Extracorporeal Membrane Oxygenation and Conventional Medical Therapy in Neonates With Persistent Pulmonary Hypertension of the Newborn: A Prospective Randomized Study

Adaptive design trials in eating disorder research: A scoping review

OBJECTIVE

This scoping review sought to map the breadth of literature on the use of adaptive design trials in eating disorder research.

METHOD

A systematic literature search was conducted in Medline, Scopus, PsycInfo, Emcare, Econlit, CINAHL and ProQuest Dissertations and Theses. Articles were included if they reported on an intervention targeting any type of eating disorder (including anorexia nervosa, bulimia nervosa, binge-eating disorder, and other specified feeding or eating disorders), and employed the use of an adaptive design trial to evaluate the intervention. Two independent reviewers screened citations for inclusion, and data abstraction was performed by one reviewer and verified by a second.

RESULTS

We identified five adaptive design trials targeting anorexia nervosa, bulimia nervosa and binge-eating disorder conducted in the USA and Australia. All employed adaptive treatment arm switching based on early response to treatment and identified a priori stopping rules. None of the studies included value of information analysis to guide adaptive design decisions and none included lived experience perspectives.

DISCUSSION

The limited use of adaptive designs in eating disorder trials represents a missed opportunity to improve enrolment targets, attrition rates, treatment outcomes and trial efficiency. We outline the range of adaptive methodologies, how they could be applied to eating disorder research, and the specific operational and statistical considerations relevant to adaptive design trials.

PUBLIC SIGNIFICANCE

Adaptive design trials are increasingly employed as flexible, efficient alternatives to fixed trial designs, but they are not often used in eating disorder research. This first scoping review identified five adaptive design trials targeting anorexia nervosa, bulimia nervosa and binge-eating disorder that employed treatment arm switching adaptive methodology. We make recommendations on the use of adaptive design trials for future eating disorder trials.

The Story of ECMO

Extracorporeal Circulation in Neonatal Respiratory Failure: A Prospective Randomized Study. By RH Bartlett, DW Roloff, RG Cornell, AF Andrews, PW Dillon, JB Zwischenberger. Pediatrics 1985; 76:479-87. Extracorporeal membrane oxygenation (ECMO) is the use of mechanical devices to replace cardiac and pulmonary function in critical care. In the 1960s, laboratory research showed that extracorporeal circulation could be maintained for days using a membrane oxygenator. In the 1970s, the first clinical trials showed that ECMO could sustain life in severe cardiac and pulmonary failure for days or weeks, leading to organ recovery. From 1980 to 2000, ECMO became standard practice for neonatal and pediatric respiratory and cardiac failure. The critical clinical trial was a prospective randomized trial of ECMO in newborn respiratory failure, published in 1985. This is the classic article reviewed in this publication. This was the first use of a randomized, adaptive design trial to minimize the potential ethical dilemma inherent to clinical trials in which the endpoint is death. Other randomized trials followed, and ECMO is now standard practice for severe respiratory and cardiac failure in all age groups.

The History of Extracorporeal Membrane Oxygenation and the Development of Extracorporeal Membrane Oxygenation Anticoagulation

Extracorporeal membrane oxygenation (ECMO) was first started for humans in early 1970s by Robert Bartlett. Since its inception, there have been numerous challenges with extracorporeal circulation, such as coagulation and platelet activation, followed by consumption of coagulation factors and platelets, and biocompatibility of tubing, pump, and oxygenator. Unfractionated heparin (heparin hereafter) has historically been the defacto anticoagulant until recently. Also, coagulation monitoring was mainly based on bedside activated clotting time and activated partial thromboplastin time. In the past 50 years, the technology of ECMO has advanced tremendously, and thus, the survival rate has improved significantly. The indication for ECMO has also expanded. Among these are clinical conditions such as postcardiopulmonary bypass, sepsis, ECMO cardiopulmonary resuscitation, and even severe coronavirus disease 2019 (COVID-19). Not surprisingly, the number of ECMO cases has increased according to the Extracorporeal Life Support Organization Registry and prolonged ECMO support has become more prevalent. It is not uncommon for patients with COVID-19 to be on ECMO support for more than 1 year until recovery or lung transplant. With that being said, complications of bleeding, thrombosis, clot formation in the circuit, and intravascular hemolysis still remain and continue to be major challenges. Here, several clinical ECMO experts, including the "Father of ECMO"-Dr. Robert Bartlett, describe the history and advances of ECMO.

A Clinical-Scale Microfluidic Respiratory Assist Device with 3D Branching Vascular Networks

Recent global events such as COVID-19 pandemic amid rising rates of chronic lung diseases highlight the need for safer, simpler, and more available treatments for respiratory failure, with increasing interest in extracorporeal membrane oxygenation (ECMO). A key factor limiting use of this technology is the complexity of the blood circuit, resulting in clotting and bleeding and necessitating treatment in specialized care centers. Microfluidic oxygenators represent a promising potential solution, but have not reached the scale or performance required for comparison with conventional hollow fiber membrane oxygenators (HFMOs). Here the development and demonstration of the first microfluidic respiratory assist device at a clinical scale is reported, demonstrating efficient oxygen transfer at blood flow rates of 750 mL min⁻1 , the highest ever reported for a microfluidic device. The central innovation of this technology is a fully 3D branching network of blood channels mimicking key features of the physiological microcirculation by avoiding anomalous blood flows that lead to thrombus formation and blood damage in conventional oxygenators. Low, stable blood pressure drop, low hemolysis, and consistent oxygen transfer, in 24-hour pilot large animal experiments are demonstrated - a key step toward translation of this technology to the clinic for treatment of a range of lung diseases.

