Recent Advances in Kidney Replacement Therapy in Infants: A Review.

Kidney replacement therapy (KRT) is used to treat children and adults with acute kidney injury (AKI), fluid overload, kidney failure, inborn errors of metabolism, and severe electrolyte abnormalities. Peritoneal dialysis and extracorporeal hemodialysis/filtration can be performed for different durations (intermittent, prolonged intermittent, and continuous) through either adaptation of adult devices or use of infant-specific devices. Each of these modalities have advantages and disadvantages, and often multiple modalities are used depending on the scenario and patient-specific needs. Traditionally, these therapies have been challenging to deliver in infants due the lack of infant-specific devices, small patient size, required extracorporeal volumes, and the risk of hemodynamic stability during the initiation of KRT. In this review, we discuss challenges, recent advancements, and optimal approaches to provide KRT in hospitalized infants, including a discussion of peritoneal dialysis and extracorporeal therapies. We discuss each specific KRT modality, review newer infant-specific devices, and highlight the benefits and limitations of each modality. We also discuss the ethical implications for the care of infants who need KRT and areas for future research.

Continuous Kidney Replacement Therapy and Survival in Children and Young Adults: Findings From the Multinational WE-ROCK Collaborative.

RATIONALE & OBJECTIVE: There are limited studies describing the epidemiology and outcomes in children and young adults receiving continuous kidney replacement therapy (CKRT). We aimed to describe associations between patient characteristics, CKRT prescription, and survival. STUDY DESIGN: Retrospective multicenter cohort study. SETTING & PARTICIPANTS: 980 patients aged from birth to 25 years who received CKRT between 2015 and 2021 at 1 of 32 centers in 7 countries participating in WE-ROCK (Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Diseases). EXPOSURE: CKRT for acute kidney injury or volume overload. OUTCOMES: Death before intensive care unit (ICU) discharge. ANALYTICAL APPROACH: Descriptive statistics. RESULTS: Median age was 8.8 years (IQR, 1.6-15.0), and median weight was 26.8 (IQR, 11.6-55.0) kg. CKRT was initiated a median of 2 (IQR, 1-6) days after ICU admission and lasted a median of 6 (IQR, 3-14) days. The most common CKRT modality was continuous venovenous hemodiafiltration. Citrate anticoagulation was used in 62%, and the internal jugular vein was the most common catheter placement location (66%). 629 participants (64.1%) survived at least until ICU discharge. CKRT dose, filter type, and anticoagulation were similar in those who did and did not survive to ICU discharge. There were apparent practice variations by institutional ICU size. LIMITATIONS: Retrospective design; limited representation from centers outside the United States. CONCLUSIONS: In this study of children and young adults receiving CKRT, approximately two thirds survived at least until ICU discharge. Although variations in dialysis mode and dose, catheter size and location, and anticoagulation were observed, survival was not detected to be associated with these parameters. PLAIN-LANGUAGE SUMMARY: In this large contemporary epidemiological study of children and young adults receiving continuous kidney replacement therapy in the intensive care unit, we observed that two thirds of patients survived at least until ICU discharge. However, patients with comorbidities appeared to have worse outcomes. Compared with previously published reports on continuous kidney replacement therapy practice, we observed greater use of continuous venovenous hemodiafiltration with regional citrate anticoagulation.

Intraoperative Fluid Balance and Perioperative Complications in Ovarian Cancer Surgery.

BACKGROUND: Fluid overload and hypovolemia promote postoperative complications in patients undergoing cytoreductive surgery for ovarian cancer. In the present study, postoperative complications and anastomotic leakage were investigated before and after implementation of pulse pressure variation-guided fluid management (PPVGFM) during ovarian cancer surgery. PATIENTS AND METHODS: A total of n = 243 patients with ovarian cancer undergoing cytoreductive surgery at the University Hospital Bonn were retrospectively evaluated. Cohort A (CA; n = 185 patients) was treated before and cohort B (CB; n = 58 patients) after implementation of PPVGFM. Both cohorts were compared regarding postoperative complications. RESULTS: Ultrasevere complications (G4/G5) were exclusively present in CA (p = 0.0025). No difference between cohorts was observed regarding severe complications (G3-G5) (p = 0.062). Median positive fluid excess was lower in CB (p = 0.001). This was independent of tumor load [peritoneal cancer index] (p = 0.001) and FIGO stage (p = 0.001). Time to first postoperative defecation was shorter in CB (CB: d2 median versus CA: d3 median; p = 0.001). CB had a shorter length of hospital stay (p = 0.003), less requirement of intensive medical care (p = 0.001) and postoperative ventilation (p = 0.001). CB received higher doses of noradrenalin (p = 0.001). In the combined study cohort, there were more severe complications (G3-G5) in the case of a PFE ≥ 3000 ml (p = 0.034) and significantly more anastomotic leakage in the case of a PFE ≥ 4000 ml (p = 0.006). CONCLUSIONS: Intraoperative fluid reduction in ovarian cancer surgery according to a PPVGFM is safe and significantly reduces ultrasevere postoperative complications. PFEs of ≥ 3000 ml and ≥ 4000 ml were identified as cutoffs for significantly more severe complications and anastomotic leakage, respectively.

