Enhanced fluid management with continuous venovenous hemofiltration in pediatric respiratory failure patients receiving extracorporeal membrane oxygenation support

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.

Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

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.

Risk factors for mortality in surgical patients on combined continuous renal replacement therapy and extracorporeal membrane oxygenation: single-center retrospective study

OBJECTIVE

In patients receiving extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT) is increasingly being used for renal replacement and fluid management. However, critically ill surgical patients receiving combined ECMO and CRRT tend to have a high mortality rate, and there are limited studies on this population. Therefore, we aimed to investigate the risk factors for mortality in surgical patients receiving combined ECMO and CRRT.

METHODS

Data of surgical patients who underwent ECMO between December 2013 and April 2023 were retrospectively reviewed. Univariate and multivariate logistic regression analysis were used to identify the risk variables. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value of albumin and age to predict death.

RESULTS

A total of 199 patients on ECMO support were screened, of which 105 patients were included in the final analysis. Of 105 patients, 77 (73.33%) were treated with CRRT. Veno-arterial ECMO was performed in 97 cases (92.38%), and the rest were veno-venous ECMO (n = 8, 7.62%). Cardiovascular-related surgery was performed in the main patients (n = 86, 81.90%) and other types of surgery in 19 patients. In surgical patients on ECMO support, the logistic regression analysis showed that CRRT implantation, male sex, and age were the independent risks factors for mortality. Furthermore, the ROC curve analysis showed that age 48.5 years had the highest Youden index. In surgical patients on combined CRRT and ECMO, age, valvular heart disease, and albumin were the independent risk factors for prognosis. Albumin had the highest Youden index at a cutoff value of 39.95 g/L for predicting mortality, though the overall predictive value was modest (area under ROC 0.704). Age had the highest Youden index at a cutoff value of 48.5 years for predicting mortality.

CONCLUSIONS

In our cohort of surgical patients requiring ECMO, which consisted mostly of patients undergoing cardiovascular surgery requiring VA-ECMO, the need for CRRT was an independent risk factor for mortality. In the subset of patients on combined CRRT and ECMO, independent risk factors for mortality included higher age, lack of valvular heart disease, and lower serum albumin.

Managing the kidney - The role of continuous renal replacement therapy in neonatal and pediatric ECMO

Extracorporeal membrane oxygenation (ECMO) represents a lifesaving therapy utilized in in the most critically ill neonates and children with reversible cardiopulmonary failure. As a result of the severity of their critical illness these patients are among the highest risk populations for developing acute kidney injury (AKI) and disorders of fluid balance including the pathologic state of fluid overload (FO). In multiple studies AKI has been shown to occur commonly in 60-80% children treated with ECMO and is associated with adverse outcomes. In early studies evaluating ECMO in neonatal respiratory populations, the importance of fluid balance and the development of FO was recognized as an important contributor to adverse outcomes. Multiple single center studies and multicenter work have confirmed that FO occurs commonly across ECMO populations and is consistently associated with adverse outcomes. As a result of the high rates of AKI and the high rates of FO, continuous renal replacement therapy (CRRT) is increasingly utilized in neonatal and pediatric ECMO. In this state-of-the-art review, we cover the definitions, pathophysiology, incidence, and impact of AKI and FO in neonates and children supported with ECMO and summarize and appraise the evidence regarding the use of CRRT concurrently with ECMO. This review will cover the appropriate timing of this initiation, the options for providing CRRT with ECMO, overview of CRRT prescription, and the long-term implications of kidney support therapy in this population.

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.

Acute Kidney Injury and Extracorporeal Membrane Oxygenation: Review on Multiple Organ Support Options

Extracorporeal membrane oxygenation (ECMO) is a temporary life support system used to assist patients with life-threatening severe cardiac and/or respiratory insufficiency. Patients requiring ECMO can be considered the sickest patients admitted to the intensive care unit (ICU). Acute kidney injury (AKI) represents a frequent complication during ECMO, affecting up to 70% of patients, with multifactorial pathophysiology and an independent risk factor for mortality. Severe AKI requiring Continuous Renal Replacement Therapy (CRRT) occurs in 20% of ECMO patients, but multiple indications and different timing may imply a significantly higher application rate in different centers. CRRT can be run in parallel to ECMO through different vascular access, or it can be conducted in series by connecting the circuits. Anticoagulation of ECMO is typically managed with systemic heparin, but several approaches can be applied for the CRRT circuit, from no anticoagulation to the addition of intra-filter heparin or regional citrate anticoagulation. The combination of CRRT and ECMO can be considered a form of multiple organ support therapy, but this approach still requires optimization in timing, set-up, anticoagulation, prescription and delivery. The aim of this report is to review the pathophysiology of AKI, the CRRT delivery, anticoagulation strategies and outcomes of patients with AKI treated with ECMO.

Nutrition Considerations in Neonatal Extracorporeal Life Support

Extracorporeal life support (ECLS) is a life-saving therapy, but neonates who require ECLS have unique nutritional needs and require aggressive, early nutritional support. These critically ill neonates are at increased risk for long-term feeding difficulties, malnutrition, and growth failure with associated increased morbidity and mortality. Unfortunately, few studies specific to this population exist. Clinical guidelines published by the American Society for Parenteral and Enteral Nutrition are specific to this population and available to aid clinicians in appropriate nutrition regimens, but studies to date suggest that nutrition provision varies greatly from center to center and often is inadequate. Though enteral feedings are becoming more common, aggressive parenteral nutrition is still needed to ensure nutrition goals are met, including the goal of increased protein provision. Long-term complications, including the need for tube feedings and growth failure, are common in neonatal ECLS survivors, particularly those with congenital diaphragmatic hernia. Oral aversion with poor feeding and growth failure must be anticipated and recognized early if present. The nutritional implications associated with the development of acute kidney injury, fluid overload, or the use of continuous renal replacement therapy must be recognized. In this state-of-the-art review, we examine aspects of nutrition for neonates receiving ECLS including nutritional requirements, nutrition provision, current practices, long-term outcomes, and special population considerations.

Fluid Balance Management Informs Renal Replacement Therapy Use During Pediatric Extracorporeal Membrane Oxygenation: A Survey Report From the Kidney Intervention During Extracorporeal Membrane Oxygenation Group

Fluid overload (FO) and acute kidney injury (AKI) occur commonly in children supported with extracorporeal membrane oxygenation (ECMO). Continuous renal replacement therapy (CRRT) may be used to manage AKI and FO in children on ECMO. In 2012, our group surveyed ECMO centers to begin to understand the practice patterns around CRRT and ECMO. Since then, more centers are initiating ECMO for increasingly diverse indications and an increased volume of research quantifies the detrimental impacts of AKI and FO. We, therefore, investigated practice patterns of CRRT utilization during ECMO in children. A multi-point survey instrument was distributed to 116 international neonatal and pediatric ECMO centers. Sixty of 116 (51.7%) international neonatal and pediatric ECMO centers responded. All reports using CRRT on ECMO, compared with 75% from the 2012 survey. Eighty-five percent use CRRT to treat or prevent FO, an increased from 59%. The modality of CRRT therapy differed between in-line (slow continuous ultrafiltration, 84.4%) and machine-based (continuous venovenous hemodiafiltration, 87.3%) methods. Most (65%) do not have protocols for fluid management, AKI, or CRRT on ECMO. Trialing off CRRT is dictated by physician preference in 90% (54/60), with varying definitions of success. In this survey study, we found that CRRT use during pediatric ECMO has increased since 2012 with fluid management representing the predominant indication for initiation. Despite the expanded utilization of CRRT with ECMO, there remains significant practice variation in terms of method, modality, indication, the timing of initiation, fluid management, and discontinuation.

