Returning incidentally discovered Hepatitis C RNA-seq results to COPDGene study participants

The consequences of returning infectious pathogen test results identified incidentally in research studies have not been well-studied. Concerns include identification of an important health issue for individuals, accuracy of research test results, public health impact, potential emotional distress for participants, and need for IRB permissions. Blood RNA-sequencing analysis for non-human RNA in 3984 participants from the COPDGene study identified 228 participants with evidence suggestive for hepatitis C virus (HCV) infection. We hypothesized that incidentally discovered HCV results could be effectively returned to COPDGene participants with attention to the identified concerns. In conjunction with a COPDGene Participant Advisory Panel, we developed and obtained IRB approval for a process of returning HCV research results and an HCV Follow-Up Study questionnaire to capture information about previous HCV diagnosis and treatment information and participant reactions to return of HCV results. During phone calls following the initial HCV notification letter, 84 of 124 participants who could be contacted (67.7%) volunteered that they had been previously diagnosed with HCV infection. Thirty-one of these 124 COPDGene participants were enrolled in the HCV Follow-Up Study. Five of the 31 HCV Follow-Up Study participants did not report a previous diagnosis of HCV. For four of these participants, subsequent clinical HCV testing confirmed HCV infection. Thus, 30/31 Follow-Up Study participants had confirmed HCV diagnoses, supporting the accuracy of the HCV research test results. However, the limited number of participants in the Follow-Up Study precludes an accurate assessment of the false-positive and false-negative rates of the research RNA sequencing evidence for HCV. Most HCV Follow-Up Study participants (29/31) were supportive of returning HCV research results, and most participants found the process for returning HCV results to be informative and not upsetting. Newly diagnosed participants were more likely to be pleased to learn about a potentially curable infection (p = 0.027) and showed a trend toward being more frightened by the potential health risks of HCV (p = 0.11). We conclude that HCV results identified incidentally during transcriptomic research studies can be successfully returned to research study participants with a carefully designed process.

Pragmatic Tools for Sharing Genomic Research Results with the Relatives of Living and Deceased Research Participants

Returning genomic research results to family members raises complex questions. Genomic research on life-limiting conditions such as cancer, and research involving storage and reanalysis of data and specimens long into the future, makes these questions pressing. This author group, funded by an NIH grant, published consensus recommendations presenting a framework. This follow-up paper offers concrete guidance and tools for implementation. The group collected and analyzed relevant documents and guidance, including tools from the Clinical Sequencing Exploratory Research (CSER) Consortium. The authors then negotiated a consensus toolkit of processes and documents. That toolkit offers sample consent and notification documents plus decision flow-charts to address return of results to family of living and deceased participants, in adult and pediatric research. Core concerns are eliciting participant preferences on sharing results with family and on choice of a representative to make decisions about sharing after participant death.

The Final Rule: When the Rubber Meets the Road

The Common Rule originally issued in 1991 and last amended in 2005 is scheduled to be replaced on January 19, 2018 by a revised Common Rule (the final rule). The goal of the revisions is to modernize and improve applicability of the rule to a research landscape that has dramatically changed since 1991. Translating these changes into action will require comprehensive understanding of the final rule and detailed implementation planning by Human Research Protection Programs. This paper presents select changes that require substantial attention; including for example: expansion of the exempt category, changes to continuing review requirements, changes to the informed consent form and the use of single IRBs for domestic multi-site research. In addition, myriad policies, procedures and workflows will have to be developed, drastically rewritten, or just mildly tweaked.

Implementation of Electronic Consent at a Biobank: An Opportunity for Precision Medicine Research

The purpose of this study is to characterize the potential benefits and challenges of electronic informed consent (eIC) as a strategy for rapidly expanding the reach of large biobanks while reducing costs and potentially enhancing participant engagement. The Partners HealthCare Biobank (Partners Biobank) implemented eIC tools and processes to complement traditional recruitment strategies in June 2014. Since then, the Partners Biobank has rigorously collected and tracked a variety of metrics relating to this novel recruitment method. From June 2014 through January 2016, the Partners Biobank sent email invitations to 184,387 patients at Massachusetts General Hospital and Brigham and Women’s Hospital. During the same time period, 7078 patients provided their consent via eIC. The rate of consent of emailed patients was 3.5%, and the rate of consent of patients who log into the eIC website at Partners Biobank was 30%. Banking of biospecimens linked to electronic health records has become a critical element of genomic research and a foundation for the NIH’s Precision Medicine Initiative (PMI). eIC is a feasible and potentially game-changing strategy for these large research studies that depend on patient recruitment.

Harmonization and streamlining of research oversight for pragmatic clinical trials

The oversight of research involving human participants is a complex process that requires institutional review board review as well as multiple non-institutional review board institutional reviews. This multifaceted process is particularly challenging for multisite research when each site independently completes all required local reviews. The lack of inter-institutional standardization can result in different review outcomes for the same protocol, which can delay study operations from start-up to study completion. Hence, there have been strong calls to harmonize and thus streamline the research oversight process. Although the institutional review board is only one of the required reviews, it is often identified as the target for harmonization and streamlining. Data regarding variability in decision-making and interpretation of the regulations across institutional review boards have led to a perception that variability among institutional review boards is a primary contributor to the problems with review of multisite research. In response, many researchers and policymakers have proposed the use of a single institutional review board of record, also called a central institutional review board, as an important remedy. While this proposal has merit, the use of a central institutional review board for multisite research does not address the larger problem of completing non-institutional review board institutional review in addition to institutional review board review—and coordinating the interdependence of these reviews. In this article, we describe the overall research oversight process, distinguish between institutional review board and institutional responsibilities, and identify challenges and opportunities for harmonization and streamlining. We focus on procedural and organizational issues and presume that the protection of human subjects remains the paramount concern. Suggested modifications of institutional review board processes that focus on time, efficiency, and consistency of review must also address what effect such changes have on the quality of review. We acknowledge that assessment of quality is difficult in that quality metrics for institutional review board review remain elusive. At best, we may be able to assess the time it takes to review protocols and the consistency across institutions.

