Extracorporeal membrane oxygenation and the ethics of clinical research in pediatrics

Candidacy for Extracorporeal Life Support in Children After Hematopoietic Cell Transplantation: A Position Paper From the Pediatric Acute Lung Injury and Sepsis Investigators Network's Hematopoietic Cell Transplant and Cancer Immunotherapy Subgroup

OBJECTIVES

The last decade has seen improved outcomes for children requiring extracorporeal life support as well as for children undergoing hematopoietic cell transplantation. Thus, given the historically poor survival of hematopoietic cell transplantation patients using extracorporeal life support, the Pediatric Acute Lung Injury and Sepsis Investigators' hematopoietic cell transplantation and cancer immunotherapy subgroup aimed to characterize the utility of extracorporeal life support in facilitating recovery from critical cardiorespiratory illnesses in pediatric hematopoietic cell transplantation patients.

DATA SOURCES

All available published data were identified using a set of PubMed search terms for pediatric extracorporeal life support and hematopoietic cell transplantation.

STUDY SELECTION

All articles that provided original reports of pediatric hematopoietic cell transplantation patients who underwent extracorporeal life support were included. Sixty-four manuscripts met search criteria. Twenty-four were included as primary reports of pediatric hematopoietic cell transplantation patients who underwent extracorporeal life support (11 were single case reports, four single institution case series, two multi-institution case series, and seven registry reports from Extracorporeal Life Support Organization, Pediatric Heath Information System, and Virtual Pediatric Systems).

DATA EXTRACTION

All 24 articles were reviewed by first and last authors and a spread sheet was constructed including sample size, potential biases, and conclusions.

DATA SYNTHESIS

Discussions regarding incorporation of available evidence into our clinical practice were held at biannual meetings, as well as through email and virtual meetings. An expert consensus was determined through these discussions and confirmed through a modified Delphi process.

CONCLUSIONS

Extracorporeal life support in hematopoietic cell transplantation patients is being used with increasing frequency and potentially improving survival. The Pediatric Acute Lung Injury and Sepsis Investigators hematopoietic cell transplantation-cancer immunotherapy subgroup has developed a framework to guide physicians in decision-making surrounding extracorporeal life support candidacy in pediatric hematopoietic cell transplantation patients. In addition to standard extracorporeal life support considerations, candidacy in the hematopoietic cell transplantation population should consider the following six factors in order of consensus agreement: 1) patient comorbidities; 2) underlying disease necessitating hematopoietic cell transplantation; 3) hematopoietic cell transplantation toxicities, 4) family and patient desires for goals of care; 5) hematopoietic cell transplantation preparatory regimen; and 6) graft characteristics. Although risk assessment may be individualized, data are currently insufficient to clearly delineate ideal candidacy. Therefore, we urge the onco-critical care community to collaborate and capture data to provide better evidence to guide physicians' decision-making in the future.

Decision-Making, Ethics, and End-of-Life Care in Pediatric Extracorporeal Membrane Oxygenation: A Comprehensive Narrative Review

OBJECTIVES

Pediatric extracorporeal membrane oxygenation is associated with significant morbidity and mortality. We sought to summarize literature on communication and decision-making, end-of-life care, and ethical issues to identify recommended approaches and highlight knowledge gaps.

DATA SOURCES

PubMed, Embase, Web of Science, and Cochrane Library.

STUDY SELECTION

We reviewed published articles (1972-2020) which examined three pediatric extracorporeal membrane oxygenation domains: 1) decision-making or communication between clinicians and patients/families, 2) ethical issues, or 3) end-of-life care.

DATA EXTRACTION

Two reviewers independently assessed eligibility using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology.

DATA SYNTHESIS

Of 2,581 publications screened, we identified one systematic review and 35 descriptive studies. No practical guides exist for communication and decision-making in pediatric extracorporeal membrane oxygenation. Conversation principles and parent/clinician perspectives are described. Ethical issues related to consent, initiation, discontinuation, resource allocation, and research. No patient-level synthesis of ethical issues or end-of-life care in pediatric extracorporeal membrane oxygenation was identified.

