Survival and renal function in pediatric patients following extracorporeal life support with hemofiltration

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.

Long-term outcomes in patients who received veno-venous extracorporeal membrane oxygenation and renal replacement therapy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a frequent complication in patients with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO). However, little is known of long-term kidney function in ECMO survivors. We aimed to assess the long-term mortality and kidney outcomes in adult patients treated with veno-venous ECMO (VV-ECMO).

Methods

This was a single-centre retrospective study of adult patients (≥ 18 years old) who were treated with VV-ECMO at a commissioned ECMO centre in the UK between 1st September 2010, and 30th November 2016. AKI was defined and staged using the serum creatinine and urine output criteria of the Kidney Diseases: Improving Global Outcomes (KDIGO) classification. The primary outcome was 1-year mortality. Secondary outcomes were long-term mortality (up to March 2020), 1-year incidence of end-stage kidney disease (ESKD) or chronic kidney disease (CKD) among AKI patients who received renal replacement therapy (AKI-RRT), AKI patients who did not receive RRT (AKI-no RRT) and patients without AKI (non-AKI).

Results

A total of 300 patients [57% male; median age 44.5; interquartile range (IQR) 34–54] were included in the final analysis. Past medical histories included diabetes (12%), hypertension (17%), and CKD (2.3%). The main cause of severe respiratory failure was pulmonary infection (72%). AKI occurred in 230 patients (76.7%) and 59.3% received renal replacement therapy (RRT). One-year mortality was 32% in AKI-RRT patients vs. 21.4% in non-AKI patients (p = 0.014). The median follow-up time was 4.35 years. Patients who received RRT had a higher risk of 1-year mortality than those who did not receive RRT (adjusted HR 1.80, 95% CI 1.06, 3.06; p = 0.029). ESKD occurred in 3 patients, all of whom were in the AKI-RRT group. At 1-year, 41.2% of survivors had serum creatinine results available. Among these, CKD was prevalent in 33.3% of AKI-RRT patients vs. 4.3% in non-AKI patients (p = 0.004).

Conclusions

VV-EMCO patients with AKI-RRT had high long-term mortality. Monitoring of kidney function after hospital discharge was poor. In patients with follow-up creatinine results available, the CKD prevalence was high at 1 year, especially in AKI-RRT patients. More awareness about this serious long-term complication and appropriate follow-up interventions are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01046-0.

Acute kidney injury in ECMO patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at  https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

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.

Review of acute kidney injury and continuous renal replacement therapy in pediatric extracorporeal membrane oxygenation

Purpose

To review the relevant literature of acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) as it relates to pediatric extracorporeal membrane oxygenation (ECMO).

Methods

Available online relevant literature.

Results

ECMO is a therapeutic modality utilized to support patients with refractory respiratory and/or cardiac failure. AKI and fluid overload (FO) are frequently observed in this patient population. There are multiple modalities that can be utilized for AKI and FO which include the following: diuretics, in-line hemofiltration, and CRRT. There are multiple considerations when using CRRT with ECMO including access, CRRT flows, hemolysis, anticoagulation, and CRRT termination.

Conclusion

While each ECMO center has its own set of equipment, experiences, and practices, it is imperative that the international ECMO community continues to work together to provide an evidence-based approach to address the morbidity and mortality associated with AKI and FO.

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.

Oxidative Stress and Neonatal Respiratory Extracorporeal Membrane Oxygenation

Oxidative stress is a frequent condition in critically ill patients, especially if exposed to extracorporeal circulation, and it is associated with worse outcomes and increased mortality. The inflammation triggered by the contact of blood with a non-endogenous surface, the use of high volumes of packed red blood cells and platelets transfusion, the risk of hyperoxia and the impairment of antioxidation systems contribute to the increase of reactive oxygen species and the imbalance of the redox system. This is responsible for the increased production of superoxide anion, hydrogen peroxide, hydroxyl radicals, and peroxynitrite resulting in increased lipid peroxidation, protein oxidation, and DNA damage. The understanding of the pathophysiologic mechanisms leading to redox imbalance would pave the way for the future development of preventive approaches. This review provides an overview of the clinical impact of the oxidative stress during neonatal extracorporeal support and concludes with a brief perspective on the current antioxidant strategies, with the aim to focus on the potential oxidative stress-mediated cell damage that has been implicated in both short and long-term outcomes.

