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

Antithrombin III infusion improves anticoagulation in congenital diaphragmatic hernia patients on extracorporeal membrane oxygenation

PURPOSE

Achieving effective anticoagulation during neonatal extracorporeal membrane oxygenation (ECMO) without increasing the risk of hemorrhage remains challenging. The use of antithrombin III (AT-III) for this purpose has been examined, but studies have been limited to intermittent bolus dosing. We aimed to evaluate the efficacy and safety of an institutionally developed AT-III continuous infusion protocol in neonates receiving ECMO for the treatment of congenital diaphragmatic hernia (CDH).

METHODS

In this single center, retrospective study, all neonates with a CDH who received ECMO support during the study period were included. Data on anticoagulation labs and therapy, life-threatening bleeding, and circuit changes were analyzed.

RESULTS

Eleven patients were divided into two groups: patients with AT-III continuous infusion (n = 5) and without (n = 6). There were no differences in the gestational age (p = 0.29), sex (p = 1.00), ECMO duration (p = 0.59), or initial AT-III levels (p = 0.76) between groups. Patients in the AT-III infusion group had on average 18.5% higher AT-III levels (p < 0.0001). Patients receiving continuous AT-III infusions spent a significantly higher percentage of ECMO time within the therapeutic range, measured using anti-Factor Xa levels (64.9±4.2% vs. 29.1±8.57%, p = 0.008), and required fewer changes to the heparin infusion rate (6.48±0.88 vs 2.38±0.36 changes/day changes/day, p = 0.005). Multivariate analysis revealed continuous infusion of AT-III did not increase the rate of intracranial or surgical bleeding (p = 0.27).

CONCLUSION

AT-III as a continuous infusion in CDH neonates on ECMO provides a decreased need to modify heparin infusion and more consistent therapeutic anticoagulation without increasing the risk of life-threatening bleeding.

A novel strategy sequentially linking mechanical cardiopulmonary resuscitation with extracorporeal cardiopulmonary resuscitation optimizes prognosis of refractory cardiac arrest: an illustrative case series

Background

Extracorporeal membrane oxygenation (ECMO) to support cardiopulmonary resuscitation (CPR), also known as extracorporeal cardiopulmonary resuscitation (ECPR), has shown encouraging results in refractory cardiac arrest (RCA) resuscitation. However, its therapeutic benefits are linked to instant and uninterrupted chest compression (CC), besides early implementation. Mechanical CC can overcome the shortcomings of conventional manual CC, including fatigue and labor consumption, and ensure adequate blood perfusion. A strategy sequentially linking mechanical CPR with ECPR may earn extra favorable outcomes.

Case series

We present a four-case series with ages ranging from 8 to 94 years who presented with prolonged absences of return of spontaneous circulation (ROSC) after CA associated with acute fulminant myocarditis (AFM) and myocardial infarction (MI). All the cases received VA-ECMO (ROTAFLOW, Maquet) assisted ECPR, with intra-aortic balloon pump (IABP) or continuous renal replacement treatment (CRRT) appended if persistently low mean blood pressure (MAP) or ischemic kidney injury occurred. All patients have successfully weaned off ECMO and the assistant life support devices with complete neurological recovery. Three patients were discharged, except the 94-year-old patient who died of irreversible sepsis 20 days after ECMO weaning-off. These encouraging results will hopefully lead to more consideration of this lifesaving therapy model that sequentially integrates mechanical CPR with ECPR to rescue RCA related to reversible cardiac causes.

Conclusions

This successful case series should lead to more consideration of an integrated lifesaving strategy sequentially linking mechanical cardiopulmonary resuscitation with ECPR, as an extra favorable prognosis of refractory cardiac arrest related to this approach can be achieved.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00711-1.

Postcardiotomy Extracorporeal Membrane Oxygenation Support in Patients with Congenital Heart Disease

Background

This study investigated mortality and morbidity in patients requiring post-cardiotomy extracorporeal membrane oxygenation (ECMO) support after operations for congenital heart disease (CHD).

Methods

CHD patients requiring postoperative ECMO support between May 2011 and May 2021 were retrospectively reviewed. Patients were divided into non-survivors and survivors to hospital discharge. Survival outcomes and associations of various factors with in-hospital death were analyzed.

Results

Fifty patients required postoperative ECMO support. Patients' median age and weight at the time of ECMO insertion were 1.85 months (interquartile range [IQR], 0.23-14.5 months) and 3.84 kg (IQR, 3.08-7.88 kg), respectively. Twenty-nine patients (58%) were male. The median duration of ECMO support was 6 days (IQR, 3-12 days). Twenty-nine patients (58%) died on ECMO support or after ECMO weaning, and 21 (42%) survived to hospital discharge. Postoperative complications included renal failure (n=33, 66%), bleeding (n=11, 22%), and sepsis (n=15, 30%). Prolonged ECMO support (p=0.017), renal failure (p=0.005), continuous renal replacement therapy (CRRT) application (p=0.001), sepsis (p=0.012), bleeding (p=0.032), and high serum lactate (p=0.002) and total bilirubin (p=0.017) levels during ECMO support were associated with higher mortality risk in a univariate analysis. A multivariable analysis identified CRRT application (p=0.013) and a high serum total bilirubin level (p=0.001) as independent risk factors for death.

Conclusion

Postcardiotomy ECMO should be considered as an important therapeutic modality for patients unresponsive to conventional management. ECMO implementation strategies and management in appropriate patients without severe complications, particularly renal failure and/or liver failure, are crucial for achieving positive outcomes.

Ethical Considerations in Ever-Expanding Utilization of ECLS: A Research Agenda

Technological advancements and rapid expansion in the clinical use of extracorporeal life support (ECLS) across all age ranges in the last decade, including during the COVID-19 pandemic, has led to important ethical considerations. As a costly and resource intensive therapy, ECLS is used emergently under high stakes circumstances where there is often prognostic uncertainty and risk for serious complications. To develop a research agenda to further characterize and address these ethical dilemmas, a working group of specialists in ECLS, critical care, cardiothoracic surgery, palliative care, and bioethics convened at a single pediatric academic institution over the course of 18 months. Using an iterative consensus process, research questions were selected based on: (1) frequency, (2) uniqueness to ECLS, (3) urgency, (4) feasibility to study, and (5) potential to improve patient care. Questions were categorized into broad domains of societal decision-making, bedside decision-making, patient and family communication, medical team dynamics, and research design and implementation. A deeper exploration of these ethical dilemmas through formalized research and deliberation may improve equitable access and quality of ECLS-related medical care.

Noninvasive optical measurement of microvascular cerebral hemodynamics and autoregulation in the neonatal ECMO patient

BACKGROUND

Extra-corporeal membrane oxygenation (ECMO) is a life-saving intervention for severe respiratory and cardiac diseases. However, 50% of survivors have abnormal neurologic exams. Current ECMO management is guided by systemic metrics, which may poorly predict cerebral perfusion. Continuous optical monitoring of cerebral hemodynamics during ECMO holds potential to detect risk factors of brain injury such as impaired cerebrovascular autoregulation (CA).

METHODS

We conducted daily measurements of microvascular cerebral blood flow (CBF), oxygen saturation, and total hemoglobin concentration using diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy in nine neonates. We characterize CA utilizing the correlation coefficient (DCSx) between CBF and mean arterial blood pressure (MAP) during ECMO pump flow changes.

RESULTS

Average MAP and pump flow levels were weakly correlated with CBF and were not correlated with cerebral oxygen saturation. CA integrity varied between individuals and with time. Systemic measurements of MAP, pulse pressure, and left cardiac dysfunction were not predictive of impaired CA.