CONCLUSIONS

Despite numerous ethical issues reported surrounding pediatric extracorporeal membrane oxygenation, we found limited patient-level research and no practical guides for communicating with families or managing extracorporeal membrane oxygenation discontinuation.

Ethics in extracorporeal life support: a narrative review

During 50 years of extracorporeal life support (ECLS), this highly invasive technology has left a considerable imprint on modern medicine, and it still confronts researchers, clinicians and policymakers with multifarious ethical challenges. After half a century of academic discussion about the ethics of ECLS, it seems appropriate to review the state of the argument and the trends in it. Through a comprehensive literature search on PubMed, we identified three ethical discourses: (1) trials and evidence accompanying the use of ECLS, (2) ECLS allocation, decision-making and limiting care, and (3) death on ECLS and ECLS in organ donation. All included articles were carefully reviewed, arguments extracted and grouped into the three discourses. This article provides a narrative synthesis of these arguments, evaluates the opportunities for mediation and substantiates the necessity of a shared decision-making approach at the limits of medical care.

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

RATIONALE

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

OBJECTIVES

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

METHODS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Ethical and end of life considerations for neonates requiring ECMO support

ECMO has proven to be a life-saving intervention for a variety of disease entities with a high rate of survival in the neonatal population. However, ECMO requires clinical teams to engage in many ethical considerations. Even with ongoing improvements in technology and expertise, some patients will not survive a course of ECMO. An unsuccessful course of ECMO can be difficult to accept and cause a great deal of angst. These questions can result in real conflict both within the care team, and between the care team and the family. Herein we explore a range of ethical considerations that may be encountered when caring for a patient on ECMO, with a particular focus on those courses where it appears likely that the patient will not survive. We then consider how a palliative care approach may provide a tool set to help engage the team and family in confronting the difficult decision to discontinue ECMO.

Extracorporeal membrane oxygenation for pediatric cardiac arrest

Extracorporeal cardiopulmonary resuscitation (ECPR) remains a promising treatment for pediatric patients in cardiac arrest unresponsive to traditional cardiopulmonary resuscitation. With venoarterial extracorporeal support, blood is drained from the right atrium, oxygenated through the extracorporeal circuit, and transfused back to the body, bypassing the heart and lungs. The use of artificial oxygenation and perfusion thus provides the body a period of hemodynamic stability, while allowing resolution of underlying disease processes. Survival rates for ECPR patients are higher than those for traditional cardiopulmonary resuscitation (CPR), although neurological outcomes require further investigation. The impact of duration of CPR and length of treatment with extracorporeal membrane oxygenation vary in published reports. Furthermore, current guidelines for the initiation and use of ECPR are limited and may lead to confusion about appropriate use of this support. Many ethical concerns arise with this advanced form of life support. More often than not, the dilemma is not whether to withhold ECPR, but rather when to withdraw it. Although clinicians must decide if ECPR is appropriate and when further intervention is futile, the ultimate burden of choice is left to the patient's caregivers. Offering support and guidance to the patient's family as well as the patient is essential.

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.

Moral Hazard in Pediatrics

"Moral hazard" is a term familiar in economics and business ethics that illuminates why rational parties sometimes choose decisions with bad moral outcomes without necessarily intending to behave selfishly or immorally. The term is not generally used in medical ethics. Decision makers such as parents and physicians generally do not use the concept or the word in evaluating ethical dilemmas. They may not even be aware of the precise nature of the moral hazard problem they are experiencing, beyond a general concern for the patient's seemingly excessive burden. This article brings the language and logic of moral hazard to pediatrics. The concept reminds us that decision makers in this context are often not the primary party affected by their decisions. It appraises the full scope of risk at issue when decision makers decide on behalf of others and leads us to separate, respect, and prioritize the interests of affected parties.