Advances in Extracorporeal Support Technologies in Critically Ill Children

The field of pediatric heart failure is evolving, and the patient population is growing as survival after complex congenital heart surgeries is improving. Mechanical circulatory support and extracorporeal respiratory support in critically ill children has progressed to a mainstay rescue modality in pediatric intensive care medicine. The need for mechanical circulatory support is growing, since the number of organ donors does not meet the necessity. This article aims to review the current state of available mechanical circulatory and respiratory support systems in acute care pediatrics, with an emphasis on the literature discussing the challenges associated with these complex support modalities.

Silicon membranes for extracorporeal life support: a comparison of design and fabrication methodologies

Extracorporeal life support is an advanced therapy that circulates blood through an extracorporeal oxygenator, performing gas exchange outside the body. However, its use is limited by severe complications, including bleeding, clotting, and hemolysis. Semiconductor silicon-based membranes have emerged as an alternative to traditional hollow-fiber semipermeable membranes. These membranes offer excellent gas exchange efficiency and the potential to increase hemocompatibility by improving flow dynamics. In this work, we evaluate two next-generation silicon membrane designs, which are intended to be mechanically robust and efficient in gas exchange, while simultaneously reducing fabrication complexity. The "window" design features 10 µm pores on one side and large windows on the back side. The "cavern" design also uses 10 µm pores but contains a network of interconnected buried caverns to distribute the sweep gas from smaller inlet holes. Both designs were shown to be technically viable and able to be reproducibly fabricated. In addition, they both were mechanically robust and withstood 30 psi of transmembrane pressure without breakage or bubbling. At low sweep gas pressures, gas transfer efficiency was similar, with the partial pressure of oxygen in water increasing by 10.7 ± 2.3 mmHg (mean ± standard deviation) and 13.6 ± 1.9 mmHg for the window and cavern membranes, respectively. Gas transfer efficiency was also similar at higher pressures. At 10 psi, oxygen tension increased by 16.8 ± 5.7 mmHg (window) and 18.9 ± 1.3 mmHg (cavern). We conclude that silicon membranes featuring a 10 µm pore size can simplify the fabrication process and improve mechanical robustness while maintaining excellent efficiency.

Update on pre-ECMO evaluation and treatment for term infants in respiratory failure

The epidemiology, diagnostic and management approach to severe hypoxemic respiratory failure in the term and near-term neonate has evolved over time, as has the need for extracorporeal membrane oxygenation (ECMO) support in this patient population. Many patients who historically would have required ECMO support now respond to less invasive therapies, with patients requiring ECMO generally representing a higher risk and more heterogenous group of underlying diagnoses. This review will highlight these changes over time and the current available evidence for the diagnosis and management of these infants, as well as the current indications and relative contraindications to ECMO support when oxygen delivery cannot meet demand with less invasive management.

Association of Ventilator Settings With Mortality in Pediatric Patients Treated With Extracorporeal Life Support for Respiratory Failure

Extracorporeal life support (ECLS) is a treatment for acute respiratory failure that can provide extracorporeal gas exchange, allowing lung rest. However, while most patients remain mechanically ventilated during ECLS, there is a paucity of evidence to guide the choice of ventilator settings. We studied the associations between ventilator settings 24 hours after ECLS initiation and mortality in pediatric patients using a retrospective analysis of data from the Extracorporeal Life Support Organization Registry. 3497 patients, 29 days to 18 years of age, treated with ECLS for respiratory failure between 2015 and 2021, were included for analysis. 93.3% of patients on ECLS were ventilated with conventional mechanical ventilation. Common settings included positive end-expiratory pressure (PEEP) of 10 cm H 2 O (45.7%), delta pressure (ΔP) of 10 cm H 2 O (28.3%), rate of 10-14 breaths per minute (55.9%), and fraction of inspired oxygen (FiO 2 ) of 0.31-0.4 (30.3%). In a multivariate model, PEEP >10 cm H 2 O ( versus PEEP < 8 cm H 2 O, odds ratio [OR]: 1.53, 95% CI: 1.20-1.96) and FiO 2 ≥0.45 ( versus FiO 2 < 0.4; 0.45 ≤ FiO 2 < 0.6, OR: 1.31, 95% CI: 1.03-1.67 and FiO 2 ≥ 0.6, OR: 2.30; 95% CI: 1.81-2.93) were associated with higher odds of mortality. In a secondary analysis of survivors, PEEP 8-10 cm H 2 O was associated with shorter ECLS run times ( versus PEEP < 8 cm H 2 O, coefficient: -1.64, 95% CI: -3.17 to -0.11), as was ΔP >16 cm H 2 O ( versus ΔP < 10 cm H 2 O, coefficient: -2.72, 95% CI: -4.30 to -1.15). Our results identified several categories of ventilator settings as associated with mortality or ECLS run-time. Further studies are necessary to understand whether these results represent a causal relationship.

Extracorporeal membrane oxygenation as a bridge to transplant in neonates with fatal pulmonary conditions: A review

Neonates with progressive respiratory failure should be referred early for subspecialty evaluation and lung transplantation consideration. ECMO should be considered for patients with severe cardiopulmonary dysfunction and a high likelihood of death while on maximal medical therapy, either in the setting of reversible medical conditions or while awaiting lung transplantation. While ECMO offers hope to neonates that experience clinical deterioration while awaiting transplant, the risks and benefits of this intervention should be considered on an individual basis. Owing to the small number of infant lung transplants performed yearly, large studies examining the outcomes of various bridging techniques in this age group do not exist. Multiple single-centre experiences of transplanted neonates have been described and currently serve as guidance for transplant teams. Future investigation of outcomes specific to neonatal transplant recipients bridged with advanced devices is needed.

Changing populations being treated with ECMO in the neonatal period - who are the others?