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.

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.

Evaluation of Hemodynamic Performance of a Combined ECLS and CRRT Circuit in Seven Positions With a Simulated Neonatal Patient

As it is common for patients treated with extracorporeal life support (ECLS) to subsequently require continuous renal replacement therapy (CRRT), and neonatal patients encounter limitations due to lack of access points, inclusion of CRRT in the ECLS circuit could provide advanced treatment for this population. The objective of this study was to evaluate an alternative neonatal ECLS circuit containing either a Maquet RotaFlow centrifugal pump or Maquet HL20 roller pump with one of seven configurations of CRRT using the Prismaflex 2000 System. All ECLS circuit setups included a Quadrox-iD Pediatric diffusion membrane oxygenator, a Better Bladder, an 8-Fr arterial cannula, a 10-Fr venous cannula, and 6 feet of ¼-inch diameter arterial and venous tubing. The circuit was primed with lactated Ringer's solution and packed human red blood cells resulting in a total priming volume of 700 mL for both the circuit and the 3-kg pseudopatient. Hemodynamic data were recorded for ECLS flow rates of 200, 400, and 600 mL/min and a CRRT flow rate of 50 mL/min. When a centrifugal pump is used, the hemodynamic performance of any combined ECLS and CRRT circuit was not significantly different than that of the circuit without CRRT, thus any configuration could potentially be used. However, introduction of CRRT to a circuit containing a roller pump does affect performance properties for some CRRT positions. The circuits with CRRT positions B and G demonstrated decreased total hemodynamic energy (THE) levels at the post-arterial cannula site, while positions D and E demonstrated increased post-arterial cannula THE levels compared to the circuit without CRRT. CRRT positions A, C, and F did not have significant changes with respect to pre-arterial cannula flow and THE levels, compared to the circuit without CRRT. Considering hemodynamic performance, for neonatal combined extracorporeal membrane oxygenation (ECMO) and CRRT circuits with both blood pumps, we recommend the use of CRRT position A due to its hemodynamic similarities to the ECMO circuit without CRRT.

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.

Extracorporeal Life Support in Pediatric and Neonatal Critical Care: A Review

Extracorporeal life support (ECLS) is a modified form of cardiopulmonary bypass used to provide prolonged tissue oxygen delivery in patients with respiratory and/or cardiac failure. The first large-scale success of ECLS was achieved in the management of term newborns with respiratory failure. ECLS has become an accepted therapeutic modality for neonates, children, and adults who have failed conventional therapy and in whom cardiac and/or respiratory insufficiency is potentially reversible. The use of ECLS allows one to reduce other cardiopulmonary supports and apply a gentle ventilation strategy in a population of severely compromised critical care patients. ECLS has now been employed in more than 26,000 neonatal and pediatric patients with an overall survival rate of 68%. ECLS has evolved significantly over 25 years of clinical practice; patient selection for this complex and highly invasive therapy, as well as how ECLS is employed in different patient groups, is constantly changing. Generally, ECLS is used more liberally now than in the past. The number of patients requiring this support, however, is declining yearly, and those patients who receive ECLS compose a more severe subset of an intensive care population. This review provides an overview of the development of ECLS and the equipment and techniques employed. The use of ECLS for neonatal respiratory failure, pediatric respiratory failure, and cardiac support are outlined. Management of the ECLS patient is discussed in detail, and outcome of these patients is reviewed. Finally, current trends and future implications of ECLS in neonatal and pediatric critical care are addressed.

