≥ 12 h on the algorithm each day. The primary and secondary outcomes were AKI and mortality, respectively, and were assessed in the entire cohort and the sub-analysis of children from the era in which the algorithm was implemented. Two hundred and ninety-nine (median age 5.3 months; IQR: 0.2, 62.3; 45% male) children required ECMO (venoarterial in 85%). The fluid algorithm was applied in 74 patients. The overall AKI rate during ECMO was 38% (26% severe-stage 2/3). Both AKI incidence and mortality were significantly lower in patients managed on the algorithm (p = 0.02 and p = 0.05). After adjusting for confounders, utilization of the algorithm was associated with lower odds of AKI (aOR: 0.40, 95%CI: 0.21, 0.76; p = 0.005) but was not associated with a reduction in mortality. In the sub-analysis, algorithm compliance of 80-100% was associated with a 54% reduction in mortality (ref: < 60% compliant; aOR:0.46, 95%CI:0.22-1.00; p = 0.05).  Conclusion: Among the entire cohort, the use of a fluid management algorithm reduced the odds of AKI. Better compliance on the algorithm was associated with lower mortality. Multicenter studies that implement systematic fluid removal may represent an opportunity for improving ECMO-related outcomes. What is Known: • Acute kidney injury and fluid overload are associated with morbidity and mortality in children supported by extracorporeal membrane oxygenation. What is New: • A systematic and protocolized approach to fluid removal in children supported by extracorporeal membrane oxygenation reduces acute kidney injury incidence. • Greater adherence to a protocolized fluid removal algorithm is associated with a reduction in mortality.

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.

Assessment of fluid removal using ultrasound, bioimpedance and anthropometry in pediatric dialysis: a pilot study

BACKGROUND

Fluid overload is associated with morbidity and mortality in children receiving dialysis. Accurate clinical assessment is difficult, and using deuterium oxide (D₂O) to measure total body water (TBW) is impractical. We investigated the use of ultrasound (US), bioimpedance spectroscopy (BIS), and anthropometry to assess fluid removal in children receiving maintenance hemodialysis (HD).

METHODS

Participants completed US, BIS, and anthropometry immediately before and 1-2 h after HD for up to five sessions. US measured inferior vena cava (IVC) diameter, lung B-lines, muscle elastography, and dermal thickness. BIS measured the volume of extracellular (ECF) and intracellular (ICF) fluid. Anthropometry included mid-upper arm, calf and ankle circumferences, and triceps skinfold thickness. D₂O was performed once pre-HD. We assessed the change in study measures pre- versus post-HD, and the correlation of change in study measures with percent change in body weight (%∆BW). We also assessed the agreement between TBW measured by BIS and D₂O.

RESULTS

Eight participants aged 3.4-18.5 years were enrolled. Comparison of pre- and post-HD measures showed significant decrease in IVC diameters, lung B-lines, dermal thickness, BIS %ECF, mid-upper arm circumference, ankle, and calf circumference. Repeated measures correlation showed significant relationships between %∆BW and changes in BIS ECF (r_rm =0.51, 95% CI 0.04, 0.80) and calf circumference (r_rm=0.80, 95% CI 0.51, 0.92). BIS TBW correlated with D₂O TBW but overestimated TBW by 2.2 L (95% LOA, -4.75 to 0.42).

CONCLUSION

BIS and calf circumference may be helpful to assess changes in fluid status in children receiving maintenance HD. IVC diameter, lung B-lines and dermal thickness are potential candidates for future studies.

Positive fluid balance and diuretic therapy are associated with mechanical ventilation and mortality in preterm neonates in the first fourteen postnatal days

BACKGROUND

Fluid overload leads to poor neonatal outcomes. Diuretics may lower the rates of mechanical ventilation (MV) and mortality in neonates with fluid overload.

METHODS

This is a retrospective study of preterm neonates ≤ 36 weeks of gestational age (GA) in the first 14 postnatal days in a level IV NICU in 2014-2020. We evaluated the epidemiology of fluid balance in the first 14 postnatal days and its association with MV and mortality and studied the association of diuretics with fluid balance, MV, and mortality.

RESULTS

In 1383 included neonates, the overall median lowest and peak fluid balances were - 7.8% (IQR: - 11.7, - 4.6) and 8% (3, 16) on days 3 (2, 5) and 13 (5, 14), respectively. Fluid balance distribution varied significantly by GA. Peak fluid balance of ≥ 10% was associated with increased odds of MV on days 7 and 14 with highest odds ratios (OR) of MV in neonates with fluid balance ≥ 15%. Peak fluid balance of ≥ 15% was associated with the greatest odds of mortality. Diuretics were used more frequently in neonates with younger GA, smaller birthweight, positive fluid balance, and those on MV.