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).

Acute Kidney Injury in Acute Heart Failure - When to worry and when not to worry?

Acute kidney injury is common in patients with acute decompensated heart failure. It is more common in patients with acute heart failure who suffer from chronic kidney disease. Worsening renal function is often defined as a rise in serum creatinine of more than 0.3 milligrams per deciliter (26.5 µmol/L), which by definition, is acute kidney injury stage one. Perhaps the term acute kidney injury is more appropriate than worsening renal function as it is used universally by nephrologists, internists, and other medical practitioners. In health, the heart and the kidney support each other to maintain body's homeostasis. In disease, the heart and the kidney can adversely affect each other's function causing further clinical deterioration. In patients presenting with acute heart failure and fluid overload, therapy with diuretics for decongestion often causes a rise in serum creatinine and acute kidney injury. However, in the longer term the decongestion improves survival and prevents hospital admissions despite rising serum creatinine and acute kidney injury. It is important to realize that renal venous congestion due to increased right sided heart pressures in acute heart failure is a major cause of kidney dysfunction and hence decongestion therapy improves kidney function in the longer term. This review provides a perspective on the acceptable acute kidney injury with decongestion therapy which is associated with improved survival; as opposed to acute kidney injury due to tubular injury related to sepsis or nephrotoxic drugs, which is associated with poor survival.

SGLT2 Inhibitors Correct Fluid Overload in Adult Kidney Transplant Recipients-A Prospective Observational Study.

In this longitudinal observational study, we measured urinary glucose concentration, body composition and volume status (bioimpedance spectroscopy) and plasma renin and aldosterone concentrations in n = 22 kidney transplant recipients (KTRs) initiating on SGLT2I at baseline (BL), and after 1 week and 1, 3, and 6 months. Estimated glomerular filtration rate (eGFR) decreased by -2 mL/min/1.73 m2 (IQR -10-0) after 1 week and remained stable thereafter. Urinary glucose concentration was 10 (3-24) g/g creatinine after 1 week and correlated with eGFR (r2 = 0.273; p = 0.057). SGLT2I did not affect HbA1c, fasting blood glucose, body weight, fat or lean mass. SGLT2I decreased fluid overload dependent on baseline overhydration (OH, r2 = 0.54, p = 0.0003) without occurrence of dehydration. Plasma aldosterone increased at day 7, while plasma renin did not change significantly. In conclusion, SGLT2I corrected fluid overload in patients with elevated overhydration at baseline, while in euvolemic KTRs fluid status remained stable without reduction of body water below the reference range, thus promoting the safety of SGLT2I therapy in patients following kidney transplantation. Glucosuria, together with effects of SGLT2I on blood glucose control and body weight, is attenuated in KTRs dependent on eGFR.

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.

Kidney Increase Natriuresis but Not Glomerular Filtration Under Veno-venous ECMO, a Retrospective Study.

PURPOSE: Acute kidney injury is a frequent complication of acute respiratory distress syndrome (ARDS). We aim to study the evolution of kidney function in patients presenting severe ARDS and requiring veno-venous extracorporeal membrane oxygenation (VV ECMO). METHODS: We conducted a multicenter retrospective study, including adult patients requiring VV ECMO for ARDS. The primary outcome was the evolution of the serum creatinine level after VV ECMO initiation. Secondary outcomes were change in urine output, and urine biochemical parameters after VV ECMO initiation. RESULTS: One hundred and two patients were included. VV ECMO was initiated after a median of 6 days of mechanical ventilation, mainly for ARDS caused by COVID-19 (73%). Serum creatinine level did not significantly differ after VV ECMO initiation (P = .20). VV ECMO was associated with a significant increase in daily urine output (+6.6 mL/kg/day, [3.8;9.3] P < .001), even after adjustment for potential confounding factors; with an increase in natriuresis. The increase in urine output under VV ECMO was associated with a reduced risk of receiving kidney replacement therapy (OR 0.4 [0.2;0.8], P = .026). CONCLUSIONS: VV ECMO initiation in severe ARDS is associated with an increase in daily urine output and natriuresis, without change in glomerular filtration rate.

