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Report On the Workshop On Diffusion of Ecmo Technology
National Institutes of Health
Technology Assessment Workshop
May 31, 1990-June 1, 1990
This statement is more than five years old and is provided solely for historical purposes. Due to the cumulative nature of medical research, new knowledge has inevitably accumulated in this subject area in the time since the statement was initially prepared. Thus some of the material is likely to be out of date, and at worst simply wrong. For reliable, current information on this and other health topics, we recommend consulting the National Institutes of Health's MedlinePlus http://www.nlm.nih.gov/medlineplus/.
This statement was originally published as: Report of the Workshop on Diffusion of ECMO Technology: Extracorporeal Membrane Oxygenation. Workshop summary; 1990 May 31-Jun 1. Bethesda (MD): National Institutes of Health, National Institute of Child Health and Human Development; NIH Publ. No. 93- 3399; Jan 1993. 93 p.
For making bibliographic reference to the statement in the electronic form displayed here, it is recommended that the following format be used: Report of the Workshop on Diffusion of ECMO Technology: Extracorporeal Membrane Oxygenation. NIH Technol Assess Statement Online 1990 May 31-Jun 1 [cited year month day]; (6):16.
This workshop, which was initiated by the National Institute of Child Health and Human Development (NICHD), is the result of the combined efforts of the NICHD, the Office of Medical Applications of Research (OMAR), the National Institute of Neurological Disorders and Stroke (NINDS), the National Heart, Lung, and Blood Institute (NHLBI), the Food and Drug Administration (FDA), and the Agency for Health Care Policy and Research (AHCPR).
A planning committee commissioned background papers which were circulated to the invited participants prior to the meeting. Presentation and discussion of the papers was followed by working groups which met to define policy and research recommendations in the areas of prevention and therapeutic alternatives, identification of populations to benefit from ECMO, research needs, and policy concerns. Recommendations of the working groups were reviewed in plenary session. The resulting Summary with Policy and Research Recommendations is presented below, followed by abstracts of the commissioned papers.
Extracorporeal Membrane Oxygenation (ECMO) is a new, highly invasive therapy that is being investigated and utilized in newborn infants with cardiorespiratory failure. The apparent increasing use of this technology, especially in new patient populations, as well as concerns about long-term outcome stimulated an invitational forum sponsored by multiple U.S. Government agencies. The specific focus of the forum was diffusion of ECMO technology.
Development and use of this technology in newborns is relatively well defined and documented. The literature includes reports on technical details and clinical application up to and including recent controlled trials. An organization, ELSO, or Extracorporeal Life Support Organization, was formally established in 1989 by investigators and clinicians who previously had been involved in regular meetings and the sharing of information and establishment of guidelines. A patient registry supported by Federal and private funds has been maintained.
Current State of Knowledge Concerning Populations To Benefit and Indications for Use
Certain patients with a high risk of morbidity and mortality are appropriate candidates for ECMO when pulmonary function and other studies suggest that mechanical ventilation will be unsuccessful or cause undue harm. ECMO should no longer be considered an extraordinary or rescue therapy for moribund infants over 2 kilograms. Early consultation with ECMO units concerning infants within defined weight and disease categories is encouraged to facilitate timely, safe transfer.
Term and Near-Term Newborns
Infants born at greater than 35 weeks gestation with the following disease states should be considered candidates:
Meconium Aspiration Syndrome (MAS) and Persistent Pulmonary Hypertension of the Newborn (PPHN)
A small portion of babies with clinical manifestations of MAS and PPNN may not respond to conventional therapy. Initial stabilization and a trial of conventional therapy should be instituted before consideration of ECMO.
Congenital Diaphragmatic Hernia (CDH)
Mechanical ventilation, general physiologic support, and early surgical repair remain the current standard of care for CDH. ECMO may improve survival in infants with CDH who have continued respiratory failure after repair. Given the increased vulnerability of the congenitally hypoplastic lung to mechanical ventilation, institution of ECMO should be considered earlier in these infants than in infants with PPNN. However, ECMO is not appropriate for infants with severe pulmonary hypoplasia. Delayed repair following stabilization (which may include ECMO) is currently under study and is not at present a preferred treatment.