Ethical issues in neonatal research involving human subjects

Research involving critically ill neonates creates many ethical challenges. Neonatal clinical research has always been hard to perform, is very expensive, and may generate some unique ethical concerns. This article describes some examples of historical and modern controversies in neonatal research, discusses the justification for research involving such vulnerable and fragile patients, clarifies current federal regulations that govern research involving neonates, and suggests ways that clinical investigators can develop and implement ethically grounded human subjects research.

Severe Tumor Lysis Syndrome and Acute Pulmonary Edema Requiring Extracorporeal Membrane Oxygenation Following Initiation of Chemotherapy for Metastatic Alveolar Rhabdomyosarcoma

We present an 8-year-old male with metastatic alveolar rhabdomyosarcoma (ARMS) who developed precipitous cardiopulmonary collapse with severe tumor lysis syndrome (TLS) 48 hr after initiation of chemotherapy. Despite no detectable pulmonary metastases, acute hypoxemic respiratory failure developed, requiring extracorporeal membrane oxygenation (ECMO). Although TLS has been reported in disseminated ARMS, this singular case of life-threatening respiratory deterioration developing after initiation of chemotherapy presented unique therapeutic dilemmas. We review the clinical aspects of this case, including possible mechanisms of respiratory failure, and discuss the role of ECMO utilization in pediatric oncology.

The evolving ethics of infant dialysis

In this paper, we review ethical issues that arise when families and doctors face clinical decisions about renal replacement therapy for an infant with end-stage renal disease (ESRD). Over the last 20 years, many centers have begun to routinely offer renal replacement therapy. However, doctors and nurses both continue to view such therapy as optional, rather than mandatory. We speculate that the burdens of therapy on the family, and the uncertainties about satisfactory outcomes have led to a situation in which renal replacement therapy remains desirable, but non-obligatory. We discuss the reasons why this is likely to remain so, and the ways in which renal replacement therapy for infants with ESRD is similar to, or different from, other clinical situations in pediatrics. Finally, we propose a research agenda to answer questions that are crucial to making good ethical decisions about infant dialysis.

Ethics of emerging technologies and their transition to accepted practice: intestinal transplant for short bowel syndrome

Parental counseling becomes complex when considering the use of emerging technologies, especially if it is unclear whether the level of evidence is sufficient to transform the proposed therapy into accepted practice. This paper addresses ethical issues underlying medical decision-making and counseling in the setting of emerging treatments, when long-term outcomes are still in the process of being fully validated. We argue that the ethical transition of emerging technologies, ideally from ethically impermissible to permissible, to obligatory, depends primarily on two factors: outcome data (or prognosis) and treatment feasibility. To illustrate these points, we will use intestinal transplant for short bowel syndrome (SBS) as a specific example. After reviewing the data, this paper will identify the ethical justifications for both comfort care only and intestinal transplant in patients with ultra SBS, and argue that both are ethically permissible, but neither is obligatory. The approach outlined will not only be valuable as ultra SBS outcomes data continue to change, but will also be applicable to other novel therapies as they emerge in perinatal medicine.

Extracorporeal membrane oxygenation after stem cell transplant: clinical decision-making in the absence of evidence

OBJECTIVE

To discuss the ethical dilemmas that arise in considering innovative therapies for critically ill children when there is little data to support their use.

DESIGN

Case report of a 13-yr-old patient after autologous peripheral blood stem cell transplant for stage III neuroblastoma with sepsis and hemodynamic instability who survived to discharge after a 6-day course of extracorporeal membrane oxygenation (ECMO) support. The case serves as a source of discussion of the following: the use of available data in deciding to proceed with an unproved therapy, the approach to conversations to obtain informed consent, and the need for institutional oversight and hypothesis-driven data collection to advance pediatric critical care.

SETTING

Pediatric intensive care unit at a university hospital.

PATIENT

One adolescent with stage III neuroblastoma.

RESULTS

Despite a lack of data to support the use of ECMO in a neutropenic oncology patient after autologous peripheral blood stem cell transplant, our patient had clinical features that suggested he was a reasonable ECMO candidate. His family gave informed consent to use ECMO and he survived. It is ethical to consider and use innovative therapies when patient characteristics are suggestive that the therapy may be successful even in the absence of evidence. This requires physicians' attention to the best interest of the patient and should occur in the setting of informed consent and rigorous data collection.