Continuous renal replacement therapy in patients treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life‐saving therapy utilized for patients with severe life‐threatening cardiorespiratory failure. Patients treated with ECMO are among the most severely ill encountered in critical care and are at high‐risk of developing multiple organ dysfunction, including acute kidney injury (AKI) and fluid overload. Continuous renal replacement therapy (CRRT) is increasingly utilized inpatients on ECMO to manage AKI and treat fluid overload. The indications for renal replacement therapy for patients on ECMO are similar to those of other critically ill populations; however, there is wide practice variation in how renal supportive therapies are utilized during ECMO. For patients requiring both CRRT and ECMO, CRRT may be connected directly to the ECMO circuit, or CRRT and ECMO may be performed independently. This review will summarize current knowledge of the epidemiology of AKI, indications and timing of CRRT, delivery of CRRT, and the outcomes of patients requiring CRRT with ECMO.

A review on extracorporeal membrane oxygenation and kidney injury

Extracorporeal membrane oxygenation (ECMO) is inevitable external life support in case of cardiac and respiratory failure since the 1970s. Acute kidney injury (AKI) and the requirement of renal replacement therapy (RRT) is a potential risk among these patients. This review aims to give an overview of the risk of AKI, RRT, and associated mortality among the patients who received ECMO for any of its indications. PubMed database was searched to find the relevant literature and the reference list of included studies was also searched for additional studies. The incidence of AKI ranged from 30% to 78% and RRT from 47% to 60% in ECMO patients. The pathophysiology of AKI in ECMO is multifactorial, and includes ischaemia, RBCs breakdown, comorbidity, conversion of zymogen form of pro-inflammatory mediators, structural alteration of the kidney, coadministration of nephrotoxic drugs, coagulation abnormality, and oxidative stress. ECMO was associated with the higher incidence of renal abnormalities, AKI, requirement of RRT, and associated mortality. Patients who underwent RRT had improved renal function and reduced overall mortality compared to the non-RRT group among the ECMO patients. Currently, there is no consensus evidence to support the superior use of the inline hemofilter system over continuous renal replacement therapy among patients who had AKI during ECMO.

Renal Replacement Therapy in Neonates

Acute kidney injury (AKI) is a highly prevalent disease entity in the NICU, affecting nearly one-quarter of critically ill neonates by some reports. Though medical management remains the mainstay in the treatment of AKI, renal replacement therapy (RRT) is indicated when conservative measures are unable to maintain electrolytes, fluid balance, toxins, or waste products within a safe margin. Several modalities of RRT exist for use in neonatal populations, including peritoneal dialysis, hemodialysis, and continuous RRT. It is the aim of this review to introduce each of these RRT modalities, as well as to discuss their technical considerations, benefits, indications, contraindications, and complications.

Post-operative renal failure management in mechanical circulatory support patients

Acute kidney injury (AKI) occurs commonly in patients requiring mechanical circulatory support (MCS) after cardiothoracic surgery. The prognostic implications of AKI in this patient group relate closely to the pathophysiology and risk factors associated with the underlying disease; pre-operative, intra-operative, and post-operative variables; hemodynamic factors; and type of support device used. General approaches to AKI management, including prevention strategies, medical management, and hemodynamic support, are also applicable in patients requiring MCS. Approaches to renal replacement therapy vary depend on patient factors, device-specific factors, and local preferences and experience. In this invited narrative review, we discuss the pathophysiology, risk factors, and prognostic implications of AKI in post-operative adult patients following institution of MCS. Management strategies for AKI are presented with a focus on those supported with either extracorporeal membrane oxygenation or a ventricular assist device.

Fluid Balance and Recovery of Native Lung Function in Adult Patients Supported by Venovenous Extracorporeal Membrane Oxygenation and Continuous Renal Replacement Therapy

Fluid overload is associated with increased mortality in adult patients with acute respiratory distress syndrome. In patients requiring venovenous extracorporeal membrane oxygenation (VV-ECMO), the effects of fluid removal on survival and lung recovery remain undefined. We assessed the impact of early fluid removal in adult patients supported by VV-ECMO and concomitant continuous renal replacement therapy, in an 18-bed tertiary intensive care unit between 2010 and 2015. Twenty-four patients met inclusion criteria, of these 15 (63%) survived to hospital discharge. In our patient group, a more negative cumulative daily fluid balance was strongly associated with improved pulmonary compliance (2.72 ml/cmH2O per 1 L negative fluid balance; 95% confidence interval [CI]: 1.61-3.83; P < 0.001). In addition, a more negative mean daily fluid balance was associated with improved pulmonary compliance (4.37 ml/cmH2O per 1 L negative fluid balance; 95% CI: 2.62-6.13; P < 0.001). Survivors were younger and had lower mean daily fluid balance (-0.33 L [95% CI: -1.22 to -0.06] vs. -0.07 L [95% CI: -0.76 to 0.06]; P = 0.438) and lower cumulative fluid balance up to day 14 (-4.60 L [95% CI: -8.40 to -1.45] vs. -1.00 L [95% CI: -4.60 to 0.90]; P = 0.325), although the fluid balance effect alone did not reach statistical significance.

Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy: a multicenter retrospective cohort study

OBJECTIVE

The aim of this study was to characterize continuous renal replacement therapy (CRRT) utilization on extracorporeal membrane oxygenation (ECMO) and to determine the association of both fluid overload (FO) at CRRT initiation and fluid removal during CRRT with mortality in a large multicenter cohort.

METHODS

Retrospective chart review of all children < 18 years of age concurrently treated with ECMO and CRRT from January 1, 2007, to December 31, 2011, at six tertiary care children's hospital. Children treated with hemodialysis or peritoneal dialysis were excluded from the FO analysis.

MEASUREMENTS AND MAIN RESULTS

A total of 756 of the 1009 children supported with ECMO during the study period had complete FO data. Of these, 357 (47.2%) received either CRRT or were treated with an in-line filter and thus entered into the final analysis. Survival to ECMO decannulation was 66.4% and survival to hospital discharge was 44.3%. CRRT initiation occurred at median of 1 day (IQR 0, 2) after ECMO initiation. Median FO at CRRT initiation was 20.1% (IQR 5, 40) and was significantly lower in ECMO survivors vs. non-survivors (15.3% vs. 30.5% p = 0.005) and in hospital survivors vs. non-survivors (13.5% vs. 25.9%, p = 0.004). Median FO at CRRT discontinuation was significantly lower in ECMO survivors (23% vs. 37.6% p = 0.002) and hospital survivors vs. non-survivors (22.6% vs. 36.1%, p = 0.002). In ECMO survivors, after adjusting for pH at CRRT initiation, non-renal complications, ECMO mode, support type, center, patient age and AKI, FO at CRRT initiation (p = 0.01), and FO at CRRT discontinuation (p = 0.0002) were independently associated with duration of ECMO. In a similar multivariable analysis, FO at CRRT initiation (adjusted adds ratio [aOR] 1.09, 95% CI 1.00-1.18, p = 0.045) and at CRRT discontinuation (aOR 1.11, 95% CI 1.03-1.19, p = 0.01) were independently associated with hospital mortality.

CONCLUSIONS

In a multicenter pediatric ECMO cohort, this study demonstrates that severe FO was very common at CRRT initiation. We found an independent association between the degree of FO at CRRT initiation with adverse outcomes including mortality and increased duration of ECMO support. The results suggest that intervening prior to the development of significant FO may be a clinical therapeutic target and warrants further evaluation.

Extracorporeal Cardiopulmonary Resuscitation (ECPR) in Infants and Children: A Single-Center Retrospective Study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used to rescue patients with cardiac arrest refractory to conventional therapy, necessitating evaluation of factors that may affect outcomes.

METHODS

A single-center retrospective review of pediatric patients (<21 years old) who underwent ECPR from January 2010 to November 2017. Comparisons between nonsurvivors and survivors, to decannulation and discharge, were made. Factors associated with survival and rate of complications were examined.