Extracorporeal life support via extracorporeal membrane oxygenation (ECMO) has served the sickest of neonates for almost 50 years. Naturally, the characteristics of neonates receiving ECMO have changed. Advances in care have averted the need for ECMO for some, while complex cases with uncertain outcomes, previously not eligible for ECMO, are now considered. Characterizing the disease states and outcomes for neonates on ECMO is challenging as many infants do not fall into classic categories, i.e. meconium aspiration syndrome (MAS), respiratory distress syndrome (RDS), or congenital diaphragmatic hernia (CDH). Since 2017, over one third of neonatal respiratory ECMO runs reported to the Extracorporeal Life Support Organization Registry are grouped as Other, a catch-all that encompasses those with a diagnosis not included in the classic categories. This review summarizes the historical neonatal ECMO population, reviews advances in therapy and technology impacting neonatal care, and addresses the unknowns in the ever-growing category of Other.

Performing chest computed tomography on pediatric patients on extracorporeal membrane oxygenation (ECMO): a stepwise approach

Chest CT in pediatric patients on extracorporeal membrane oxygenation (ECMO) can be done safely and provide valuable high-quality diagnostic images to help guide patient management. An understanding of the basics of the ECMO circuit, cannula locations, where and how to inject contrast media, and how to time image acquisition is vital for the radiologist. Additionally, understanding the precautions associated with performing these exams is essential to ensure the safety of the child. This article provides a brief review of pediatric ECMO and its challenges and considerations, as well as a stepwise approach to perform and optimize these exams safely.

Persistent pulmonary hypertension of the newborn: Historical perspectives

For many decades, persistent pulmonary hypertension of the newborn (PPHN) remained a baffling disorder, often confused with cyanotic congenital heart disease, with a very high mortality. Originally described as a condition characterized by clear lung fields and profound hypoxemia, modern diagnostic techniques and novel therapeutics have improved the outcomes of affected newborns. This paper will review the historical aspects of PPHN and enable the reader to see how far we have come but also how far we have to go in conquering this unique disorder.

Predictors of circuit health in neonatal patients receiving extracorporeal membrane oxygenation (ECMO)

To identify predictors of neonatal ECMO circuit health, a retrospective analysis of circuit functional pressure and flow parameters as well as infant clotting values were collected 48 h prior to and 24 h post circuit change. Circuit impairment was defined as need for partial or total circuit change. Statistical analysis used multivariate statistics and non-parametric Mann–Whitney U-test with possible non-normality of measurements. A total of 9764 ECMO circuit and clotting values in 21 circuits were analyzed. Circuit delta-P mean, and maximum values increased from 8.62 to 48.59 mmHg (p < 0.011) and 16.00 to 53.00 mmHg (p < 0.0128) respectively prior to need for circuit change. Maximum and mean Pump Flow Revolutions per minute (RPM) increased by 75% (p < 0.0043) and 81% (p < 0.0057), respectively. Mean plasma free hemoglobin (pfHb) increased from 26.45 to 76.00 mg/dl, (p < 0.0209). Sweep, venous pressure, and clotting parameters were unaffected. ECMO circuit delta-P, RPM, and pfHb were early predictors of circuit impairment.

ECMO in neonates: The association between cerebral hemodynamics with neurological function

Extracorporeal membrane oxygenation (ECMO) is a superior life support technology, commonly employed in critical patients with severe respiratory or hemodynamic failure to provide effective respiratory and circulatory support, which is especially recommended for the treatment of critical neonates. However, the vascular management of neonates with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is still under controversy. Reconstruction or ligation for the right common carotid artery (RCCA) after ECMO is inconclusive. This review summarized the existed studies on hemodynamics and neurological function after vascular ligation or reconstruction hoping to provide better strategies for vessel management in newborns after ECMO. After reconstruction, the right cerebral blood flow can increase immediately, and the normal blood supply can be restored rapidly. But the reconstructed vessel may be occluded and stenotic in long-term follow-ups. Ligation may cause lateralization damage, but there could be no significant effect owing to the establishment of collateral circulation. The completion of the circle of Willis, the congenital anomalies of cerebral or cervical vasculature, the duration of ECMO, and the vascular condition at the site of arterial catheterization should be assessed carefully before making the decision. It is also necessary to follow up on the reconstructed vessel sustainability, and the association between cerebral hemodynamics and neurological function requires further large-scale multi-center studies.

Defining and understanding the "extra-corporeal membrane oxygenation gap" in the veno-venous configuration: Timing and causes of death

In‐hospital mortality of adult veno‐venous extracorporeal membrane oxygenation (V‐V ECMO) patients remains invariably high. However, little is known regarding timing and causes of in‐hospital death, either on‐ECMO or after weaning. The current review aims to investigate the timing and causes of death of adult patients during hospital admittance for V‐V ECMO, and to define the V‐V ECMO gap, which is represented by the patients that are successfully weaned of ECMO but still die during hospital stay. A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V‐V ECMO patients from January 2006 to December 2020 were screened. Studies that did not report on at least on‐ECMO mortality and discharge rate were excluded from analysis as they could not provide the required information regarding the proposed V‐V ECMO‐gap. Mortality rates on‐ECMO and after weaning, as well as weaning and discharge rates, were analyzed as primary outcomes. Secondary outcomes were the causes of death and complications. Initially, 35 studies were finally included in this review. Merely 24 of these studies (comprising 975 patients) reported on prespecified V‐V ECMO outcomes (on‐ECMO mortality and discharge rate). Mortality on V‐V ECMO support was 27.8% (95% confidence interval (CI) 22.5%‐33.2%), whereas mortality after successful weaning was 12.7% (95% CI 8.8%‐16.6%, defining the V‐V ECMO gap). 72.2% of patients (95% CI 66.8%‐77.5%) were weaned successfully from support and 56.8% (95% CI 49.9%‐63.8%) of patients were discharged from hospital. The most common causes of death on ECMO were multiple organ failure, bleeding, and sepsis. Most common causes of death after weaning were multiorgan failure and sepsis. Although the majority of patients are weaned successfully from V‐V ECMO support, a significant proportion of subjects still die during hospital stay, defining the V‐V ECMO gap. Overall, timing and causes of death are poorly reported in current literature. Future studies on V‐V ECMO should describe morbidity and mortality outcomes in more detail in relation to the timing of the events, to improve patient management, due to enhanced understanding of the clinical course.