ECMO is appropriate for a limited number of infants with respiratory failure due to sepsis who do not respond to other therapy. However, studies of children with multiple organ failure (including respiratory) secondary to sepsis, who are treated with ECMO, reveal higher morbidity and mortality compared to other groups treated with ECMO. The indication for ECMO in this group requires further research.
Respiratory Distress Syndrome (RDS)
Apparent RDS in infants of greater than 2 kilograms birthweight appears in a small number of infants and may include other entitles as yet poorly defined. ECMO is appropriate when optimal ventilatory management fails.
ECMO is not appropriate for infants under 2 kilograms and 36 weeks gestation except under carefully controlled research protocols.
Postneonatal Pediatric Patients
ECMO is currently being used as rescue therapy for severe respiratory failure in pediatric patients (1 month to 16 years) in a small number of centers. There is an urgent need to define mortality and morbidity risks as well as natural history in this diverse diagnostic group. It should not be assumed that the favorable results of treatment achieved with ECMO with certain term newborn problems can be transferred to those of the older patient. Any use should be considered experimental and should be undertaken with Institutional Review Board (IRB) approval in pediatric intensive care units by experienced pediatric intensivists and ECMO teams with careful data collection and reporting.
ECMO is also being used as an adjunct to cardiac surgery in a small number of centers. As in pediatric respiratory failure, these early trials should be done with IRB approval in pediatric intensive care units, by experienced intensivists and ECMO teams, following protocols with careful data collection and reporting.
Patients with Irreversible and Hopeless Conditions
ECMO is a temporizing and not a corrective intervention. Repair and recovery is necessary for patients to benefit. There may be some infants with irreversible organ dysfunction or damage with no hope of correction who may be appropriately excluded from ECMO treatment. Each institution should establish a mechanism of review for such infants.
Prevention and Therapeutic Alternatives
The number of centers that offer ECMO treatment has increased dramatically, however, alternative therapies and prevention have not been adequately explored. There is a serious lack of knowledge regarding epidemiologic factors that influence the requirement for ECMO therapy.
The actual incidence of conditions treated with ECMO, such as PPHN, is not well documented. Furthermore, inter-institutional differences in ECMO utilization are substantial and the relative effectiveness of alternatives versus ECMO is unclear. In the ECMO registry, inborn patients represent only 7 percent of the population receiving ECMO treatment, suggesting that management of outborn patients before they are referred is a major factor determining the requirement for ECMO treatment.
Studies of obstetric and/or neonatal care practices that either prevent or increase the use of ECMO therapy are needed. It is well known that a substantial portion of babies referred for ECMO do not receive the treatment. The ECMO registry might serve as a valuable resource to identify perinatal care practices that influence or determine need. Examples of practices that some feel differ extensively include early recognition and intervention when meconium is present at birth, use of tolazoline, and ventilatory management including the extent of over ventilation.
Particular note should be made of the deficit of information regarding the importance of ventilatory care practices. Retrospective evidence suggests that the mode of ventilation may modify or predispose to a need for subsequent ECMO therapy in infants who develop progressive lung disease. High levels of oxygen alone may result in lung damage; furthermore, the definition of an "acceptable" low level of arterial oxygen (PaO2) varies considerably between institutions. A concept has emerged in recent years that a lower PaO2 than previously accepted might be indicated.
Education and prevention strategies should be developed based upon epidemiologic information about current practices and their impact on the need for ECMO. It is not yet known whether the use of ECMO can be reduced through education of physicians, nurses, and others concerned with the care of critically ill neonates, but the effort should be undertaken.
Based on present knowledge and understanding of the use of ECMO and the infants needing this mode of treatment, the following summary statements regarding prevention and therapies were derived:
- Educational needs of pertinent individuals (physicians, nurses, respiratory therapists) should be determined from practice and epidemiologic studies. Efforts directed toward modifying care practices of the at-risk fetus, the newborn, and the ill newborn should be undertaken. This pertains especially to the physicians responsible for care of the newborn in the delivery room and the physician responsible for management of the infant on a ventilator.
- Continued use and improvement of presently available alternative therapies should be pursued. The use of ECMO for infants who do not meet the presently- accepted criteria for term or near-term infants mentioned above must be considered clinical research and take place only with consideration of alternatives and within appropriately designed trials. Research should continue to determine if there are additional alternatives to ECMO therapy.