CONCLUSIONS

The boundaries among standard therapy, innovative therapy, and research can be quite fluid. This case illustrates the ethical imperative to consider therapies that may be appropriate for a critically ill child even without evidence predictive of success, to have entry criteria and treatment protocols for such therapies, and to collect data from such experiences to advance the standard of care.

A dose of our own medicine: alternative medicine, conventional medicine, and the standards of science

The discussion about complementary and alternative medicine (CAM) is sometimes rather heated. “Quackery!” the cry goes. A large proportion “of unconventional practices entail theories that are patently unscientific.” “It is time for the scientific community to stop giving alternative medicine a free ride. There cannot be two kinds of medicine — conventional and alternative. There is only medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work.” “I submit that if these treatments cannot withstand the test of empirical research, … then we have wasted a lot of time and effort. The time has been wasted on all the people who have spent years learning falsehoods about acupuncture points and the principles of homeopathy. And the patients have wasted their time, money, and efforts receiving treatments that were not what they were represented to be or were harmful.”

Extracorporeal membrane oxygenation 2001. The odyssey continues

Extracorporeal membrane oxygenation was established as a standard of care by demonstrating its ability to save lives in moribund infants. The designs of early studies provided no living cohorts of similarly ill patients by which to measure accurately other (and perhaps to many more important) outcomes of interest: long-term neurodevelopmental outcomes or cost. Prospective cohort studies of neurodevelopmental outcomes post-ECMO demonstrate: (1) because ECMO, as used, saves lives, there will be an increase in the absolute number of handicapped children surviving; (2) there is little evidence that ECMO creates a relative increase in the percent of handicapped children surviving severe respiratory failure. The high direct costs of an ECMO program are measured and well publicized. When such costs are compared with similar therapies in other fields (in such terms as cost per survivor), the cost of ECMO does not seem to be an outlier. Trials of newer therapies, such as iNO, show the capacity to decrease the use of ECMO but have failed to demonstrate either cost-effectiveness or better long-term outcomes. It has not been shown that either society or individual patients have benefited from the decreased need for ECMO.

The ethics of drug research in children

The obligation of society to improve the welfare of its members requires the conduct of paediatric drug trials. Nevertheless, research activities must satisfy obligations to individual participants. The obligation to protect the welfare of children requires that nontherapeutic research procedures generally involve no more than minimal risk. It also requires that randomisation occurs only when the relative merits of therapeutic procedures remain unsettled among the relevant community of experts. The duty to respect the developing autonomy of children requires that they be included in decision-making about research participation in a manner consistent with the level of their decision-making capacity. However, when children lack mature decision-making capacities, the duty of parents to protect their welfare may properly constrain their choices. Justice requires that the benefits and burdens of research be distributed in a manner that assures equal opportunity for all children. Vulnerable children should receive special protection against the burdens of nontherapeutic research procedures. The benefits of participating in clinical trials should be available to all children with serious illnesses for which current treatment is unsatisfactory. Justice also requires that initiatives be undertaken to rectify current shortcomings in the scope of paediatric drug research. Striking an appropriate balance between obligations to conduct research and to protect the interests of participants is essential to the moral integrity of paediatric drug research.

Evaluation of ethical conflicts associated with randomized, controlled trials in critically ill children

OBJECTIVE

To determine whether randomized, controlled trials (RCTS) of potentially life-sustaining therapies in critically ill infants and children cause an ethical conflict for physician investigators and if ethical conflicts affect protocol implementation.

DESIGN

Descriptive survey.