Membrane Lung and Blood Pump Use During Prolonged Extracorporeal Membrane Oxygenation: Trends From 2002 to 2017

Extracorporeal life support (ECLS) has grown in its application since its first clinical description in the 1970s. The technology has been used to support a wide variety of mechanical support modalities and diseases, including respiratory failure, cardiorespiratory failure, and cardiac failure. Over many decades and safety and efficacy studies, followed by randomized clinical trials and thousands of clinical uses, ECLS is considered as an accepted treatment option for severe pulmonary and selected cardiovascular failure. Extracorporeal life support involves the use of support artificial organs, including a membrane lung and blood pump. Over time, changes in the technology and the management of ECLS support devices have evolved. This manuscript describes the use of membrane lungs and blood pumps used during ECLS support from 2002 to 2017 in over 65,000 patients reported to the Extracorporeal Life Support Organization Registry. Device longevity and complications associated with membrane lungs and blood pump are described and stratified by age group: neonates, pediatrics, and adults.

The Current State of Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a significant cause of morbidity and mortality in children. Children with PARDS often require intensive care admission and mechanical ventilation. Unfortunately, beyond lung protective ventilation, there are limited data to support our management strategies in PARDS. The Pediatric Acute Lung Injury Consensus Conference (PALICC) offered a new definition of PARDS in 2015 that has improved our understanding of the true epidemiology and heterogeneity of the disease as well as risk stratification. Further studies will be crucial to determine optimal management for varying disease severity. This review will present the physiologic basis of PARDS, describe the unique pediatric definition and risk stratification, and summarize the current evidence for current standards of care as well as adjunctive therapies.

Neonatal ECMO

Extracorporeal membrane oxygenation (ECMO) is becoming increasingly utilized to manage neonates with cardiac and respiratory failure. The procedure involves extensive anticoagulation in a sick neonate with underlying disease pathology. In addition, the immature hemostatic system in the neonate adds to the complexity of titrating the necessary anticoagulation. This places the infant at greater risk for life threatening hemorrhage and thrombosis. Managing anticoagulation in these infants is extremely challenging and needs the expertise of a physician with a thorough knowledge of the intricacies of developmental hemostasis and limitations of the current laboratory techniques available to manage anticoagulation. This article provides a brief overview of the developing hemostatic system of the neonate and the challenges associated with managing anticoagulation in this vulnerable population of patients.

Position of draining venous cannula in extracorporeal membrane oxygenation for respiratory and respiratory/circulatory support in adult patients

Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients with severe pulmonary and/or cardiac failure. Blood is drained from the venous system and pumped through a membrane oxygenator where it is oxygenated. For pulmonary support, the blood is returned to the patient via a vein (veno-venous ECMO) and for pulmonary/circulatory support it is returned via an artery (veno-arterial ECMO).

Veno-venous ECMO can be performed either with a single dual-lumen cannula or with two separate single-lumen cannulas. If the latter is chosen, flow direction can either be from the inferior caval vein (IVC) to the right atrium or the opposite. Earlier research has shown that drainage from the IVC yields less recirculation and therefore the IVC to right atrium route has become the standard in most centers for veno-venous ECMO with two cannulas. However, recent research has shown that recirculation can be minimized using a multistage draining cannula in the optimal position inserted via the right internal jugular vein and with blood return to the femoral vein. The clinical results with this route are excellent.

In veno-arterial ECMO the most common site for blood infusion is the femoral artery. If venous blood is drained from the IVC, the patient is at risk of developing a dual circulation (Harlequin syndrome, North-South syndrome, differential oxygenation) meaning a poor oxygenation of the upper part of the body, while the lower part has excellent oxygenation. By instead draining from the superior caval vein (SVC) via a multistage cannula inserted in the right internal jugular vein this risk is neutralized.

In conclusion, the authors argue that draining blood from the SVC and right atrium via a multistage cannula inserted in the right internal jugular vein is equal or better than IVC drainage both in veno-venous two cannula ECMO and in veno-arterial ECMO with blood return to the femoral artery.

Anticoagulation during ECMO in neonatal and paediatric patients

Extracorporeal Membrane Oxygenation (ECMO) is a form of Extracorporeal Life Support (ECLS) which is used frequently in the paediatric and neonatal setting to support either the pulmonary, or both the pulmonary and cardiac systems. Management of ECMO requires the use of systemic anticoagulation to prevent patient and circuit based thrombosis, which in turn increases the risk of haemorrhage. A number of coagulation tests, laboratory and point of care based, are used to monitor anticoagulation, however the evidence for correlation of the test results with level of anticoagulant and clinical outcomes in children remains poor.

Evaluating quality of life of extracorporeal membrane oxygenation survivors using the pediatric quality of life inventory survey

PURPOSE

This study assesses the impact of extracorporeal membrane oxygenation (ECMO) associated morbidities on long-term quality of life (QOL) outcomes.

METHODS

A single center, retrospective review of neonatal and pediatric non-cardiac ECMO survivors from 1/2005-7/2016 was performed. The 2012 Pediatric Quality of Life Inventory™ (PedsQL™) survey was administered. Clinical outcomes and QOL scores between groups were compared.