Diuretic response after neonatal cardiac surgery: a report from the NEPHRON collaborative.

BACKGROUND: Multicenter early diuretic response (DR) analysis of single furosemide dosing following neonatal cardiac surgery is lacking to inform whether early DR predicts adverse clinical outcomes. METHODS: We performed a retrospective cohort study utilizing data from the NEPHRON registry. Random forest machine learning generated receiver operating characteristic-area under the curve (ROC-AUC) and odds ratios for mechanical ventilation (MV) and respiratory support (RS). Prolonged MV and RS were defined using ≥ 90th percentile of observed/expected ratios. Secondary outcomes were prolonged CICU and hospital length of stay (LOS) and kidney failure (stage III acute kidney injury (AKI), peritoneal dialysis, and/or continuous kidney replacement therapy on postoperative day three) assessed using covariate-adjusted ROC-AUC curves. RESULTS: A total of 782 children were included. Cumulative urine output (UOP) metrics were lower in prolonged MV and RS patients, but DR poorly predicted prolonged MV (highest AUC 0.611, OR 0.98, sensitivity 0.67, specificity 0.53, p = 0.006, 95% OR CI 0.96-0.99 for cumulative 6-h UOP) and RS (highest AUC 0.674, OR 0.94, sensitivity 0.75, specificity 0.54, p < 0.001, 95% CI 0.91-0.97 UOP between 3 and 6 h). Secondary outcome results were similar. DR had fair discrimination for kidney failure (AUC 0.703, OR 0.94, sensitivity 0.63, specificity 0.71, 95% OR CI 0.91-0.98, p < 0.001, cumulative 6-h UOP). CONCLUSIONS: Early DR poorly discriminated patients with prolonged MV, RS, and LOS in this cohort, though it may identify severe postoperative AKI phenotype. Future work is warranted to determine if early DR or late postoperative DR later, in combination with other AKI metrics, may identify a higher-risk phenotype.

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.

Assessment of volume status of pediatric hemodialysis patients.

BACKGROUND: Accurate volume status assessment and dry weight achievement are the most challenging goals for a nephrologist. We aimed to evaluate the role of ultrasonographic parameters including lung ultrasound and inferior vena cava (IVC) measurements as practical methods of volume status assessment in children on hemodialysis by comparing them with established techniques, such as clinical evaluation and bioimpedance spectroscopy. METHODS: A prospective cross-sectional study compared pre- and post-dialysis volume status using bioimpedance spectroscopy (BIS) parameters and clinical data with ultrasonographic lung B-lines and IVC parameters in children on regular hemodialysis. RESULTS: A total 60 children (mean age 9.4 ± 2.8 years) were enrolled. Twenty patients (33.3%) were clinically overloaded to varying degrees (17 patients had mild to moderate signs of fluid overload and 3 patients had moderate to severe signs of fluid overload). All other patients (66.7%) were clinically euvolemic. Sonographic parameters were significantly lower post-dialysis than pre-dialysis, including lung B-line count and IVC diameter. IVC collapsibility index mean was significantly higher post-dialysis than pre-dialysis. There was a significant correlation between the lung B-line count, IVC parameters, and BIS-measured overhydration both before and after hemodialysis. Nine patients had ≥ 8 B-lines post-dialysis, only three of them were hypertensive. CONCLUSIONS: Clinical criteria alone are not specific for determining accurate fluid status in pediatric hemodialysis patients. Lung B-line score, IVC parameters, and BIS may be complementary to each other and to clinical data. Lung B-lines outperform IVC measurements and BIS in subclinical volume overload detection in pediatric hemodialysis patients.

Characteristics and outcomes of children ≤ 10 kg receiving continuous kidney replacement therapy: a WE-ROCK study.