RESULTS

Seventy patients were supported with ECPR. Forty-nine (70%) patients survived to decannulation and 38 (54%) patients to discharge. There was no statistical difference between baseline characteristics of survivors and nonsurvivors, including age at cannulation, weight (kg), time to cannulation (minutes), and total time on extracorporeal membrane oxygenation (hours). Survivors to discharge had significantly higher pH prior to cannulation compared to nonsurvivors (7.11 ± 0.24 vs 6.97 ± 0.21, P = .01). Of all, 23.2% of patients received renal replacement therapy (RRT), 39.4% had significant bleeding, 22.5% had thrombotic complications, and 68.8% had neurologic injury on imaging studies. A greater number of nonsurvivors received RRT compared to survivors to discharge (35.5% vs 10.8%, P = .02). There were no differences in bleeding or thrombotic complications or radiographically established neurologic injury.

CONCLUSIONS

Although ECPR effectively increases overall survival, a better characterization of long-term outcomes is needed.

Outcomes among Patients Treated with Renal Replacement Therapy during Extracorporeal Membrane Oxygenation: A Single-Center Retrospective Study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) are modalities used in critically ill patients suffering organ failure and metabolic derangements. Although the effects of CRRT have been extensively studied, the impact of simultaneous CRRT and ECMO is less well described. The purpose of this study is to evaluate the incidence and the impact of CRRT on outcomes of patients receiving ECMO.

METHODS

A single center, retrospective chart review was conducted for patients receiving ECMO therapy over a 6-year period. Patients who underwent combined ECMO and CRRT were compared to those who underwent ECMO alone. Intergroup -statistical comparisons were performed using Wilcoxon/Kruskal-Wallis and chi-square tests. Logistic regression was performed to identify independent risk factors for mortality.

RESULTS

The demographic and clinical data of 92 patients who underwent ECMO at our center were reviewed including primary diagnosis, indications for and mode of ECMO support, illness severity, oxygenation index, vasopressor requirement, and presence of acute kidney injury. In those patients that required ECMO with CRRT, we reviewed urine output prior to initiation, modality used, prescribed dose, net fluid balance after 72 h, requirement of renal replacement therapy (RRT) at discharge, and use of diuretics prior to RRT initiation. Our primary endpoint was survival to hospital discharge. During the study period, 48 patients required the combination of ECMO with CRRT. Twenty-nine of these patients survived to hospital discharge. Of the 29 survivors, 6 were dialysis dependent at hospital discharge. The mortality rate was 39.5% with combined ECMO/CRRT compared to 31.4% among those receiving ECMO alone (p = 0.074). Of those receiving combined therapy, nonsurvivors were more likely to have a significantly positive net fluid balance at 72 h (p = 0.001). A multivariate linear regression analysis showed net positive fluid balance and increased age were independently associated with mortality.

CONCLUSIONS

Use of CRRT is prevalent among patients undergoing ECMO, with over 50% of our patient population receiving combination therapy. Fluid balance appears to be an important variable associated with outcomes in this cohort. Rates of renal recovery and overall survival were higher compared to previously published reports among those requiring combined ECMO/CRRT.

Acute Kidney Injury in Pediatric Patients on Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-analysis

Background: Acute kidney injury (AKI) is a well-established complication of extra-corporal membrane oxygenation (ECMO) in the adult population. The data in the pediatric and neonatal population is still limited. Moreover, the mortality risk of AKI among pediatric patients requiring ECMO remains unclear. Thus, this meta-analysis aims to assess the incidence of AKI, AKI requiring renal replacement therapy and AKI associated mortality in pediatric/neonatal patients requiring ECMO. Methods: A literature search was performed utilizing MEDLINE, EMBASE, and the Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring renal replacement therapy (RRT) and the risk of mortality among pediatric patients on ECMO with AKI. Random-effects meta-analysis was used to calculate the pooled incidence of AKI and the odds ratios (OR) for mortality. Results: 13 studies with 3523 pediatric patients on ECMO were identified. Pooled incidence of AKI and AKI requiring RRT were 61.9% (95% confidence interval (CI): 39.0-80.4%) and 40.9% (95%CI: 31.2-51.4%), respectively. A meta-analysis limited to studies with standard AKI definitions showed a pooled estimated AKI incidence of 69.2% (95%CI: 59.7-77.3%). Compared with patients without AKI, those with AKI and AKI requiring RRT while on ECMO were associated with increased hospital mortality ORs of 1.70 (95% CI, 1.38-2.10) and 3.64 (95% CI: 2.02-6.55), respectively. Conclusions: The estimated incidence of AKI and severe AKI requiring RRT in pediatric patients receiving ECMO are high at 61.9% and 40.9%, respectively. AKI among pediatric patients on ECMO is significantly associated with reduced patient survival.

Early continuous renal replacement therapy during infant extracorporeal life support is associated with decreased lung opacification

Lung opacification on chest radiography (CXR) is common during extracorporeal life support (ECLS), often resulting from pulmonary edema or inflammation. Concurrent use of continuous renal replacement therapy (CRRT) during ECLS is associated with improved fluid balance and cytokine filtration; through modification of these pathologic states, CRRT may modulate lung opacification observed on CXRs. We hypothesize that early CRRT use during infant ECLS decreases lung opacification on CXR. We conducted a retrospective cohort study comparing CXRs from infants receiving ECLS and early CRRT (n = 7) to matched infants who received ECLS alone (n = 7). The CXR obtained prior to ECLS, all CXRs obtained within the first 72 h of ECLS, and daily CXRs for the remainder of the ECLS course were analyzed. The outcome measure was the degree of opacification, determined by independent assessment of two, blinded pediatric radiologists using a modified Edwards et al.'s lung opacification scoring system (from Score 0: no opacification to Score 5: complete opacification). 220 CXRs were assessed (cases: 93, controls: 127). Inter-rater reliability was established (Cohen's weighted к = 0.74; p < 0.0001, good agreement). At baseline, the mean opacification score difference between cases and controls was 1 point (cases: 1.8, controls 2.8; p = 0.049). Using mixed modeling analysis for repeated measures accounting for differences at baseline, the average overall opacification score was 1.2 points lower in cases than controls (cases: 2.1, controls: 3.3; p < 0.0001). The overall distribution of scores was lower in cases than controls. Early CRRT utilization during infant ECLS was associated with decreased lung opacification on CXR.

Neonatal Cardiac ECMO in 2019 and Beyond

Worldwide, the use of Extracorporeal Membrane Oxygenation (ECMO) for cardiac failure has been steadily increasing in the neonatal population and has become a widely accepted modality. Especially in centers caring for children with (congenital) heart disease, ECMO is now an essential part of care available for those with severe heart failure as a bridge to recovery, long term mechanical support, or transplantation. Short-term outcomes depend very much on indication. Hospital survival is ~40% for all neonatal cardiac ECMO patients combined. ECMO is being used for pre- and/or post-operative stabilization in neonates with congenital heart disease and in neonates with medical heart disease such as myocarditis, cardiomyopathy or refractory arrhythmias. ECMO use during resuscitation (ECPR) or for sepsis is summarized elsewhere in this special edition of Frontiers in Pediatrics. In this review article, we will discuss the indications for neonatal cardiac ECMO, the difficult process of patients' selection and identifying the right timing to initiate ECMO, as well as outline pros and cons for peripheral vs. central cannulation. We will present predictors of mortality and, very importantly, predictors of survival: what can be done to improve the outcomes for your patients. Furthermore, an overview of current insights regarding supportive care in neonatal cardiac ECMO is given. Additionally, we will address issues specific to neonates with single ventricle physiology on ECMO, for example cannulation strategies and the influence of shunt type (Blalock-Taussig shunt vs. "right ventricle to pulmonary artery" shunt). We will not only focus on short term outcomes, such as hospital survival, but also on the importance of long-term neuro-developmental outcomes, and we will end this review with suggestions for future research.