The increasing use of ECMO especially in new patient populations creates an urgent need for further research. Clinical studies are needed to determine when ECMO is the most appropriate treatment alternative and what technical improvements are safe and feasible. The short-term and long-term effects of ECMO on the nervous system, pulmonary system, cardiac system, and the blood in all age groups must be further defined. Quality of life as well as specific biologic parameters should be studied.
The Ideal Prospective Randomized Controlled Clinical Trial
The baby at risk for severe neonatal cardiopulmonary problems should be identified before or shortly after birth. The decision to enroll an ill neonate should be made within hours after birth with random assignment to one of several alternative therapeutic interventions. In parallel, the patient should be matched both to a control baby with similar problems of less severity that does not meet study entrance criteria and to a healthy matched control baby. Preintervention parameters should be measured to survey organ dysfunction resulting from the underlying disease process itself. Subsequently, appropriate parameters should be measured during the time of therapeutic intervention. Short-term outcomes (hours to weeks), intermediate outcomes (months), and long-term outcomes (years) should be determined in a prospective randomized controlled clinical trial.
Because of rapidly-changing technological improvements, it is necessary to accrue patients over a limited time period. Multi-center collaboration to ensure adequate patient entry is necessary. A severity and/or prognosis index is needed to ensure balanced risk among the alternative treatment arms.
Table 1: Parameters and Techniques to Determine Organ Function During Animal Model and Clinical Studies* Animal model studies Clinical studies Neurologic
- Perfusion/hemodynamics (Doppler)
- Electrophysiologic (EEG, EP's)
- Non-invasive imaging (NMR, NIRS, US)
- Metabolic (NMR, NIRS)
- Behavior assessment
- Perfusion/hemodynamics (Doppler)
- Electrophysiologic (EEG, EP's)
- Non-invasive imaging (NMR, NIRS, US)
- Metabolic (NMR, NIRS)
- Neurodevelopmental assessment
- Pulmonary vascular resistance control
-- anatomy of development
-- mechanics of hyperreactivity
- Surfactant dynamics
- Pulmonary function tests (PFT's)
- Surfactant dynamics
- Pulmonary pathology
- Long-term PFT's
- Myocardial oxygen consumption
- Coronary artery flow
- Ventricular function (echocardiography)
- Cardiac pathology
- Impact of biomaterials on cellular elements and vasoactive substances
- Impact of circuity on cellular elements
- Coagulation parameters
- Vasoactive substances
Abbreviations: ABG -- arterial blood gases, CBC -- complete blood count, EEG -- electroencephalography, EPs -- evoked potentials, NIRS -- near infrared spectroscopy, NMR -- nuclear magnetic resonance, PFTs -- pulmonary function tests, US -- ultrasound.
Assessment of Expanded Clinical Indications
ECMO may eventually prove to be an appropriate therapy for certain premature neonates, but the risks for this population appear greater and the benefits less certain at this time. Any application of ECMO to the premature neonatal population should be limited to strict clinical research protocols.
ECMO following cardiac surgery is currently in use in some centers and requires careful evaluation by clinical research protocols to determine who should be a postsurgical candidate for ECMO and to determine risk versus benefit.
Role of Animal Studies
Animal studies will be necessary to answer certain key questions relevant to clinical studies. Research with animal models to define the pathogenesis and treatment of such pulmonary vascular disorders as persistent pulmonary hypertension could lead to increased prevention and less need for ECMO or its alternatives. A better understanding of the optimal timing for initiation and discontinuation of ECMO may be derived from animal research.
ECMO could possibly be used to simulate the process of in utero hypoxia-ischemia in an animal research model, thereby permitting serial observations and elucidation of pathogenesis.
Specific Studies of Organ Function and Dysfunction
Table 1 lists the key organ systems affected both by the underlying diseases leading to cardiopulmonary failure and by the therapeutic intervention. The critical parameters and techniques used to assess organ function in the clinical situation and in animal models are outlined. With new and promising techniques rapidly becoming available, it will be possible to assess pulmonary, cardiac, blood, and neurologic parameters before, during, and after the ECMO procedure.