CONCLUSIONS

Positive fluid balance negatively impacts pulmonary status. The odds of MV and death increase significantly as peak fluid balance percentage increases in all GA groups. The impact of diuretics on MV and death in preterm neonates needs further evaluation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Diuretics in pediatrics

Diuretics are frequently prescribed drugs and help managing several pathological conditions, including acute and chronic kidney disease, nephrotic syndrome, congestive heart failure, ascites, systemic and pulmonary hypertension. Diuretic classes include among others osmotic diuretics and carboanhydrase inhibitors, loop diuretics, thiazides, and potassium-sparing diuretics. In this educational article, we aim at reviewing indications, mechanisms of action, and side effects, as well as basic pharmacokinetics considerations and data on diuretics in children, supporting practicing clinicians in choosing (and understanding the background of) the best-suited diuretic regimen for the individual patient. Newer diuretic classes like vaptans and sodium glucose type 2 cotransporter inhibitors, the recent controversies on hydrochlorothiazide, and the issue of diuretic resistance, will also be briefly addressed.

CONCLUSION

This educational review offers a didactical overview of diuretics in Pediatrics.

WHAT IS KNOWN

• Diuretics are frequently prescribed drugs in both adults and children. • They increase water and sodium excretion, reducing fluid overload.

WHAT IS NEW

• This article reviews indications, mechanisms of action, side effects, and basic pharmacokinetics facts on diuretics in Paediatrics. • It also addresses current issues, like the management of diuretic resistance, the recent controversy on hydrochlorothiazide, and the novel classes vaptans and gliflozins.

Assessment of fluid status in neonatal dialysis: the need for new tools

BACKGROUND

Assessment of fluid status in neonatal dialysis has largely focused on traditional tools including clinical assessment, serial weights, and blood pressure (BP) measurements. However, in infants on kidney replacement therapy, the assessment of fluid overload is problematic due to errors in weight assessment, subtlety of physical exam findings, and inaccuracy of non-invasive BP measurements. In this presentation of a neonate with bilateral renal agenesis requiring kidney replacement therapy, the treating team assessed a number of variables in determining the ultrafiltration prescription for dialysis across 2 modalities (hemodialysis and continuous kidney replacement therapy).

COMPLICATIONS

Fluid overload, cardiomegaly, and worsened respiratory status occurred when attempting to assess the neonate's fluid status by traditional markers (weights, blood pressures, physical exam findings). B-type natriuretic peptide (BNP) was obtained and was noted to correlate with the degree of fluid overload.

KEY MANAGEMENT POINTS

Compared to traditional tools for assessment of fluid status in pediatric dialysis, BNP assisted the medical team in optimizing the volume status of the subject and determining optimal daily ultrafiltration goals. Due to the rapid release in response to myocardial stretch and the lack of kidney clearance of the peptide, BNP may represent an objective, timely, and reliable index of volume status in the pediatric dialysis patient.

Neonatal fluid overload-ignorance is no longer bliss

Excessive accumulation of fluid may result in interstitial edema and multiorgan dysfunction. Over the past few decades, the detrimental impact of fluid overload has been further defined in adult and pediatric populations. Growing evidence highlights the importance of monitoring, preventing, managing, and treating fluid overload appropriately. Translating this knowledge to neonates is difficult as they have different disease pathophysiologies, and because neonatal physiology changes rapidly postnatally in many of the organ systems (i.e., skin, kidneys, and cardiovascular, pulmonary, and gastrointestinal). Thus, evaluations of the optimal targets for fluid balance need to consider the disease state as well as the gestational and postmenstrual age of the infant. Integration of what is known about neonatal fluid overload with individual alterations in physiology is imperative in clinical management. This comprehensive review will address what is known about the epidemiology and pathophysiology of neonatal fluid overload and highlight the known knowledge gaps. Finally, we provide clinical recommendations for monitoring, prevention, and treatment of fluid overload.

Acute kidney injury and early fluid load in a retrospective cohort of neonatal sepsis

BACKGROUND

Sepsis and acute kidney injury (AKI) are associated with mortality in the newborn intensive care unit (NICU). There is a paucity of studies that describe AKI and fluid overload in neonatal sepsis and their association with mortality.

METHODS

Retrospective study of neonates with culture positive sepsis admitted to the NICU between June 2020 and June 2021 was conducted. Primary outcome was in-hospital mortality according to AKI as defined by the neonatal modified Kidney Diseases Improving Outcomes criteria. Secondary outcomes were early fluid overload and vasopressor use.