Retrospective study on the effects of the prognosis of patients treated with extracorporeal membrane oxygenation combined with continuous renal replacement therapy

Background

Patients undergoing extracorporeal membrane oxygenation (ECMO) treatment often have severe fluid overload and electrolyte imbalances and may even suffer acute kidney injury (AKI). It is often necessary to use continuous renal replacement therapy (CRRT). In this study, we aimed to retrospectively analyze the prognosis of patients treated with ECMO combined with CRRT and to find the independent factors that affect the survival rate.

Methods

There were 32 patients who were treated with ECMO combined with CRRT in our hospital from January 2007 to December 2017 who were analyzed. All of the patients were divided into a survival group and death group. The clinical indicators and biochemical indexes of the two groups were observed, and their differences were compared. Multivariate logistic regression analysis was carried out to determine the independent risk factors.

Results

The fluid balance at ECMO day 3, SOFA score and lactate at CRRT initiation, sequential organ failure assessment (SOFA) score at ECMO weaning, CRRT duration, ECMO to CRRT interval, mechanical ventilation (MV) duration, length of ICU, and overall hospital length of stay were statistically significant (P<0.05). The clinical biochemical indexes at CRRT initiation and ECMO weaning [serum creatinine, pH, white blood cell (WBC), hemoglobin (Hb), bilirubin]; patient's age, gender and BMI; and the fluid balance at ECMO days 1 and 7 were not statistically significance (P>0.05). The fluid balance at ECMO day 3 and lactate at CRRT initiation by multivariable logistic regression analysis were independent risk factors affecting patient prognosis.

Conclusions

The fluid balance at ECMO day 3 and lactate at CRRT initiation are the prognosis independent risk factors for ECMO + CRRT patients.

Fluid Overload in Critically Ill Children

Background: A common practice in the management of critically ill patients is fluid resuscitation. An excessive administration of fluids can lead to an imbalance in fluid homeostasis and cause fluid overload (FO). In pediatric critical care patients, FO can lead to a multitude of adverse effects and increased risk of morbidity. Objectives: To review the literature highlighting impact of FO on a multitude of outcomes in critically-ill children, causative vs. associative relationship of FO with critical illness and current pediatric fluid management guidelines. Data Sources: A literature search was conducted using PubMed/Medline and Embase databases from the earliest available date until June 2017. Data Extraction: Two authors independently reviewed the titles and abstracts of all articles which were assessed for inclusion. The manuscripts of studies deemed relevant to the objectives of this review were then retrieved and associated reference lists hand-searched. Data Synthesis: Articles were segregated into various categories namely pathophysiology and sequelae of fluid overload, assessment techniques, epidemiology and fluid management. Each author reviewed the selected articles in categories assigned to them. All authors participated in the final review process. Conclusions: Recent evidence has purported a relationship between mortality and FO, which can be validated by prospective RCTs (randomized controlled trials). The current literature demonstrates that "clinically significant" degree of FO could be below 10%. The lack of a standardized method to assess FB (fluid balance) and a universal definition of FO are issues that need to be addressed. To date, the impact of early goal directed therapy and utility of hemodynamic parameters in predicting fluid responsiveness remains underexplored in pediatric resuscitation.

Management of Fluid Overload in the Pediatric ICU

The implications and management of fluid overload in pediatric critical care remain areas of ongoing controversy. Consensus definitions and methods of quantitating fluid overload continue to evolve, paralleling our growing understanding of fluid dynamics in critically ill patients. Fluid overload has been associated with adverse outcomes in some patient populations; guidelines for fluid management therapies are sparse and have little supporting data. Conflicting data for efficacy of therapies such as diuretic medications and renal replacement therapy are likely reflective of an incomplete understanding of the dynamic relationship between critical illness and fluid overload. Although some guidance regarding diuresis, continuous renal replacement therapy, and fluid balance goals is elucidated in the following chapters, it is important to recognize that further research into these management strategies is required before standardized approaches to management can be established.

Neonatal Extracorporeal Life Support: A Review of Nutrition Considerations

Critically ill neonates who require extracorporeal life support have particular nutrition needs. These infants require prescription of aggressive, early nutrition support by knowledge providers. Understanding the unique metabolic demands and nutrition requirements of these fragile patients is paramount, particularly if additional therapies such as aggressive diuretic regimens or continuous renal replacement therapy are used concurrently. Although the American Society for Parenteral and Enteral Nutrition has published guidelines for this population, a review of each nutrition component is warranted because few studies exist specific to this population. Long-term complications in survivors of neonatal extracorporeal life support, particularly in patients with select diagnoses such as congenital diaphragmatic hernia, can be significant and must be recognized and anticipated. This review focuses on recognizing the nutrition needs of neonatal patients requiring extracorporeal life support, appraising the available data to guide selection of an appropriate mode of nutrition delivery, and describing the anticipated long-term nutrition implications of extracorporeal life support provision during the neonatal period.

Association Between Fluid Balance and Outcomes in Critically Ill Children: A Systematic Review and Meta-analysis

IMPORTANCE

After initial resuscitation, critically ill children may accumulate fluid and develop fluid overload. Accruing evidence suggests that fluid overload contributes to greater complexity of care and worse outcomes.

OBJECTIVE

To describe the methods to measure fluid balance, define fluid overload, and evaluate the association between fluid balance and outcomes in critically ill children.

DATA SOURCES

Systematic search of MEDLINE, EMBASE, Cochrane Library, trial registries, and selected gray literature from inception to March 2017.

STUDY SELECTION

Studies of children admitted to pediatric intensive care units that described fluid balance or fluid overload and reported outcomes of interest were included. No language restrictions were applied.

DATA EXTRACTION AND SYNTHESIS

All stages were conducted independently by 2 reviewers. Data extracted included study characteristics, population, fluid metrics, and outcomes. Risk of bias was assessed using the Newcastle-Ottawa Scale. Narrative description of fluid assessment methods and fluid overload definitions was done. When feasible, pooled analyses were performed using random-effects models.

MAIN OUTCOMES AND MEASURES

Mortality was the primary outcome. Secondary outcomes included treatment intensity, organ failure, and resource use.

RESULTS

A total of 44 studies (7507 children) were included in this systematic review and meta-analysis. Of those, 27 (61%) were retrospective cohort studies, 13 (30%) were prospective cohort studies, 3 (7%) were case-control studies, and 1 study (2%) was a secondary analysis of a randomized trial. The proportion of children with fluid overload varied by case mix and fluid overload definition (median, 33%; range, 10%-83%). Fluid overload, however defined, was associated with increased in-hospital mortality (17 studies [n = 2853]; odds ratio [OR], 4.34 [95% CI, 3.01-6.26]; I2 = 61%). Survivors had lower percentage fluid overload than nonsurvivors (22 studies [n = 2848]; mean difference, -5.62 [95% CI, -7.28 to -3.97]; I2 = 76%). After adjustment for illness severity, there was a 6% increase in odds of mortality for every 1% increase in percentage fluid overload (11 studies [n = 3200]; adjusted OR, 1.06 [95% CI, 1.03-1.10]; I2 = 66%). Fluid overload was associated with increased risk for prolonged mechanical ventilation (>48 hours) (3 studies [n = 631]; OR, 2.14 [95% CI, 1.25-3.66]; I2 = 0%) and acute kidney injury (7 studies [n = 1833]; OR, 2.36 [95% CI, 1.27-4.38]; I2 = 78%).

CONCLUSIONS AND RELEVANCE

Fluid overload is common and is associated with substantial morbidity and mortality in critically ill children. Additional research should now ideally focus on interventions aimed to mitigate the potential for harm associated with fluid overload.