RESULTS

Of 74 patients eligible, 64% (35 NICU, 12 PICU) completed the survey. Mean time since ECMO was 5.5±3years. ECMO duration for venoarterial (VA) and venovenous (VV) were similar (median 9 vs. 7.5days, p=0.09). VA ECMO had higher overall complication rate (64% vs. 36%, p=0.06) and higher neurologic complication rate (52% vs. 9%, p=0.002). ECMO mode and ICU type did not impact QOL. However, patients with neurologic complications (n=15) showed a trend towards lower overall QOL (63/100±20 vs. 74/100±18, p=0.06) compared to patients without neurologic complications. A subset analysis of patients with ischemic or hemorrhagic intracranial injuries (n=13) had significantly lower overall QOL (59/100±19 vs. 75/100±18, p=0.01) compared to patients without intracranial injuries.

CONCLUSION

Neurologic complication following ECMO is common, associated with VA mode, and negatively impacts long-term QOL. Given these associations, when clinically feasible, VV ECMO may be considered as first line ECMO therapy.

TYPE OF STUDY

Retrospective review.

LEVEL OF EVIDENCE

II.

Does Extracorporeal Membrane Oxygenation Improve Survival in Pediatric Acute Respiratory Failure?

RATIONALE

Extracorporeal membrane oxygenation (ECMO) has supported gas exchange in children with severe respiratory failure for more than 40 years, without ECMO efficacy studies.

OBJECTIVES

To compare the mortality and functional status of children with severe acute respiratory failure supported with and without ECMO.

METHODS

This cohort study compared ECMO-supported children to pair-matched non-ECMO-supported control subjects with severe acute respiratory distress syndrome (ARDS). Both individual case matching and propensity score matching were used. The study sample was selected from children enrolled in the cluster-randomized RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) clinical trial. Detailed demographic and daily physiologic data were used to match patients. The primary endpoint was in-hospital mortality. Secondary outcomes included hospital-free days, ventilator-free days, and change in functional status at hospital discharge.

MEASUREMENTS AND MAIN RESULTS

Of 2,449 children in the RESTORE trial, 879 (35.9%) non-ECMO-supported patients with severe ARDS were eligible to match to 61 (2.5%) ECMO-supported children. When individual case matching was used (60 matched pairs), the in-hospital mortality rate at 90 days was 25% (15 of 60) for both the ECMO-supported and non-ECMO-supported children (P > 0.99). With propensity score matching (61 matched pairs), the ECMO-supported in-hospital mortality rate was 15 of 61 (25%), and the non-ECMO-supported hospital mortality rate was 18 of 61 (30%) (P = 0.70). There was no difference between ECMO-supported and non-ECMO-supported patients in any secondary outcomes.

CONCLUSIONS

In children with severe ARDS, our results do not demonstrate that ECMO-supported children have superior outcomes compared with non-ECMO-supported children. Definitive answers will require a rigorous multisite randomized controlled trial.

[Extracorporeal life support and heart-lung transplant in children]

Extracorporeal life support and heart and/or lung transplant are the last resort in children with end-stage cardiac and/or pulmonary failure and short-term life threaten. Currently, circulatory support is used as a bridge to recovery or as a bridge to transplant but not as a destination therapy. The Excor Berlin Heart is the long-lasting external pneumatic ventricular assist system that is currently available from infancy to adulthood. Long-term prognosis after pediatric cardiac and/or pulmonary transplant is conditioned by the occurrence of graft failure, coronary disease of the cardiac graft, viral infections and bronchiolitis obliterans of the pulmonary graft, the incidence of which increase with time. The scarcity of grafts and the risk of acute rejection due to lack of compliance with immunosuppressive treatment require the transplant specialized teams to choose the best candidates according to psychosocial and biological criteria. The next expected developments concern mainly long-term ventricular assistance with systems that allow for greater autonomy and a return to the child's home.

Oxygenation and Lung Morphology in a Rabbit Pediatric ARDS- Model under High Peak Pressure Ventilation plus Nitric Oxide and Surfactant Compared with Veno-venous ECMO

The aim of the study is to investigate which of two treatment options of saline lavage induced ARDS in rabbits is better in terms of oxygenation and prevention of barotrauma: combined high peak pressure ventilation with surfactant administration and inhaled nitric oxide or veno-venous ECMO combined with low peak inspiratory pressure ventilation.

Materials and Methods

After saline lavage (10 cc/kg repeated as long as foamy retrieval was observed) two combined therapeutic strategies were examined: ventilation with high inspiratory pressures (35 cm H2O) with additional exogenous surfactant administration (100 mg/kg) and inhaled nitric oxide (10 PPM) (n=5, group 1) and low inspiratory pressure (20 cm H2O) ventilation under veno-venous ECMO support (n=5, group 2). The FiO2 was maintained at 1.0 in both groups. The paO2/FiO2 ratio was calculated in 30 minute intervals for 4 hours. After that the animals were sacrificed and the lungs examined macro- and microscopically. Aeration was described in a semiquantitative method using the alveolar expansion index. Oxygenation in group 1 was significantly better than in group 2, it increased significantly after surfactant but not after additional nitric oxide administration. However, the lungs in group 1 showed severe signs of baro/ergotrauma (Hyaline membranes, air leaks, infiltration of polymorphonuclear (PMN) granulocytes and macrophages, break down of alveolar capillary membranes) after 4 hrs of combined therapy, whereas the lungs in group 2 appeared normal. Adding surfactant and NO to a high tidal volume ventilation improved oxygenation, but did not prevent baro/ergotrauma. Ventilation with low inspiratory pressures combined with ECMO caused little baro/ergotrauma but adequate oxygenation could not be achieved, probably due to anatomical features of the rabbit which do not allow appropriate blood flow within the ECMO-circuit.