BACKGROUND: Continuous kidney replacement therapy (CKRT) is often used for acute kidney injury (AKI) or fluid overload (FO) in children ≤ 10 kg. Intensive care unit (ICU) mortality in children ≤ 10 kg reported by the prospective pediatric CRRT (ppCRRT, 2001-2003) registry was 57%. We aimed to evaluate characteristics associated with ICU mortality using a contemporary registry. METHODS: The Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK) registry is a retrospective, multinational, observational study of children and young adults aged 0-25 years receiving CKRT (2015-2021) for AKI or FO. This analysis included patients ≤ 10 kg at hospital admission. PRIMARY AND SECONDARY OUTCOMES: ICU mortality and major adverse kidney events at 90 days (MAKE-90) defined as death, persistent kidney dysfunction, or dialysis within 90 days, respectively. RESULTS: A total of 210 patients were included (median age 0.53 years (IQR, 0.1, 0.9)). ICU mortality was 46.5%. MAKE-90 occurred in 150/207 (72%). CKRT was initiated at a median 3 days (IQR 1, 9) after ICU admission and lasted a median 6 days (IQR 3, 16). On multivariable analysis, pediatric logistic organ dysfunction score (PELOD-2) at CKRT initiation was associated with increased odds of ICU mortality (aOR 2.64, 95% CI 1.68-4.16), and increased odds of MAKE-90 (aOR 2.2, 95% CI 1.31-3.69). Absence of comorbidity was associated with lower MAKE-90 (aOR 0.29, 95%CI 0.13-0.65). CONCLUSIONS: We report on a contemporary cohort of children ≤ 10 kg treated with CKRT for acute kidney injury and/or fluid overload. ICU mortality is decreased compared to ppCRRT. The extended risk of death and morbidity at 90 days highlights the importance of close follow-up.

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.

Fluid administration and fluid accumulation in intensive care units-Protocol for an international inception cohort study (FLUID-ICU).

INTRODUCTION: Fluid accumulation is associated with adverse outcomes in critically ill patients admitted to the intensive care unit (ICU). Fluid administration in the ICU may be a clinically relevant source of fluid accumulation in ICU patients. However, the extent is unknown, and no standard definition exists. We aim to provide epidemiological data on fluid accumulation, risk factors, use of fluid removal strategies, patient outcomes and describe current fluid administration practices in the ICU. METHODS: We will conduct an international 14-day inception cohort study including a minimum of 1000 acutely admitted adult ICU patients. Data will be collected from medical records and laboratory reports at baseline and daily from ICU admission to discharge with a maximum of 28 days. Follow-up will be performed on day 90 after inclusion. The primary outcome is the number of patients with fluid accumulation. Secondary outcomes include the number of days with fluid accumulation, use of active fluid removal, days alive without life support at day 28, days alive and out of hospital day 90, and all-cause mortality at day 90. Furthermore, we will assess risk factors for fluid accumulation and its association with 90-day mortality and report on the types of fluid administration. CONCLUSION: This international inception cohort study will provide contemporary epidemiological data on fluid administration and fluid accumulation in adult ICU patients.

Furosemide versus placebo for fluid overload in intensive care patients-The randomised GODIF trial second version: Statistical analysis plan.

BACKGROUND: Fluid overload is associated with increased mortality in intensive care unit (ICU) patients. The GODIF trial aims to assess the benefits and harms of fluid removal with furosemide versus placebo in stable adult patients with moderate to severe fluid overload in the ICU. This article describes the detailed statistical analysis plan for the primary results of the second version of the GODIF trial. METHODS: The GODIF trial is an international, multi-centre, randomised, stratified, blinded, parallel-group, pragmatic clinical trial, allocating 1000 adult ICU patients with moderate to severe fluid overload 1:1 to furosemide versus placebo. The primary outcome is days alive and out of hospital within 90 days post-randomisation. With a power of 90% and an alpha level of 5%, we may reject or detect an improvement of 8%. The primary analyses of all outcomes will be performed in the intention-to-treat population. For the primary outcome, the Kryger Jensen and Lange method will be used to compare the two treatment groups adjusted for stratification variables supplemented with sensitivity analyses in the per-protocol population and with further adjustments for prognostic variables. Secondary outcomes will be analysed with multiple linear regressions, logistic regressions or the Kryger Jensen and Lange method as suitable with adjustment for stratification variables. CONCLUSION: The GODIF trial data will increase the certainty about the effects of fluid removal using furosemide in adult ICU patients with fluid overload. TRIAL REGISTRATIONS: EudraCT identifier: 2019-004292-40 and ClinicalTrials.org: NCT04180397.

Incidence and risks of excessive distension absorption in hysteroscopic surgery using 5% mannitol solution: a retrospective descriptive study.

