The impact of extracorporeal membrane oxygenation on survival in pediatric patients with acute respiratory failure. Pediatric Critical Care Study Group

Epidemiology of Acute Respiratory Failure in US Children: Outcomes and Resource Use

OBJECTIVE

Acute respiratory failure recalcitrant to conventional management often requires specialized organ-supportive technologies to optimize outcomes. Variation in the availability of these technologies prompted testing of the hypothesis that outcomes and resource use will vary by not only patient characteristics but also hospital characteristics and receipt of organ-supportive technology.

METHODS

Retrospective study of children 0 to 20 years old hospitalized for acute respiratory failure using the 2019 Kids' Inpatient Database. Multivariable regression models identified factors associated with mortality, length of hospitalization, and costs.

RESULTS

Of an estimated 75 365 hospitalizations nationally, 97% were to urban teaching hospitals, 57% were of children < 6 years, and 58% were of males. Complex chronic conditions (CCC) existed in 62%, multiorgan dysfunction in 35%, and extreme illness severity in 54%. Mortality was 7%, length of stay 15 days, and hospital costs $77 168. Elevated mortality was associated with cumulative organ dysfunction (odds ratio [OR]:2.31, 95% confidence interval [CI]: 2.22-2.42), CCC (OR: 5.49, 95% CI: 4.73-6.37), transfer, higher illness severity, and cardiopulmonary resuscitation. Lower mortality was associated with extracorporeal membrane oxygenation (OR: 0.36, 95% CI: 0.28-0.47) and new tracheostomy (OR: 0.30, 95% CI: 0.25-0.35). Longer hospitalization was associated with transfer, infancy, CCC, higher illness severity, cumulative organ dysfunction, and urban hospitals. Higher costs accrued with noninfants, cumulative organ dysfunction, private insurance, and urban teaching hospitals.

CONCLUSIONS

Hospitalizations for pediatric acute respiratory failure incurred substantial mortality and resource consumption. Efforts to reduce mortality and resource consumption should address interhospital transfer, access to organ-supportive technology, and drivers of higher severity-adjusted resource consumption at urban hospitals.

Pediatric venoarterial and venovenous ECMO

Extracorporeal membrane oxygenation (ECMO) is an invaluable resource in the treatment of critically ill children with cardiopulmonary failure.  To date, over 36,000 children have been placed on ECMO and the utilization of this life saving treatment continues to expand with advances in ECMO technology.  This article offers a review of pediatric ECMO including modes and sites of ECMO cannulation, indications and contraindications, and cannulation techniques.  Furthermore, it summarizes the basic principles of pediatric ECMO including circuit maintenance, nutritional support, and clinical decision making regarding weaning pediatric ECMO and decannulation.  Finally, it gives an overview of common pediatric ECMO complications including overall mortality and long-term outcomes of ECMO survivors. The goal of this article is to provide a comprehensive review for healthcare professionals providing care for pediatric ECMO patients.

The Impact of the Society of Critical Care Medicine's Flagship Journal: Critical Care Medicine: Reflections of Critical Care Pioneers

On the 50th anniversary of the Society of Critical Care Medicine's journal Critical Care Medicine, critical care pioneers reflect on the importance of the journal to their careers and to the development of the field of adult and pediatric critical care.

Pediatric ECMO Candidates at Non-ECMO Centers: Transfer, Cannulate, or Treat Locally?

Pediatric inpatient and intensive care specialists working outside of tertiary medical centers confront difficult clinical scenarios related to how best to care for extremely ill children who may or may not benefit from advanced medical technology, and these clinicians are often faced with limited local availability. Extracorporeal membrane oxygenation (ECMO) is a technology that is only available at a subset of tertiary care centers, and the decision to risk the transfer of a child for the potential benefit of ECMO is challenging. This article is aimed at addressing the main factors and ethical principles related to this decision-making: (1) whether ECMO is the standard of care, (2) clinical decision analysis of the risks and benefits, (3) informed consent and education of the parents and/or guardians, and (4) institutional leadership decision-making. A decisional framework is proposed that incorporates a thoughtful shared decision-making algorithm.

Bridging the Gap Between Intensivists and Primary Care Clinicians in Extracorporeal Membrane Oxygenation for Respiratory Failure in Children: A Review

IMPORTANCE

Extracorporeal membrane oxygenation (ECMO) is a form of advanced life support that may be used in children with refractory respiratory or cardiac failure. While it is required infrequently, in the US, ECMO is used to support childhood respiratory failure as often as children receive kidney or heart transplants. ECMO is complex, resource intensive, and potentially lifesaving, but it is also associated with risks of short-term complications and long-term adverse effects, most importantly with neurodevelopmental outcomes that are relevant to all pediatric clinicians, even those remote from the child's critical illness.