Neurologic status is a crucial outcome measure for assessing the long- term functional results of therapeutic intervention. Comprehensive neurologic and developmental assessments by age-appropriate evaluative instruments are needed. Information from neuroimaging, cerebral hemodynamic, neurophysiologic, and neurochemical studies are required before, during, and after the intervention so that outcomes may be related to specific events either preceding or during treatment.
Cardiopulmonary studies require ongoing monitoring of pulmonary function tests, arterial blood gases, and myocardial physiology. Factors controlling pulmonary vascular resistance (systemic mediators, hyperreactivity mechanisms, and changing surfactant dynamics) are of particular interest. Research concerning the effects of intervention on ventricular function and coronary artery flow are also crucial.
Both cellular and plasma blood components can be affected by the ECMO apparatus. Such blood changes (cells, vasoactive substances, and coagulation factors) can have a major impact on systemic physiology.
Studies to Improve ECMO Technology
A number of improvements in ECMO technology are under development. Veno-venous catheterization would be a less invasive technique compared to veno-arterial catheterization. Carotid reanastomosis may prove to be possible. The use of anticoagulative circuits may eliminate the need for systemic heparinization with its accompanying risks. Circuit control and monitoring systems when combined with measurement of critical clinical parameters may increase the precision and delicacy of the intervention. The use of biomaterials as components of the ECMO system would be expected to significantly reduce complications of hypersensitivity or embolization. Careful evaluation of the immediate efficacy and safety, as well as the long-term outcome of these various modifications will be necessary.
Studies to Improve Alternative Therapies
Alternative treatments for cardiopulmonary failure in the neonate are currently being explored. These include the use of surfactant, high- frequency ventilation, negative-pressure ventilation, liquid ventilation, and nitric oxide. A spectrum of "conservative" or "conventional" ventilatory assistance interventions, which are either already in use or are being developed, require controlled trials to determine their relative effectiveness.
Outcome Analysis (Follow-up Studies)
All studies require rigorous delineation of outcome analysis. The short-term outcomes include death, neurologic function (including EEG, neuroimaging, and clinical parameters), and cardiorespiratory function as defined by physiologic parameters. The long-term outcomes include death, health status (disease, disability, morbidity), and both global and system-specific functional status (psychomotor development, quality of life, and social adaptive functioning). Long-term outcomes also should be analyzed with respect to total health care utilization and cost.
The ultimate goal would be to analyze specific factors present before or during the ECMO procedure with regard to possible relationship to specific functional deficits detected at follow-up. It is essential to follow children long enough (school age or beyond) to assess motor performance and higher critical functions, including right versus left hemisphere cognitive processes. Contacts between physicians and parents established at the beginning of ECMO therapy should be maintained to facilitate study.
Policy Considerations Influencing the Diffusion of Ecmo
ECMO is a relatively new technology, so it is not surprising that few, if any, policies currently influence its use at existing centers or its spread to other facilities. Even technologies with longer histories have few formal policies governing their use. Decisions about who will perform medical and surgical procedures and where they will be performed are often under the control of hospitals and other health care facilities, as well as being strongly influenced by the organizations that pay for such procedures. Professional organizations, accrediting bodies, the Federal Food and Drug Administration, and state regulatory agencies also establish policies.
To make ECMO available to those infants who would benefit from it, and in the most cost effective manner, the development of three types of policies is recommended:
- Those that would promote effective and efficient use of existing ECMO centers and avoid inefficient and expensive proliferation.
- Those that would monitor the quantity and quality of ECMO treatment.
- Those that would encourage long-term studies.
To promote effective and efficient use of existing ECMO centers and avoid inefficient and expensive proliferation, the following should be implemented:
- Planning at the state and regional levels. This should include obtaining epidemiologic information that can be used to forecast the need for ECMO in various geographic areas.
- Development of guidelines for ECMO centers. Such guidelines should include staffing needs, minimum number of cases per year, acceptance criteria, data to be collected and submitted to the registry, quality criteria, and other aspects of care. (For the present, such guidelines should be limited to the use of ECMO with neonates.) Expansion of the technology for the treatment of pediatric or adult patients would necessitate the development of additional guidelines. Several organizations should be involved in the development of guidelines. The Extracorporeal Life Support Organization (ELSO) has already developed guidelines and the Committee on the Fetus and Newborn of the American Academy of Pediatrics (AAP) has issued "Recommendations on ECMO" (Pediatrics 85:618-619, 1990). These groups should be encouraged to remain active in guideline development. The Agency for Health Care Policy and Research (AHCPR) now has a mandate to develop practice guidelines; although its work to date has been primarily in relation to practices supported by Medicare, it should be expanding to other fields in the near future. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) should be asked to become involved in accreditation of ECMO centers(see next bulleted section).