Global implementation of genomic medicine: We are not alone

Around the world, innovative genomic-medicine programs capitalize on singular capabilities arising from local health care systems, cultural or political milieus, and unusual selected risk alleles or disease burdens. Such individual efforts might benefit from the sharing of approaches and lessons learned in other locales. The U.S. National Human Genome Research Institute and the National Academy of Medicine recently brought together 25 of these groups to compare projects, to examine the current state of implementation and desired near-term capabilities, and to identify opportunities for collaboration that promote the responsible practice of genomic medicine. Efforts to coalesce these groups around concrete but compelling signature projects should accelerate the responsible implementation of genomic medicine in efforts to improve clinical care worldwide.

Central institutional review board review for an academic trial network

PROBLEM

Translating discoveries into therapeutics is often delayed by lengthy start-up periods for multicenter clinical trials. One cause of delay can be multiple institutional review board (IRB) reviews of the same protocol.

APPROACH

When developing the Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT; hereafter, NN), the National Institute of Neurological Disorders and Stroke (NINDS) established a central IRB (CIRB) based at Massachusetts General Hospital, the academic medical center that received the NN clinical coordinating center grant. The 25 NN sites, located at U.S. academic institutions, agreed to required CIRB use for NN trials.

OUTCOMES

To delineate roles and establish legal relationships between the NN sites and the CIRB, the CIRB executed reliance agreements with the sites and their affiliates that hold federalwide assurance for the protection of human subjects (FWA); this took, on average, 84 days. The first NN protocol reviewed by the CIRB achieved full approval to allow participant enrollment within 56 days and went from grant award to the first patient visit in less than four months. The authors describe anticipated challenges related to institutional oversight responsibilities versus regulatory CIRB review as well as unanticipated challenges related to working with complex organizations that include multiple FWA-holding affiliates.

NEXT STEPS

The authors anticipate that CIRB use will decrease NN trial start-up time and thus promote efficient trial implementation. They plan to collect data on timelines and costs associated with CIRB use. The NINDS plans to promote CIRB use in future initiatives.

Returning a Research Participant's Genomic Results to Relatives: Analysis and Recommendations

Genomic research results and incidental findings with health implications for a research participant are of potential interest not only to the participant, but also to the participant's family. Yet investigators lack guidance on return of results to relatives, including after the participant's death. In this paper, a national working group offers consensus analysis and recommendations, including an ethical framework to guide investigators in managing this challenging issue, before and after the participant's death.

Return of Genetic Research Results to Participants and Families: IRB Perspectives and Roles

We surveyed IRB chairs' perspectives on offering individual genetic research results to participants and families, including family members of deceased participants, and the IRB's role in addressing these issues. Given a particular hypothetical scenario, respondents favored offering results to participants but not family members, giving choices at the time of initial consent, and honoring elicited choices. They felt IRBs should have authority regarding the process issues, but a more limited role in medical and scientific issues.

Canadian Research Ethics Board Leadership Attitudes to the Return of Genetic Research Results to Individuals and Their Families

Genomic research may uncover results that have direct actionable benefit to the individual. An emerging debate is the degree to which researchers may have responsibility to offer results to the biological relatives of the research participant. In a companion study to one carried out in the United States, we describe the attitudes of Canadian Research Ethics Board (REB) chairs to this issue and their opinions as to the role of the REB in developing related policy.

Genomic medicine: too great expectations?

As advances in genomic medicine have captured the interest and enthusiasm of the public, an unintended consequence has been the creation of unrealistic expectations. Because these expectations may have a negative impact on individuals as well as genomics in general, it is important that they be understood and confronted.

Ethical and practical guidelines for reporting genetic research results to study participants: updated guidelines from a National Heart, Lung, and Blood Institute working group

In January 2009, the National Heart, Lung, and Blood Institute convened a 28-member multidisciplinary Working Group to update the recommendations of a 2004 National Heart, Lung, and Blood Institute Working Group focused on Guidelines to the Return of Genetic Research Results. Changes in the genetic and societal landscape over the intervening 5 years raise multiple questions and challenges. The group noted the complex issues arising from the fact that technological and bioinformatic progress has made it possible to obtain considerable information on individuals that would not have been possible a decade ago. Although unable to reach consensus on a number of issues, the working group produced 5 recommendations. The working group offers 2 recommendations addressing the criteria necessary to determine when genetic results should and may be returned to study participants, respectively. In addition, it suggests that a time limit be established to limit the duration of obligation of investigators to return genetic research results. The group recommends the creation of a central body, or bodies, to provide guidance on when genetic research results are associated with sufficient risk and have established clinical utility to justify their return to study participants. The final recommendation urges investigators to engage the broader community when dealing with identifiable communities to advise them on the return of aggregate and individual research results. Creation of an entity charged to provide guidance to institutional review boards, investigators, research institutions, and research sponsors would provide rigorous review of available data, promote standardization of study policies regarding return of genetic research results, and enable investigators and study participants to clarify and share expectations for the handling of this increasingly valuable information with appropriate respect for the rights and needs of participants.