High-Frequency Oscillatory Ventilation and Nitric Oxide: Alternative or Complementary to ECMO

One hundred and seventy-seven term or near-term neonates were referred to an ECMO center for severe PPHN-associated diseases. In 2 time periods from 1987 to 1991 and from 1992 to April 1995 alternative treatment modes were tried in an attempt to obviate ECMO. During the first time period patients underwent trial high-frequency oscillatory ventilation before ECMO. In the second time period patients first received inhaled NO followed by HFOV in a non-responders. If this also failed HFOV was combined with I NO. In both time periods about 40% of the patients were spared ECMO treatment by these alternative treatment modalities. I NO only benefited 15% of the ECMO candidates who apparently had fared just as well on HFOV alone in the preceding time period. While patients who were improved by I NO were spared HFOV with its potential severe complications, i.e. air leaks and cardiocirculatory instability, more extended long-term studies will have to show which of these 2 treatment modalities (INO or HFOV) should be given first priority in an attempt to avoid ECMO in neonates with severe respiratory failure.

An overview of medical ECMO for neonates

Extracorporeal membrane oxygenation (ECMO), a life-saving therapy for respiratory and cardiac failure, was first used in neonates in the 1970s. The indications and criteria for ECMO have changed over the years, but it continues to be an important option for those who have failed other medical therapies. Since the Extracorporeal Life Support Organization (ELSO) Registry was established in 1989, more than 29,900 neonates have been placed on ECMO for respiratory failure, with 84% surviving their ECMO course, and 73% surviving to discharge or transfer. In this chapter, we will review the basics of ECMO, patient characteristics and criteria, patient management, ECMO complications, special uses of neonatal ECMO, and patient outcomes.

Clinical trial designs and models for analgesic medications for acute pain in neonates, infants, toddlers, children, and adolescents: ACTTION recommendations

Clinical trials to test the safety and efficacy of analgesics across all pediatric age cohorts are needed to avoid inappropriate extrapolation of adult data to children. However, the selection of acute pain models and trial design attributes to maximize assay sensitivity, by pediatric age cohort, remains problematic. Acute pain models used for drug treatment trials in adults are not directly applicable to the pediatric age cohorts-neonates, infants, toddlers, children, and adolescents. Developmental maturation of metabolic enzymes in infants and children must be taken into consideration when designing trials to test analgesic treatments for acute pain. Assessment tools based on the levels of cognitive maturation and behavioral repertoire must be selected as outcome measures. Models and designs of clinical trials of analgesic medications used in the treatment of acute pain in neonates, infants, toddlers, children, and adolescents were reviewed and discussed at an Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) Pediatric Pain Research Consortium consensus meeting. Based on extensive reviews and continuing discussions, the authors recommend a number of acute pain clinical trial models and design attributes that have the potential to improve the study of analgesic medications in pediatric populations. Recommendations are also provided regarding additional research needed to support the use of other acute pain models across pediatric age cohorts.

Pediatric ECMO Research: The Case for Collaboration

The use of extracorporeal membrane oxygenation (ECMO) in the pediatric age has increased considerably in the last decade, as has the complexity of cases and the variety of indications outside of the neonatal age. However, no randomized controlled trials have been attempted to date to test ECMO as an intervention in non-neonatal pediatric patients with critical illness. In this review, we provide a brief overview of the history of clinical research in pediatric ECMO and discuss methodological challenges including heterogeneity of ages and diagnoses in the pediatric ECMO population, rapid advances in technology and clinical practice related to ECMO, feasibility of enrolling critically ill children on ECMO in clinical research studies, and variability in ECMO management across institutions and countries. Lastly, we discuss opportunities and existing infrastructure for future multicenter, multi-network research collaborations for pediatric ECMO studies.

Extracorporeal Membrane Oxygenation Support in Neonates: A Single Medical Center Experience in Taiwan

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) was used in neonates with severe cardiopulmonary failure who failed to respond to conventional therapy. We started to apply neck venoarterial ECMO (VA-ECMO) in neonatal patients from 2000. In this study, we have focused on neonates who received ECMO support and described the current status of ECMO in neonates for both cardiac and pulmonary support and the risk factors associated with their outcomes.

METHODS

Data were retrieved from our ECMO database for the neonates (age < 28 days) who received neck VA-ECMO support from January 2005 to June 2015.

RESULTS

In total, 27 neonates, including 21 with respiratory support and six with cardiac support, were enrolled in this study. Sixteen (59.2%) patients survived to hospital discharge, and only one patient had a poor neurological outcome. The survival rate for respiratory support was 61.9% in which meconium aspiration syndrome with persistent pulmonary hypertension of a newborn had a superior outcome (11/13, 84.6%) and congenital diaphragmatic hernia had the worst outcome (4/7, 57.1%). The survival rate in the cardiac support group was only 50%. The median ECMO duration and hospital stay were 6 (1∼35.8) days and 37 (23∼232) days, respectively, for survivors. Furthermore, 11 (52.3%) neonates of 21 outborn patients were put on ECMO in other hospitals by our mobile ECMO team for respiratory support, and their survival (81.8%) was significantly better than those from in-house ECMO institution (40%).

CONCLUSION

This is the first report for ECMO in neonatal disease in Taiwan. We achieved an overall survival rate of 59.2% with good neurological outcomes in this 10-year experience. ECMO could be a useful transportation tool for critical neonates who have a poor response to ventilator support.

Extracorporeal membrane oxygenation in 61 neonates: Single-center experience

BACKGROUND

There have been few reports on the outcome of extracorporeal membrane oxygenation (ECMO) in newborn Japanese infants.