OBSERVATIONS

The 2009 influenza A(H1N1) pandemic, along with randomized clinical trials of adult respiratory ECMO support and conventional management, have catalyzed sustained growth in the use of ECMO. The adult trials built on earlier neonatal ECMO randomized clinical trials that demonstrated improved survival in severe perinatal lung disease. For children outside of the neonatal period, there appear to have been no respiratory ECMO clinical trials. Applying evidence from adult respiratory failure or perinatal lung disease to children outside the neonatal period has important potential pitfalls. For these children, the underlying diseases and risks of ECMO are different. Despite these differences, both neonates and older children are at risk of neurologic complications, such as intracranial hemorrhage, ischemic stroke, and seizures, and those complications may contribute to adverse neurodevelopmental outcomes. Without specific screening, subtle neurodevelopmental impairments may be missed, but when they are identified, children have the opportunity to receive therapy to optimize long-term development.

CONCLUSIONS AND RELEVANCE

All pediatric clinicians should be aware not only of the potential benefits and complications of ECMO but also that survivors need effective screening, support, and follow-up.

Evaluation of Severity of Illness Scores in the Pediatric ECMO Population

Though commonly used for adjustment of risk, severity of illness and mortality risk prediction scores, based on the first 24 h of intensive care unit (ICU) admission, have not been validated in the pediatric extracorporeal membrane oxygenation (ECMO) population. We aimed to determine the association of Pediatric Index of Mortality 2 (PIM2), Pediatric Risk of Mortality Score III (PRISM III) and Pediatric Logistic Organ Dysfunction (PELOD) scores with mortality in pediatric patients on ECMO. This was a retrospective cohort study of children ≤18 years of age included in the Pediatric ECMO Outcomes Registry (PEDECOR) from 2014 to 2018. Logistic regression and Receiver Operating Characteristics (ROC) curves were used to calculate the area under the curve (AUC) to evaluate association of mortality with the scores. Of the 655 cases, 289 (44.1%) did not survive until hospital discharge. AUCs for PIM2, PRISM III, and PELOD predicting mortality were 0.52, 0.52, and 0.51 respectively. PIM2, PRISM III, and PELOD scores are not associated with odds of mortality for pediatric patients receiving ECMO. These scores for a general pediatric ICU population should not be used for prognostication or risk stratification of a select population such as ECMO patients.

Trends in Mortality and Costs of Pediatric Extracorporeal Life Support

BACKGROUND

Extracorporeal life support (ECLS) has been used for >30 years as a life-sustaining therapy in critically ill patients for a variety of indications. In the current study, we aimed to examine trends in use, mortality, length of stay (LOS), and costs for pediatric ECLS hospitalizations.

METHODS

We performed a retrospective cohort study of pediatric patients (between the ages of 28 days and <21 years) on ECLS using the 2008-2015 National Inpatient Sample, the largest all-payer inpatient hospitalization database generated from hospital discharges. Nonparametric and Cochran-Armitage tests for trend were used to study in-hospital mortality, LOS, and hospitalization costs.

RESULTS

Of the estimated 5847 patients identified and included for analysis, ECLS was required for respiratory failure (36.4%), postcardiotomy syndrome (25.9%), mixed cardiopulmonary failure (21.7%), cardiogenic shock (13.1%), and transplanted graft dysfunction (2.9%). The rate of ECLS hospitalizations increased 329%, from 11 to 46 cases per 100 000 pediatric hospitalizations, from 2008 to 2015 (P < .001). Overall mortality decreased from 50.3% to 34.6% (P < .001). Adjusted hospital costs increased significantly ($214 046 ± 11 822 to 324 841 ± 25 621; P = .002) during the study period despite a stable overall hospital LOS (46 ± 6 to 44 ± 4 days; P = .94).

CONCLUSIONS

Use of ECLS in pediatric patients has increased with substantially improved ECLS survival rates. Hospital costs have increased significantly despite a stable LOS in this group. Dissemination of this costly yet life-saving technology warrants ongoing analysis of use trends to identify areas for quality improvement.