CONCLUSIONS

Our pilot results suggest that systemic measures alone cannot distinguish impaired CA from intact CA during ECMO. Furthermore, optical neuromonitoring could help determine patient-specific ECMO pump flows for optimal CA integrity, thereby reducing risk of secondary brain injury.

IMPACT

Cerebral blood flow and oxygenation are not well predicted by systemic proxies such as ECMO pump flow or blood pressure. Continuous, quantitative, bedside monitoring of cerebral blood flow and oxygenation with optical tools enables new insight into the adequacy of cerebral perfusion during ECMO. A demonstration of hybrid diffuse optical and correlation spectroscopies to continuously measure cerebral blood oxygen saturation and flow in patients on ECMO, enabling assessment of cerebral autoregulation. An observation of poor correlation of cerebral blood flow and oxygenation with systemic mean arterial pressure and ECMO pump flow, suggesting that clinical decision making guided by target values for these surrogates may not be neuroprotective. ~50% of ECMO survivors have long-term neurological deficiencies; continuous monitoring of brain health throughout therapy may reduce these tragically common sequelae through brain-focused adjustment of ECMO parameters.

Cerebral Hemodynamic Profile in Ischemic and Hemorrhagic Brain Injury Acquired During Pediatric Extracorporeal Membrane Oxygenation

OBJECTIVES

To describe the cerebral hemodynamic profiles associated with ischemic and hemorrhagic brain injury during neonatal and pediatric extracorporeal membrane oxygenation.

DESIGN

A retrospective cohort study.

SETTING

Tertiary PICU.

PATIENTS

Forty-seven neonatal and pediatric patients (0-15 yr of age) placed on extracorporeal membrane oxygenation from January 2014 to December 2018.

MEASUREMENTS AND MAIN RESULTS

Continuous monitoring of mean arterial pressure and cerebral tissue oxygen saturation was conducted through entire extracorporeal membrane oxygenation run. Wavelet analysis was performed to assess changes in cerebral autoregulation and to derive pressure-dependent autoregulation curves based on the mean arterial pressure and cerebral tissue oxygen saturation data. Patients were classified into three brain injury groups: no-injury, ischemic injury, and hemorrhagic injury based on neuroimaging results. No-injury patients (n = 23) had minimal variability in the autoregulation curve over a broad range of blood pressure. Ischemic injury (n = 16) was more common than hemorrhagic injury (n = 8), and the former was associated with increased mortality and morbidity. Ischemic group showed significant abnormalities in cerebral autoregulation in the lower blood pressure range, suggesting pressure-dependent cerebral perfusion. Hemorrhagic group had highest average blood pressure as well as the lowest cerebral tissue oxygenation saturation, suggesting elevated cerebral vascular resistance. Mean heparin dose during extracorporeal membrane oxygenation was lower in both ischemic and hemorrhagic groups compared with the no-injury group.

CONCLUSIONS

This study outlines distinct differences in underlying cerebral hemodynamics associated with ischemic and hemorrhagic brain injury acquired during extracorporeal membrane oxygenation. Real-time monitoring of cerebral hemodynamics in patients acquiring brain injury during extracorporeal membrane oxygenation can help optimize their management.

Drug Disposition and Pharmacotherapy in Neonatal ECMO: From Fragmented Data to Integrated Knowledge

Extracorporeal membrane oxygenation (ECMO) is a lifesaving support technology for potentially reversible neonatal cardiac and/or respiratory failure. As the survival and the overall outcome of patients rely on the treatment and reversal of the underlying disease, effective and preferentially evidence-based pharmacotherapy is crucial to target recovery. Currently limited data exist to support the clinicians in their every-day intensive care prescribing practice with the contemporary ECMO technology. Indeed, drug dosing to optimize pharmacotherapy during neonatal ECMO is a major challenge. The impact of the maturational changes of the organ function on both pharmacokinetics (PK) and pharmacodynamics (PD) has been widely established over the last decades. Next to the developmental pharmacology, additional non-maturational factors have been recognized as key-determinants of PK/PD variability. The dynamically changing state of critical illness during the ECMO course impairs the achievement of optimal drug exposure, as a result of single or multi-organ failure, capillary leak, altered protein binding, and sometimes a hyperdynamic state, with a variable effect on both the volume of distribution (Vd) and the clearance (Cl) of drugs. Extracorporeal membrane oxygenation introduces further PK/PD perturbation due to drug sequestration and hemodilution, thus increasing the Vd and clearance (sequestration). Drug disposition depends on the characteristics of the compounds (hydrophilic vs. lipophilic, protein binding), patients (age, comorbidities, surgery, co-medications, genetic variations), and circuits (roller vs. centrifugal-based systems; silicone vs. hollow-fiber oxygenators; renal replacement therapy). Based on the potential combination of the above-mentioned drug PK/PD determinants, an integrated approach in clinical drug prescription is pivotal to limit the risks of over- and under-dosing. The understanding of the dose-exposure-response relationship in critically-ill neonates on ECMO will enable the optimization of dosing strategies to ensure safety and efficacy for the individual patient. Next to in vitro and clinical PK data collection, physiologically-based pharmacokinetic modeling (PBPK) are emerging as alternative approaches to provide bedside dosing guidance. This article provides an overview of the available evidence in the field of neonatal pharmacology during ECMO. We will identify the main determinants of altered PK and PD, elaborate on evidence-based recommendations on pharmacotherapy and highlight areas for further research.

Nosocomial Infections in Neonates Supported by Extracorporeal Membrane Oxygenation: First French Retrospective Study

How to cite this article: Rambaud J, Allioux C, Jean S, Guilbert J, Guellec I, Demoulin M, et al. Nosocomial Infections in Neonates Supported by Extracorporeal Membrane Oxygenation: First French Retrospective Study. Indian J Crit Care Med 2019;23(9):392–395.

Training-induced white matter microstructure changes in survivors of neonatal critical illness: A randomized controlled trial

In a nationwide randomized controlled trial, white matter microstructure was assessed before and immediately after Cogmed Working-Memory Training (CWMT) in school-age neonatal critical illness survivors. Eligible participants were survivors (8-12 years) with an IQ ≥ 80 and a z-score of ≤ -1.5 on (working)memory test at first assessment. Diffusion Tensor Imaging was used to assess white matter microstructure. Associations between any training-induced changes and improved neuropsychological outcome immediately and one year post-CWMT were evaluated as well. The trial was conducted between October 2014-June 2017 at Erasmus MC-Sophia, Rotterdam, Netherlands. Researchers involved were blinded to group allocation. Participants were randomized to CWMT(n = 14) or no-intervention(n = 20). All children completed the CWMT. Global fractional anisotropy(FA) increased significantly post-CWMT compared to no-intervention(estimated-coefficient = .007, p = .015). Increased FA(estimated coefficient = .009, p = .033) and decreased mean diffusivity(estimated-coefficient = -.010, p = .018) were found in the left superior longitudinal fasciculus(SFL) post-CWMT compared no-intervention. Children after CWMT who improved with >1SD on verbal working-memory had significantly higher FA in the left SLF post-CWMT(n = 6; improvement = .408 ± .01) than children without this improvement post-CWMT(n = 6; no-improvement = .384 ± .02), F(1,12) = 6.22, p = .041, ηp2 = .47. No other structure-function relationships were found post-CWMT. Our findings demonstrate that white matter microstructure and associated cognitive outcomes are malleable by CWMT in survivors of neonatal critical illness.

Predictors and outcomes of early post-operative veno-arterial extracorporeal membrane oxygenation following infant cardiac surgery

Background

We aimed to determine predictors of, and outcomes after, veno-arterial extracorporeal membrane oxygenation instituted within 48 h after cardiac surgery (early ECMO) in young infants.