Adjunctive Therapies During Extracorporeal Membrane Oxygenation to Enhance Multiple Organ Support in Critically Ill Children

Since the advent of extracorporeal membrane oxygenation (ECMO) over 40 years ago, there has been increasing interest in the use of the extracorporeal circuit as a platform for providing multiple organ support. In this review, we will examine the evidence for the use of continuous renal replacement therapy, therapeutic plasma exchange, leukopheresis, adsorptive therapies, and extracorporeal liver support in conjunction with ECMO.

The role of fluid overload in the prediction of outcome in acute kidney injury

Our understanding of the epidemiology and the impact of acute kidney injury (AKI) and fluid overload on outcomes has improved significantly over the past several decades. Fluid overload occurs commonly in critically ill children with and without associated AKI. Researchers in pediatric AKI have been at the forefront of describing the impact of fluid overload on outcomes in a variety of populations. A full understanding of this topic is important as fluid overload represents a potentially modifiable risk factor and a target for intervention. In this state-of-the-art review, we comprehensively describe the definition of fluid overload, the impact of fluid overload on kidney function, the impact of fluid overload on the diagnosis of AKI, the association of fluid overload with outcomes, the targeted therapy of fluid overload, and the impact of the timing of renal replacement therapy on outcomes.

The Impact of Fluid Overload on Outcomes in Children Treated With Extracorporeal Membrane Oxygenation: A Multicenter Retrospective Cohort Study

OBJECTIVE

To characterize the epidemiology of fluid overload and its association with mortality and duration of extracorporeal membrane oxygenation in children treated with extracorporeal membrane oxygenation.

DESIGN

Retrospective cohort study.

SETTING

Six tertiary children's hospital ICUs.

PATIENTS

Seven hundred fifty-six children younger than 18 years old treated with extracorporeal membrane oxygenation for greater than or equal to 24 hours from January 1, 2007, to December 31, 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Overall survival to extracorporeal membrane oxygenation decannulation and hospital discharge was 74.9% (n = 566) and 57.7% (n = 436), respectively. Median fluid overload at extracorporeal membrane oxygenation initiation was 8.8% (interquartile range, 0.3-19.2), and it differed between hospital survivors and non survival, though not between extracorporeal membrane oxygenation survivors and non survivors. Median peak fluid overload on extracorporeal membrane oxygenation was 30.9% (interquartile range, 15.4-54.8). During extracorporeal membrane oxygenation, 84.8% had a peak fluid overload greater than or equal to 10%; 67.2% of patients had a peak fluid overload of greater than or equal to 20% and 29% of patients had a peak fluid overload of greater than or equal to 50%. The median peak fluid overload was lower in patients who survived on extracorporeal membrane oxygenation (27.2% vs 44.4%; p < 0.0001) and survived to hospital discharge (24.8% vs 43.3%; p < 0.0001). After adjusting for acute kidney injury, pH at extracorporeal membrane oxygenation initiation, nonrenal complications, extracorporeal membrane oxygenation mode, support type, center and patient age, the degree of fluid overload at extracorporeal membrane oxygenation initiation (p = 0.05), and the peak fluid overload on extracorporeal membrane oxygenation (p < 0.0001) predicted duration of extracorporeal membrane oxygenation in survivors. Multivariable analysis showed that peak fluid overload on extracorporeal membrane oxygenation (adjusted odds ratio, 1.09; 95% CI, 1.04-1.15) predicted mortality on extracorporeal membrane oxygenation; fluid overload at extracorporeal membrane oxygenation initiation (adjusted odds ratio, 1.13; 95% CI, 1.05-1.22) and peak fluid overload (adjusted odds ratio, 1.18; 95% CI, 1.12-1.24) both predicted hospital morality.

CONCLUSIONS

Fluid overload occurs commonly and is independently associated with adverse outcomes including increased mortality and increased duration of extracorporeal membrane oxygenation in a broad pediatric extracorporeal membrane oxygenation population. These results suggest that fluid overload is a potential target for intervention to improve outcomes in children on extracorporeal membrane oxygenation.

Implementing a practice change: early initiation of continuous renal replacement therapy during neonatal extracorporeal life support standardizes care and improves short-term outcomes

PURPOSE

We hypothesized that a standardized approach to early continuous renal replacement therapy (CRRT) during neonatal extracorporeal life support (ECLS) results in greater homogeneity of CRRT initiation times with improvements in fluid balance and outcomes.

METHODS

Retrospective analysis of data (2007-2015) obtained from neonates treated prior to (E1; n = 32) and after (E2; n = 31) a 2011 practice change: CRRT initiation within 48 h of ECLS.

RESULTS

Birthweight, gestational age, ECLS mode, and age at ECLS initiation were similar to each epoch. Survival [E1: median 75%, E2: 71%] and length of ECLS [E1: median 221 h, E2: 180 h] were comparable. During E2, 100% of infants received CRRT (vs. E1: 37%; p < 0.001) and 97% of infants initiated CRRT within 48 h of ECLS (vs. E1: 13%; p < 0.001). Control charts demonstrate reduced practice variation. Elapsed time from ECLS to CRRT differed between Epochs [E1: median 105 h, E2: 9 h; p < 0.001] as did weight at CRRT initiation [E1: 4.13 kg (29% above baseline), E2: 3.19 kg (0%); p < 0.001]. Significant differences in weight change were noted on days 6 and 7 (E1: 14%, E2: 2%; raw data comparison yielded p < 0.05) and curves were different (p < 0.05).

CONCLUSIONS

We successfully implemented a practice change, initiating CRRT within 48 h of ECLS cannulation, leading to decreased practice variation and improved short-term outcomes including decreased weight gain at CRRT initiation and faster return to baseline weight during the first 7 days of ECLS. We did not demonstrate changes in duration of ECLS, invasive ventilation, or survival.

3-month prognostic impact of severe acute renal failure under veno-venous ECMO support: Importance of time of onset

PURPOSE

Veno-venous ECMO is increasingly used for the management of refractory ARDS. In this context, acute kidney injury (AKI) is a major and frequent complication, often associated with poor outcome. We aimed to identify characteristics associated with severe renal failure (Kidney Disease Improving Global Outcome (KDIGO) 3) and its impact on 3-month outcome.

METHODS

Between May 2009 and April 2016, 60 adult patients requiring VV-ECMO in our University Hospital were prospectively included.

RESULTS

AKI occurrence was frequent (75%; n=45), 51% of patients (n=31) developed KDIGO 3 - predominantly prior to ECMO insertion - and renal replacement therapy was required in 43% (n=26) of cases. KDIGO 3 was associated with a lower mechanical ventilation weaning rate (24% vs 68% for patients with no AKI or other stages of AKI; p<0.001) and a higher 90-day mortality rate (72% vs 32%, p=0.002). Multivariate logistic regression suggested that KDIGO 3 occurrence prior to ECMO insertion, as well as PaCO2>57mmHg and mSOFA>12 were independent risks factors for 90-day mortality.

CONCLUSION

KDIGO 3 AKI occurrence is correlated with the severity of patients' clinical condition prior to ECMO insertion and is negatively associated with 90-day survival.

Continuous Renal Replacement Therapy: Case Vignettes

The most common indication for continuous renal replacement therapy (CRRT) in critically ill patients is acute kidney injury with hemodynamic instability. Typically, the patient has metabolic disturbances and potential or actual fluid overload that require intervention. Certain critical care diagnoses and/or conditions or therapies present unique CRRT management approaches. Case vignettes are used to present the unique management of CRRT in critically ill patients with rhabdomyolysis, heart failure, and respiratory failure requiring extracorporeal membrane oxygenation.