Extra-Corporeal Membrane Oxygenation for Neonatal Respiratory Support

To review our experience with Extra-Corporeal Membrane Oxygenation (ECMO) for respiratory support in neonates. From 1989 to 2018 2114 patients underwent respiratory ECMO support, with 764 (36%) neonates. Veno-Venous (V-V) cannulation was used in 428 (56%) neonates and Veno-Arterial (V-A) in 336 (44%). Historically V-V ECMO was our preferred modality, but due to lack of suitable cannula in the last 7 years V-A was used in 209/228 (92%) neonates. Mean and inter-quartile range of ECMO duration was 117 hours (inter-quartile range 90 to 164 hours). Overall 724 (95%) neonates survived to ECMO decannulation, with 640 (84%) hospital discharge. Survival varied with underlying diagnosis: meconium aspiration 98% (354/362), persistent pulmonary hypertension 80% (120/151), congenital diaphragmatic hernia 66% (82/124), sepsis 59% (35/59), pneumonia 86% (6/7), other 71% (43/61). Survival was 86% with V-V and 80% with V-A cannulation, better than ELSO Registry with 77% V-V and 63% V-A. Major complications: cerebral infarction/hemorrhage in 4.7% (31.1% survival to discharge), renal replacement therapy in 17.6% (58.1% survival to discharge), new infection in 2.9%, with negative impact on survival (30%). Following a circuit design modification and subsequent reduction in heparin requirement, intracerebral hemorrhage decreased to 9/299 (3.0%) radiologically proven cerebral infarction/hemorrhage. We concluded (1) outcomes from neonatal ECMO in our large case series were excellent, with better survival and lower complication rate than reported in ELSO registry. (2) These results highlight the benefits of ECMO service in high volume units. (3) The similar survival rate seen in neonates with V-A and V-V cannulation differs from the ELSO register; this may reflect the change in cannulation enforced by lack of suitable V-V cannula and all neonates undergoing V-A cannulation.

Extra-corporeal membrane oxygenation in paediatric acute respiratory distress syndrome: overrated or underutilized?

Extracorporeal membrane oxygenation (ECMO) is a modified form of cardiopulmonary bypass which may provide support for severe cardiorespiratory failure including paediatric acute respiratory distress syndrome (PARDS). While ECMO was initially demonstrated to successfully support neonates with severe respiratory failure, the use of ECMO has expanded rapidly to support both paediatric and adult respiratory failure. Extracorporeal Life Support Organization (ELSO) registry data shows that the use of ECMO for paediatric respiratory failure has expanded rapidly over the past decades with increasing use of venovenous ECMO. Despite the increasing complexity of children supported by ECMO for ARDS, outcomes have remained consistent with survival to hospital discharge greater than 50%. ECMO complications are still common and potentially devastating, especially neurological complications. There is grade 1 evidence to support the use of ECMO in both neonatal and adult respiratory failure but evidence in paediatric respiratory failure is confined to case series and case-control studies. While there are no published guidelines for use of ECMO in PARDS, in particular no clearly defined inclusion and exclusion criteria, current evidence suggests that children with severe ARDS may benefit from ECMO support, with survival to hospital discharge equivalent or better than conventional management in children with severe ARDS.

Advances in Pediatric Critical Care Research in India

Over last 2 decades, there has been a significant progress made in the field of pediatric critical care in India. There has been complementary and parallel growth in the pediatric critical care services in India and the number of pediatric critical care providers who are either formally trained in India or who have returned to India after their formal training abroad. The pediatric critical care community in India has recognized obvious differences in profiles of critical illnesses and patients between Indian subcontinent and the West. Therefore there is a growing interest in generating scientific evidence through local research which would be applicable to critically ill children in Indian subcontinent. This article focuses on advances in pediatric critical care research in India and its future directions.

Development of Risk Indices for Neonatal Respiratory Extracorporeal Membrane Oxygenation

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has saved thousands of newborns. Population comparisons for research and quality initiatives require risk-matching, but no indices exist for this population. We sought to create a pre-ECMO risk index using the registry data from the Extracorporeal Life Support Organization. We analyzed 5,455 neonatal (<30 days old) respiratory VA-ECMO patients for the period 2000-2010. Multivariate regression examining the impact of pre-ECMO variables on survival to hospital discharge was performed to create the Pittsburgh Index for Pre-ECMO Risk (PIPER), which was ultimately was based on seven pre-ECMO variables. Each PIPER quartile demonstrated increasing mortality by 15% (R = 0.98) and was associated with increased complications on ECMO. Further modeling to include on-ECMO complications (PIPER), including complications and length of time on ECMO, increased the predictive power of the model, with 21% increases in mortality per PIPER quartile (R = 0.97). Our developed indices provide the first steps towards risk-adjusting patients for meaningful comparisons amongst patient populations. There may be additional clinically relevant measures, both pre- and on-ECMO, which could provide better predictive capability. Future work will focus on finding these additional measures and expansion of our techniques to include other patient populations.

Coagulation monitoring correlation with heparin dose in pediatric extracorporeal life support

Objectives:

Extracorporeal Life Support (ECLS) risks thrombotic and hemorrhagic complications. Optimal anti-coagulation monitoring is controversial. We compared coagulation tests evaluating the heparin effect in pediatric ECLS.