Methods

Patients ≤ 6 weeks old having cardiac surgery from 2003 to 2012 were enrolled prospectively. Patients cannulated pre-operatively, intra-operatively, or ≥ 48 h post-operatively were excluded. Variables at p ≤ 0.1 on univariate regression were entered into multiple logistic regression to predict early ECMO. Early-ECMO cases were matched 1:2 for six demographic variables, and death by age 2 years old (determined using conditional logistic regression; presented as odds ratio (OR), 95% confidence interval (CI)) and General Adaptive Composite scores at age 2 years (determined using Wilcoxon rank sum) were compared; p ≤ 0.05 was considered statistically significant.

Results

Of 565 eligible patients over the 10-year period, 20 had early ECMO instituted at a mean (standard deviation) of 12.4 (11.4) h post-operatively, 10 of whom had extracorporeal cardiopulmonary resuscitation. Of early-ECMO patients, 8 (40%) were found to have residual anatomic defects requiring intervention with catheterization (n = 1) and/or surgery (n = 7). On multiple regression, the post-operative day 1 highest vasoactive-inotrope score (OR 1.02; 95%CI 1.06,1.08; p < 0.001), highest lactate (OR 1.2; 95%CI 1.06,1.35; p = 0.003), and lowest base deficit (OR 0.82; 95%CI 0.71,0.94; p = 0.004), CPB time (OR 1.01; 95%CI 1.00,1.02; p = 0.002), and single-ventricle anatomy (OR 5.35; 95%CI 1.66,17.31; p = 0.005) were associated with early ECMO. Outcomes at 2 years old compared between early-ECMO and matched patients were mortality 11/20 (55%) vs 11/40 (28%) (OR 3.22, 95%CI 0.98,10.63; p = 0.054) and General Adaptive Composite median 65 [interquartile range (IQR) 58, 81.5] in 9 survivors vs 93 [IQR 86.5, 102.5] in 29 survivors (p = 0.02).

Conclusions

The identified risk factors for, and outcomes after, having early ECMO may aid decision making in the acute period and confirm that neurodevelopmental follow-up for these children is necessary. The hypothesis that earlier institution of ECMO may improve long-term outcomes requires further study.

Regional Cerebral Abnormalities Measured by Frequency-Domain Near-Infrared Spectroscopy in Pediatric Patients During Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is a form of advanced cardiorespiratory support provided to critically ill patients with severe respiratory or cardiovascular failure. While children undergoing ECMO therapy have significant risk for neurological morbidity, currently there is a lack of reliable bedside tool to detect the neurologic events for patients on ECMO. This study assessed the feasibility of frequency-domain near-infrared spectroscopy (NIRS) for detection of intracranial complications during ECMO therapy. The frequency-domain NIRS device measured the absorption coefficient (µa) and reduced scattering coefficient (µs') at six cranial positions from seven pediatric patients (0-16 years) during ECMO support and five healthy controls (2-14 years). Regional abnormalities in both absorption and scattering were identified among ECMO patients. A main finding in this study is that the abnormalities in scattering appear to be associated with lower-than-normal µs' values in regional areas of the brain. Because light scattering originates from the intracellular structures (such as nuclei and mitochondria), a reduction in scattering primarily reflects loss or decreased density of the brain matter. The results from this study indicate a potential to use the frequency-domain NIRS as a safe and complementary technology for detection of intracranial complications during ECMO therapy.

Implementing and Assessing a Standardized Protocol for Weaning Children Successfully From Extracorporeal Life Support

Extracorporeal life support (ECLS) weaning is a complex interdisciplinary process with no clear guidelines. To assess ventricular and pulmonary function as well as hemodynamics including end-organ recovery during ECLS weaning, we developed a standardized weaning protocol. We reviewed our experience 2 years later to assess its feasibility and efficacy. In 2015 we established an inter-professional, standardized, stepwise protocol for weaning from ECLS. If the patient did not require further surgery, weaning was conducted bedside in the intensive care unit (ICU). Most of the weaning procedures are guided via echocardiography. Data acquisition began at baseline level, followed by four-step course (each step lasting 10 min), entailing flow-reduction and ending 30 min after decannulation. Moreover, data from the preprotocol era are presented. Between May 2015 and 2017, 26 consecutive patients (18 male), median age 177 days (2 days-20 years) required ECLS with median support of 4 (2-11) days. Excluding eight not weanable patients, 21 standardized weaning procedures were protocolled in the remaining 18 children. Our generally successful protocol-guided weaning rate (with at least 24-h survival) was 89%, with a discharge home rate of 58%. Practical application of the novel standard protocol seems to facilitate ECLS weaning and to improve its success rate. The protocol can be administered as part of standard bedside ICU assessment.

Thromboprophylaxis in Extracorporeal Circuits: Current Pharmacological Strategies and Future Directions

The development of extracorporeal devices for organ support has been a part of medical history and progression since the late 1900s. These types of technology are primarily used and developed in the field of critical care medicine. Unfractionated heparin, discovered in 1916, has really been the only consistent form of thromboprophylaxis for attenuating or even preventing the blood-biomaterial reaction that occurs when such technologies are initiated. The advent of regional anticoagulation for procedures such as continuous renal replacement therapy and plasmapheresis have certainly removed the risks of systemic heparinization and heparin effect, but the challenges of the blood-biomaterial reaction and downstream effects remain. In addition, regional anticoagulation cannot realistically be applied in a system such as extracorporeal membrane oxygenation because of the high blood flow rates needed to support the patient. More recently, advances in the technology itself have resulted in smaller, more compact extracorporeal life support (ECLS) systems that can-at certain times and in certain patients-run without any form of anticoagulation. However, the majority of patients on ECLS systems require some type of systemic anticoagulation; therefore, the risks of bleeding and thrombosis persist, the most devastating of which is intracranial hemorrhage. We provide a concise overview of the primary and alternate agents and monitoring used for thromboprophylaxis during use of ECLS. In addition, we explore the potential for further biomaterial and technologic developments and what they could provide when applied in the clinical arena.

Impairment of cerebral autoregulation in pediatric extracorporeal membrane oxygenation associated with neuroimaging abnormalities

Extracorporeal membrane oxygenation (ECMO) is a life-supporting therapy for critically ill patients with severe respiratory and/or cardiovascular failure. Cerebrovascular impairment can result in hemorrhagic and ischemic complications commonly seen in the patients supported on ECMO. We investigated the degree of cerebral autoregulation impairment during ECMO as well as whether it is predictive of neuroimaging abnormalities. Spontaneous fluctuations of mean arterial pressure (MAP) and cerebral tissue oxygen saturation ([Formula: see text]) were continuously measured during the ECMO run. The dynamic relationship between the MAP and [Formula: see text] fluctuations was assessed based on wavelet transform coherence (WTC). Neuroimaging was conducted during and/or after ECMO as standard of care, and the abnormalities were evaluated based on a scoring system that had been previously validated among ECMO patients. Of the 25 patients, 8 (32%) had normal neuroimaging, 7 (28%) had mild to moderate neuroimaging abnormalities, and the other 10 (40%) had severe neuroimaging abnormalities. The degrees of cerebral autoregulation impairment quantified based on WTC showed significant correlations with the neuroimaging scores ([Formula: see text]; [Formula: see text]). Evidence that cerebral autoregulation impairment during ECMO was related to the patients' neurological outcomes was provided.

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.

The use of neonatal extracorporeal life support in pediatric cardiac intensive care unit

AIM

The aim of the study is to evaluate extracorporeal life support system (ECLS) employed in neonates in pediatric cardiac intensive care unit.

MATERIAL AND METHODS

Twenty-five neonates that required ECLS in between November 2010 and November 2015 were evaluated.