Mainstreaming animal-assisted therapy

The term animal-assisted therapy (AAT) commonly refers to the presentation of an animal to one or more persons for the purpose of providing a beneficial impact on human health or well-being. AAT is an ideal example of "One Health" because of numerous studies and widespread testimonials indicating that many humans feel better in the presence of pets and other domesticated animals, and, conversely, that some of those creatures appear to respond positively to human company for their emotional and perhaps physical betterment. Many AAT studies have claimed a wide range of human health benefits, but much of the research is characterized by small-scale interventions among disparate fields, resulting in criticisms about weak study design or inconsistent methodology. Such criticisms contrast with the strongly held belief among many that interaction with friendly animals has a strong and innate value for the persons involved. Consequently the appeal of AAT in human medicine today may be generally characterized as a "push" by enthusiastic advocates rather than a "pull" by prescribing physicians. To fully integrate AAT into conventional medical practice as an accepted therapeutic modality, more convincing intervention studies are necessary to confirm its clinical merits, along with an understanding of the underlying mechanism of the human response to the company of friendly animals.

Centralized banks for human embryonic stem cells: a worthwhile challenge

Centralized banking of human embryonic stem (hES) cells is an endeavor that can benefit individual research efforts and enhance international collaboration but is complicated by the fact that the science is rapidly evolving in an environment of heterogeneous laws, guidelines, and ethical standards. Written from the vantage point of regulatory professionals, this article provides an overview of the benefits of and challenges facing hESC banking enterprises in general with a focus on a global centralized banking effort.

The Bartlett et al extracorporeal membrane oxygenation case series from 1977, with expert commentary provided by Dr P. Pearl O'Rourke

In this Classic Papers feature, we highlight Dr. Robert H. Bartlett's ground-breaking case series from 1977 reporting 28 pediatric and adult patients supported by extracorporeal membrane oxygenation (ECMO). Dr. P. Peal O'Rourke, who conducted early, innovative clinical research on ECMO, provides her perspective on the state of critical care for children in the late 1970s, how this paper and Dr. Bartlett himself influenced it, and difficulties faced in developing ECMO programs in the 1980s. Dr. Bartlett offers answers to questions about how his work on ECMO began, the reaction of the critical care community to the use of ECMO, and how challenges in studying ECMO in clinical trials have been approached.

Left ventricular dysfunction during extracorporeal membrane oxygenation in a hypoxemic swine model

BACKGROUND

Perfusion of the coronary circulation with hypoxemic blood from the left ventricle has been postulated to cause myocardial dysfunction during venoarterial extracorporeal membrane oxygenation for respiratory support.

METHODS

We investigated this hypothesis in 10 anesthetized open-chest piglets (7 to 9 kg) undergoing venoarterial extracorporeal membrane oxygenation after placement of minor-axis sonomicrometry crystals and left ventricular micromanometer. The left atrial partial pressure of oxygen was made hypoxemic (25 to 40 mm Hg) after initiation of extracorporeal membrane oxygenation by ventilation with a hypoxic gas mixture. Left ventricular contractile function, including peak LV pressure, shortening fraction, maximum rate of increase of left ventricular pressure, velocity of circumferential fiber shortening, end-systolic pressure-minor axis dimension relationship, and preload recruitable dimensional stroke work, was measured or calculated on extracorporeal membrane oxygenation before (baseline) and at 4 and 6 hours after rendering the left atrial blood hypoxemic.

RESULTS

Left ventricular shortening fraction and velocity of circumferential fiber shortening were significantly lower (p < 0.05) at 4 and 6 hours when compared with baseline. The slope of the end-systolic pressure-minor axis dimension relationship decreased but was not significantly different at 4 and 6 hours when compared with baseline owing to poor linear correlation (r = 0.30 to 0.93). The preload recruitable dimensional stroke work was more linear (r = 0.87 to 0.99), and the slope was significantly lower (p < 0.01) at 4 and 6 hours when compared with baseline.

CONCLUSIONS

Hypoxemic cardiac output from the left ventricle during venoarterial extracorporeal membrane oxygenation is associated with depression of left ventricular systolic function in this animal model. Current use of venoarterial extracorporeal membrane oxygenation for respiratory support may not provide adequate oxygen supply to the myocardium.

Effect of extracorporeal membrane oxygenation on left ventricular function of swine

BACKGROUND

Previous clinical and experimental investigations have produced inconsistent data describing the effects of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on intrinsic left ventricular (LV) function. We report an animal model that allows investigation of the effects of VA ECMO on the mechanics of the LV using two load-insensitive indices: end-systolic pressure-minor axis dimension relationship (ESPDR) and preload recruitable dimensional stroke work (PRDSW).

METHODS

Eight piglets (5 to 11 kg) were anesthetized, instrumented, and placed on VA ECMO. Throughout the experiment, systemic and left atrial partial pressure of oxygen were maintained between 100 to 200 mm Hg. At ECMO flow rate of 50% of baseline cardiac output, data were collected prior to ECMO, at 4 and 6 hours during ECMO, and after weaning from ECMO. Data measured or calculated for each time point included heart rate, LV pressures and minor axis dimensions at different pre-loads, first derivative of LV pressure with respect to time, velocity of circumferential fiber length shortening (VCF), LV shortening fraction (LVSF), ESPDR, and PRDSW.

RESULTS

A significant (p < 0.05) decrease in LVSF and VCF was seen at 4 and 6 hours during ECMO when compared to baseline, but the ESPDR and PRDSW did not change during ECMO.