Methods:

A retrospective study of children (<18yrs) undergoing ECLS over 12 months in a tertiary pediatric intensive care unit (PICU). Variables included anti-Factor Xa activity (anti-Xa), activated partial thromboplastin time (aPTT), activated clotting time (ACT) and thromboelastogram (TEG®6s) parameters: ratio and delta reaction (R) times (the ratio and difference, respectively, between R times in kaolin assays with and without heparinase). Test results were correlated with unfractionated heparin infusion rate (IU/kg/hr) at the time of sampling. Mean test results of each ECLS run were evaluated according to the presence/absence of complications.

Results:

Thirty-two ECLS runs (31 patients) generated 695 data-points for correlation. PICU mortality was 22% and the thrombotic complication rate was 66%. The proportion of variation in coagulation test results explained by heparin dose was 13.3% for anti-Xa, 11.9% for ratio R time, and 9.9% for delta R time, compared with <1% for ACT and aPTT. Incorporating individual variation, age and antithrombin activity in a model with heparin dose explained less than 50% of the variation in test results. Correlation varied according to age, day of ECLS run and between individuals, with parallel dose-response lines noted between patients. Significantly lower mean anti-Xa was observed in PICU non-survivors and runs with thrombosis.

Conclusion:

Lower anti-Xa was observed in ECLS runs with complications. Although absolute results from anti-Xa and TEG6®s showed the best correlation with heparin dose, a large proportion of variation in results was unexplained by heparin, while dose response was similar between individuals. Population pharmacokinetic/pharmacodynamic modelling is required, as well as prospective trials to delineate the superior means of adjusting heparin therapy to prevent adverse clinical outcomes.

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.

Pediatric Acute Hypoxemic Respiratory Failure: Management of Oxygenation

Acute hypoxemic respiratory failure (AHRF) is one of the hallmarks of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which are caused by an inflammatory process initiated by any of a number of potential systemic and/or pulmonary insults that result in heterogeneous disruption of the capillary-pithelial interface. In these critically sick patients, optimizing the management of oxygenation is crucial. Physicians managing pediatric patients with ALI or ARDS are faced with a complex array of options influencing oxygenation. Certain treatment strategies can influence clinical outcomes, such as a lung protective ventilation strategy that specifies a low tidal volume (6 mL/kg) and a plateau pressure limit (30 cm H2O). Other strategies such as different levels of positive end expiratory pressure, altered inspiration to expiration time ratios, recruitment maneuvers, prone positioning, and extraneous gases or drugs may also affect clinical outcomes. This article reviews state-of-the-art strategies on the management of oxygenation in acute hypoxemic respiratory failure in children.

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

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

Hematological changes during short-term tidal flow extracorporeal life support

Various methods exist in the clinical practice of long-term venovenous (VV) extracorporeal life support (ECLS). Among the clinical techniques used are single venous access with a dual-lumen catheter, and cannulation of the jugular and femoral veins. Tidal flow VV ECLS uses a single-lumen catheter to achieve both venous drainage and arterialized reinfusion through a series of tubing occluders that are automated by a pump. A single venous occluder tidal flow system with a 15 Fr single-lumen cannula (n- 6) and passive filling M pump was compared to a conventional 14 Fr dual-lumen cannula (n- 7) and roller pump for four hours of VV ECLS. The changes in platelet count and plasma-free hemoglobin (pHgb) were compared. The results showed a decline in platelet counts typical of ECLS in both groups that were not significantly different from each other. A small elevation in pHgb did not rise above normal clinical levels of 15 mg/dL in either group after four hours of ECLS. Some recirculation was observed and needs to be addressed in future studies. Single occluder tidal flow ECLS may be feasible and efficacious for long-term application once recirculation is resolved and the system evaluated for long-term support.

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.

Venovenous Extracorporeal Life Support in Single-Ventricle Patients with Acute Respiratory Distress Syndrome

There is new and growing experience with venovenous extracorporeal life support (VV ECLS) for neonatal and pediatric patients with single-ventricle physiology and acute respiratory distress syndrome (ARDS). Outcomes in this population have been defined but could be improved; survival rates in single-ventricle patients on VV ECLS for respiratory failure are slightly higher than those in single-ventricle patients on venoarterial ECLS for cardiac failure (48 vs. 32-43%), but are lower than in patients with biventricular anatomy (58-74%). To that end, special consideration is necessary for patients with single-ventricle physiology who require VV ECLS for ARDS. Specifically, ARDS disrupts the balance between pulmonary and systemic blood flow through dynamic alterations in cardiopulmonary mechanics. This complexity impacts how to run the VV ECLS circuit and the transition back to conventional support. Furthermore, these patients have a complicated coagulation profile. Both venous and arterial thrombi carry marked risk in single-ventricle patients due to the vulnerability of the pulmonary, coronary, and cerebral circulations. Finally, single-ventricle palliation requires the preservation of low resistance across the pulmonary circulation, unobstructed venous return, and optimal cardiac performance including valve function. As such, the proper timing as well as the particular conduct of ECLS might differ between this population and patients without single-ventricle physiology. The goal of this review is to summarize the current state of knowledge of VV ECLS in the single-ventricle population in the context of these special considerations.