RESULTS

The median age was 12 days (range 3-28 days) and the median body weight was 3 kg (range 2.5-5 kg). Venoarterial ECLS was performed in all of the cases. Ascendan aorta-right atrial cannulation in 22 patients and neck cannulation in three patients were performed. The reason for ECLS was E-CPR in two patients, inability to wean from cardiopulmonary bypass (CPB) in seven patients, respiratory insufficiency and hypoxia in nine patients, low cardiac output (LCOS) in seven patients. Median duration of ECLS was four days (range 1-15). Hemorrhagic complications developed in 15, renal complications in 13, pulmonary complications in 12, infectious complications in 11, neurologic complications in three and mechanical complications in two of the patients. Weaning was successful in 15 of the patients. Eleven patients were successfully discharged.

CONCLUSION

ECLS is an important treatment option that is performed successfully in many centers around the world to maintain life support in patients unresponsive to medical treatment. The utilization of this modality especially in newborns with congenital heart disease should be taken into consideration.

Minimal invasive lung support via umbilical vein with a double-lumen cannula in a neonatal lamb model: a proof of principle

PURPOSE

Acute respiratory distress syndrome, with the need for invasive mechanical ventilation (MV) remains a major cause of neonatal mortality and morbidity. Although venovenous extracorporeal lung support (VV-ECLS) has become a standard of care procedure in neonatal patients with acute pulmonary failure there are no reports regarding the use of a double-lumen cannula for extracorporeal minimal invasive lung support via the umbilical vein.

METHODS

A neonatal lamb model was used (n = 3). Umbilical vein was cannulated with a double-lumen catheter allowing venovenous extracorporeal gas exchange. Cannula was positioned with its tip in the right atrium. VV-ECLS was started and ventilation was stopped. Providing oxygenation and CO2 removal solely through VV-ECLS hemodynamics, blood gases were measured.

RESULTS

Total VV-ECLS without MV was applied to all three neonatal lambs. Time on venovenous ECLS was 60, 120 and 120 min. Initial pCO2 was 60, 56 and 65 mmHg compared to 31, 32 and 32 mmHg at the end of VV-ECLS. Initial pO2 was 30, 27 and 26 mmHg compared to 22, 19 and 23 mmHg. Initial lactate was 5, 10 and 3.7 mmol/l compared to 13.3, 12.6 and 11.3 mmol/l at the end of VV-ECLS. MAP at baseline was 51, 52 and 65 mmHg compared to 36, 38 and 41 mmHg at the end of VV-ECLS. In all three lambs inotropes were admitted to maintain MAD >35 mmHg.

CONCLUSION

Even without mechanical ventilation we were able to sufficiently remove pCO2 with our new minimal invasive VV-ECLS using a double-lumen catheter via the umbilical vein, supporting the idea of a lung protective strategy in neonatal acute respiratory failure. pO2 was measured 22, 19 and 23 mmHg, respectively, at the end of VV-ECLS, at least partially caused by recirculation phenomenon, which could possibly be improved by different cannula design. Inotropic support was necessary during VV-ECLS to achieve targeted MAD > 35 mmHg. While technically feasible, this new approach might allow further research in the field of extracorporeal lung support and therefore will follow the concept of a lung protective strategy in acute neonatal respiratory failure.

"Awake Veno-arterial Extracorporeal Membrane Oxygenation" in Pediatric Cardiogenic Shock: A Single-Center Experience

In pediatric patients with acute refractory cardiogenic shock (CS), extracorporeal membrane oxygenation (ECMO) remains an established procedure to maintain adequate organ perfusion. In this context, ECMO can be used as a bridging procedure to recovery, VAD or transplantation. While being supported by ECMO, most centers tend to keep their patients well sedated and supported by invasive ventilation. This may be associated with an increased risk of therapy-related morbidity and mortality. In order to optimize clinical management in pediatric patients with ECMO therapy, we report our strategy of veno-arterial ECMO (VA-ECMO) in extubated awake and conscious patients. We therefore present data of six of our patients with CS, who were treated by ECMO being awake without continuous analgosedation and invasive ventilation. Of these six patients, four were <1 year and two >14 years of age. Median time on ECMO was 17.4 days (range 6.9-94.2 days). Median time extubated, while receiving ECMO support was 9.5 days. Mean time extubated was 78 % of the total time on ECMO. Three patients reached full recovery of cardiac function on "Awake-VA-ECMO," whereas the other three were successfully bridged to destination therapy (VAD, heart transplantation, withdrawal). Four out of our six patients are still alive. Complications related to ECMO therapy (i.e., severe bleeding, site infection or dislocation of cannulas) were not observed. We conclude that "Awake-VA-ECMO" in extubated, spontaneously breathing conscious pediatric patients is feasible and safe for the treatment of acute CS and can be used as a "bridging therapy" to recovery, VAD implantation or transplantation.

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.

Calcium homeostasis disorder during and after neonatal extracorporeal membrane oxygenation

BACKGROUND AND AIMS

Extracorporeal membrane oxygenation (ECMO) is used during pediatric resuscitation in case of refractory hypoxemia or septic shock under maximum therapy. Previous studies describe calcium homeostasis dysregulation. The aim of this study was to confirmed of calcium homeostasis dysregulation in neonates under ECMO and supposed news explanation.

SUBJECTS AND METHODS

From November 2012 to July 2013, we performed a prospective single center observational study. Eleven neonatal patients were included. Blood was obtained before and during ECMO (day 7, 14 and 21) for parathyroid hormone (PTH), protein adjusted serum calcium, ionized calcium, magnesium, and calcitriol levels. All surviving patients underwent a consultation up to 6 months after ECMO weaning.

RESULTS

During ECMO PTH was inadequately high with normal serum calcium on day 7 (PTH: 73.54 ± 40 ng/l; calcemia: 2.33 ± 0.21 mmol/l), day 14 (PTH: 57.63 ± 29.57 ng/l; calcemia: 2.44 ± 0.43 mmol/l) and day 21 (PTH: 54.93 ± 8.43 ng/l; calcemia: 2.13 ± 0.09 mmol/l). The absence of correlation between serum calcium and PTH levels seem to confirm the dysregulation of PTH - serum calcium metabolism during ECMO. Six months after ECMO weaning, we noticed hypercalcemia with normal PTH.

CONCLUSIONS

We confirmed the existence of severe disturbances of calcium homeostasis in neonates on ECMO and supposed the possible damage of calcium regulation. We did not succeed in finding clear explanations of these disturbances.

Diverse Morbidity and Mortality Among Infants Treated with Venoarterial Extracorporeal Membrane Oxygenation

Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is utilized for cardiopulmonary failure. We aimed to qualify and quantify the predictors of morbidity and mortality in infants requiring VA-ECMO.

Methods: Data was collected from 170 centers participating in the extracorporeal life support organization (ELSO) registry. Relationships between in-hospital mortality and risk factors were assessed using logistic regression. Survival was defined as being discharged from the hospital.

Results: Six hundred and sixty-two eligible records were reviewed. Mortality occurred in 303 (46%) infants. Congenital diaphragmatic hernia patients (OR=3.83, 95% CI 1.96-7.49, p<0.001), cardiac failure with associated shock (OR= 2.90, 95% CI 1.46-5.77, p=0.002), and pulmonary failure including respiratory distress syndrome (OR=4.06, 95% CI 1.72-9.58, p=0.001) had the highest odds of mortality in this cohort. Birth weight (BW) < 3 kg (OR=1.83, 95% CI 1.21-2.78, p=0.004), E-CPR (OR=3.35, 95% CI 1.57-7.15, p=0.002), hemofiltration (OR=2.04, 95% CI 1.32-3.16, p=0.001), and dialysis (OR=6.13, 95% CI 1.70-22.1, p<0.001) were all independent predictors of mortality.

Conclusion: Infants requiring VA-ECMO experience diverse sequelae and their mortality are high.