SUBJECTS

A convenience sample of 1,050 physicians from a national pediatric critical care meeting mailing list.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The survey return rate was 41% (n = 415). Of the returned surveys, 81% (n = 331) were answered by pediatric intensivists and fellows. The remaining 19% (n = 84) were completed by other physician subspecialists. Overall, 74% had experience with RCTs involving a potentially life-saving therapy (25% had experience with three or more trials, and 26% had never participated in this type of study). The vast majority of the respondents (96%) indicated that they believe RCTs of potentially life-sustaining therapies are ethical; however, only 10% stated that they never experienced an ethical conflict with these types of studies. Most respondents (84%) indicated that published data from uncontrolled trials may bias them toward an investigational therapy. Furthermore, only 35% of the respondents indicated that they always maintain strict protocol adherence when the condition of a control patient deteriorates and parents request the experimental treatment. There was a significant association between physicians who experienced an ethical conflict and the likelihood that they would do the following if the condition of a control patient deteriorated: fail to maintain strict protocol adherence (p = .05); alter the protocol in response to parental requests for the experimental treatment (p < .01); or seek compassionate use of the experimental treatment (p < .01).

CONCLUSIONS

Although physicians consider RCTs of potentially life-sustaining therapies ethical, they acknowledge that this type of study sometimes creates an ethical conflict. Published results of uncontrolled trials lead to investigator bias in randomized trials and preclude equipoise. Our results indicate that RCTs involving life-sustaining therapies may be biased, lack consistent protocol implementation, and raise concern that data from these studies are potentially flawed.

Termination of extracorporeal membrane oxygenation for cardiac support

The determination of when to stop extracorporeal membrane oxygenation (ECMO) rests upon demonstration of the return of adequate cardiac function to support vital organs and permit subsequent recovery. In general, patients with myocardial stun will recover function within several days. Factors that limit recovery include elevated end diastolic pressures leading to marginal myocardial perfusion, ongoing organ damage, massive anasarca, or progressive deterioration in lung function. Following a trial of slow weaning of ECMO support to condition the heart to take over the entire system flow requirements, decannulation can be accomplished in a standard fashion. When weaning is not successful and additional time does not lead to adequate recovery of cardiac function, physicians and nurses must be prepare to realistically advise families regarding such options as cardiac transplantation or withdrawal of support. It is critically important to provide an open and nonjudgmental environment for families to make these difficult decisions. The greatest difficulties involve ethical and emotional decisions that need to be made in a timely fashion to prevent undo burden on the patient when further ECMO support is futile.

Do sick newborn infants benefit from participation in a randomized clinical trial?

BACKGROUND

Adult participants in randomized controlled trials often have better outcomes than patients who are eligible but not enrolled.

OBJECTIVE

To examine whether newborn infants who were allocated to placebo in an investigational drug trial had better outcomes than infants who were eligible but not randomized (eligible NR).

STUDY DESIGN

During a randomized controlled trial of antithrombin therapy in premature infants with respiratory distress syndrome, data were collected prospectively on all 76 infants in the eligible NR group. Study outcomes were compared with those of all 61 infants who were randomized to placebo. The same exogenous surfactant was used in all patients.

RESULTS

In the placebo group the mean (SD) birth weight was 1201 (314) g, mean (SD) gestational age was 28.8 (2.3) weeks, and 51% were male. In infants in the eligible NR group, mean (SD) birth weight was 1141 (262) g, mean (SD) gestational age was 28.3 (2. 3) weeks, and 58% were male; 57% of infants in both groups had been exposed to steroids before birth. The median duration of mechanical ventilation was reduced from 6.2 days in the eligible NR group to 4. 8 days in the placebo group (P =.008). There was also a trend toward less frequent and less severe intraventricular hemorrhage in trial participants.

CONCLUSIONS

These data are consistent with the hypothesis that sick newborn infants may benefit from participation in a randomized controlled trial.

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

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency in the treatment of acute respiratory failure in pediatric patients. Our objective in this study was to test the hypothesis that ECMO improves outcome in pediatric patients with acute respiratory failure.

DESIGN

Multicenter, retrospective cohort analysis.

SETTING

Forty one pediatric intensive care units participated in the study under the auspices of the Pediatric Critical Care Study Group.

PATIENTS

All pediatric patients admitted to the participating institutions with acute respiratory failure during 1991 were included. Patients with congenital heart disease, contraindications to ECMO, or incomplete data were excluded, yielding a data set of 331 patients from 32 hospitals.