Practical considerations to drug dosing in children with acute kidney injury

Medication dosing for children with acute kidney injury (AKI) needs to be individualized based on pharmacokinetic and pharmacodynamic principles of the prescribed drugswhenever possible to optimize therapeutic outcome and to minimize toxicity. The pediatric RIFLE criteria should be prospectively utilized to identify patients at highest risk of developing AKI. Serum creatinine and urine output along with volume status should be utilized to guide drug dosing when urinary biomarkers including kidney injury molecule 1, interleukin-18, or neutrophil gelatinase-associated lipocalin are not readily available. Because of the presence of a positive fluid balance in early stages of AKI, the dosing regimen for many drugs, especially antimicrobial agents, should be initiated at a larger loading dose based on the expected volume of distribution to achieve target serum concentrations.When possible, therapeutic drug monitoring should be utilized for those medications where serum drug concentrations can be obtained in a clinically relevant time frame. For these medications, close monitoring of serum drug concentrations is highly recommended. This review addresses drug-dosing strategies in pediatric patients with AKI including the roles of therapeutic drug monitoring and newer kidney injury biomarkers.

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.

Impact of Kidney Disease on Survival in Neonatal Extracorporeal Life Support

OBJECTIVE

To investigate the prevalence and survival to discharge of neonates with kidney disease who received extracorporeal life support.

DESIGN

We analyzed the Extracorporeal Life Support Organization international registry of neonates (< 30 d old) who received extracorporeal life support from 1989 to 2012. We used International Classification of Diseases and Related Health Problems, 9th Revision, Clinical Modification, codes to identify neonates with kidney disease at time of cannulation for extracorporeal life support.

SETTING

Participating Extracorporeal Life Support Organization centers.

PATIENTS

All neonates who received extracorporeal life support at an Extracorporeal Life Support Organization center from 1989 to 2012.

INTERVENTIONS

We performed bivariate logistic regression to estimate associations between survival and covariates. We used unadjusted and adjusted logistic regression to compare survival to discharge between neonates with and without kidney disease. Odds ratios were estimated separately for three groups based on extracorporeal life support indication: pulmonary indication without congenital diaphragmatic hernia, pulmonary indication with congenital diaphragmatic hernia, and cardiac indication. Adjusted models included covariates identified as significant in bivariate models for each group.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was survival to discharge from hospitalization. Of the 28,755 neonates who received extracorporeal life support, 405 had kidney disease (extracorporeal life support indication: 210 pulmonary indication without congenital diaphragmatic hernia, 65 pulmonary indication with congenital diaphragmatic hernia, and 130 cardiac indication). Survival was lower in neonates with kidney disease than those without (49% vs 82% pulmonary indication without congenital diaphragmatic hernia, 25% vs 51% pulmonary indication with congenital diaphragmatic hernia, 21% vs 41% cardiac indication). Kidney disease was associated with reduced survival in adjusted models (95% CI for odds ratio 0.31-0.59 pulmonary indication without congenital diaphragmatic hernia, 0.27-0.89 pulmonary indication with congenital diaphragmatic hernia, 0.31-0.77 cardiac indication).

CONCLUSIONS

Neonates with kidney disease who receive extracorporeal life support have poorer survival to discharge compared with other neonates who receive extracorporeal life support, suggesting that kidney disease should be considered when making extracorporeal life support initiation decisions.

Outcome of patients on combined extracorporeal membrane oxygenation and continuous renal replacement therapy: a retrospective study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy used in the management of cardiopulmonary failure. Continuous renal replacement therapy (CRRT) is often added to the treatment for the correction of fluid and electrolyte imbalance in patients with acute kidney injury. Most of the literature on the use of combined ECMO and CRRT has been on pediatric patients. There are limited outcome data on the use of these combined modalities in adult patients.

METHODS

This is a retrospective analysis of all the patients above the age of 18 years who underwent combined ECMO and CRRT at a tertiary care medical center during the period January 2007 to January 2012. The primary outcomes measured were mortality at one year and renal recovery or dialysis dependence at one month.

RESULTS

A total of 40 patients who were treated concurrently with ECMO and CRRT were identified. The mean age was 47.01 ± 18.29 years. The most common indications for initiation of CRRT were combined fluid overload and electrolyte imbalance. Mortality at one month was (32/40) 80%. Among the 8 survivors (20%), 3 patients required continuation of hemodialysis and 5 patients were independent of dialysis at 30 days.