OBJECTIVE: To clarify the incidence of excessive distension absorption in hysteroscopic surgery using 5% mannitol solution, evaluate the associated risks, and help to establish a safe fluid deficit threshold for such complication. DESIGN: Retrospective descriptive study. SETTING: Academic medical center. PATIENTS: Ten thousand six hundred ninety-three patients underwent inpatient hysteroscopic surgery with 5% mannitol perfusion using a monopolar electrosurgical instrument from Jan. 2015 to Sep. 2020. INTERVENTION(S): None. This study has been approved by the Ethics Committee of Sun Yat-sen Memorial Hospital. MEASUREMENTS AND MAIN RESULTS: A fluid deficit of more than 1000 mL was defined as the diagnostic criteria for excessive distension absorption. The overall incidence of excessive distension absorption in this study was 0.46% (49/10693). The incidence was 2.57% (16/623) for transcervical resection of fibroid (TCRF), 2.36% (9/381) for retained products of conception (RPOC) removal, 1.20% (6/501) for hysteroscopic uterine septum resection (HSR), 0.48% (4/828) for transcervical resection of the endometrium (TCRE), and 0.53% (14/2621) for transcervical resections of adhesion (TCRA). Excessive distension absorption could occur within seven minutes in HSR. Among the patients diagnosed with excessive distension absorption, 30.77% (12/39) exhibited signs or symptoms related to circulation overload with a fluid deficit under 2500 mL, and 10.26% (4/39) developed pulmonary edema. CONCLUSION: Excessive distension absorption could happen in all kinds hysteroscopic surgical treatment including RPOC removal and TCRA which were rarely reported. The overall incidence of excessive distension absorption could be low. But it would be five times higher in certain procedures such as TCRF, RPOC removal and TCRA. Resection using a needle electrode in HSR and TCRA may contribute to the short time development of excessive distension absorption. 30.77% of the patients could not tolerate the fluid deficit of less than 2500 mL which was set as a threshold for isotonic distending media and presented with circulation overload related signs or symptoms.

Ultrafiltration Tolerance: A Phenotype That We Need to Recognize.

BACKGROUND: The evaluation and management of fluid balance are key challenges in critical care patients who require renal replacement therapies because cumulative fluid balance is an independent factor that increases morbidity and mortality in different clinical scenarios. SUMMARY: One of the strategies when fluid overload is refractory to diuretics is extracorporeal fluid removal (i.e., net ultrafiltration [UFNET] during kidney replacement therapy). However, problems with UFNET without individualized assessment are cardiovascular events and intradialytic hypotension, events that contribute to decreasing organ perfusion and sympathetic stress. Therefore, we must consider and try to predict the best timing for the start of ultrafiltration and find the point where the patient is most tolerant to ultrafiltration, making a simile to the concept of fluid tolerance. KEY MESSAGES: UFNET is a continuous and dynamic process, going through moments of tolerance and intolerance to ultrafiltration; as nephrologists, we must take the necessary measures to move through this period.

Transesophageal echocardiographic acquisition of the venous excess ultrasound exam-a case series and technical description.

PURPOSE: Obtaining an objective, reproducible, and accurate assessment of volume status is one of the more difficult tasks in the perioperative arena. Since its advent in 2020, the Venous Excess Ultrasound (VExUS) score has gained popularity in the minimally invasive assessment of venous congestion. The VExUS exam has been well described as an additional series of images (hepatic vein, portal vein, and intrarenal vein) obtained with a phased-array probe during a transthoracic echocardiogram. Nevertheless, there are no descriptions of comprehensive VExUS exams performed using transesophageal echocardiography (TEE)-a modality that is routinely employed in patients undergoing cardiac surgery. CLINICAL FEATURES: We describe techniques to acquire and interpret a comprehensive TEE-supported VexUS exam, which may be used to optimize the perioperative care of cardiac surgical patients. CONCLUSION: Given the risks of fluid overload in critically ill cardiac surgery patients, TEE-supported VExUS examination may be a way to reduce morbidity in this population.