Infections in Children Receiving Extracorporeal Life Support

Objective.

To describe risk factors for and the outcome of infections in children receiving extracorporeal life support (ECLS) and to determine the need for removal of foreign bodies with bloodstream infections (BSIs) in children receiving ECLS.

Design.

Retrospective cohort study.

Setting.

Tertiary care children's hospital.

Patients.

Children receiving ECLS from May 1997 through May 2007.

Methods.

For patients with documented infections, medical records were examined for demographic, clinical, and laboratory details. Patients with and without documented infections were compared with regard to demographic characteristics and ECLS course.

Results.

One hundred seventeen patients underwent ECLS for a total of 878 days (median, 5.12 days). Thirty-five patients (29.9%) developed 55 infections, including 21 BSIs (38.2%), 20 urinary tract infections (36.4%), 6 ventilator-associated pneumonia episodes (10.9%), 2 viral infections (3.6%), and 6 miscellaneous infections (10.9%). The rates (in cases per 1,000 ECLS-days) were 23.9 for BSI, 22.8 for urinary tract infection, and 6.8 for ventilator-associated pneumonia. There were no significant differences in the demographic characteristics, indications for ECLS, or ECLS course between infected and uninfected patients, except for the median duration of ECLS (10.1 vs 3.8 days; P < .001). One death was attributed to infection. Resolution of BSI occurred without removal of foreign bodies in 18 (85.7%) of 21 children.

Conclusions.

Longer duration of ECLS was the only identified risk factor for infection. Mortality was not statistically significantly different between infected and uninfected patients. Most BSIs that occurred during ECLS cleared without removal of foreign bodies.

Artificial Placenta - Lung Assist Devices for Term and Preterm Newborns with Respiratory Failure

Respiratory insufficiency is a major cause of neonatal mortality and long-term morbidity, especially in very low birth weight infants. Today, non-invasive and mechanical ventilation are commonly accepted procedures to provide respiratory support to newborns, but they can reach their limit of efficacy. To overcome this technological plateau and further reduce mortality rates, the technology of an “artificial placenta”, which is a pumpless lung assist device connected to the umbilical vessels, would serve to expand the therapeutic spectrum when mechanical ventilation becomes inadequate to treat neonates with severe respiratory insufficiency.

The first attempts to create such an artificial placenta took place more than 60 years ago. However, there has been a recent renaissance of this concept, including developments of its major components like the oxygenator, vascular access via umbilical vessels, flow control, as well as methods to achieve hemocompatibility in extracorporeal circuits. This paper gives a review of past and current development, animal experiments and human case studies of artificial placenta technology.

Extended survival and re-hospitalisation among paediatric patients requiring extracorporeal membrane oxygenation for primary cardiac dysfunction

BACKGROUND

Although survival to hospital discharge among children requiring extracorporeal membrane oxygenation support for medical and surgical cardio-circulatory failure has been reported in international registries, extended survival and re-hospitalisation rates have not been well described in the literature.

MATERIAL AND METHODS

This is a single-institution, retrospective review of all paediatric patients receiving extracorporeal membrane oxygenation for primary cardiac dysfunction over a 5-year period.

RESULTS

A total of 74 extracorporeal membrane oxygenation runs in 68 patients were identified, with a median follow-up of 5.4 years from hospital discharge. Overall, 66% of patients were decannulated alive and 25 patients (37%) survived to discharge. There were three late deaths at 5 months, 20 months, and 6.8 years from discharge. Of the hospital survivors, 88% required re-hospitalisation, with 63% of re-admissions for cardiac indications. The median number of hospitalisations per patient per year was 0.62, with the first re-admission occurring at a mean time of 9 months after discharge from the index hospitalisation. In all, 38% of patients required further cardiac surgery.

CONCLUSIONS

Extended survival rates for paediatric hospital survivors of cardiac extracorporeal membrane oxygenation support for medical and post-surgical indications are encouraging. However, re-hospitalisation within the first year following hospital discharge is common, and many patients require further cardiac surgery. Although re-admission hospital mortality is low, longer-term follow-up of quality-of-life indicators is required

Examining palliative care team involvement in automatic consultations for children on extracorporeal life support in the pediatric intensive care unit

BACKGROUND

Extracorporeal life support (ECLS) is an advanced form of life-sustaining therapy that creates stressful dilemmas for families. In May 2009, Seattle Children's Hospital (SCH) implemented a policy to involve the Pediatric Advanced Care Team (PACT) in all ECLS cases through automatic referral.

OBJECTIVE

Our aim was to describe PACT involvement in the context of automatic consultations for ECLS patients and their family members.

METHODS

We retrospectively examined chart notes for 59 consecutive cases and used content analysis to identify themes and patterns.

RESULTS

The degree of PACT involvement was related to three domains: prognostic uncertainty, medical complexity, and need for coordination of care with other services. Low PACT involvement was associated with cases with little prognostic uncertainty, little medical complexity, and minimal need for coordination of care. Medium PACT involvement was associated with two categories of cases: 1) those with a degree of medical complexity but little prognostic uncertainty; and 2) those that had a degree of prognostic uncertainty but little medical complexity. High PACT involvement had the greatest medical complexity and prognostic uncertainty, and also had those cases with a high need for coordination of care.

CONCLUSIONS

We describe a framework for understanding the potential involvement of palliative care among patients receiving ECLS that explains how PACT organizes its efforts toward patients and families with the highest degree of need. Future studies should examine whether this approach is associated with improved patient and family outcomes.

Cerebral aspects of neonatal extracorporeal membrane oxygenation: a review

BACKGROUND

Neonatal extracorporeal membrane oxygenation (ECMO) is a lifesaving therapeutic approach in newborns suffering from severe, but potentially reversible, respiratory insufficiency, mostly complicated by neonatal persistent pulmonary hypertension. However, cerebral damage, intracerebral hemorrhage as well as ischemia belong to the most devastating complications of ECMO.

OBJECTIVES

The objectives are to give insights into what is known from the literature concerning cerebral damage related to neonatal ECMO treatment for pulmonary reasons.

METHODS

A short introduction to ECMO indications and technical aspects of ECMO are provided for a better understanding of the process. The remainder of this review focuses on outcome and especially on (potential) risk factors for cerebral hemorrhage and ischemia during ECMO treatment.

RESULTS

Although neonatal ECMO treatment shows improved outcome compared to conservative treatment in cases of severe respiratory insufficiency, it is related to disturbances in various aspects of neurodevelopmental outcome. Risk factors for cerebral damage are either related to the patient's disease, EMCO treatment itself, or a combination of both.

CONCLUSION

It is of ongoing importance to further understand pathophysiological mechanisms resulting in cerebral hemorrhage and ischemia due to ECMO and to develop neuroprotective strategies and approaches.

Pediatric outcomes after extracorporeal membrane oxygenation for cardiac disease and for cardiac arrest: a review

We reviewed reported survival and neurological outcomes, and predictors of these outcomes for pediatric cardiac extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR). We searched PubMed from 2000 to April 2011. Cumulative survival after cardiac ECMO in children was 788/1755 (45%); renal dysfunction, dialysis, neurologic complication, lactate, and ECMO duration consistently predicted this outcome, whereas single ventricle and ECPR did not. Neurological outcomes after cardiac ECMO were based on poorly described telephone questions in two studies for 47 patients with 51% significantly impaired and detailed follow-up testing for 42 patients in three studies with mental delay in 38% and mental score >85 (average or above) in 33%. Cumulative survival after ECPR in children was 371/762 (49%); noncardiac disease, renal dysfunction, neurologic complication, and pH on extracorporeal life support consistently predicted this outcome, whereas duration of CPR did not. Neurological outcomes after ECPR were based predominantly on the pediatric cerebral performance category (PCPC) score by chart review, with 161/181 (79%) having PCPC <2. No study reported detailed follow-up testing for survivors of ECPR. Survival outcomes of most cardiac subgroups were similar, except for concerning mortality in cavopulmonary connection patients. Priority areas for study include identification of potentially modifiable predictors of long-term outcomes.