- Development of an accreditation procedure. ECMO centers should be accredited, or licensed, or designated. Models for such accreditation are those currently used by the 10 American College of Surgeons (ACS) for Cancer and Trauma Centers. The JCAHO might be asked to form an ad hoc ECMO Accreditation Task Force, which should include representatives from groups such as ELSO, AAP and ACS. Other groups that might be involved in the process are Federal and state rate-setting agencies and state maternal and child health agencies because of their concern for children with special health care needs.
- Encouragement of the development of hospital "strategic alliances." Hospitals can work together to promote efficient utilization of existing centers through regional cooperation. Alliances have the potential to stabilize referrals, secure economy of scale, and promote continuing education of staff. This model of collaboration already exists in the Community Clinical Oncology Program.
- Development of funding policies that encourage use of existing ECMO centers and discourage inappropriate proliferation. Medicaid and other third-party payers should provide reimbursement for ECM treatment outside of the state in which the infant resides and for transportation to and from ECMO regional centers.
To monitor the quality and quantity of ECMO treatment, the following recommendations concerning data and case registration are made:
- Continuation and improvement of the existing ELSO case registry-- The case registry should be used as a management and research tool in order to determine efficacy and effectiveness. It should be able to indicate quality problems such as institutions that treat too few infants or have high failure rates. It should be used to help develop long-term outcome studies.
- Formation of an advisory board--This board should develop a list of data elements and undertake other relevant tasks, such as the development of procedures and incentives for establishing and maintaining data quality.
- Development of a permanent funding base--Funding of the registry should be the ultimate responsibility of participating ECMO centers. The Federal Government and foundations have assisted with initial efforts and should continue in the short term.
- Participation in the registry should be required for accreditation.
- The registry should be used to monitor the relevance of guidelines.
Diffusion of Medical Technology: The Case of Ecmo
Ann Lennarson Greer, Ph.D.
University of Wisconsin - Milwaukee
This overview distills accepted diffusion theory and the author's ongoing research to outline factors and dynamics which come into play around high-cost, high-risk, highly-complex technologies like Extracorporeal Membrane Oxygenation (ECMO). Three themes are developed. The first is the need to understand adoption of new technology as a social process wherein a consensus for change develops among local medical colleagues who communicate directly with one another in a situation of common circumstances, pressures, and experience. The second concerns the fact of medical technologies such as ECMO diffusing into practice even as they continue to change and develop. With such dynamic technologies, the state-of-the-art is as much a consequence of practice as of science. The third theme concerns the fact that hospital technology adoptions engage multiple interests, decision-makers, and criteria for adoption. The assessments of doctors are combined with those of businessmen and organizational planners in a dynamic local process which drives adoption and use. There is a brief discussion of the difficulties of using guidelines to affect this process.
Extracorporeal Life Support: State-of-the-art 1990
Robert H. Bartlett, M.D. Charles Stolar, M.D.
University of Michigan Medical Center and
Columbia Presbyterian Medical Center
The apparatus and techniques of extracorporeal circulation are routinely used for a few hours to permit surgery on the heart. With several modifications, extracorporeal circulation can be used for days or weeks to support the life of patients with severe cardiac or pulmonary failure. The procedure involves cannulation of major vessels without thoracotomy, carefully titrated partial anticoagulation with heparin, and continuous high-flow extracorporeal circulation through a membrane lung. Depending on the cannulation and application, this procedure has been called extracorporeal life support (ECLS), extracorporeal CO2 removal (ECCOR), extracorporeal heart assist, extracorporeal lung assist, and extracorporeal membrane oxygenation (ECMO). In this report the abbreviations ECLS and ECMO are used interchangably. ECLS is not a therapy, but a mechanical support system which allows time for the damaged heart or lungs to heal in a milieu of normal perfusion and gas exchange, while "resting" the damaged organs from the effects of mechanical ventilation and inotropic drugs. In the last decade ECLS has grown rapidly from a research protocol to clinical practice. It has been the most successful in neonatal respiratory failure and is now considered standard therapy for full-term infants with severe respiratory failure. It is the only method of mechanical cardiac support in children. It is a reasonable (albeit extraordinary) approach to the management of severe respiratory failure in children and adults.