INTERVENTIONS

Conventional mechanical ventilation, high-frequency ventilation, and extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Multivariate logistic regression analysis was used to identify factors associated with survival. In a second analysis, pairs of ECMO and non-ECMO patients, matched by severity of disease and respiratory diagnosis, were compared. The use of ECMO (p = .0082), but not the use of high-frequency ventilation, was associated with a reduction in mortality. Other factors independently associated with mortality included oxygenation index (p < .0001), Pediatric Risk of Mortality score (PRISM) (p < .0001) and the Paco2 (p = .045). In 53 diagnosis- and risk-matched pairs, there was a significantly lower mortality rate (26.4% vs. 47.2%; p < .01) in the ECMO-treated patients. When all patients were stratified into mortality risk quartiles on the basis of oxygenation index and PRISM score, the proportion of deaths among ECMO-treated patients in the 50% to 75% mortality risk quartile was less than half the proportion in the non-ECMO treated patients (28.6% vs. 71.4% p < .05)> No effect was seen in the other quartiles.

CONCLUSIONS

The use of ECMO was associated with an improved survival in pediatric patients with respiratory failure. The lack of association of outcome with treatment in the ECMO-capable hospital or with another tertiary technology (i.e. high-frequency ventilation) suggests that ECMO itself was responsible for the improved outcome. Further studies of this procedure are warranted but require broad-based multi-institutional participation to provide sufficient statistical power and sensitivity to demonstrate efficacy.

Probability of survival after prolonged extracorporeal membrane oxygenation in pediatric patients with acute respiratory failure. Extracorporeal Life Support Organization

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency for respiratory failure that is unresponsive to conventional therapy. We examined the relationship between duration of ECMO and outcome to understand whether prolonged ECMO (duration of the procedure for > 14 days) was more commonly associated with futile therapy or eventual recovery.

DESIGN

A cohort study of all patients reported to the Pediatric ECMO Registry for Acute Respiratory Failure of the Extracorporeal Life Support Organization.

SETTING

Tertiary hospitals (n = 83) capable of providing extracorporeal support for pediatric patients.

PATIENTS

Children (n = 382) between the ages of 1 wk and 18 yrs of age with severe respiratory failure.

INTERVENTIONS

Extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

The death or live hospital discharge of ECMO-treated patients, together with the post-ECMO mechanical ventilation course, were examined as a function of duration of ECMO and of pre-ECMO respiratory status. The occurrence of complications and the causes of death were also noted. The criteria used to initiate ECMO, as well as the determination of the futility of further ECMO, were determined by local practice at individual centers. There were 382 patients treated with ECMO, of whom 184 (48%) survived. The proportional survival in the patients treated for the longest duration was similar to the overall group. The cause of death was given for 168 patients: 32 neurologic deaths; nine deaths due to ECMO complications; and 30 deaths due to nonpulmonary organ failure. There were 97 deaths due to elective ECMO termination; 80 of these deaths occurred after the determination of the futility of anticipating pulmonary recovery. The latter deaths occurred at widely varying durations of ECMO, with a median of 282 hrs. However, at that same duration, 47 eventual survivors (26% of all survivors) continued to receive ECMO. By discriminant analysis, the survival rate was independently related (r2 = .18; p < .0001) to peak ventilator inspiratory pressure before ECMO and duration of intubation before ECMO, patient age, and the occurrence of several complications.

CONCLUSIONS

While the survival rate in pediatric patients receiving ECMO appears related to the severity of lung disease and to the occurrence of ECMO complications, the survival rate in patients treated with ECMO courses of > 2 wks was similar to the survival rate of patients treated for shorter periods of time. ECMO was terminated in some patients for pulmonary futility at durations of ECMO associated with survival in substantial numbers of patients in whom ECMO was continued.