Activated partial thromboplastin time is a better trending tool in pediatric extracorporeal membrane oxygenation

OBJECTIVES

To determine whether activated partial thromboplastin times are a better heparin management tool than activated clotting times in pediatric extracorporeal membrane oxygenation.

DESIGN

A single-center retrospective analysis of perfusion and patient records.

SETTING

Academic pediatric tertiary care center.

PATIENTS

Pediatric patients (<21 yrs old) requiring extracorporeal membrane oxygenation support initiated at Children's Hospital of Pittsburgh.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Point-of-care activated clotting time and activated partial thromboplastin time values, clinical laboratory activated partial thromboplastin time values, weight-normalized heparin administration (units/kg/hr), and reported outcomes were collected for pediatric patients treated for cardiac and/or respiratory failure with extracorporeal membrane oxygenation. Spearman's ranked correlations were performed for each coagulation test compared to heparin dosage. The Bland-Altman test was used to determine the validity of the point-of-care activated partial thromboplastin time. Hazard analysis was conducted for outcomes and complications for patients whose heparin management was based on the clinical laboratory activated partial thromboplastin time or the activated clotting time. Only the clinical laboratory activated partial thromboplastin time showed a correlation (ρ = 0.40 vs. ρ = -0.04 for activated clotting time) with the heparin administration (units/kg/hr). Point-of-care activated partial thromboplastin time and activated partial thromboplastin time values correlated well (ρ = 0.76), with <5% of samples showing a difference outside 2 SDs, but differences in their absolute values (Δactivated partial thromboplastin time = 100 secs) preclude them from being interchangeable measures. Furthermore, despite no effective change in the mean activated clotting time, cardiac patients showed a significantly improved correlation to heparin dose for all coagulation tests (e.g., point-of-care activated partial thromboplastin time ρ = 0.60). Management of patients with the clinical laboratory activated partial thromboplastin time did not significantly affect patient survival rates but did significantly reduce bleeding complications and significantly increased clotting in the extracorporeal membrane oxygenation circuit. A hazard analysis demonstrated that bleeding complications were associated with an increased risk of mortality, whereas clotting complications in the extracorporeal membrane oxygenation circuit were not.

CONCLUSIONS

The activated clotting time is not an accurate monitoring tool for heparin management in pediatricextracorporeal membrane oxygenation. The point-of-care activated partial thromboplastin time correlates well with the clinical laboratory activated partial thromboplastin time but cannot be substituted for the clinical laboratory activated partial thromboplastin time values. Management of pediatric extracorporeal membrane oxygenation patients with the clinical laboratory activated partial thromboplastin time reduced bleeding complications which are associated with increases in mortality.

Mechanical bridging to orthotopic heart transplantation in children

This article discusses the main methods currently used in clinical practice to support patients with end-stage heart failure and the research into new devices under development, particularly for young children. With an increasing demand on the supply of organs available for heart transplant, alternative strategies are being sought to maintain patients with end-stage cardiac failure for longer periods of time. Devices that support a failing heart, allowing cardiac recovery in some cases, or more commonly accommodate the time to source a suitable donor heart for transplantation, provide crucial therapeutic options. Extra-corporeal membrane oxygenation and ventricular assist devices are the mainstay of such bridging therapy. Although providing essential support to critically ill patients, they are not without their own significant associated risks. Therapeutic advances aim to reduce the risks associated with these bridging systems, and new artificial devices are being developed to improve this supportive care.

A pilot study comparing two polymethylpentene extracorporeal membrane oxygenators

OBJECTIVE

We compared two polymethylpentene oxygenators being used in our unit: the Maquet Quadrox-iD paediatric and the Medos Hilite 800LT.

STUDY DESIGN

A mono-centric, prospective pilot study was conducted on ten consecutive newborn patients who had been admitted to our hospital service for extracorporeal circulation (EC) treatment. We examined the rate of oxygen transfer, the CO2 removal capacity and the average sweep gas flow required to produce this result. We also assessed the disturbances of haemostasis, the need for labile blood products and the membrane oxygenator lifetime and cost of use.

CONCLUSIONS

According to our study, it seems to us that Medos Hilite 800LT membrane oxygenators demonstrate greater oxygen transfer and CO2 removal capacity than Maquet Quadrox-iD paediatric membrane oxygenators, at a similar cost. These results lead us to conclude that it is reasonable to continue using Medos Hilite 800LT membrane oxygenators. A broader comparison study would be necessary in order to support these initial results.

Red blood cell transfusion volume and mortality among patients receiving extracorporeal membrane oxygenation

Background:

Red blood cell (RBC) transfusion is used in the critically ill with low hemoglobin concentrations to optimize oxygen utilization and delivery imbalance. Data suggest that RBC transfusion is also independently associated with significant morbidity. We seek to characterize RBC transfusion volumes among patients receiving extracorporeal membrane oxygenation (ECMO) support and test the hypothesis that red blood cell transfusion volume is an independent risk factor for mortality.

Methods:

Records of all patients receiving ECMO support from 2001 through 2010 at a university-affiliated children’s hospital were retrospectively reviewed.

Results:

Among 484 ECMO runs reviewed, indications for ECMO were classified as cardiac (40%), non-cardiac (42%) or institution of ECMO during cardiopulmonary resuscitation (CPR) (18%). Median duration of ECMO support was 4.6 days, with overall survival to hospital discharge significantly higher among non-cardiac patients (60%) relative to patients supported for cardiac (37%) or external CPR (ECPR) indications (34%, p<0.001). Median RBC transfusion volumes with respect to ECMO indication were significantly greater among cardiac (105 mL/kg/day ECMO) and ECPR patients (66 mL/kg/day ECMO) relative to patients supported for non-cardiac indications (20 mL/kg/day ECMO, p<0.001). Among patients supported with ECMO for non-cardiac indications alone (n=203), independent of covariates, including weight, venoarterial mode of ECMO support, presence of congenital diaphragmatic hernia and complications, including hemorrhage, neurologic injury, and renal insufficiency, each RBC transfusion volume of 10 mL/kg/day ECMO was associated with a 24% increase in the odds of in-hospital mortality (OR 1.024, 95% CI 1.004-1.046, p=0.018).

Conclusions:

Greater red blood cell transfusion volumes among patients supported with ECMO for non-cardiac indications are independently associated with an increase in odds of mortality. A prospective investigation of restrictive RBC transfusion practices while receiving ECMO may be warranted in this population.

Hemolytic and thrombocytopathic characteristics of extracorporeal membrane oxygenation systems at simulated flow rate for neonates

OBJECTIVE

A state-of-the-art centrifugal pump combined with hollow-fiber oxygenator for extracorporeal membrane oxygenation has potential advantages such as smaller priming volumes and decreased potential to cause tubing rupture as compared with the traditional roller head/silicone membrane systems. Adoption of these state-of-the-art systems has been slow in neonates as a result of past evidence of severe hemolysis that may lead to renal failure and increased mortality. Extracorporeal systems have also been linked to platelet dysfunction, a contributing factor toward intracranial hemorrhage, a leading cause of infant morbidity. Little data exist comparing the centrifugal systems with the roller systems in terms of hemolysis and platelet aggregation at low flow rates commonly used in neonatal extracorporeal membrane oxygenation.

DESIGN

Prospective, comparative laboratory study.

SETTING

University research laboratory.

SUBJECTS

Centrifugal pump, roller pump, hollow-fiber oxygenator, and silicone membrane oxygenator.