Early Continuous Renal Replacement Therapy Improves Nutrition Delivery in Neonates During Extracorporeal Life Support

OBJECTIVE

Optimizing nutrition in neonatal patients as soon as possible after extracorporeal life support (ECLS) initiation is imperative as malnutrition can worsen both short- and long-term outcomes. Fluid restriction, used to manage the fluid overload that commonly complicates neonatal ECLS, severely impairs nutrition delivery. Continuous renal replacement therapy (CRRT) can be used to help manage fluid overload. We hypothesize that early CRRT utilization ameliorates the need for fluid restriction and allows providers to prescribe higher parenteral nutrition (PN) volumes leading to better nutrition delivery.

DESIGN

The design of the study was a retrospective chart review, and the setting was a single, level III neonatal intensive care unit.

SUBJECTS

Neonatal patients (n = 42) treated with ECLS between January 1, 2008, and December 31, 2013.

INTERVENTIONS

Comparisons were made between 2 groups: neonates who received ECLS without early CRRT initiation (group 1; n = 23) and with early CRRT initiation (group 2; n = 19).

MAIN OUTCOME MEASURES

The main outcome measures were goal total fluid intake, prescribed PN volume, protein, glucose infusion rate, intralipid, and kilocalories.

RESULTS

Infants who received early CRRT were prescribed higher mean total fluid intake goals (group 1: 99 mL/kg/day vs. group 2: 119 mL/kg/day, P < .001) and higher mean volumes of PN (group 1: 61 mL/kg/day vs. group 2: 81 mL/kg/day, P < .001) over the first 72 hours of ECLS compared with infants who did not receive early CRRT. Early CRRT receivers also were prescribed greater mean amounts of protein during the first 72 hours of ECLS (group 1: 2.7 g/kg/day vs. group 2: 3 g/kg/day, P = 0.03). There were no significant changes noted in prescribed glucose infusion rates, intralipid, or total kilocalories.

CONCLUSIONS

Institution of early CRRT in neonates on ECLS allows for administration of greater volumes of PN with improved protein delivery. This study characterizes one benefit of early CRRT initiation in neonates on ECLS and suggests these patients could experience improved nutritional outcomes.

Review of Extracorporeal Membrane Oxygenation and Dialysis-Based Liver Support Devices for the Use of Nephrologists

Acute kidney injury in the intensive care unit (ICU) is a manifestation of an underlying severe illness that commonly involves other organ systems. Pulmonary, cardiac, and hepatic failures are the most prevalent. This article provides a simplified review of the technical aspects of extracorporeal cardiopulmonary and liver support devices used in the adult ICU patient, as well as a summary of the most relevant and up-to-date clinical evidence that supports their use.

Extracorporeal Life Support: Four Decades and Counting

Extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS) is a form of heart lung bypass that is used to support neonates, pediatrics, and adult patients with cardiorespiratory failure for days or weeks till organ recovery or transplantation. Venoarterial (VA) and venovenous (VV) ECLS are the most common modes of support. ECLS circuit components and monitoring have been evolving over the last 40 years. The technology is safer, simpler, and more durable with fewer complications. The use of neonatal respiratory ECLS use has been declining over the last two decades, while adult respiratory ECLS is growing especially since the H1N1 influenza pandemic in 2009. This review provides an overview of ECLS evolution over the last four decades, its use in neonatal, pediatric and adults, description of basic principles, circuit components, complications, and outcomes as well as a quick look into the future.

Continuous Renal Replacement Therapy Applications on Extracorporeal Membrane Oxygenation Circuit

BACKGROUND AND AIMS

Continuous venovenous hemofiltration or hemodiafiltration is used frequently in pediatric patients, but experience of continuous renal replacement therapy (CRRT) application on extracorporeal membrane oxygenation (ECMO) circuit is still limited. Among several methods used for applying CRRT on ECMO patients, we aim to share our experience on inclusion of a CRRT device in the ECMO circuit which we believe is easier and safer to apply.

MATERIALS AND METHODS

The data were collected on demographics, outcomes, and details of the treatment of ECMO patients who had CRRT. During the study period of 3 years, venous cannula of ECMO circuit before pump was used for CRRT access for both the filter inlet and outlet of CRRT machine to minimize the thromboembolic complications. The common indication for CRRT was fluid overload.

RESULTS

CRRT was used in 3.68% of a total number of patients admitted and 43% of patients on ECMO. The patients have undergone renal replacement therapy for periods of time ranging between 24 h and 25 days (260 h mean). The survival rate of this group of patients with multiorgan failure was 33%. Renal recovery occurred in all of the survivors. Complications such as electrolyte imbalance, hypothermia, and bradykinin syndrome were easily managed.

CONCLUSIONS

Adding a CRRT device on ECMO circuit is a safe and effective technique. The major advantages of this technique are easy to access, applying CRRT without extra anticoagulation process, preventing potential hemodynamic disturbances, and increased clearance of solutes and fluid overload using larger hemofilter.

The Incidence of Acute Kidney Injury and Its Effect on Neonatal and Pediatric Extracorporeal Membrane Oxygenation Outcomes: A Multicenter Report From the Kidney Intervention During Extracorporeal Membrane Oxygenation Study Group

OBJECTIVE

In a population of neonatal and pediatric patients on extracorporeal membrane oxygenation; to describe the prevalence and timing of acute kidney injury utilizing a consensus acute kidney injury definition and investigate the association of acute kidney injury with outcomes (length of extracorporeal membrane oxygenation and mortality).

DESIGN

Multicenter retrospective observational cohort study.

SETTING

Six pediatric extracorporeal membrane oxygenation centers.

PATIENTS

Pediatric patients (age, < 18 yr) on extracorporeal membrane oxygenation at six centers during a period of January 1, 2007, to December 31, 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Complete data were analyzed for 832 patients on extracorporeal membrane oxygenation. Sixty percent of patients had acute kidney injury utilizing the serum creatinine Kidney Disease Improving Global Outcomes criteria (AKI) and 74% had acute kidney injury using the full Kidney Disease Improving Global Outcomes criteria including renal support therapy (AKI). Of those who developed acute kidney injury, it was present at extracorporeal membrane oxygenation initiation in a majority of cases (52% AKI and 65% AKI) and present by 48 hours of extracorporeal membrane oxygenation support in 86% (AKI) and 93% (AKI). When adjusted for patient age, center of support, mode of support, patient complications and preextracorporeal membrane oxygenation pH, the presence of acute kidney injury by either criteria was associated with a significantly longer duration of extracorporeal membrane oxygenation support (AKI, 152 vs 110 hr; AKI, 153 vs 99 hr) and increased adjusted odds of mortality at hospital discharge (AKI: odds ratio, 1.77; 1.22-2.55 and AKI: odds ratio, 2.50; 1.61-3.90). With the addition of renal support therapy to the model, acute kidney injury was associated with a longer duration of extracorporeal membrane oxygenation support (AKI, 149 vs 121 hr) and increased risk of mortality at hospital discharge (AKI: odds ratio, 1.52; 1.04-2.21).

CONCLUSION

Acute kidney injury is present in 60-74% of neonatal-pediatric patients supported on extracorporeal membrane oxygenation and is present by 48 hours of extracorporeal membrane oxygenation support in 86-93% of cases. Acute kidney injury has a significant association with increased duration of extracorporeal membrane oxygenation support and increased adjusted odds of mortality at hospital discharge.

Severe ARDS caused by adenovirus: early initiation of ECMO plus continuous renal replacement therapy

The reported survival rates of patients with acute respiratory distress syndrome (ARDS) caused by human adenovirus (HAdV) pneumonia are poor. The results do not differ much in immunocompetent patients supported by extracorporeal membrane oxygenation (ECMO). We report two immunocompetent patients with severe ARDS complicating HAdV pneumonia who were treated successfully and survived to discharge. Compared with previous cases, our cases might have benefited from several factors. First, the time interval between mechanical ventilator support and ECMO implantation was shorter. Second, we implemented conservative fluid management as recommended by the ARDS network using continuous renal replacement therapy (CRRT). Third, we administered an antiviral agent as early as possible. A clinical trial of early ECMO with CRRT and the administration of cidofovir in patients with severe ARDS complicating HAdV pneumonia are needed to confirm our results.