CONCLUSIONS

Mortality of patients treated with combined ECMO and CRRT is high. Initiation of CRRT in these patients is simply an indicator of severity of illness and fatality. Younger age, higher arterial pH, left ventricular dysfunction and use of VA ECMO are associated with improved survival in these patients.

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.

CKD and hypertension during long-term follow-up in children and adolescents previously treated with extracorporeal membrane oxygenation

BACKGROUND AND OBJECTIVES

Many children receiving extracorporeal membrane oxygenation develop AKI. If AKI leads to permanent nephron loss, it may increase the risk of developing CKD. The prevalence of CKD and hypertension and its predictive factors during long-term follow-up of children and adolescents previously treated with neonatal extracorporeal membrane oxygenation were determined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between November of 2010 and February of 2014, neonatal survivors of extracorporeal membrane oxygenation who visited the prospective follow-up program at 1, 2, 5, 8, 12, and 18 years of age were screened for CKD and hypertension (BP≥95th percentile of reference values). CKD was suspected in children with either an eGFR<90 ml/min per 1.73 m(2) or proteinuria (urinary protein-to-creatinine ratio >0.50 for children ages ≤24 months and >0.20 at >24 months). The RIFLE classification (risk, injury, or failure as 150%, 200%, or 300% of serum creatinine reference values) was used to define AKI during extracorporeal membrane oxygenation without preemptive hemofiltration.

RESULTS

Median follow-up of 169 screened participants was 8.2 years (interquartile range=5.2-12.1 years). Nine children had a lower eGFR, but all rates were >60 ml/min per 1.73 m(2). Proteinuria was observed in 20 children (median=0.26 mg protein/mg creatinine; interquartile range=0.23-0.32 mg protein/mg creatinine), and 32 children had hypertension. Only history of AKI was associated with CKD (P=0.004). Children with RIFLE scores injury and failure had 4.3 times higher odds of CKD signs or hypertension than those without AKI (95% confidence interval, 1.6 to 12.1; P=0.004).

CONCLUSIONS

Altogether, 54 participants (32%) had at least one sign of CKD and/or hypertension. However, most values were marginally abnormal, with no immediate consequences for clinical care. Nevertheless, a prevalence of 32% clearly indicates that survivors of neonatal extracorporeal membrane oxygenation, especially those with AKI, are at risk of a more rapid decline of kidney function with increasing age. Therefore, screening for CKD development in adulthood is recommended.

Acute kidney injury in the neonate

Critically ill neonates are at risk for acute kidney injury (AKI). AKI has been associated with increased risk of morbidity and mortality in adult and pediatric patients, and increasing evidence suggests a similar association in the neonatal population. This article describes the current AKI definitions (including their limitations), work on novel biomarkers to define AKI, diagnosis and management strategies, long-term outcomes after AKI, and future directions for much-needed research in this important area.

Impact of fluid balance on outcome of adult patients treated with extracorporeal membrane oxygenation

PURPOSE

To assess the relationship between early daily fluid balance (FB) and 90-day outcome in adult patients treated with extracorporeal membrane oxygenation (ECMO).

DESIGN

Retrospective observational study.

SETTING

Tertiary referral centre for ECMO.

PATIENTS

115 patients treated with ECMO for refractory heart failure and 57 patients treated with ECMO for refractory respiratory failure.

METHODS

We analysed the association between early daily FB versus hospital and 90-day mortality using multivariable logistic regression model, Cox proportional-hazards model and propensity score.

RESULTS

We obtained detailed demographic, clinical, and biochemical data, daily FB, and continuous renal replacement days. Fifty-seven per cent of patients had acute kidney injury (AKI) at ECMO initiation, and 60 % (n = 103) of patients received continuous renal replacement therapy (CRRT) during ECMO course, beginning at a median of 1 (0-3.5) days after ECMO initiation. Overall 90-day mortality was 24 %. Survivors exhibited lower daily FB from day 3 to day 5. After adjustments, Acute Physiology and Chronic Health Evaluation (APACHE) III, CRRT during the first 3 days, major bleeding event at day 1 and positive FB on day 3 were independent predictors of 90-day mortality. Positive FB at ECMO day 3 remained an independent predictor of hospital and 90-day mortality, regardless of the statistical model used or the inclusion of a propensity score to have positive FB.