RéSUMé: OBJECTIF: L'obtention d'une évaluation objective, reproductible et précise du statut volémique est l'une des tâches les plus difficiles dans l'arène périopératoire. Depuis son introduction en 2020, le score VExUS (pour Venous Excess Ultrasound, soit échographie de l'excès veineux) a gagné en popularité dans l'évaluation minimalement invasive de la congestion veineuse. L'examen échographique VExUS a été bien décrit en tant que série supplémentaire d'images (veine hépatique, veine porte et veine intrarénale) obtenues à l'aide d'une sonde type « phased-array ¼ lors d'un échocardiogramme transthoracique. Néanmoins, il n'existe aucune description d'examens VExUS complets réalisés à l'aide d'une sonde d'ETO (échocardiographie transœsophagienne), une modalité couramment utilisée chez les patient·es bénéficiant d'une chirurgie cardiaque. CARACTéRISTIQUES CLINIQUES: Nous décrivons des techniques permettant d'acquérir et d'interpréter un examen VexUS complet par ETO, qui peut être utilisé pour optimiser les soins périopératoires de la patientèle en chirurgie cardiaque. CONCLUSION: Compte tenu des risques de surcharge hydrique chez la patientèle gravement malade en chirurgie cardiaque, l'examen VExUS basé sur l'ETO peut être un moyen de réduire la morbidité dans cette population.

Predictors of fluid overload in allogeneic hematopoietic cell transplant patients receiving post-transplant cyclophosphamide.

BACKGROUND: Fluid overload (FO) commonly occurs during hospitalization for allogeneic hematopoietic cell transplantation (HCT). Grade 2-4 FO is associated with day +100 non-relapse mortality.1 Post-transplant cyclophosphamide (PTCY) for graft-versus-host disease prevention requires aggressive IV hydration to prevent hemorrhagic cystitis. MATERIALS AND METHODS: This is a single-center, retrospective, observational study conducted at an academic medical center via electronic chart review. Included patients received allogeneic HCT followed by PTCY on days +3 and +4. Patients were excluded for age < 18 years or incarceration. Primary endpoints are incidence of Grade 2-4 FO and associated risk factors. Descriptive and inferential statistics (i.e., Fisher's exact test, multivariable regression analysis) were used. RESULTS: Of 97 patients screened, 95 were included and 2 were excluded due to absence of weight measurements needed to grade FO. Median age was 60 years, 66.3% were male, 91.6% received reduced-intensity conditioning, 72.6% received haploidentical HCT, 44.2% were ECOG 0, and 11.6% had diastolic dysfunction. Incidence of grade 2-4 FO was 33.7% (n = 32). Univariate analyses found age (continuous; p = 0.04) and BSA < 1.7 m2 (p = 0.006) as independent factors associated with grade 2-4 FO. Multivariable regression analysis found 3.3% higher risk with every 1-year increase in age ranging from f 20 to 78 years (OR 1.033, 95% CI 1.001, 1.006; p = 0.0453) and 82.8% lower risk with BSA ≥ 1.7 m2 (OR 0.172, 95% CI 0.051, 0.588; p = 0.005) after adjusting for co-variates. CONCLUSION(S): Increasing age and BSA < 1.7 m2 are risk factors associated with grade 2-4 FO during hospitalization for allogeneic HCT with PTCY.

Use of Bioimpedance Spectroscopy for Postoperative Fluid Management in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass.

OBJECTIVE: To assess whether bioimpedance spectroscopy analysis (BIA) can be used as a tool to guide postoperative fluid management in patients undergoing cardiac surgery. DESIGN: An observational study. SETTING: A single tertiary hospital. PARTICIPANTS: Patients who underwent cardiac surgery with cardiopulmonary bypass between June and November 2023 who were able to undergo BIA measurements. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Correlations between BIA measurements of extracellular fluid (ECF) and total body water (TBW) volumes and daily changes in weight and 24-hour net intake and output (I/O) of fluids were assessed. Correlations between predischarge ECF volume as a percentage of TBW volume (ECF%TBW) and predischarge pro-B-type natriuretic peptide (Pro-BNP) levels and readmissions were analyzed. Changes in daily ECF volume significantly correlated with daily weight changes (p < 0.01) and 24-hour I/O (p < 0 .01). TBW volume significantly correlated with daily weight changes (p < 0.01) and with 24-hour I/O (p = 0.04). Daily weight changes did not correlate with 24-hour I/O (p = 0.06). The patients with predischarge ECF%TBW(%) greater than or equal to 51 had significantly higher predischarge Pro-BNP than those with ECF%TBW(%) less than 51 (p < 0.01). Patients who had heart failure revisits or admissions after discharge had a higher predischarge ECF%TBW(%) on index admission compared with patients who did not have heart failure readmissions (p = 0.01). CONCLUSIONS: BIA measurements in postoperative cardiac surgery patients may be a valuable tool to quantitatively determine fluid status to help guide fluid management in this patient population. Further studies validating the use of BIA for postoperative care in this population are warranted.