CONCLUSIONS

VA ECMO alone changes some of the load-dependent parameters of contractility, but intrinsic function of the heart is not significantly affected as measured by load-insensitive indices of LV performance.

Attitudes toward limitation of support in a pediatric intensive care unit

OBJECTIVE

To prospectively determine opinions of members of a pediatric intensive care unit (PICU) team regarding the appropriateness of aggressive care. The types of support that caregivers sought to limit and their reasons for wanting these limits were collected over time.

DESIGN

Prospective survey of caregiver opinions.

SETTING

PICU in an academic tertiary care children's hospital.

SUBJECTS

A total of 68 intensive care nurses, 11 physicians attending in the PICU, 10 critical care and anesthesia fellows, and 24 anesthesia and pediatric residents.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During a 6-month period, 503 patients were admitted to the PICU. Within this time period, 52.4% of all deaths were preceded by limitation of support, with 100% of noncardiac surgical deaths preceded by limitation of medical interventions. At least one caregiver wished to limit care for 63 of these patients (12.5%). When caregivers wished to limit support they most frequently wished to limit invasive modes of support such as cardiopulmonary resuscitation (94%) and hemodialysis (83%). The ethical rationales identified most often for wishing to limit support were burden vs. benefit (88%) and qualitative futility (83%). Preadmission quality of life was cited less frequently (50%). Caregivers were less likely to limit care on the basis of quality of life. Nurses and physicians in the PICU were very similar to each other in the types of support they thought should be limited and their ethical rationales.

CONCLUSIONS

When making decisions about whether or not to limit care for a patient, caregivers were more likely to rely on the perceived benefit to the patient than preadmission quality of life.

Nonpulmonary organ failure and outcome in children treated with high-frequency oscillatory ventilation

PURPOSE

The purpose of this study was to quantitate the contribution of nonpulmonary organ failure to mortality of patients treated with high-frequency oscillatory ventilation (HFOV) and to determine which gas-exchange differences are associated with improvement on HFOV.

MATERIALS AND METHODS

Charts of all patients treated with HFOV in our pediatric intensive care unit from January 1992 until January 1997 were retrospectively reviewed.

RESULTS

Sixty-six patients were treated and 21 patients improved during HFOV (group 1); 45 patients did not improve (group 2). Seventeen patients (26%) had isolated respiratory failure and their mortality was 12%. Percentages of patients with 2, and 3 or more organ failure were 45%, 29%, and their mortality was significantly higher, 67% and 95%, respectively. Patients with primary respiratory failure demonstrated a significantly greater risk of improvement on HFOV (RR ratio of 2.5, 95% CI 1.5 to 4.2). There was a significantly greater proportion of patients with primary cardiac failure who did not improve on HFOV compared with all other patients. Oxygenation index significantly improved over the first 72 hours for both groups, but then significantly worsened over the next 48 hours in group 2 but not in group 1.

CONCLUSION

Patients with nonpulmonary organ failure were significantly less likely to improve on HFOV and had a significantly higher mortality than patients with isolated respiratory failure. Children who do not improve on HFOV appear to reach a plateau in oxygenation indices after 3 days of HFOV.

Clinical uses and controversies of neuromuscular blocking agents in infants and children

OBJECTIVE

To review the pharmacology of neuromuscular blocking drugs (NMBDs), their use in critically ill or injured infants and children, and the relevance of developmental changes in neuromuscular transmission.

DATA SOURCES

Computerized search of the medical literature.

STUDY SELECTION

Studies specifically examining the following were reviewed: a) the developmental changes in neuromuscular transmission; b) the pharmacokinetics and pharmacodynamics of all clinically available NMBDs in neonates, infants, children, and adults; and c) clinical experience with NMBDs in the critical care setting. Particular attention was directed toward studies in the pediatric population.

DATA SYNTHESIS

Neuromuscular transmission undergoes maturational changes during the first 2 months of life. Alterations in body composition and organ function affect the pharmacokinetics and pharmacodynamics of the NMBDs throughout active growth and development. Numerous NMBDs have been developed during the last two decades with unique pharmacologic profiles and potential clinical advantages. The NMBDs are routinely used in critically ill or injured patients of all ages. This widespread use is associated with rare but significant clinical complications, such as prolonged weakness.

CONCLUSIONS

Significant gaps in our knowledge of the pharmacokinetics and pharmacodynamics of NMBDs in infants and children continue to exist. Alterations in electrolyte balance and organ-specific drug metabolism may contribute to complications with the use of NMBDs in the critical care arena.

High-frequency oscillatory ventilation with partial liquid ventilation in a model of acute respiratory failure

OBJECTIVE

To determine whether there is an improvement in oxygenation when partial liquid ventilation and high-frequency oscillatory ventilation are combined in the treatment of acute lung injury, compared with high-frequency oscillatory ventilation alone.

DESIGN

Controlled animal trial.

SETTING

Research laboratory in a university setting.

SUBJECTS

Ten 3-kg piglets.

INTERVENTIONS

Anesthetized piglets underwent high-frequency oscillatory ventilation, with mean airway pressure of 20 cm H2O, before induction of acute lung injury with repeated saline lavage. When PaO2 values were < 100 torr (< 13.3 kPa), five animals were randomized to receive escalating doses (3, 15, and 30 mL/kg) of perflubron at 60-min intervals. The other five animals remained on high-frequency oscillatory ventilation only. Sham dosing was performed at 60-min intervals in these animals. Arterial blood gases were obtained in both groups at baseline, after injury, and after perflubron and sham doses.