CONCLUSIONS

Positive FB at ECMO day 3 is an independent predictor of 90-day mortality. Further interventional studies aimed at testing the value of strategy of tight control of FB during the early ECMO period are now warranted.

Acute kidney injury in children: an update on diagnosis and treatment

The concept and definition of acute kidney injury (AKI) in adults and children has undergone significant change in recent years. Biomarker assessment is aiding in description, defining and understanding timing of AKI. AKI demonstrates unique characteristics in association with sepsis and septic shock, organ dysfunction, and fluid overload. Treatment remains problematic, but growing experience with pediatric continuous renal replacement therapies has improved the delivery of care in children. Increasingly, continuous renal replacement therapy is provided in combination with other extracorporeal technologies, and approaches are advancing to improve combined therapy use.

Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy

OBJECTIVE

In pediatric patients, fluid overload at continuous renal replacement therapy initiation is associated with increased mortality. The aim of this study was to characterize the association between fluid overload at continuous renal replacement therapy initiation, fluid removal during continuous renal replacement therapy, the kinetics of fluid removal and mortality in a large pediatric population receiving continuous renal replacement therapy while on extracorporeal membrane oxygenation.

DESIGN

Retrospective chart review.

SETTING

Tertiary children's hospital.

PATIENTS

Extracorporeal membrane oxygenation patients requiring continuous renal replacement therapy from July 2006 to September 2010.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Overall intensive care unit survival was 34% for 53 patients that were initiated on continuous renal replacement therapy while on extracorporeal membrane oxygenation during the study period. Median fluid overload at continuous renal replacement therapy initiation was significantly lower in survivors compared to nonsurvivors (24.5% vs. 38%, p = .006). Median fluid overload at continuous renal replacement therapy discontinuation was significantly lower in survivors compared to nonsurvivors (7.1% vs. 17.5%, p = .035). After adjusting for percent fluid overload at continuous renal replacement therapy initiation, age, and severity of illness, the change in fluid overload at continuous renal replacement therapy discontinuation was not significantly associated with mortality (p = .212). Models investigating the rates of fluid removal in different periods, age, severity of illness, and fluid overload at continuous renal replacement therapy initiation found that fluid overload at continuous renal replacement therapy initiation was the most consistent predictor of survival.

CONCLUSIONS

Our data demonstrate an association between fluid overload at continuous renal replacement therapy initiation and mortality in pediatric patients receiving extracorporeal membrane oxygenation. The degree of fluid overload at continuous renal replacement therapy discontinuation is also associated with mortality, but appears to reflect the effect of fluid overload at initiation. Furthermore, correction of fluid overload to ≤ 10% was not associated with improved survival. These results suggest that intervening prior to the development of significant fluid overload may be more clinically effective than attempting fluid removal after significant fluid overload has developed. Our findings suggest a role for earlier initiation of continuous renal replacement therapy in this population, and warrant further clinical studies.

A multicenter international survey of renal supportive therapy during ECMO: the Kidney Intervention During Extracorporeal Membrane Oxygenation (KIDMO) group

Acute kidney injury and fluid overload (FO) are associated with increased mortality in critically ill patients, including the subset supported with extracorporeal membrane oxygenation (ECMO). The indication for and method of application of renal support therapy (RST) during ECMO is largely unknown beyond single-center experiences. The current study uses a survey design to document practice variation regarding RST, including indication, method of interface with the ECMO circuit, and prescribing practices. Sixty-five international ECMO centers (31%) responded to an online electronic survey regarding RST during ECMO. Nearly a quarter of centers (23%) reported using no RST during ECMO. Among those using the therapy, the predominant mode of therapy applied was convection and included slow continuous ultrafiltration and continuous venovenous hemofiltration. The predominant indication for RST was the treatment (43%) or prevention (16%) of FO. Nephrology rather than critical care medicine is reported as the prescribing service in a majority of centers with a significant difference between US centers and non-US centers. The results of this study identify a wide variation in practice regarding RST during ECMO that will offer multiple important avenues for further research by this group and others regarding the interface of RST and ECMO.