Extracorporeal support in children with pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVE

Extracorporeal life support has undergone a revolution in the past several years with the advent of new, miniaturized equipment and success in supporting patients with a variety of illnesses. Most experience has come with the use of extracorporeal membrane oxygenation, a modified form of cardiopulmonary bypass that can support the heart, lungs, and circulation for days to months at a time. To describe the recommendations for the use of extracorporeal membrane oxygenation in children with pediatric acute respiratory distress syndrome based on a review of the literature and expert opinion.

DESIGN

Consensus conference of experts in pediatric acute lung injury.

METHODS

A panel of 27 experts met over the course of 2 years to develop a taxonomy to define pediatric acute respiratory distress syndrome and to make recommendations regarding treatment and research priorities. The extracorporeal support subgroup comprised two international experts. When published data were lacking, a modified Delphi approach emphasizing strong professional agreement was used.

RESULTS

The Pediatric Acute Lung Injury Consensus Conference experts developed and voted on a total of 151 recommendations addressing the topics related to pediatric acute respiratory distress syndrome, 11 of which related to extracorporeal support. All recommendations had agreement, with 10 recommendations (91%) achieving strong agreement. These recommendations included the utilization of extracorporeal support for reversible causes of pediatric acute respiratory distress syndrome, consideration of quality of life when making the decision to use extracorporeal support, and the use of the Extracorporeal Life Support Organization registry to report all extracorporeal support activity, among others.

CONCLUSIONS

Pediatric extracorporeal membrane oxygenation for pediatric acute respiratory distress syndrome could benefit from more specific data collection and collaboration of focused investigators to establish validated criteria for optimal application of extracorporeal membrane oxygenation and patient management protocols. Until that time, consensus opinion offers some insight into guidelines.

Pediatric Extracorporeal Membrane Oxygenation: An Introduction for Emergency Medicine Physicians

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) therapy has supported critically ill pediatric patients in the intensive care unit setting with cardiac and respiratory failure. This therapy is beginning to transition to the emergency department setting.

OBJECTIVE OF REVIEW

This article describes the fundamentals of ECMO and familiarizes the emergency medicine physician with its use in critically ill pediatric patients.

DISCUSSION

ECMO can be utilized as either venoarterial (VA) or venovenous (VV), to support oxygenation and perfusion in respiratory failure, sepsis, cardiac arrest, and environmental hypothermia.

Extracorporeal life support: experience with 2,000 patients

This is a review of the University of Michigan experience with extracorporeal life support (ECLS) also known as extracorporeal membrane oxygenation (ECMO). Two thousand patients were managed with ECMO from 1973 to 2010. The first 1,000 patients were reported previously. Of the 2,000 patients, 74% were weaned from ECLS, and 64% survived to hospital discharge. In patients with respiratory failure, survival to hospital discharge was 84% in 799 neonates, 76% in 239 children, and 50% in 353 adults. Survival in patients with cardiac failure was 45% in 361 children and 38% in 119 adults. ECLS during extracorporeal cardiopulmonary resuscitation was performed in 129 patients, with 41% surviving to discharge. Survival decreased from 74 to 55% between the first and second 1,000 patients. The most common complication was bleeding at sites other than the head, with an incidence of 39%, and the least frequent complication was pump malfunction, with a 2% incidence. Intracranial bleeding or infarction occurred in 8% of patients, with a 43% survival rate. This is the largest series of ECLS at one institution reported in the world to date. Our experience has shown that ECLS saves lives of moribund patients with acute pulmonary and cardiac failure in all age groups.

Clinical Applications of Extracorporeal Membranous Oxygenation: A Mini-Review

The clinical usage of extracorporeal membranous oxygenation began more than 40 years ago. Although the indications for its use have expanded over the years, it has been challenging to conduct randomized controlled trials to prove that extracorporeal membranous oxygenation is more effective than traditional approaches. Through a review of retrospective reports and data from registries, we attempted to evaluate the appropriateness of its application for acute respiratory distress syndrome, cardiopulmonary resuscitation, postcardiotomy cardiogenic shock, and sepsis. Our investigation revealed that using extracorporeal membranous oxygenation when readily available is appropriate for all patients with cardiopulmonary resuscitation or postcardiotomy cardiogenic shock, and for selected patients with acute respiratory distress syndrome or sepsis.

KEY WORDS

Acute respiratory distress syndrome; Cardiopulmonary resuscitation; Extracorporeal membranous oxygenation; Postcardiotomy cardiogenic shock; Sepsis.