Over 3,000 infant cases have been treated in the United States. There are more than 60 neonatal centers offering ECLS as standard treatment. Currently the treatment is used for moribund infants with 83 percent survival overall and 95 percent survival in the most experienced centers. The incidence of pulmonary or neurologic handicap (approximately 20 percent)3 is lower than that of other neonatal intensive care unit (ICU) graduates. Two prospective randomized studies have demonstrated the effectiveness of ECLS in newborn infants, and two studies have documented an overall decrease in hospitalization and expense in neonates. Thus, although ECLS is the ultimate example of high-tech, labor and resource-intensive, expensive, invasive procedures, it routinely results in healthy children at less cost, resource utilization, and morbidity than the previous conventional treatment. (We wish this were true for liver and bone marrow transplantation or cancer chemotherapy.) A study group of active centers was organized in 1989--the Extracorporeal Life Support Organization (ELSO).
The results of ventilator and pharmacologic management in neonatal respiratory failure are excellent. Only a few neonates managed primarily at major centers fail to respond to treatment. There may be several deaths in any year if there are many cases of diaphragmatic hernia and neonatal sepsis. There may be none at all if only meconium aspiration and persistent fetal circulation are treated. Nonetheless, there are still approximately 3,000 deaths from respiratory failure in full-term infants each year in the United States. Almost all of these deaths are preventable. Why does extracorporeal support result in routine recovery of infants who are moribund with acute respiratory failure? Certainly there is nothing therapeutic about anticoagulation and extracorporeal circulation. Lung recovery must result from "resting" the lung from high pressure and high oxygen concentration. Simply by sustaining the life of the infant through a few days (which usually includes total lack of lung function) recovery of aeration, pulmonary blood flow and ultimate survival almost always results. This should suggest to us that there is something about the ventilator or pharmacologic management of this small group of full-term infants that contributes to pulmonary dysfunction. Obviously, a change in treatment aimed at preventing progression to severe respiratory failure would be better than treating established respiratory failure with ECMO.
Because most of the clinical application of ECMO is currently in newborn infants, this description and discussion will refer primarily to that group of patients. The basic principles of extracorporeal circulation, gas exchange, and systemic oxygen delivery apply to patients of all sizes and ages.
Neurological Outcome After Extracorporeal Membrane Oxygenation Therapy in the Newborn
Jan Goddard-Finegold, M.D.
Associate Professor of Pediatrics and Pathology
Division of Pediatric Neurology
Baylor College of Medicine and
The Texas Children's Hospital
Extracorporeal membrane oxygenation (ECMO) has been used in over 3,500 neonates with severe respiratory failure since the 1970's. Although the neurologic morbidity of the procedure has not been fully evaluated, the permanent ligation of the right common carotid artery and jugular vein and the systemic heparinization that usually accompany ECMO have been felt by many neonatal physicians to be associated with unacceptable neurologic risk. The true neurologic risk has been difficult to assess, because studies of the efficacy of ECMO to date have been difficult to control. Further application of ECMO for the treatment of severe respiratory failure in newborn infants is being questioned because of the technical complexity of the procedure, its labor intensiveness and expense, and recent reports of increasing survival of infants after updated conventional medical therapy.
In this report the mortality and neurological morbidity from published studies, the types of neurological handicaps that have been documented in survivors of ECMO and conventional medical therapy, new cerebral hemodynamic data in post-ECMO patients, and results of neuroimaging and neuropathology studies are presented. In addition, some suggestions for future studies are offered.
Extracorporeal Membrane Oxygenation Versus Conventional Medical Therapy for Management of Persistent Pulmonary Hypertension of the Neonate: A Decision Analysis
Craig Fleming, M.D.
Department of Medicine
Department of Community and Family Medicine and Program in Medical Information Science
Dartmouth Medical School
White River Junction Veteran Affairs Medical Center
White River Junction, Vermont
Terry A. Hurlbut, M.D.