MEASUREMENTS AND MAIN RESULTS

Statistically significant improvements in oxygenation were demonstrated in animals that received 3 mL/kg of perflubron with high-frequency oscillatory ventilation compared with animals receiving high-frequency oscillatory ventilation alone (253 +/- 161 vs. 90 +/- 30 torr [33.65 +/- 21.46 vs. 12.0 +/- 4.0 kPa], p < .05). Improvements in oxygenation with additional administration of perflubron were not greater than the improvements seen in the high-frequency oscillatory ventilation-only group. PaCO2 and pH were similar in both groups at all times. No hemodynamic compromise occurred in either group of animals.

CONCLUSIONS

The combination of low-dose perflubron with high-frequency oscillatory ventilation leads to more rapid improvement in arterial oxygenation than high-frequency oscillatory ventilation alone, in a piglet model of acute lung injury. Although the group receiving high-frequency oscillatory ventilation alone eventually achieved PaO2 values that were equivalent to the group receiving high-frequency ventilation and perflubron, the combination of perflubron with high-frequency oscillatory ventilation may permit effective oxygenation and ventilation at lower mean airway pressures by facilitating alveolar expansion and decreasing intrapulmonary shunt.

Morphine pharmacokinetics during continuous infusion of morphine sulfate for infants receiving extracorporeal membrane oxygenation

OBJECTIVES

To determine a) if serum morphine concentration changes during the first 3 hrs of extracorporeal membrane oxygenation (ECMO); and b) if absorption of morphine onto the membrane oxygenator is responsible for these changes. Also, morphine clearance during the first 5 days of ECMO was studied.

DESIGN

Prospective, open-label study with consecutive patient enrollment.

SETTING

Neonatal intensive care unit at a university-affiliated, children's hospital.

SUBJECTS

Eleven neonates with severe persistent pulmonary hypertension of the newborn receiving continuous intravenous infusions of morphine sulfate and requiring ECMO.

INTERVENTIONS

Blood samples were obtained from the subjects and ECMO circuits at predetermined time intervals.

MEASUREMENTS AND MAIN RESULTS

Serum morphine concentration was determined using high-performance liquid chromatography. Morphine concentrations were no different from baseline at 5 mins, 1 hr, or 3 hrs after beginning ECMO. There was no significant difference in morphine concentration from samples taken immediately proximal and distal to the membrane oxygenator at 5 mins, 1 hr, and 3 hrs after the start of ECMO. Morphine clearance was calculated on days 1, 3, and 5 of ECMO. The mean value for morphine clearance was 11.7 +/- 9.3 (SD) ml/min/kg (range 2.6 to 34.5).

CONCLUSIONS

The initiation of ECMO does not lead to a significant decrease in serum morphine concentration and there is no uptake of morphine onto the membrane oxygenator of the ECMO circuit. Morphine clearance for infants receiving ECMO is variable.

Cardiac rhabdomyoma with cardiac arrest

Images

A prospective study of femoral catheter-related thrombosis in children

OBJECTIVES

To establish the incidence and correlate clinical findings of femoral venous catheter-related thrombus formation in critically ill children.

RESEARCH DESIGN

Observational prospective blinded study.

SETTING

University-affiliated pediatric hospital intensive care unit.

PATIENTS

Twenty children admitted to the pediatric intensive care unit who had percutaneous femoral venous catheters placed while in the pediatric intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS

Duplex Doppler ultrasonography evaluation of femoral vein catheters at 1 to 2, 3 to 5, and 7 to 10 days after placement was used to detect the presence of thrombus formation and venous occlusion. Demographic patient data, pediatric risk of mortality scores, and clinical findings, including leg swelling and whether catheters would aspirate blood, were also recorded. Continuous data were analyzed using the Mann-Whitney U Test, and categorical data were compared with Fisher's Exact Test. Statistical significance was assigned at a P value of .05 or less.

CONCLUSIONS

The overall incidence of catheter-related femoral vein thrombus formation was 35% (7/20). Ipsilateral leg swelling and the inability to aspirate blood from the catheter were significantly associated with thrombus formation. Patients who developed thrombi were younger and smaller than those who did not. In six of seven patients, thrombus formation was clinically occult when first demonstrated by ultrasonography.

Repair of a laryngotracheoesophageal cleft in an infant by means of extracorporeal membrane oxygenation

Few survivors have been reported following attempted repair of laryngotracheoesophageal clefts (LTECs). The major challenge is maintaining oxygenation, both during the surgical repair and during the postoperative period of healing. We report a neonate with an LTEC extending to the carina whose successful repair was facilitated by extracorporeal membrane oxygenation (ECMO) begun intraoperatively and continued postoperatively for 11 days. The intraoperative surgical exposure of the defect was excellent. Postoperative trauma to the fresh tracheal repair from ventilatory pressures and endotracheal tube motion was eliminated through the use of ECMO. The patient was discharged without a tracheotomy and with a normal voice, cry, and swallow. According to this result, the use of ECMO may represent a significant advance in facilitating the correction of major laryngotracheoesophageal anomalies. The rationale, advantages, disadvantages, and potential pitfalls of this approach are presented, as well as preoperative and postoperative documentation of our results.

Spontaneous pneumomediastinum

A case of spontaneous pneumomediastinum with cervical emphysema is reported. Spontaneous pneumomediastinum may complicate processes that decrease pulmonary interstitial pressure or increase intraalveolar pressure leading to alveolar rupture. Free air may then tract along blood vessels and decompress into the soft tissues of the neck. Clinical symptoms include neck and chest pain, dysphonia, and shortness of breath. Care is supportive unless the patient has a history of trauma or foreign body aspiration. Symptoms typically resolve within days.