Continuous renal replacement therapy in children

Over the past several decades, the epidemiology of acute kidney injury (AKI) in children has changed significantly. Pediatric patients with AKI frequently have co-morbid conditions, substantial fluid overload, and marked disease severity. At the same time, continuous renal replacement therapy (CRRT) has become the preferred modality for the management of these patients. This manuscript provides a state-of-the-art review of the technical aspects of pediatric CRRT and examines the most recent data regarding CRRT indications, timing of initiation, dosing, and outcomes in critically ill children.

Renal replacement therapy in critically ill patients receiving extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure used in neonates, children, and adults with severe, reversible, cardiopulmonary failure. On the basis of single-center studies, the incidence of AKI occurs in 70%-85% of ECMO patients. Those with AKI and those who require renal replacement therapy (RRT) are at high risk for mortality, independent of potentially confounding variables. Fluid overload is common in ECMO patients, and is one of the main indications for RRT. RRT to maintain fluid balance and metabolic control is common in some but not all centers. RRT on ECMO can be performed via an in-line hemofilter or by incorporating a standard continuous renal replacement machine into the ECMO circuit. Both of these methods require specific technical considerations to provide safe and effective RRT. This review summarizes available epidemiologic data and how they apply to our understanding of AKI pathophysiology during ECMO, identifies indications for RRT while on ECMO, reviews technical elements for RRT application in the setting of ECMO, and finally identifies specific research-focused questions that need to be addressed to improve outcomes in this at-risk population.

Recovery of renal function and survival after continuous renal replacement therapy during extracorporeal membrane oxygenation

OBJECTIVE

To assess the outcome of pediatric patients supported by concomitant extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT).

DESIGN, SETTING, AND PATIENTS

Acute kidney injury is associated with mortality in ECMO patients. CRRT in patients on ECMO provides an efficient and potentially beneficial method of acute kidney injury management. Concern that concomitant CRRT use increases the risk of developing anuria and chronic renal failure limits its use in some centers. We hypothesized that development of chronic renal failure is rare with concurrent ECMO and CRRT. We evaluated the outcomes of 154 ECMO/CRRT patients cared for over 10 yrs at a referral pediatric medical center.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 68 (44%) ECMO/CRRT survivors, 45 were assigned a pediatric risk, injury, failure, loss and end-stage (referred to as "pRIFLE") score at CRRT initiation. Seventeen (38%) patients met the criteria for Risk, 15 (33%) for Injury, and 10 (22%) for Failure. Two Failure patients later met End stage criteria. Of all survivors, 18 (26%) required ongoing renal replacement therapy (15 required continuous veno-venous hemofiltration, two required peritoneal dialysis, and one patient required intermittent hemodialysis) post ECMO discontinuation. Renal recovery occurred in 65 (96%) of 68 patients before discharge. One neonatal patient had sepsis-induced renal injury on transfer, but had normal creatinine 1 month later. Two pediatric patients with vasculitis and primary renal disease at presentation (both meeting Failure criteria) developed end-stage renal disease. One received peritoneal dialysis and subsequent renal transplant. The other has diminished function without need for renal replacement therapy.

CONCLUSION

In the absence of primary renal disease, chronic renal failure did not occur after concurrent use of CRRT with ECMO. Concern for precipitating chronic renal failure by using CRRT during ECMO is not substantiated by this large single-center experience. Consistent with previous reports, mortality is higher in patients receiving concomitant CRRT and ECMO compared with those receiving ECMO alone. Mortality is similar to patients requiring CRRT who are not on ECMO. Additional studies are warranted to determine the optimal role of CRRT use in ECMO patients.