Significant social events and increasing use of life-sustaining treatment: trend analysis using extracorporeal membrane oxygenation as an example

BACKGROUND

Most studies have examined the outcomes of patients supported by extracorporeal membrane oxygenation as a life-sustaining treatment. It is unclear whether significant social events are associated with the use of life-sustaining treatment. This study aimed to compare the trend of extracorporeal membrane oxygenation use in Taiwan with that in the world, and to examine the influence of significant social events on the trend of extracorporeal membrane oxygenation use in Taiwan.

METHODS

Taiwan's extracorporeal membrane oxygenation uses from 2000 to 2009 were collected from National Health Insurance Research Dataset. The number of the worldwide extracorporeal membrane oxygenation cases was mainly estimated using Extracorporeal Life Support Registry Report International Summary July 2012. The trend of Taiwan's crude annual incidence rate of extracorporeal membrane oxygenation use was compared with that of the rest of the world. Each trend of extracorporeal membrane oxygenation use was examined using joinpoint regression.

RESULTS

The measurement was the crude annual incidence rate of extracorporeal membrane oxygenation use. Each of the Taiwan's crude annual incidence rates was much higher than the worldwide one in the same year. Both the trends of Taiwan's and worldwide crude annual incidence rates have significantly increased since 2000. Joinpoint regression selected the model of the Taiwan's trend with one joinpoint in 2006 as the best-fitted model, implying that the significant social events in 2006 were significantly associated with the trend change of extracorporeal membrane oxygenation use following 2006. In addition, significantly social events highlighted by the media are more likely to be associated with the increase of extracorporeal membrane oxygenation use than being fully covered by National Health Insurance.

CONCLUSIONS

Significant social events, such as a well-known person's successful extracorporeal membrane oxygenation use highlighted by the mass media, are associated with the use of life-sustaining treatment such as extracorporeal membrane oxygenation.

Factors associated with mortality in pediatric patients requiring extracorporeal life support for severe pneumonia

OBJECTIVES

In children with respiratory failure secondary to pneumonia, extracorporeal life support can be lifesaving. Our goal was to identify variables associated with mortality in children with pneumonia requiring extracorporeal life support.

DESIGN

Data query and abstraction from a multicenter, international registry of extracorporeal life support, the Extracorporeal Life Support Organization Registry.

SETTING

Extracorporeal Life Support Organization registry data from 1985 to 2010.

PATIENTS

Patients ≤ 18 yr of age who received extracorporeal life support for respiratory failure secondary to pneumonia.

INTERVENTIONS

None.

MEASUREMENTS AND OUTCOMES

Clinical variables, year of extracorporeal life support, and extracorporeal life support center location were collected. The primary outcome was survival at hospital discharge. Results are reported as predictive margins, which allow estimation of standardized mortality rates and differences for risk factors.

RESULTS

One thousand four hundred eighty-nine children were included. The median (interquartile range) age and duration of extracorporeal life support were 5.7 months (2.5-21.5) and 11 days (7-18). Arterial cannulation was performed in 65% of patients. Mortality was 39%. There was no relationship between mortality and age or pathogen. Duration of extracorporeal life support had a biphasic relationship on mortality; mortality decreased 1.3% per day on extracorporeal life support until 14 days and then increased by 1.8% per day thereafter. Other independent predictors of mortality (p < 0.05) were pre-extracorporeal life support factors including duration of mechanical ventilation, peak inspiratory pressure, arterial oxygen saturation, pH, cardiac arrest, need for an arterial cannula, decade of extracorporeal life support, international extracorporeal life support center, and decrease in FIO2 over the first 24 hrs on extracorporeal life support.

CONCLUSIONS

In children with severe pneumonia receiving extracorporeal life support, prognostic factors associated with increased risk of death included extracorporeal life support treatment exceeding 14 days, arterial cannulation, longer duration of mechanical ventilation, and decreased ability to wean ventilator FIO2 over the first 24 hrs on extracorporeal life support. Analysis of the Extracorporeal Life Support Organization registry can identify prognostic variables, which may influence medical decision making, resource utilization, and family counseling.

Prolonged extracorporeal membrane oxygenation for children with respiratory failure

OBJECTIVE

Extracorporeal membrane oxygenation is used to support children with respiratory failure. When extracorporeal membrane oxygenation duration is prolonged, decisions regarding ongoing support are difficult as a result of limited prognostic data.

DESIGN

Retrospective case series.

SETTING

Multi-institutional data reported to the Extracorporeal Life Support Organization Registry.