The clinical role of near infrared spectroscopy

Near infrared spectroscopy is a non-invasive bedside technique which allows cotside observation of cerebral haemodynamics and oxygenation in sick newborn infants. Methods have been described for measurement of cerebral blood flow and volume, as well as other tests of the cerebral circulation. The techniques is still under intensive development and further advances and refinements can be expected, but a present it is essentially a technique for research and investigations rather than a clinical tool.

Neonatal extracorporeal membrane oxygenation (ECMO): clinical trials and the ethics of evidence

Neonatal extracorporeal membrane oxygenation (ECMO), a technology for the treatment of respiratory failure in newborns, is used as a case study to examine statistical and ethical aspects of clinical trials and to illustrate a proposed 'ethics of evidence', an approach to medical uncertainty within the context of contemporary biomedical ethics. Discussion includes the twofold aim of the ethics of evidence: to clarify the role of uncertainty and scientific evidence in medical decision-making, and to call attention to the need to confront the irreducible nature of uncertainty.

Pulmonary changes following extracorporeal membrane oxygenation: autopsy study of 23 cases

Extracorporeal membrane oxygenation (ECMO) has become an established mode of therapy in many centers for potentially fatal neonatal respiratory failure refractory to conventional therapy. We reviewed the findings of 23 autopsies of patients placed on ECMO therapy during the period from 1988 to 1992 at our institution in order to document the pulmonary histopathologic changes and to correlate such changes with the duration of treatment. Interstitial and intra-alveolar hemorrhages, as well as hyaline membrane formation, were the most common findings during the first few days of therapy. Reactive epithelial hyperplasia (bronchial and type II pneumocytes), squamous metaplasia, and smooth muscle hyperplasia were observed as early as 2 to 3 days after initiation of ECMO therapy. Interstitial fibrosis was noted only after 7 days of ECMO therapy. In three patients treated for 15, 19, and 21 days there was replacement of the terminal airways and alveoli by tall columnar and mucin-producing epithelium. Alveolar and bronchiolar calcifications were noted in seven of the 23 cases in this series. Pulmonary vascular changes were seen in association with persistent fetal circulation, meconium aspiration, and respiratory distress syndrome. These changes are most likely due to the compounded effect of ECMO and the underlying pulmonary insult.

Extracorporeal life support in paediatrics

Extracorporeal membrane oxygenation (ECMO) is a life support technique based on modifications of heart-lung bypass technology. It is used to support severe but potentially reversible pulmonary or cardiopulmonary failure. There is increasing use of the technique for neonates and a return of interest in its use for adults. The number of non-neonatal paediatric patients receiving pulmonary support with ECMO worldwide is, however, small, and survival rates average less than 50%. Initial experience in 15 patients aged 3 months to 5 years with a high survival and low morbidity is reported.

Evaluation and policy considerations in the introduction of extracorporeal membrane oxygenation

The introduction of extracorporeal membrane oxygenation (ECMO) in Australia was associated with establishment of the technology at two teaching hospitals followed by appraisal through a consensus conference and a subsequent synthesis report and cost analysis. The assessments and associated policy processes have helped to define the place of the technology, but many uncertainties remain due to limited relevance of results from other countries, the preliminary nature of local data and absence of controlled trials. This experience raises questions concerning approaches by professional groups, funding authorities and assessment agencies in dealing with specialised new techniques which are associated with a small national caseload.

Ethical principles governing research in child and adolescent psychiatry

This paper examines the ethical principles governing research in child and adolescent psychiatry. The guidelines for protection of children and adolescents are research subjects are discussed. These include the principle of nonmaleficence and beneficence (the risk-benefit ratio), the principle of autonomy (informed consent and confidentiality), and the principle of justice (fair distribution of benefits and burdens of research). In the light of recent national efforts to help promote responsible research practice, the ethical standards relating to the protection of scientific integrity as well as research advocacy, training, and stewardship are also discussed.

Advances in pediatric surgical critical care

The advances in pediatric intensive care outlined here point out the differences between children and adults that need to be considered when taking care of children with surgical diseases. In the past, advances in pediatric critical care have not kept pace with advances in adult care, but these and other new techniques have rapidly closed this gap in knowledge.