The evolution of patient selection criteria and indications for extracorporeal life support in pediatric cardiopulmonary failure: next time, let's not eat the bones

Bill James, baseball statistician and author, tells the story of hungry cavemen sitting about a campfire, waiting for tomatoes to ripen. One has the inspiration to throw an ox on the fire, and the first barbecue ensued and was endured. After eating, the conversation goes something like this. "There were some good parts." "Yeah, but there were some bad parts." And the smart one says, "This time, let's not eat the bones." The evolution of patient selection criteria for the use of extracorporeal support (ECLS) is a bit like those cavemen and their first barbecued ox. Extracorporeal life support technology and application to patient care is the unique result of a long standing history of ambitious attempt, evaluation, debate, collaboration and extension.

Acute kidney injury and renal replacement therapy independently predict mortality in neonatal and pediatric noncardiac patients on extracorporeal membrane oxygenation

OBJECTIVE

To determine the independent impact of acute kidney injury (AKI) and renal replacement therapy (RRT) in infants and children who receive extracorporeal membrane oxygenation. Despite continued expertise/technological advancement, patients who receive extracorporeal membrane oxygenation have high mortality. AKI and RRT portend poor outcomes independent of comorbidities and illness severity in several critically ill populations.

DESIGN

Retrospective cohort study. The primary variables explored are AKI (categorical complication code for serum creatinine > 1.5 mg/dL or International Statistical Classification of Diseases and Related Health Problems, Revision 9 for acute renal failure), and RRT (complication/Current Procedural Terminology code for dialysis or hemofiltration). Multiple variables previously associated with mortality in this population were controlled, using logistic stepwise regression. Decision tree modeling was performed to determine optimal variables and cut points to predict mortality.

PATIENTS

Critically ill neonates (0-30 days old) and children (> 30 days but < 18 yrs old) in the Extracorporeal Life Support Organization registry.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Neonatal mortality was 2175 (27.4%) of 7941. Nonsurvivors experienced more AKI (413 [19%] of 2175 vs. 225 [3.9%] of 5766, p < .0001), and more received RRT (863 [39.7%] of 2175 vs. 923 [16.0%] of 5766, p < .0001) than survivors. Pediatric mortality was 816 (41.6%) of 1962. Pediatric nonsurvivors similarly experienced more AKI (264 [32.3%] of 816 vs. 138 [12.0%] of 1146, p < .0001) and RRT (487 [58.9%] of 816 vs. 353 [30.8%] of 1146, p < .0001) than survivors. After adjusting for confounding variables, the adjusted odds ratio for neonatal group was 3.2 (p < .0001) post AKI and 1.9 (p < .0001) given RRT. Similarly, the pediatric adjusted odds ratio for mortality was 1.7 (p < .001) post AKI and 2.5 (p < .0001) given RRT. AKI and RRT were essential in the neonatal and pediatric mortality decision trees.

CONCLUSIONS

After adjusting for known predictors of mortality, AKI and RRT independently predict mortality in neonates and children, who receive extracorporeal membrane oxygenation. Ascertainment of AKI risk factors, testing novel therapies, and optimizing the timing/delivery of RRT may positively impact survival.

Significance of hemolysis on extracorporeal life support after cardiac surgery in children

Hemolysis is common during extracorporeal life support (ECLS). Elevated levels of circulating plasma free hemoglobin (FHb) has been linked to the development of hemoglobinuria nephropathy. Its clinical significance in patients receiving ECLS remains unknown. Medical records of 104 children <3 years old who required ECLS after repair of congenital heart disease were reviewed. Forty-two patients required continuous renal replacement therapy (CRRT) during ECLS (CRRT group), and 62 patients did not (no-CRRT group). For all patients, FHb level and the degree of fluid overload at the end of ECLS predicted the mortality rate during ECLS. Compared with the no-CRRT group, the CRRT group had a higher mortality rate during ECLS, a higher peak FHb level during ECLS, a higher FHb level at the end of ECLS, and more days of ECLS. In the CRRT group, the FHb level at the end of ECLS predicted death during ECLS. In the no-CRRT group, the peak FHb level was associated with a worse renal function. In conclusion, elevated FHb levels were associated with renal dysfunction and death during ECLS in children undergoing cardiac surgery. Further studies are needed to elucidate the cause-effect relationship in our findings.