PATIENTS

Patients aged 1 month to 18 yrs supported with extracorporeal membrane oxygenation for respiratory failure from 1993 to 2007 who received support for ≥ 21 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 3213 children supported with extracorporeal membrane oxygenation during the study period, 389 (12%) were supported ≥ 21 days. Median patient age was 9.1 months (interquartile range, 2.5-41.7 months). Median weight was 6.7 kg (interquartile range, 3.5-15.8 kg). Survival for this group was 38%, significantly lower than survival reported for children supported ≤ 14 days (61%, p < .001). Among children supported with extracorporeal membrane oxygenation for ≥ 21 days, no differences were found between survivors and nonsurvivors with regard to acute pulmonary diagnosis, pre-extracorporeal membrane oxygenation comorbidities, pre-extracorporeal membrane oxygenation adjunctive therapies, or pre-extracorporeal membrane oxygenation blood gas parameters. Only peak inspiratory pressure was significantly different in survivors. Complications occurring on extracorporeal membrane oxygenation were more common among nonsurvivors. The use of inotropic infusion (odds ratio 1.64; 95% confidence interval 1.07-2.52), acidosis (pH <7.2) during extracorporeal membrane oxygenation (odds ratio 2.62; 95% confidence interval 1.51-4.55), and male gender (odds ratio 1.95; 95% confidence interval 1.21-3.15) were independently associated with increased odds of death.

CONCLUSION

Survival declines with duration of extracorporeal membrane oxygenation. Male gender and inadequate cardiorespiratory status during extracorporeal membrane oxygenation increased the risk of death. Prolonged support with extracorporeal membrane oxygenation appears reasonable unless multiorgan failure develops.

The critically-ill pediatric hemato-oncology patient: epidemiology, management, and strategy of transfer to the pediatric intensive care unit

Cancer is a leading cause of death in children. In the past decades, there has been a marked increase in overall survival of children with cancer. However, children whose treatment includes hematopoietic stem cell transplantation still represent a subpopulation with a higher risk of mortality. These improvements in mortality are accompanied by an increase in complications, such as respiratory and cardiovascular insufficiencies as well as neurological problems that may require an admission to the pediatric intensive care unit where most supportive therapies can be provided. It has been shown that ventilatory and cardiovascular support along with renal replacement therapy can benefit pediatric hemato-oncology patients if promptly established. Even if admissions of these patients are not considered futile anymore, they still raise sensitive questions, including ethical issues. To support the discussion and potentially facilitate the decision-making process, we propose an algorithm that takes into account the reason for admission (surgical versus medical) and the hemato-oncological prognosis. The algorithm then leads to different types of admission: full-support admission, "pediatric intensive care unit trial" admission, intensive care with adapted level of support, and palliative intensive care. Throughout the process, maintaining a dialogue between the treating physicians, the paramedical staff, the child, and his parents is of paramount importance to optimize the care of these children with complex disease and evolving medical status.

Pharmacokinetic changes in patients receiving extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a form of prolonged cardiopulmonary bypass used to temporarily sustain cardiac and/or respiratory function in critically ill patients. Extracorporeal membrane oxygenation further complicates the management of critically ill patients who already have profound physiologic derangements with consequent altered pharmacokinetics. The purpose of this study is to identify and critically review the published literature describing pharmacokinetics in the presence of ECMO. This review revealed a dearth of data describing pharmacokinetics during ECMO in critically ill adults, with most of the available data originating in neonates. Of concern, the present data indicate substantial variability and a lack of predictability in drug behavior in the presence of ECMO. The most common mechanisms by which ECMO affects pharmacokinetics are sequestration in the circuit, increased volume of distribution, and decreased drug elimination. While lipophilic drugs and highly protein-bound drugs (eg, voriconazole and fentanyl) are significantly sequestered in the circuit, hydrophilic drugs (eg, β-lactam antibiotics, glycopeptides) are significantly affected by hemodilution and other pathophysiologic changes that occur during ECMO. Although the published literature is insufficient to make any meaningful recommendations for adjusting therapy for drug dosing, this review systematically describes the available data enabling clinicians to make conclusions based on available data. Furthermore, this review serves to highlight the need for well-designed and conducted clinical and laboratory-based studies to provide the data from which robust dosing guidance can be developed to improve clinical outcomes in this most unwell cohort of patients.

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.

Development of a collaborative program to provide extracorporeal membrane oxygenation for adults with refractory hypoxemia within the framework of a pandemic

OBJECTIVE

We report the process used to rapidly develop a collaborative adult respiratory extracorporeal membrane oxygenation program as a response to caring for young adult patients with refractory hypoxemia in the setting of the pH1N1 pandemic.

DESIGN

Interdisciplinary response of a complex medical system to a public health crisis. PATIENTS, INTERVENTIONS, MEASUREMENTS, AND MAIN RESULTS: After the successful use of extracorporeal membrane oxygenation in young adults with pH1N1-induced acute respiratory distress syndrome refractory to conventional therapies, an adult venovenous extracorporeal membrane oxygenation program was implemented over an 8-wk period. Implementation of this program involved a number of key steps that were crucial in the development process, including administrative and institutional support, multidisciplinary leadership and collaboration, extensive interdisciplinary educational initiatives, and substantial technical modifications.