RESULTS

Thirty-three percent of neonates had AKI with sepsis, and 57% of cases were severe AKI. AKI was associated with mortality after adjusting for variables that were different between survivors and non-survivors (aOR 5.7 [95% CI 1.1-36], p = 0.04). Early fluid overload occurred in 27% of neonates who were at higher risk of having AKI with sepsis (OR 7.4 [95% CI 1.6-26.0], p = 0.01) and higher risk of mortality (aOR 17.8 [95% CI 2-7545], p = 0.02).

CONCLUSIONS

AKI and early fluid overload are associated with mortality in sepsis in our retrospective cohort. Mitigating AKI and early fluid overload in sepsis might be a fruitful strategy in reducing mortality with sepsis. A higher resolution version of the Graphical abstract is available as Supplementary information.

Rationale and Need for Simpler and Effective Miniaturized Bedside Ultrafiltration Devices

Fluid overload in different acute or chronic clinical settings results in unfavorable outcomes. The use of restrictive strategies for fluid control or the use of diuretics is frequently ineffective and requires extracorporeal ultrafiltration for the removal of excess volume. These extracorporeal treatments are performed with bulky machinery and require highly specialized personnel. The creation of a miniaturized device for extracorporeal ultrafiltration (artificial diuresis) would fill the technological gap in this sector by responding to the needs of cost containment and rehabilitation of the patient. In this article, we explain the rationale that led to the design of this device.

Bio-impedance spectroscopy for total body water assessment in pediatric surgical patients: A single center pilot cohort study

BACKGROUND

Excess peri‑operative fluid administration is associated with higher morbidity and mortality. We aimed to examine the feasibility of bio-impedance spectroscopy (BIS) to record serial peri‑operative fluid volumes in the pediatric surgical population.

METHODS

Children who underwent major elective general surgery from March 2019 to March 2020 were included. Total body water (TBW) assessment by BIS was recorded prior to surgery and on subsequent post-operative days (POD). We recorded the duration, tolerance and completion of each BIS assessment. We used Spearman coefficient and Bland Altman analysis to examine correlation and agreement between fluid balance (FB) in ml/kg calculated from intake/output (IO) recording and measured by BIS.

RESULTS

20 (87%) of 23 consented patients, median age 2.5 (1-17) years and 13 (65%) male, completed pre-operative and post-operative measurements, and were included in the analysis. Median time required for BIS assessments was 10 (5-15) minutes, and there were no recorded side effects or intolerance. The correlation coefficient for fluid balance measurements on POD 1 between BIS and IO methods was 0.59 (p = 0.01); mean bias (limits) of agreement was 26 (111 to 163) mL/kg. The trend in TBW measured by BIS declined from POD 1-3, while the recorded FB increased.

CONCLUSION

Bedside BIS is feasible and well-tolerated. Despite moderate correlation between fluid balance assessment by BIS and IO on POD 1, the wide limits of agreement between values from these methods preclude their use interchangeably. The role of BIS in assessment of fluid status in the pediatric surgical population should be further examined.

LEVEL OF EVIDENCE

Level III.

Applying bio-impedance vector analysis (BIVA) to adjust ultrafiltration rate in critically ill patients on continuous renal replacement therapy: A randomized controlled trial

BACKGROUND

Bioimpedance vector analysis (BIVA) has been suggested as a valuable tool in assessing volume status in critically ill patients. However, its effectiveness in guiding fluid removal by continuous renal replacement therapy (CRRT) has not been evaluated.

METHODS

In this randomized controlled trial, 65 critically ill patients receiving CRRT were allocated on a 1:1 ratio to have UF prescribed and adjusted using BIVA fluid assessment in the intervention group (32 patients) or conventional clinical parameters (33 patients). The primary outcome was the lean body mass (LBM) water content at CRRT discontinuation, and the secondary outcomes included the mortality rate, urinary output, the duration of ventilation support, and ICU stay.

RESULTS

The study group was associated with a lower water content of LBM (80.7 ± 9.4 vs. 85.9 ± 10.4%; p < 0.05), and a higher mean UF-rate and urinary output (1.5 ± 0.8 vs. 1.2 ± 0.5 ml/kg/h and 0.9 ± 0.9 vs 0.5 ± 0.6 ml/kg/h, both: p < 0.05). The mortality rate, the length of ICU stay, and ventilation support duration were similar.

CONCLUSION

BIVA guided UF prescription may be associated with a lower rate of fluid overload. Larger studies are required to evaluate its impact on patients' outcomes.