INTERVENTIONS

Comparative study using two pumps, the centrifugal Jostra Rotaflow (Maquet, Wayne, NJ) and the roller-head (Jostra, Maquet, Wayne, NJ), and two oxygenators, polymethlypentene Quadrox-D (Maquet) and silicone membrane (Medtronic, Minneapolis, MN). Five test runs of four circuit combinations were examined for hemolysis and platelet aggregation during 6 hrs of continuous use in a simulated in vitro extracorporeal membrane oxygenation circuit circulating whole swine blood at 300 mL/min.

MEASUREMENTS AND MAIN RESULTS

Hemolysis was assessed by spectrophometric measurement of plasma-free hemoglobin. Platelet aggregation was evaluated using monoclonal CD61 antibody fluorescent flow cytometry profiles. All of the extracorporeal membrane oxygenation systems created plasma-free hemoglobin at a similar rate compared with static blood control. There was no difference in the mean normalized index of hemolysis of the centrifugal/hollow-fiber oxygenator system as compared with the roller-head/silicone membrane systems (0.0032 g/100 L vs. 0.0058 g/100 L, p ≥ .7). None of the extracorporeal membrane oxygenation systems had a significant increase in platelet aggregation above baseline.

CONCLUSIONS

In a low-flow neonatal environment, a state-of-the-art centrifugal pump combined with new fiber-type oxygenators appear to be safe in regard to hemolysis and platelet aggregation.

ECMO after prolonged cardiopulmonary resuscitation as a successful bridge to immediate cardiac retransplant in a 6-year-old girl

Heart failure, life-threatening arrhythmias, and sudden cardiac death are common complications in patients with advanced chronic cardiac allograft rejection--the major limiting factor of long-term survival after heart transplant. In patients with sustained cardiorespiratory arrest refractory to cardiopulmonary resuscitation extracorporeal membrane oxygenation therapy is a therapeutic option. We report the case of a 6-year-old girl with severe chronic allograft vasculopathy who was successfully bridged to cardiac retransplant through extracorporeal membrane oxygenation therapy after prolonged cardiopulmonary resuscitation. Our case demonstrates extracorporeal membrane oxygenation as a rescuing therapeutic option in high-risk, bridge-to-transplant patients, with cardiac arrest. Even after prolonged cardiopulmonary resuscitation, there were no neurologic events, and our patient recovered without any neurologic damage.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults

BACKGROUND

Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails.

METHODS

In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively.

RESULTS

The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed.

CONCLUSIONS

The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

Innovative clinical trial design for pediatric therapeutics

Until approximately 15 years ago, sponsors rarely included children in the development of therapeutics. US and European legislation has resulted in an increase in the number of pediatric trials and specific label changes and dosing recommendations, although infants remain an understudied group. The lack of clinical trials in children is partly due to specific challenges in conducting trials in this patient population. Therapeutics in special populations, including premature infants, obese children and children receiving extracorporeal life support, are even less studied. National research networks in Europe and the USA are beginning to address some of the gaps in pediatric therapeutics using novel clinical trial designs. Recent innovations in pediatric clinical trial design, including sparse and scavenged sampling, population pharmacokinetic analyses and 'opportunistic' studies, have addressed some of the historical challenges associated with clinical trials in children.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines

BACKGROUND

Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.

METHODS

The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.

RESULTS

In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.

CONCLUSIONS

Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.

Extracorporeal life support in pediatric cardiac dysfunction

BACKGROUND

Low cardiac output (LCO) after corrective surgery remains a serious complication in pediatric congenital heart diseases (CHD). In the case of refractory LCO, extra corporeal life support (ECLS) extra corporeal membrane oxygenation (ECMO) or ventricle assist devices (VAD) is the final therapeutic option. In the present study we have reviewed the outcomes of pediatric patients after corrective surgery necessitating ECLS and compared outcomes with pediatric patients necessitating ECLS because of dilatated cardiomyopathy (DCM).

METHODS

A retrospective single-centre cohort study was evaluated in pediatric patients, between 1991 and 2008, that required ECLS. A total of 48 patients received ECLS, of which 23 were male and 25 female. The indications for ECLS included CHD in 32 patients and DCM in 16 patients.

RESULTS

The mean age was 1.2 ± 3.9 years for CHD patients and 10.4 ± 5.8 years for DCM patients. Twenty-six patients received ECMO and 22 patients received VAD. A total of 15 patients out of 48 survived, 8 were discharged after myocardial recovery and 7 were discharged after successful heart transplantation. The overall mortality in patients with extracorporeal life support was 68%.

CONCLUSION

Although the use of ECLS shows a significantly high mortality rate it remains the ultimate chance for children. For better results, ECLS should be initiated in the operating room or shortly thereafter. Bridge to heart transplantation should be considered if there is no improvement in cardiac function to avoid irreversible multiorgan failure (MFO).

Factors associated with survival in pediatric extracorporeal membrane oxygenation--a single-center experience

AIM

We aimed to examine outcomes of extracorporeal membrane oxygenation (ECMO) therapy in the pediatric population and identify pre-ECMO and on-ECMO characteristics that are associated with survival.

METHODS

We retrospectively reviewed the ECMO records at our institution between 1999 and 2008 and selected pediatric patients who were cannulated for respiratory failure or hemodynamic instability resistant to conventional interventions. We recorded details of pre-ECMO clinical characteristics, including blood gas variables and mechanical ventilatory support, and details of ECMO therapy including survival off ECMO and to hospital discharge. Predictors of survival were analyzed using logistic regression modeling and a prediction algorithm was developed.

RESULTS

Of the 445 ECMO runs, data from 58 consecutive patients were analyzed: 57% were successfully decannulated, and 48% survived to discharge from the hospital. The cohort included 32 (55%) female patients, 22 postoperative patients (38%), and 15 (26%) with an immunosuppressive condition, with a median age of 5 years and weight 19.5 kg, The mean duration of pre-ECMO respiratory support was 3 days, in the form of high-frequency oscillatory ventilation (n = 28, 48%) and conventional mechanical ventilation (n = 13, 22%). The median duration (interquartile range) of ECMO support was 142 hours (60, 321) or 5.9 days. Pre-ECMO pH above 7.2 (P < .001) and oxygenation index below 35 (P = .021) were associated with the highest survival rates. Pre-ECMO PaCO(2) and duration of mechanical ventilation were not associated with survival.

CONCLUSIONS

Based on our results, ECMO therapy should be considered early in children with oxygenation index greater than 35 with worsening metabolic status. The restriction of ECMO based on ventilator days alone needs to be revisited in this era of lung protective ventilation.

Comparison of perfusion quality in hollow-fiber membrane oxygenators for neonatal extracorporeal life support

Perfusion quality is an important issue in extracorporeal life support (ECLS); without adequate perfusion of the brain and other vital organs, multiorgan dysfunction and other deficits can result. The authors tested three different pediatric oxygenators (Medos Hilite 800 LT, Medtronic Minimax Plus, and Capiox Baby RX) to determine which gives the highest quality of perfusion at flow rates of 400, 600, and 800 mL/min using human blood (36 degrees C, 40% hematocrit) under both nonpulsatile and pulsatile flow conditions. Clinically identical equipment and a pseudo-patient were used to mimic operating conditions during neonatal ECLS. Traditionally, the postoxygenator surplus hemodynamic energy value (SHE(post), extra energy obtained through pulsatile flow) is the one relied upon to give a qualitative determination of the amount of perfusion in the patient; the authors also examined SHE retention through the membrane, as well as the contribution of SHE(post) to the postoxygenator total hemodynamic energy (THE(post)). At each experimental condition, pulsatile flow outperformed nonpulsatile flow for all factors contributing to perfusion quality: the SHE(post) values for pulsatile flow were 4.6-7.6 times greater than for nonpulsatile flow, while the THE(post) remained nearly constant for pulsatile versus nonpulsatile flow. For both pulsatile and nonpulsatile flow, the Capiox Baby RX oxygenator was found to deliver the highest quality of perfusion, while the Minimax Plus oxygenator delivered the least perfusion. It is the authors' recommendation that the Baby RX oxygenator running under pulsatile flow conditions be used for pediatric ECLS, but further studies need to be done in order to establish its effectiveness beyond the FDA-approved time span.