Drowning and immersion injuries in children

Drowning and immersion injuries are leading causes of mortality and morbidity in children. An increasing amount of epidemiologic information is available. New modalities for managing respiratory failure, such as extracorporeal membrane oxygenation, are being explored. The realization that aggressive neurointensive care does not improve desirable outcome after near-drowning has led to investigations on preventing secondary brain injury that focus on monitoring and restoring cerebral oxygenation and circulation, reversing hypothermia, and maintaining normal blood glucose levels. Efforts at early neurologic prognostication and identification of victims who are likely to die or persist in a vegetative state are increasingly accurate and are highly relevant. Critical care physicians are more likely to withhold or withdraw support from victims who have minimal likelihood of meaningful recovery.

Extracorporeal membrane oxygenation: support for overwhelming pulmonary failure in the pediatric population. Collective experience from the extracorporeal life support organization

Data from the Extracorporeal Life Support Organization (ELSO) regarding the use of extracorporeal membrane oxygenation (ECMO) in pediatric patients with respiratory failure are reviewed. Two hundred eighty-five children between the ages of 14 days and 18 years were supported with ECMO between January 1982 and September 1991. Although these data represent the experience of 52 ECMO centers, seven centers accounted for over 50% of the total. The patients had a mean age of 33 +/- 48 months with a median age of 13 months: 137 (48%) were male and 148 (52%) were female. There were numerous primary pulmonary diagnoses: the two most common were presumed viral pneumonia (32%) and adult respiratory distress syndrome (28%). Entry criteria for ECMO, although poorly defined and specific to each institution, attempted to identify children with an 85% to 100% predicted mortality. The survival rate with ECMO was 47% (135/285). Pre-ECMO mechanical ventilatory support was extreme with an FIO2 .97 +/- .07 and a mean airway pressure (MAP) 23.6 +/- 8 cm H2O used to achieve PaO2 of 50 +/- 39 and PaCO2 51 +/- 22 mm Hg. The MAP was significantly higher in nonsurvivors versus survivors (25.3 +/- 8.7 v 22.0 +/- 7.1 cm H2O, P < .01). The duration of ECMO was 4 hours to 35.5 days with a mean of 245 +/- 165 hours, which is approximately 10 days. Duration for survivors was 222 +/- 151 hours compared with 266 +/- 176 hours for nonsurvivors. ECMO complications are divided into two categories: mechanical (directly related to the ECMO circuit) and medical (patient related).(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation is still a relatively new technology that has recently achieved recognition after initial clinical disappointment in the late 1970s. At present, it is considered standard therapy for the full-term infant with PPHN who fails CMV and extraordinary, heroic therapy for older children and adults with ARF or cardiac failure, or both. Currently, the emphasis is on developing new technologies for increasing safety and effectiveness. Areas of interest include heparinless circuits, carotid artery reconstruction, improved monitoring, and expanding applications of VV ECMO. As ECMO becomes safer and more effective, it is believed that new and expanding patient populations will emerge to include premature infants, earlier intervention in term infants, and more liberal application to pediatric and adult populations.

Delayed repair and preoperative ECMO does not improve survival in high-risk congenital diaphragmatic hernia

It has been suggested that delayed repair with preoperative stabilization might improve survival in high-risk (symptomatic within 6 hours of birth) congenital diaphragmatic hernia (CDH). This study compares the results of immediate operation versus delayed repair using extracorporeal membrane oxygenation (ECMO) when necessary. Since we first used ECMO in 1984, 101 high-risk CDH infants have been treated. Prior to 1987, we used immediate repair and postoperative ECMO if necessary. Between 1987 and 1990 we combined delayed operation (24 to 36 hours) with preoperative ECMO as necessary. No infant in this series was excluded from ECMO therapy unless absolute contraindications existed (prematurity, intracranial hemorrhage, or other major anomalies). Fifty-five patients received immediate operation and 46 had delayed repair. The two groups were comparable populations based on gestational age, birth weight, age at onset of symptoms, Apgar scores, best postductal PO2 (BPDPO2), and frequency of antenatal diagnosis. There was no statistically significant difference in overall survival between the two groups. Differences in survival among subpopulations (BPDPO2 greater than 100 or less than 100, antenatal diagnosis, inborn v outborn) also are not significant. The requirement for ECMO was similar in both groups. Survivors in the delayed repair group were ventilated longer and on ECMO longer, but had fewer late deaths (greater than 21 days) and fewer pulmonary sequelae (O2 dependency at discharge) than infants in the immediate repair group (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotoxicity during treatment of severe childhood asthma

We prospectively evaluated 20 patient admissions for severe exacerbation of childhood asthma at The Children's Hospital, Boston, to detect evidence of cardiotoxicity. Evidence of cardiotoxicity was found in all six patient admissions for which isoproterenol infusion was utilized. This included marked elevation of serum creatine phosphokinase isoenzyme (CPK-MB) levels and electrocardiogram abnormalities consistent with transient myocardial ischemia. Peak serum CPK-MB levels were significantly lower and electrocardiogram abnormalities were significantly less frequent during 14 patient admissions for which isoproterenol infusion was not utilized. Risk factors associated with cardiotoxicity included tachycardia, hypercapnia, acidosis, and intravenous isoproterenol therapy. We conclude that cardiotoxicity is not infrequent during therapy for severe exacerbations of childhood asthma. Electrocardiograms and measurement of serum CPK-MB levels are sensitive, useful, and readily obtained indicators of cardiotoxicity. Abnormalities of these studies may detect cardiotoxicity prior to the occurrence of more blatant or catastrophic manifestations of cardiotoxicity. We therefore recommend serial monitoring of serum CPK-MB levels and electrocardiograms for all children requiring an admission to the intensive care unit for management of severe asthmatic exacerbation.