Kidney-lung connections in acute and chronic diseases: current perspectives

Lung and kidney functions are intimately related in both health and disease. The regulation of acid-base equilibrium, modification of partial pressure of carbon dioxide and bicarbonate concentration, and the control of blood pressure and fluid homeostasis all closely depend on renal and pulmonary activities. These interactions begin in fetal age and are often responsible for the genesis and progression of diseases. In gestational age, urine is a fundamental component of the amniotic fluid, acting on pulmonary maturation and growth. Moreover, in the first trimester of pregnancy, kidney is the main source of proline, contributing to collagen synthesis and lung parenchyma maturation. Pathologically speaking, the kidneys could become damaged by mediators of inflammation or immuno-mediated factors related to a primary lung pathology or, on the contrary, it could be the renal disease that determines a consecutive pulmonary damage. Furthermore, non immunological mechanisms are frequently involved in renal and pulmonary diseases, as observed in chronic pathologies such as sleep apnea syndrome, pulmonary hypertension, progressive renal disease and hemodialysis. Kidney damage has also been related to mechanical ventilation. The aim of this review is to describe pulmonary-renal interactions and their related pathologies, underscoring the need for a close collaboration between intensivists, pneumologists and nephrologists.

Impact of Acute Kidney Injury on Outcome in Patients With Severe Acute Respiratory Failure Receiving Extracorporeal Membrane Oxygenation

OBJECTIVES

Extracorporeal lung support is currently used in the treatment of patients with severe respiratory failure until organ recovery and as a bridge to further therapeutic modalities. The aim of our study was to evaluate the impact of acute kidney injury on outcome in patients with acute respiratory distress syndrome under venovenous extracorporeal membrane oxygenation support and to analyze the association between prognosis and the time of occurrence of acute kidney injury and renal replacement therapy initiation.

DESIGN

Retrospective observational study.

SETTING

A large European extracorporeal membrane oxygenation center, University Medical Center Regensburg, Germany.

PATIENTS

A total of 262 consecutive adult patients with acute respiratory distress syndrome have been treated with extracorporeal membrane oxygenation between January 2007 and May 2012.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Patient median age was 49 years (range, 18-78 yr); 183 (69.8%) were male. The leading cause of lung failure was pneumonia. The median Sequential Organ Failure Assessment score was 12.0 (8.8-15.0), and the median lung injury score was 3.3 (3.3-3.7). The median extracorporeal membrane oxygenation support duration was 9 days (6-15 d). One hundred eighty-three patients (69.8%) were successfully weaned and 156 patients (59.9%) survived to hospital discharge. One hundred thirty-one patients (50.0%) were treated with renal replacement therapy during extracorporeal membrane oxygenation support. The survival rate was significantly lower in patients requiring renal replacement therapy compared with those without renal replacement therapy (47.3% vs 71.8%; p < 0.001) overall. The Kaplan-Meier survival curves differed significantly for patients without renal replacement therapy versus patients with renal replacement therapy prior to extracorporeal membrane oxygenation support (p = 0.003). Furthermore, the multivariate logistic regression analysis suggests that the necessity of renal replacement therapy prior to extracorporeal membrane oxygenation insertion was an independent risk factor for mortality (95% CI, 0.77-0.88; p < 0.001). However, the necessity of renal replacement therapy during extracorporeal membrane oxygenation support was not an independent risk factor for mortality in these patients (p = 0.37).

CONCLUSIONS

Acute kidney injury is a major complication in acute respiratory distress syndrome probably mirroring severe systemic disease. In our cohort, development of acute kidney injury requiring renal replacement therapy prior to extracorporeal membrane oxygenation insertion was negatively associated with survival, whereas acute kidney injury that developed during extracorporeal membrane oxygenation support was not.

Extracorporeal Membrane Oxygenation and the Kidney

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is an effective therapy for patients with reversible cardiac and/or respiratory failure. Acute kidney injury (AKI) often occurs in patients supported with ECMO; it frequently evolves into chronic kidney damage or end-stage renal disease and is associated with a reported 4-fold increase in mortality rate. Although AKI is generally due to the hemodynamic alterations associated with the baseline disease, ECMO itself may contribute to maintaining kidney dysfunction through several mechanisms.

SUMMARY

AKI may be related to conditions derived from or associated with extracorporeal therapy, leading to a reduction in renal oxygen delivery and/or to inflammatory damage. In particular, during pathological conditions requiring ECMO, the biological defense mechanisms maintaining central perfusion by a reduction of perfusion to peripheral organs (such as the kidney) have been identified as pretreatment and patient-related risk factors for AKI. Hormonal pathways are also impaired in patients supported with ECMO, leading to failures in mechanisms of renal homeostasis and worsening fluid overload. Finally, inflammatory damage, due to the primary disease, heart and lung crosstalk with the kidney or associated with extracorporeal therapy itself, may further increase the susceptibility to AKI. Renal replacement therapy can be integrated into the main extracorporeal circuit during ECMO to provide for optimal fluid management and removal of inflammatory mediators.

KEY MESSAGES

AKI is frequently observed in patients supported with ECMO. The pathophysiology of the associated AKI is chiefly related to a reduction in renal oxygen delivery and/or to inflammatory damage. Risk factors for AKI are associated with a patient's underlying disease and ECMO-related conditions.

Effects of Renal Replacement Therapy in Patients Receiving Extracorporeal Membrane Oxygenation: A Meta-Analysis

The use of renal replacement therapy (RRT) in patients receiving extracorporeal membrane oxygenation (ECMO) is increasing, but the effect of RRT on ECMO is controversial. We performed a meta-analysis to determine whether RRT is related to higher mortality in patients receiving ECMO. We searched MEDLINE, EMBASE, the Cochrane Library, and KoreaMed and found 43 observational studies with 21,624 patients receiving ECMO and then compared inpatient mortality rates of patients receiving ECMO both with and without RRT. The risk ratio (RR) of mortality between patients receiving RRT and those not receiving RRT tended to decrease as the mortality of the group not receiving RRT increased. Among patients with RRT use rates of 30% and higher, the overall mortality rates for all patients receiving ECMO tended to decrease. We found that the increase in the RR for RRT tended to be greater the longer the initiation of RRT was delayed. We suggest that in patients receiving ECMO who have high RRT use rates, RRT may decrease mortality rates.

Urinary Neutrophil Gelatinase-Associated Lipocalin Predicts Renal Injury Following Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the course of urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule-1 levels in young children during extracorporeal membrane oxygenation and concomitant continuous hemofiltration. Furthermore, to evaluate whether these levels predict outcome.

DESIGN

Prospective observational cohort study from July 2010 to July 2013.

SETTING

ICU of a level III university children's hospital.

PATIENTS

Thirty-one extracorporeal membrane oxygenation-treated children up to 1 year were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were weaned from extracorporeal membrane oxygenation after a median of 162 hours (interquartile range, 83-304). Throughout the study, 58% of the patients met the criteria for acute kidney injury (i.e., Risk Injury Failure Loss End-Stage Renal Disease-Risk or higher defined as an increase in serum creatinine corresponding to ≥ 150% when compared with age-specific reference values). Levels of both biomarker patterns changed significantly throughout extracorporeal membrane oxygenation (urinary neutrophil gelatinase-associated lipocalin, p < 0.001 and urinary kidney injury molecule-1, p = 0.005, linear mixed model analyses). Urinary neutrophil gelatinase-associated lipocalin levels were already high before extracorporeal membrane oxygenation, whereas urinary kidney injury molecule-1 levels increased throughout the first extracorporeal membrane oxygenation day and peaked at 12-24 hours. Also, urinary neutrophil gelatinase-associated lipocalin levels at 12-24 hours of extracorporeal membrane oxygenation therapy were higher among patients with acute kidney injury post extracorporeal membrane oxygenation (p = 0.002, Mann-Whitney U test). Biomarker levels did not differ between survivors and nonsurvivors.