Continuous venovenous hemofiltration with or without extracorporeal membrane oxygenation in children

OBJECTIVES

We report the frequency of usage, patient demographics, and outcomes in children treated with continuous venovenous hemofiltration (CVVH) in three pediatric intensive care units (PICUs), with one unit providing combined extracorporeal membrane oxygenation (ECMO) and CVVH.

DESIGN

Prospective database analysis.

SETTING

Three regional PICUs in the Trent Haemofiltration Network with two general PICUs admitting 450-500 patients annually and the other providing regional cardiac support and a supraregional service for ECMO (600-650 admissions annually with 50 ECMO patients).

PATIENTS

Children who underwent CVVH alone or in combination with ECMO or other therapies between January 2000 and December 2002.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 115 children (58 male) treated, with a median age of 18 months (range 1 day to 17 yrs) and median weight of 12 kg (range 1.8-119 kg). In the two PICUs without ECMO, CVVH was undertaken in 2.5% of admissions annually compared with 3% of annual admissions to the PICU with an ECMO service. Fifty-five patients received CVVH alone (group 1), while 53 patients underwent CVVH in conjunction with ECMO (group 2). In addition, five patients received plasmafiltration followed by CVVH, and two patients were treated with combined CVVH and molecular adsorbents recirculating system. Mean duration of therapy in group 1 was 142 hrs (1-840 hrs) and in group 2,231 hrs (3-1104 hrs). Overall patient survival was 43% with 29 of 55 (53%) CVVH patients surviving and 18 of 53 (34%) of those treated with ECMO plus CVVH.

CONCLUSIONS

Performing CVVH in a heterogeneous population with large age and weight ranges poses significant clinical and technical challenges. The low frequency of CVVH use, as well as the use of other extracorporeal therapies, also raises problems with maintaining nursing skills. Objective clinical and biochemical markers for commencing CVVH alone or in combination with ECMO remain to be defined.

Continuous renal replacement therapy in neonates and young infants during extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a therapy that ensures adequate tissue oxygen delivery in patients suffering cardiac and/or respiratory failure that are unresponsive to conventional therapy. During ECMO, it is common to see a decrease in urine output that may be associated with acute renal failure. In this context, continuous renal replacement therapy (CRRT) should be considered. Our aim is to evaluate a pioneer experience in Latin America, related to the use of CRRT in a group of neonatal-pediatric patients during ECMO. We conducted a retrospective review of patients treated with ECMO at our institution between May 2003 and May 2005. Twelve infants were treated with ECMO, six of them also underwent CRRT. The main reasons for CRRT initiation were fluid overload and progressive azotemia. Observed complications were clots in the filter and excessive ultrafiltration. CRRT was successful in fluid management and solute clearance in all patients. Discharge survival rate was 83%, all of them with normal renal function. Concurrent CRRT with ECMO is technically feasible and efficacious in the management of fluid overload and solute clearance. We report the first experience with these therapies in a Latin American neonatal-pediatric ECMO program associated with the Extracorporeal Life Support Organization.

Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery

BACKGROUND

Extracorporeal life support (ECLS) has been used for over two decades in select patients after cardiac surgery. We previously described factors associated with death in this population. We now review our recent experience to reassess factors related to mortality.

METHODS

All pediatric patients who received ECLS support within 7 days after surgery between July 1995 and June 2001 were examined to describe clinical features associated with survival. We compared the results with our prior report to assess changes in practice and outcome.

RESULTS

Seventy-four patients were followed. Fifty percent survived to discharge. Hospital survival was not significantly related to patient age, cannulation site, or indication. Thirty-five percent of patients required hemofiltration while on ECLS and were significantly less likely to survive (23% vs 65%). A multivariate analysis combining all children from our prior report with the present cohort revealed that patients who received hemofiltration were five times more likely to die (odds ratio 5.01, 95% confidence interval 2.11-11.88). Children with an adequate two-ventricular repair had lower risk of death (odds ratio 0.42, 95% confidence interval 0.19-0.91) after adjusting for patient age, study period, and hours elapsed before initiation of ECLS after surgery.

CONCLUSIONS

Patients with an adequate two-ventricle repair have significantly higher hospital survival, whereas those with single ventricle physiology or need for dialysis have decreased survival.