METHODS

A review was carried out of 61 neonates with ECMO between January 1995 and December 2015 at a single center. ECMO was used in neonates with oxygenation index >20 after conventional treatment. Background factors, such as etiology, vascular access mode (veno-venous [VV] or veno-arterial [VA]), number of days with ECMO, and early ECMO (within 24 h after birth), were analyzed in relation to outcome with respect to survival to hospital discharge (SHD).

RESULTS

Survival to hospital discharge was achieved in 35 infants (57%), while the remaining 26 died during hospital stay. Gestational age at birth was significantly higher and number of days with ECMO was significantly lower in SHD infants compared with those with adverse outcome (median, 4.0 vs 5.5 days, respectively; P = 0.008). The SHD rate was significantly higher for those with VV than VA vascular access mode (78%, 18/23 vs 45%, 17/38, respectively; P = 0.016), and for those with than without early ECMO (72%, 28/39 vs 32%, 7/22, respectively; P = 0.003). The SHD rate was relatively high in neonates with meconium aspiration syndrome (86%, 12/14), persistent pulmonary hypertension associated with hypoxic ischemic encephalopathy (75%, 6/8), and emphysema (80%, 4/5). On stepwise logistic regression analysis two independent factors of SHD were identified: early ECMO (OR, 9.63; 95%CI: 2.47-37.6) and ECMO length <8 days (OR, 8.05; 95%CI: 1.94-33.5).

CONCLUSIONS

Neonates with early ECMO and those with ECMO duration <8 days may benefit from ECMO with respect to SHD.

Laboratory and clinical predictors of 30-day survival for patients on Extracorporeal Membrane Oxygenation (ECMO): 8-Year experience at Albert Einstein College of Medicine, Montefiore Medical Center

PURPOSE

Survival of patients on ECMO has remained stable in every population. Laboratory values predictors of survival are required to improve patient care.

MATERIALS AND METHODS

Clinical Looking Glass software was used to assess Electronic Medical Records (EMRs) of patients at Albert Einstein College of Medicine, Montefiore Medical Center (2007-2014).

RESULTS

Our population comprises of 166 adults and was divided in survivors and non-survivors, within 30days. Indications for ECMO were cardiac (65%), respiratory (25%) and infectious diseases (<10%). Eighty six patients (51.8%) survived the procedure. Gender, body weight, ejection fraction, diastolic blood pressure, and socio-economic status did not differ among survivors and non-survivors. In contrast, younger patients (45yo vs 55yo, p=0.0001) and higher systolic blood pressure (115mmHg vs 103mmHg, p=0.025) have favorable outcome. Univariate analysis shows that pre-cannulation values for creatinine (p=0.0003), chloride (p=0.009), bicarbonate (p=0.015) and pH (p=0.03) have prognostic value. Post-cannulation aPTT, pH, platelet and lymphocyte counts also have discriminative power. Notably, multiple logistic regressions for Multivariate Analysis identified chloride (OR 1.07; 95% CI 1.02-1.13; p=0.004), pH (OR 3.35; 95% CI 1.89-5.9; p<0.0001) and aPTT (OR 0.98; 95% CI 0.976-0.998; p=0.024) as independent risk factors for 30-day mortality. These results imply that pre-existing renal conditions and hemostatic dysregulation contribute to poor outcome. Finally, patients on VV-ECMO have increase odds of survival (OR 1.88; 95% CI 1.06-3.34; p=0.029).

CONCLUSIONS

Laboratory markers identified herein may guide the management of patients on ECMO.

Should Extracorporeal Membrane Oxygenation Be Offered? An International Survey

OBJECTIVES

To assess the current attitudes of extracorporeal membrane oxygenation (ECMO) program directors regarding eligibility for ECMO among children with cardiopulmonary failure.

STUDY DESIGN

Electronic cross-sectional survey of ECMO program directors at ECMO centers worldwide within the Extracorporeal Life Support Organization directory (October 2015-December 2015).

RESULTS

Of 733 eligible respondents, 226 (31%) completed the survey, 65% of whom routinely cared for pediatric patients. There was wide variability in whether respondents would offer ECMO to any of the 5 scenario patients, ranging from 31% who would offer ECMO to a child with trisomy 18 to 76% who would offer ECMO to a child with prolonged cardiac arrest and indeterminate neurologic status. Even physicians practicing the same specialty sometimes held widely divergent opinions, with 50% of pediatric intensivists stating they would offer ECMO to a child with severe developmental delay and 50% stating they would not. Factors such as quality of life and neurologic status influenced decision making and were used to support decisions for and against offering ECMO.

CONCLUSIONS

ECMO program directors vary widely in whether they would offer ECMO to various children with cardiopulmonary failure. This heterogeneity in physician decision making underscores the need for more evidence that could eventually inform interinstitutional guidelines regarding patient selection for ECMO.

The Utility of Nurse-Managed Extracorporeal Life Support in an Adult Cardiac Intensive Care Unit

BACKGROUND

The use of extracorporeal life support (ECLS) worldwide has increased exponentially since 2009. The patient requiring ECLS demands an investment of hospital resources, including personnel. Educating bedside nurses to manage ECLS circuits broadens the availability of trained providers.

METHODS

Experienced cardiothoracic intensive care unit (CTICU) nurses underwent training to manage ECLS circuits, including volume assessment, treatment of arterial blood gas values, the physiology of ECLS, and recognition of common emergencies. In addition to lectures and a written examination, simulation using water circuits and an ICU model allowed assessment of skills and understanding of concepts. Performance assessments were completed regularly at the bedside, and skills revalidation occurred every 6 months. A sequential cohort of 40 patients was tracked over 1 year.

RESULTS

Despite doubling the census of ECLS patients in 1 year, management by specially trained CTICU nurses has positively affected patient care and outcomes. At a single institution, 40 patients had a median of 6 days (interquartile range, 2 to 226 days) of support in 2014, leading to 767 patient-days of support. Survival to hospital discharge increased to 45% in 2014. Most survivors were weaned from support. Neurologic injury was the most common cause of death, followed by failure to qualify for advanced therapies.