CONCLUSIONS

The increased urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule-1 levels confirm that renal tubular damage occurs in critically ill infants in need of extracorporeal membrane oxygenation. The fact that the maximal urinary neutrophil gelatinase-associated lipocalin levels were measured 24 hours earlier than urinary kidney injury molecule-1 supports the use of biomarker combinations rather than a single biomarker to identify patients at risk of acute kidney injury. Finally, since urinary neutrophil gelatinase-associated lipocalin levels at 12-24 hours of extracorporeal membrane oxygenation therapy were associated with acute kidney injury post extracorporeal membrane oxygenation, this marker may facilitate more timely adjustment of therapeutic interventions.

Outcomes associated with the use of renal replacement therapy in children receiving extracorporeal membrane oxygenation after heart surgery: a multi-institutional analysis

BACKGROUND

The primary objective of this investigation was to study the association between renal replacement therapy (RRT) and outcomes in children receiving extracorporeal membrane oxygenation (ECMO).

METHODS

Patients aged ≤18 years receiving ECMO before or after a pediatric heart operation at a Pediatric Health Information System (PHIS)-participating hospital (2004-2013) were included. The associations between RRT and study outcomes were computed using multivariate logistic regression analysis.

RESULTS

A total of 3,502 patients from 43 hospitals qualified for inclusion. Of these, 484 (14 %) patients received RRT at some point during their hospital stay. After adjusting for patient and center characteristics, the odds of mortality were significantly higher in the RRT group (OR: 1.86, 95 % CI: 1.46- 2.37, p < 0.0001). However, there were considerable reductions in adjusted odds of mortality, compared to unadjusted odds of mortality. In adjusted models, length of ECMO was longer by 0.81 days (95 % CI: 0.13- 1.49, p = 0.02) in patients receiving RRT.

CONCLUSIONS

We demonstrated worsening outcomes in children receiving ECMO with RRT compared to children receiving ECMO without RRT. Although the results could reflect confounding by severity of illness, they provide a rationale for prospective testing of use of RRT in critically ill children receiving ECMO with heart surgery.

Hemofiltration is not associated with increased mortality in children receiving extracorporeal membrane oxygenation

OBJECTIVES

To investigate whether the use of continuous renal replacement therapy is independently associated with increased in-hospital mortality in children on extracorporeal membrane oxygenation.

DESIGN

Retrospective, 1:1 propensity-matched cohort study.

SETTING

Tertiary PICU.

PATIENTS

Eighty-six children on extracorporeal membrane oxygenation, 43 of whom also received hemofiltration.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, pre-extracorporeal membrane oxygenation hemodynamic data, fluid status, and biochemistry tests were collected, as well as duration of extracorporeal membrane oxygenation, blood product use, complications, and mortality. Forty-three children receiving extracorporeal membrane oxygenation and continuous renal replacement therapy were matched to a cohort of 43 children on extracorporeal membrane oxygenation not receiving continuous renal replacement therapy. The main indication for hemofiltration was fluid overload in 29 patients (67.4%), renal failure in nine patients (20.9%), and electrolyte abnormalities in five patients (11.6%). The median duration of hemofiltration was 108 hours (47-209 hr). Patients receiving hemofiltration had a longer duration of extracorporeal membrane oxygenation (127 hr [94-302 hr] vs 121 hr [67-182 hr]; p = 0.05) and received more platelet transfusions (0.91 mL/kg/hr [0.43-1.58 mL/kg/hr] vs 0.63 mL/kg/hr [0.30-0.79 mL/kg/hr]; p = 0.01). There were otherwise no differences in mechanical or patient-related complications between both groups. There was no difference in the proportion of patients who were successfully decannulated (81.4% vs 74.4%; p = 0.44), survived to ICU discharge (65.1% vs 55.8%; p = 0.38), or survived to hospital discharge (62.8% vs 48.8%; p = 0.19) in the controls versus the hemofiltration group.

CONCLUSIONS

In-hospital mortality was similar between children on extracorporeal membrane oxygenation with and without hemofiltration although hemofiltration appeared to be associated with a slight increase in the duration of extracorporeal membrane oxygenation and more liberal platelet transfusions.

Combination of extracorporeal membrane oxygenation and continuous renal replacement therapy in critically ill patients: a systematic review

Introduction

Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients presenting acute cardiac and/or pulmonary dysfunctions, who are at high risk of developing acute kidney injury and fluid overload. Continuous renal replacement therapy (CRRT) is commonly used in intensive care units (ICU) to provide renal replacement and fluid management. We conducted a review to assess the feasibility, efficacy and safety of the combination of ECMO and CRRT and to illustrate the indications and methodology of providing renal replacement therapy during the ECMO procedure.

Method

We searched for all published reports of a randomized controlled trial (RCT), quasi-RCT, or other comparative study design, conducted in patients undergoing ECMO plus CRRT. Two reviewers independently selected potential studies and extracted data. We used the modified Jadad scale and the Newcastle-Ottawa for quality assessment of RCTs and non-RCTs, respectively. Statistical analyses were performed using RevMan 5.2.

Results

We identified 19 studies meeting the eligibility criteria (seven cohort, six case control, one historically controlled trial and five studies of technical aspects). There are three major methods for performing CRRT during ECMO: ‘independent CRRT access’, ‘introduction of a hemofiltration filter into the ECMO circuit (in-line hemofilter)’ and ‘introduction of a CRRT device into the ECMO circuit’. We conducted a review with limited data synthesis rather than a formal meta-analysis because there could be greater heterogeneity in a systematic review of non-randomized studies than that of randomized trials. For ECMO survivors receiving CRRT, overall fluid balance was less than that in non-CRRT survivors. There was a higher mortality and a longer ECMO duration when CRRT was added, which may reflect a relatively higher severity of illness in patients who received ECMO plus CRRT.

Conclusions

The combination of ECMO and CRRT in a variety of methods appears to be a safe and effective technique that improves fluid balance and electrolyte disturbances. Prospective studies would be beneficial in determining the potential of this technique to improve the outcome in critically ill patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0675-x) contains supplementary material, which is available to authorized users.

Evaluation of plasma exchange and continuous veno-venous hemofiltration for the treatment of severe avian influenza A (H7N9): a cohort study

Avian influenza A (H7N9) is a severe disease with high mortality. Hypercytokinemia is thought to play an important role in the pathogenesis. This study was to investigate the efficiency of plasma exchange (PE) + continuous veno-venous hemofiltration (CVVH) on the removal of inflammatory mediators and their benefits in the management of fluid overload and metabolic disturbance. In total, 40 H7N9-infected patients were admitted to our hospital. Sixteen critically ill H7N9-infected patients received combination of PE and CVVH. Data from these 16 patients were collected and analyzed. The effects of PE + CVVH on plasma cytokine/chemokine levels and clinical outcomes were examined. H7N9-infected patients had increased plasma levels compared to healthy controls. After 3 h of PE + CVVH treatment, the cytokine/chemokine levels descended remarkably to lower levels and were maintained thereafter. PE + CVVH also benefited the management of fluid, cardiovascular dysfunction and metabolic disturbance. Of the 16 critically ill patients who received PE + CVVH, 10 patients survived. PE + CVVH decreased the plasma cytokine/chemokine levels significantly. PE + CVVH were also beneficial to the management of severe avian influenza A (H7N9).