CONCLUSIONS

In the setting of the pH1N1 influenza pandemic, an adult respiratory extracorporeal membrane oxygenation program was successfully developed to complement an established neonatal-pediatric program. This program expansion integrated all of the necessary components involved in the development process from start to finish and confirms that a healthcare system can respond very quickly and successfully to an urgent healthcare need.

Extracorporeal membrane oxygenation for pediatric respiratory failure: Survival and predictors of mortality

OBJECTIVE

The last multicentered analysis of extracorporeal membrane oxygenation in pediatric acute respiratory failure was completed in 1993. We reviewed recent international data to evaluate survival and predictors of mortality.

DESIGN

Retrospective case series review.

SETTING

The Extracorporeal Life Support Organization Registry, which includes data voluntarily submitted from over 115 centers worldwide, was queried. The work was completed at the Division of Pediatric Critical Care, Department of Pediatrics, Primary Children's Medical Center, University of Utah, Salt Lake City, UT.

SUBJECTS

Patients aged 1 month to 18 yrs supported with extracorporeal membrane oxygenation for acute respiratory failure from 1993 to 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 3,213 children studied. Overall survival remained relatively unchanged over time at 57%. Considerable variability in survival was found based on pulmonary diagnosis, ranging from 83% for status asthmaticus to 39% for pertussis. Comorbidities significantly decreased survival to 33% for those with renal failure (n = 329), 16% with liver failure (n = 51), and 5% with hematopoietic stem cell transplantation (n = 22). The proportion of patients with comorbidities increased from 19% during 1993 to 47% in 2007. Clinical factors associated with mortality included precannulation ventilatory support longer than 2 wks and lower precannulation blood pH.

CONCLUSIONS

Although the survival of pediatric patients with acute respiratory failure treated with extracorporeal membrane oxygenation has not changed, this treatment is currently offered to increasingly medically complex patients. Mechanical ventilation in excess of 2 wks before the initiation of extracorporeal membrane oxygenation is associated with decreased survival.

Acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a common diagnosis among children admitted to pediatric intensive care units. This heterogeneous disorder has numerous pulmonary and non-pulmonary causes and is associated with a significant risk of mortality. Many supportive therapies exist for ARDS. SEARCH: Literature search was performed by using the key words ARDS and related topics on the Pubmed search engine maintained by the National Heart, Lung, Blood Institute. Pediatric randomized controlled trials that have been published in the last 10 years were included. Emphasis was placed on pediatric literature, although sentinel adult studies have been included. Most of the evidence presented is of levels I and II.

RESULTS

Low tidal volume is the only strategy that has consistently improved outcome in ARDS. A tidal volume of ≤ 6 mL/kg predicted body weight should be used. Ventilator induced lung injury may result in systemic effects with multi-system organ failure, and all efforts should be made to minimize this. Positive end-expiratory pressure should be used to judiciously maintain lung recruitment. There is insufficient evidence to routinely use high frequency ventilation, prone positioning, or inhaled nitric oxide. Calfactant therapy is promising and may be considered in children with direct lung injury and ARDS. Current literature does not support routine use of corticosteroids for non-resolving ARDS.

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

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

Extracorporeal membrane oxygenation in adults with severe respiratory failure: a multi-center database

OBJECTIVE

To evaluate clinical and treatment factors for patients recorded in the Extracorporeal Life Support Organization (ELSO) registry and survival of adult extracorporeal membrane oxygenation (ECMO) respiratory failure patients.

DESIGN AND PATIENTS

Retrospective case review of the ELSO registry from 1986-2006. Data were analyzed separately for the entire time period and the most recent years (2002-2006).

RESULTS

Of 1,473 patients, 50% survived to discharge. Median age was 34 years. Most patients (78%) were supported with venovenous ECMO. In a multi-variate logistic regression model, pre-ECMO factors including increasing age, decreased weight, days on mechanical ventilation before ECMO, arterial blood pH <or= 7.18, and Hispanic and Asian race compared to white race were associated with increased odds of death. For the most recent years (n = 600), age and PaCO(2) >or= 70 compared to PaCO(2) <or= 44 were also associated with increased odds of death. The two diagnostic categories acute respiratory failure and asthma compared to ARDS were associated with decreased odds of mortality as was venovenous compared to venoarterial mode. CPR and complications while on ECMO including circuit rupture, central nervous system infarction or hemorrhage, gastrointestinal or pulmonary hemorrhage, and arterial blood pH < 7.2 or >7.6 were associated with increased odds of death.

CONCLUSIONS

Survival among this cohort of adults with severe respiratory failure supported with ECMO was 50%. Advanced patient age, increased pre-ECMO ventilation duration, diagnosis category and complications while on ECMO were associated with mortality. Prospective studies are needed to evaluate the role of this complex support mode.