Extracorporeal life support for treatment of children with enterovirus 71 infection-related cardiopulmonary failure

PURPOSE

Enterovirus 71 (EV71) infection leading to cardiopulmonary failure (CPF) is rare, but usually fatal. In such cases, intensive cardiorespiratory support is essential for survival. In this study, we report our experience in the treatment of EV71-related CPF with extracorporeal life support (ECLS).

METHODS

This was a retrospective study of a total of 13 children, aged 16 +/- 10 months, with EV71-related hemodynamically unstable CPF, which was refractory to conventional treatments, who were rescued by transsternal ECLS from 2000 to 2008. The clinical manifestations and outcomes of the 13 children (present cohort) were compared with those of 10 children (past cohort) who had EV71-related CPF without ECLS between 1998 and 2000.

RESULTS

Among these 13 patients, 10 were successfully weaned off ECLS and survived. The myocardial recovery time was 71 +/- 28 (median, 69) h, and the ECLS duration was 93 +/- 33 (median, 93) h. Six surviving patients had a good neurological outcome at hospital discharge. All surviving patients had some neurological sequelae but showed improvement at follow-up, including dysphagia in nine, central hypoventilation in seven, limb weakness in six and seizure in three. The present cohort had better neurological outcomes (46 vs. 0%, P = 0.005) and a higher survival rate (77 vs. 30%, P = 0.024) than the past cohort, respectively.

CONCLUSIONS

Patients with EV71-related CPF supported by ECLS had a higher survival rate and fewer neurological sequelae than those who only received conventional treatments. ECLS is an effective alternative method for treatment of children with refractory EV71-related CPF.

Extracorporeal membrane oxygenation for the treatment of children with severe hemodynamic alteration in perioperative cardiovascular surgery

BACKGROUND

This article summarizes the use of extracorporeal membrane oxygenation (ECMO) for the treatment of children with severe hemodynamic alteration in perioperative cardiovascular surgery.

METHODS

Four children with congenital heart disease (CHD) (3 boys and 1 girl, aged 6 days to 4 years and weighing 2.8-15 kg) associated with severe heart failure and/or hypoxemia were treated with ECMO cardiopulmonary support in perioperative cardiovascular surgery between July 2007 and July 2008. We retrospectively analyzed the medical records of the 4 children.

RESULTS

Of the 4 children, 2 survived and 2 died. The survivors were treated with venoarterial (VA) ECMO due to severe low output syndrome after arterial switch operation. They were weaned successfully from 22-hour and 87-hour ECMO support, and discharged 20 days and 58 days after ECMO explantation, respectively. The other boy treated with venovenous ECMO died of severe hypoxemia and metabolic acidosis. The other girl with VSD, treated with VA ECMO because of failure to wean from cardiopulmonary bypass, died from irreversible heart failure 11 hours after ECMO explantation. The main complications in this series included pulmonary hemorrhage, blood tamponade, surgical site bleeding, hemolysis and hyperbilirubinemia.

CONCLUSIONS

ECMO is an effective therapy for patients with severe heart failure in the perioperative cardiovascular surgery. The keys to successful ECMO are selection of indications, time to set up ECMO, and good management of complications during ECMO.

Effect of bladderbox alarms during venoarterial extracorporeal membrane oxygenation on cerebral oxygenation and hemodynamics in lambs

To determine the effects of bladderbox alarms during venoarterial extracorporeal membrane oxygenation (va-ECMO) on cerebral oxygenation and hemodynamics, six lambs were prospectively treated with va-ECMO and bladderbox alarms were simulated. Changes in concentrations of oxyhemoglobin (deltacO2Hb), deoxyhemoglobin (deltacHHb), and total Hb (deltactHb) were measured using near infrared spectrophotometry. Fluctuations in Hb oxygenation index (deltaHbD) and cerebral blood volume (deltaCBV) were calculated. Heart rate (HR), mean arterial pressure (MAP), blood flow in the left carotid artery (Qcar), and central venous pressure (CVP) were registered. Bladderbox alarms were simulated by increasing the ECMO flow or partially clamping the venous cannula and resolved by decreasing the ECMO flow, unclamping the cannula, or intravascular volume administration. CBV, HbD, MAP, and Qcar decreased significantly during bladderbox alarms, whereas HR and CVP increased. After the bladderbox alarms, CBV and HbD increased significantly to values above baseline. For HbD, this increase was higher during intravascular volume administration.MAP, Qcar, and CVP recovered to preexperiment values but increased further with volume administration. HR was increased at the end of our measurements. We conclude that Bladderbox alarms during va-ECMO treatment result in significant fluctuations in cerebral oxygenation and hemodynamics, a possible risk factor for intracranial lesions.

[Percutaneous extracorporeal life support in acute severe hemodynamic collapses: single centre experience in 100 consecutive patients]

BACKGROUND

Extracorporeal life support (ECLS) is a circulatory assistance device that is increasingly used in adults undergoing cardiopulmonary arrest (CPA) or hemodynamic collapse when conventional therapies fail.

OBJECTIVES

To assess the feasibility and outcomes of 100 consecutive arteriovenous percutaneous ECLS procedures at the Grenoble University Hospital between January 2002 and September 2007.

METHODS

Monocentric descriptive registry with one-year prospective follow-up.

RESULTS

An ECLS device was successfully used in 93% of patients. Its indication was cardiogenic shock in 50% of the cases, CPA in 38% of the cases and unsuccessful weaning of cardiopulmonary bypass (CPB) after cardiothoracic surgery in 12% of the cases. Direct complications of ECLS were observed in 56% of patients, the most frequent being hemorrhage at the intravenous puncture site requiring red blood cell transfusions (26%), and lower limb ischemia (19%). Weaning from ECLS was achieved in 33 patients (44% cardiogenic shocks, 13% CPAs, 50% CPB weaning failures) and 20 patients were discharged from the hospital (26% cardiogenic shocks, 10.5% CPAs and 25% CPB weaning failures). All are still living without any serious sequelae (mean follow-up period of 16.8 months).

CONCLUSION

The use of ECLS in CPA patients, especially with cardiogenic shock, is feasible with satisfactory survival rates, given the extreme severity of their initial state.

Neurologic outcome at school entry for newborns treated with extracorporeal membrane oxygenation for noncardiac indications

The neurologic outcomes at school age in children who underwent neonatal extracorporeal membrane oxygenation for noncardiac indications in a single institution surviving till the age of 5 years was determined by standardized neurologic assessment. Of 42 newborns undergoing extracorporeal membrane oxygenation, 24 underwent neurologic assessment by a single neurologist at 5 years of age. In all, 12 (50%) had a normal neurologic outcome. Lower gestational age and birth weight was found to be associated with an abnormal outcome as was septic shock as an indication for extracorporeal membrane oxygenation initiation. The number of peri-extracorporeal membrane oxygenation complications experienced by a child was associated with later epilepsy. Although invasive and implemented in critically ill infants, half of newborns undergoing extracorporeal membrane oxygenation will have a normal neurologic outcome at school age. Preexisting factors, rather than factors related to the extracorporeal membrane oxygenation itself, appear to be greater determinants of later neurologic outcomes.