Program in Medical Information Science
Dartmouth Medical School
Harold C. Sox, M.D.
Department of Medicine
Dartmouth Medical School
The use of extracorporeal membrane oxygenation (ECMO) to treat severe respiratory failure in the full-term infant with persistent pulmonary hypertension of the neonate (PPHN) has grown dramatically in recent years. Two randomized studies have established the efficacy of ECMO vs. conventional medical therapy (CMT) for severely-ill infants. But, because ECMO is invasive and resource intensive, controversy persists over the proper role for ECMO in the management of PPHN. Of particular concern is whether ECMO is more effective than CMT for the less-sick infant. We reviewed the medical literature and built a decision analysis model to compare the risks and benefits of ECMO with CMT for management of infants with PPHN. The model predicts that ECMO is the preferred therapy when the probability of death with conventional therapy is >43 percent. CMT is the best choice when the expected mortality is <17 percent. In neonates for whom the risk of death is intermediate, the choice between ECMO and CMT is ambiguous because of imprecision in present data on the risk of long-term sequelae. To define the proper roles for ECMO and CMT in treating infants with PPHN, we need clinical prediction rules that can accurately represent differences in severity of illness for these infants and a better understanding of the impact of preventive measures and recent improvements in conventional therapy for PPHN. Meanwhile, ECMO should be used cautiously in less-sick infants,
Extracorporeal Membrane Oxygenation: Cost, Organization, and Policy Considerations
Rachel M. Schwartz, M.P.H. Katharine K. Willrich, B.A. David E. Gagnon, M.P.H.
National Perinatal Information Center
The cost of ECMO has not been studied extensively from the perspective of individual per case cost or from the perspective of system costs. In this research, the authors explore cost from both perspectives and, for the latter, place it within the policy context of the tremendous expansion which has occurred and is planned to occur.
In order to estimate acute cost per case for ECMO and identify whether it is more or less expensive than conventional care, some assumptions must be made about candidates for ECMO and the comparison groups. The authors use one primary assumption throughout: neo-natal ECMO candidates have an 80 percent mortality rate without ECMO and therefore most would die with conventional care. The key finding for individual cost per case is that, in the acute phase of care, conventional care patients who either live or die are less costly than ECMO cases. In addition, to be able to draw conclusions about costs per survivor or cost-benefit of ECMO, better documentation concerning the immediate, moderate, and long-term mortality and morbidity is needed.
Estimates of annual system-wide costs vary dramatically depending on the method used. The system cost for ECMO based on per case costs is at least $90 million per year for cases that occur no more frequently than 1 in 1,309 births (if all ECMO treated cases survive the acute phase of care). If we subtract the potential conventional care cost of this group (assuming 80 percent die), the excess is about $50 million dollars.
System-wide costs would rise dramatically if the reported expansion plans occur. Using organization data on the number of cases who could be seen in 15 ECMO units surveyed for this study, the authors conclude that further expansion cannot be supported by demand estimates and would therefore create unnecessary costs to the system.
As the application of high technology in the care of newborns becomes increasingly prevalent, and as health care costs assume a greater proportion of the United States gross national product, policymakers and insurers are prevailing on providers to document the costs and benefits of care.
The use of ECMO in newborns, a relatively new surgical technology for the treatment of severe acute lung disease, has grown geometrically in the last 5 years. The ECMO Registry recently documented that 1,006 cases had been treated in 1989 for a total of 3,597 in the last 10 years. The number of centers in the United States providing this service has risen from 3 in 1982 to 57 in 1989. Most recently, a 1988 - 1989 survey of obstetrical hospitals (on which these authors collaborated with the Maternal and Child Section of the American Hospital Association) revealed that of the 668 hospitals with neonatal intensive care units who responded to the survey, 41 had ECMO units (children's hospitals were not included). Of the 627 respondent centers who did not offer ECMO, 31 said they planned to open an ECMO unit within the next 18 months. Such an increase would expand the number of facilities by more than 50 percent within the next 2 - 3 years. These increments raise issues about the cost of care, the presence of sufficient cases to support this expansion and permit clinicians to provide quality care, and finally, the possible inefficiencies which result from the expansion of a service infrastructure. To develop meaningful health policy in this area, some answers are needed.