Extracorporeal life support for cardiac assist in pediatric patients. Review of ELSO Registry data

The collected data on extracorporeal membrane oxygenation (ECMO), now referred to as extracorporeal life support (ECLS), for pediatric cardiac support has not been analyzed. The purpose of this study was to review the Extracorporeal Life Support (ELSO) Registry data to evaluate the results, identify possible predictors of outcome, and attempt to establish criteria. From 1981 to June of 1990, 189 patients were placed on ECLS for cardiac assist. The age range was 0-204 months (median, 7 months). Mean time on ECLS was 115 +/- 75 hours. Fourteen patients were placed on ECLS as a bridge to transplant or for management of transplant rejection. All of the remaining 175 patients were treated in the postoperative period. The causes of mortality included lack of improvement in cardiovascular function in 69 (37%) of the patients, major central nervous system damage in 28 (15%), uncontrollable hemorrhage in three (2%), sepsis in three (2%), and pulmonary interstitial disease in two (1%). The Registry data were examined for predictors of outcome. There was no significant difference between survivors and nonsurvivors when compared for duration of ECLS, mechanical complications, arterial or venous blood gases, ventilation settings, or hemodynamics. Forty-three percent of 189 pediatric patients treated with ECLS for cardiac failure survived. The highest survival, 61%, occurred in right-sided lesions and the lowest, 18%, in post-Fontan. Mediastinal bleeding, cardiac arrest, renal failure, and prolonged intubation were all associated with a poor outcome. Most deaths were attributed to irreversible cardiac or brain injury, suggesting that results could be improved by earlier identification of high-risk patients and earlier institution of ECLS.

The effect of extracorporeal membrane oxygenation on the survival of neonates with high-risk congenital diaphragmatic hernia: 45 cases from a single institution

At The Children's Hospital, Boston (TCH), in the 3 years before extracorporeal membrane oxygenation (ECMO) was available, infants with high-risk congenital diaphragmatic hernia (CDH) had a 47% survival rate. In February 1984, ECMO was introduced and offered to all high-risk CDH infants with a 100% predicted mortality. Since February 1984, 45 infants with high-risk CDH presented to TCH. Twenty-six (58%) were supported with ECMO; 19 (42%) never met the criteria for 100% predicted mortality and were supported with conventional mechanical ventilation (CMV). Overall survival was 49%. Nine (35%) of the 26 ECMO patients survived. Thirteen (68%) of the 19 CMV patients survived. Although there was no change in survival, there was a change in the cause of death. Deaths in the ECMO group were either early (n = 8, secondary to a complication of ECMO or lack of pulmonary improvement) or late (n = 9). The late deaths were infants who were successfully weaned from ECMO, never weaned from CMV, and who died secondary to complications of chronic lung disease.

Complications of mechanical ventilation in a children's hospital multidisciplinary intensive care unit

During a 12-week period, 204 consecutive patients admitted to the multidisciplinary intensive-care unit of a children's hospital were prospectively studied for complications of mechanical ventilation.

METHOD

A respiratory therapist completed a standardized data form at the end of each shift for each ventilated patient. Patient age, sex, length of ventilation, diagnosis, and complications were noted. Complications were classified as relating to the endotracheal tube (ETT), the ventilator, or the patient's medical management, and were analyzed according to incidence (number per 100 patients or per 100 ventilator days) and to associated mortality.

RESULTS

Patients ranged in age from newborn to 24 years. Sixty-three percent were male. Twenty-one percent of patients were managed by the medical staff, 11% by the general surgical staff, and 68% by the cardiac surgical staff. Average length of ventilation was 5.2 days. Overall survival rate was 91.7%. ETT complications reported as number per 100 patients were: pre-necrosis (13.0 [4/57 orally intubated patients and 23/147 nasally intubated patients]), ETT retaping complications (6.0), ETT plugging (1.0), and self-extubation (3.0). Ventilator complications reported as number per 100 ventilator days were: alarm failures (6.5), ventilator failures (0.7), and circuit problems (7.0). Medical complications reported as number per 100 patients were: massive gastric distension (8.8), right-upper-lobe collapse (4.4), pneumothorax (4.4), subcutaneous air (1.5), and pneumoperitoneum (1.0). ETT and ventilator complications showed no association with mortality. The large number of cardiac infants less than 24 months of age (n = 101) led us to further analyze this group for survival rate. We found that the survival rate was 93% for those requiring less than 7 days mechanical ventilation and 89.3% for those requiring greater than or equal to 7 days. As the study progressed, the respiratory therapists independently noted that their attentiveness to both patient and machine increased as did their awareness of complications. The incidence of alarm failure, circuit problems, and pre-necrosis was higher among the first 103 patients compared to the 101 patients entered into the study subsequently.