CONCLUSIONS

With on-going education and assessment, including crisis training, physiology, and cannulation strategies, CTICU nurses can safely operate ECLS circuits and can increase the availability of appropriately trained providers to accommodate the exponential increase in ECLS occurrences without negatively affecting outcomes and generally at a lower cost.

Alternative designs for clinical trials in rare diseases

Evidence-based medicine requires strong scientific evidence upon which to base treatment. In rare diseases, study populations are often small, and thus this evidence is difficult to accrue. Investigators, though, should be creative and develop a flexible toolkit of methods to deal with the problems inherent in the study of rare disease. This narrative review presents alternative clinical trial designs for studying treatments of rare diseases, including cross-over and n-of-1 trials, randomized placebo-phase design, enriched enrollment, randomized withdrawal design, and classes of adaptive designs. Examples of applications of these designs are presented along with their advantages and disadvantages. Additional analytical considerations such as Bayesian analysis, internal pilots, and use of biomarkers as surrogate outcomes are further discussed. A framework for selecting appropriate clinical trial design is proposed to guide investigators in the process of selecting alternative designs for rare diseases. © 2016 Wiley Periodicals, Inc.

Clinical Research in Acute Fatal Illness

Clinical research to evaluate the effectiveness of life support systems in acute fatal illness has unique problems of logistics, ethics, and consent. There have been 10 prospective comparative trials of extracorporeal membrane oxygenation in acute fatal respiratory failure, utilizing different study designs. The trial designs were prospective controlled randomized, prospective adaptive randomized, sequential, and matched pairs. The trials were reviewed with regard to logistics, ethics, consent, statistical methods, economics, and impact. The matched pairs method is the best study design for evaluation of life support systems in acute fatal illness.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Concepts from paediatric extracorporeal membrane oxygenation for adult intensivists

Over the last 5 years, there has been a dramatic increase in the use of extracorporeal membrane oxygenation (ECMO) in adult patients with severe respiratory or cardiac failure. This contrasts to the use of the technology in neonatal and paediatric intensive care units, where it has been regarded as a standard of care for a number of conditions for over 25 years. Many innovations in ECMO circuitry or clinical management evolve first in one particular discipline and it may be helpful for individual clinicians to keep abreast of developments in ECMO across the entire age range, from neonatology to older adults. This review addresses nine concepts in ECMO that are better studied or established in paediatric medicine and considers their application in adult patients.

Extracorporeal membrane oxygenation: a breakthrough for respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a method for providing long-term treatment of a patient in a modified heart-lung machine. Desaturated blood is drained from the patient, oxygenated and pumped back to a major vein or artery. ECMO supports heart and lung function and may be used in severe heart and/or lung failure when conventional intensive care fails. The Stockholm programme started in 1987 with treatment of neonates. In 1995, the first adult patient was accepted onto the programme. Interhospital transportation during ECMO was started in 1996, which enabled retrieval of extremely unstable patients during ECMO. Today, the programme has an annual volume of about 80 patients. It has been characterized by, amongst other things, minimal patient sedation. By 31 December 2014, over 900 patients had been treated, the vast majority for respiratory failure, and over 650 patients had been transported during ECMO. The median ECMO duration was 5.3, 5.7 and 7.1 days for neonatal, paediatric and adult patients, respectively. The survival to hospital discharge rate for respiratory ECMO was 81%, 70% and 63% in the different age groups, respectively, which is significantly higher than the overall international experience as reported to the Extracorporeal Life Support Organization (ELSO) Registry (74%, 57% and 57%, respectively). The survival rate was significantly higher in the Stockholm programme compared to ELSO for meconium aspiration syndrome, congenital diaphragmatic hernia in neonates and pneumocystis pneumonia in paediatric patients.

Postoperative management of heart failure in pediatric patients

Low cardiac output syndrome (LCOS) is a well-described entity occurring in 25-65% of pediatric patients undergoing open-heart surgery. With judicious intensive care management of LCOS, most patients have an uncomplicated postoperative course, and within 24 h after cardiopulmonary bypass, the cardiac function returns back to baseline. Some patients have severe forms of LCOS not responsive to medical management alone, requiring temporary mechanical circulatory support to prevent end-organ injury and to decrease myocardial stress and oxygen demand. Occasionally, cardiac function does not recover and heart transplantation is necessary. Long-term mechanical circulatory support devices are used as a bridge to transplantation because of limited availability of donor hearts. Experience in usage of continuous flow ventricular assist devices in the pediatric population is increasing.

Clinical and billing review of extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a temporary technique for providing life support for cardiac dysfunction, pulmonary dysfunction, or both. The two forms of ECMO, veno-arterial (VA) and veno-venous (VV), are used to support cardiopulmonary and pulmonary dysfunction, respectively. Historically, ECMO was predominantly used in the neonatal and pediatric populations, as early adult studies failed to improve outcomes. ECMO has become far more common in the adult population because of positive results in published case series and clinical trials during the 2009 influenza A(H1N1) pandemic in 2009 to 2010. Advances in technology that make the technique much easier to implement likely fueled the renewed interest. Although exact criteria for ECMO are not available, patients who are good candidates are generally considered to be relatively young and suffering from acute illness that is believed to be reversible or organ dysfunction that is otherwise treatable. With the increase in the use in the adult population, a number of different codes have been generated to better identify the method of support with distinctly different relative value units assigned to each code from a very simple prior coding scheme. To effectively be reimbursed for use of the technique, it is imperative that the clinician understands the new coding scheme and works with payers to determine what is incorporated into each specific code.