In this paper, we examine several aspects of the cost of ECMO. These include: the cost of operating an ECMO unit, the marginal costs of ECMO compared to neonatal intensive care unit costs, and the acute inpatient cost per case for ECMO patients compared to that of patients meeting ECMO criteria who do not receive ECMO. While lifetime cost of newborn ECMO patients and conventional care patients is not a part of the analysis, we explore the factors necessary to create estimates. Finally, the system-wide health cost are explored with regard to the expansion and existing capacity noted above.
John H. Ferguson, M.D.
Office of Medical Applications of Research
National Institutes of Health
George A. Little, M.D.
Department of Maternal and Child Health
Dartmouth-Hitchcock Medical Center
Charlotte S. Catz, M.D.
Dorothy Gail, Ph.D.
Gil Hill, M.S.
Deborah G. Hirtz, M.D.
Jennifer Mayfield, M.D.
George C. Murray, Ph.D.
Philip H. Sheridan, M.D.
Linda L. Wright, M.D.
Sumner Yaffe, M.D.
Robert M. Arensman, M.D.
Roberta A. Ballard, M.D.
Robert H. Bartlett, M.D.
Mary Anne Berberich, Ph.D.
Alfred Brann, M.D.
F. J. Brinley, Jr., M.D., Ph.D.
L. Joseph Butterfield, M.D.
J. Devn Cornish, M.D.
Robert A. deLemos, M.D.
Joseph S. Drage, M.D.
Jonas Ellenberg, Ph.D.
Michael F. Epstein, M.D.
Philippe Evrard, M.D.
Peggy C. Ferry, M.D.
Craig Fleming, M.D.
Roger K. Freeman, M.D.
Lawrence M. Gartner, M.D.
Penny Glass, Ph.D.
Jan Goddard-Finegold, M.D.
William H. Hall
Ann Lennarson Greer, Ph.D.
Ian Gross, M.D.
Terry A. Hurlburt III, M.D.
L. Stanley James, M.D.
Arnold D. Kaluzny, Ph.D.
Martin Keszler, M.D.
Lorraine V. Klerman, Ph.D.
Theodore Kolobow, Ph.D.
Alfred N. Krauss, M.D.
Jerold F. Lucey, M.D.
Susan K. McCune, M.D.
Gerald B. Merenstein, M.D.
Valerie Mike, Ph.D.
George C. Murray, Ph.D.
Karin B. Nelson, M.D.
Michael R. Neuman, M.D., Ph.D.
Seymour Perry, M.D.
Charles R. Rosenfeld, M.D.
Alan L. Sandler, D.D.S.
Rachel Schwartz, M.P.H.
P. Pearl O'Rourke, M.D.
Billie Lou Short, M.D.
Hal C. Sox, Jr., M.D.
Giovanna M. Spinella, M.D.
Charles Stolar, M.D.
Robert Vannucci, M.D.
Richard B. Warnecke, Ph.D.
Alison Wichman, M.D.
David D. Wirtschafter, M.D.
About the NIH Technology Assessment Program
NIH Technology Assessment Conferences and Workshops are convened to evaluate available scientific information related to a biomedical technology when topic selection criteria for a Consensus Development Conference are not met. The resultant NIH Technology Assessment Statements are intended to advance understanding of the technology or issue in question and to be useful to health professionals and the public.
Some Technology Assessment Conferences and Workshops adhere to the Consensus Development Conference format because the process is altogether appropriate for evaluating highly controversial, publicized, or politicized issues. Other Conferences and Workshops are organized around unique formats. In this format, NIH Technology Assessment Statements are prepared by a nonadvocate, nonfederal panel of experts, based on: (1) presentations by investigators working in areas relevant to the consensus questions typically during a 1-1/2-day public session; (2) questions and statements from conference attendees during open discussion periods that are part of the public session; and (3) closed deliberations by the panel during the remainder of the second day and morning of the third. This statement is an independent report of the panel and is not a policy statement of the NIH or the Federal Government.
Preparation and distribution of these reports are the responsibility of the Office of Medical Applications of Research, National Institutes of Health, Bldg 31, Room 1B03, Bethesda, MD 20892.