Oxygen extraction in lamb skeletal muscle

Past studies have found that total-body O2 extraction during hypoxia was less in 1-wk-old lambs than in older animals. It was proposed that reduced O2 extraction was secondary to suppression of growth-related oxygen consumption (VO2) in tissues such as skeletal muscle, bone, kidney, and skin, rather than a defect in peripheral O2 use. To determine the capacity of immature skeletal muscle to extract O2, we isolated the hind limb circulation of eight ketamine-anesthetized, 7- to 18-d-old lambs exposed to stagnant hypoxia by inflation of a right atrial balloon catheter. Femoral arterial and venous PO2, PCO2, pH, Hb concentration, O2 saturation, and femoral arterial blood flow (Q) were measured and hind limb O2 delivery (DO2), extraction ratio, and VO2 calculated. Individual critical levels of DO2 below which VO2 was dependent on O2 supply were determined by dual-line best-fit regression analysis. In six of eight animals, VO2 was clearly independent of supply until DO2 reached critically low levels. However, O2 extraction during extreme hypoxia appeared submaximal (baseline O2 extraction ratio, 0.22 +/- 0.06; at critical levels of DO2, 0.51 +/- 0.11; at the lowest level of Q, 0.64 +/- 0.15). When 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation, was administered to four additional lambs exposed to stagnant hypoxia, O2 extraction below critical levels of DO2 increased from 0.48 +/- 0.15 to 0.79 +/- 0.10 (p less than 0.001, unpaired t test). These data suggest that initial limitations in O2 extraction were a result of the suspension of O2-consuming processes, not an irreversible defect in peripheral O2 use.

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

Thirty-nine newborn infants with severe persistent pulmonary hypertension and respiratory failure who met criteria for 85% likelihood of dying were enrolled in a randomized trial in which extracorporeal membrane oxygenation (ECMO) therapy was compared with conventional medical therapy (CMT). In phase I, 4 of 10 babies in the CMT group died and 9 of 9 babies in the ECMO group survived. Randomization was halted after the fourth CMT death, as planned before initiating the study, and the next 20 babies were treated with ECMO (phase II). Of the 20, 19 survived. All three treatment groups (CMT and ECMO in phase I and ECMO, phase II) were comparable in severity of illness and mechanical ventilator support. The overall survival of ECMO-treated infants was 97% (28 of 29) compared with 60% (6 of 10) in the CMT group (P&lt; .05).

Role of extracorporeal membrane oxygenation in selected pediatric respiratory problems

Between 1984 and 1988, 89 infants and children with severe respiratory failure were supported by extracorporeal membrane oxygenation. Major clinical diagnoses included congenital diaphragmatic hernias (34), meconium aspiration syndrome (26), and sepsis (8). Extracorporeal membrane oxygenation was used for patients with a predicted mortality rate of at least 80% based on an oxygenation index greater than 0.4. Venoarterial bypass was accomplished by way of right cervical cannulation of the common carotid artery and internal jugular vein. Overall survival was 71% but varied widely by diagnosis and progressively improved over time. The average extracorporeal membrane oxygenation run was 5.7 days. Intracranial hemorrhage was the most serious complication occurring in 16% of patients. Mechanical circuit complications were seen in 22% but rarely related to significant morbidity. Extracorporeal membrane oxygenation appears to provide effective cardiopulmonary support for selected pediatric respiratory problems. It affords those with potentially reversible pathophysiology the temporal opportunity for successful medical or surgical therapies.

Fetal diaphragmatic hernia: ultrasound diagnosis and clinical outcome in 38 cases

A previously published survey has evaluated the natural history and clinical outcome of fetal diaphragmatic hernia (CDH) in 94 cases. This study showed that the prenatal diagnosis is accurate, the mortality is high (80%), and polyhydramnios is a prenatal predictor of poor clinical outcome. As a follow-up study, 38 consecutive cases of CDH diagnosed in utero were evaluated and treated by the same surgical team. This permitted detailed assessment of prognostic factors and evaluation of the impact of extracorporeal membrane oxygenation (ECMO) on outcome. We found the following. (1) Survival is poor despite optimal postnatal therapy including ECMO. (2) Polyhydramnios is both a common prenatal marker for CDH (present in 69% of fetuses) and a predictor for poor clinical outcome (only 18% survival), but tends to occur after the second trimester. (3) Amniocentesis is indicated to rule out chromosomal abnormalities that were present in 16% of fetuses. (4) All 14 fetuses diagnosed prior to 25 weeks' gestation died. Improved postnatal therapy or surgical intervention before birth will be necessary to salvage the CDH fetus with an early gestational diagnosis or associated polyhydramnios.

Neurological complications of hemolytic-uremic syndrome

Of 78 children identified with hemolytic-uremic syndrome at the Children's Hospital, Boston, from 1976 to 1986, 16 patients (20.5%) had neurological manifestations during their hospitalization. The most common manifestations were significant alterations in consciousness (coma, stupor) in 12 patients, and either generalized or partial seizures in ten patients. Others included hemiplegia (4 patients), decerebrate posturing (3), cortical blindness (2), hallucinations (1), and dystonic posturing (1). Cranial computed tomographic scans were abnormal in eight of 11 patients scanned. The abnormalities included diffuse cerebral edema (4 patients), large vessel infarctions (3), diffuse multiple small infarcts (4), and multiple hemorrhages (1). Five patients died as a result of their central nervous system complications, and six had neurological sequelae at discharge. Five patients recovered and at discharge had no evidence of neurological dysfunction.

Use of the postductal PaO2 as a predictor of pulmonary vascular hypoplasia in infants with congenital diaphragmatic hernia

Infants with congenital diaphragmatic hernia (CDH) demonstrate a wide range of anatomic and physiologic abnormalities that result in decreased pulmonary perfusion. We have used the patients' ability to achieve at least one postductal PaO2 greater than 100 torr while on maximal ventilation with 100% oxygen during the first 24 hours of life as the clinical marker to identify the degree of pulmonary perfusion. Patients were grouped as follows: group 1 had at least one postductal PaO2 greater than 100 torr, and group 2 patients never had a postductal PaO2 above 100 torr. To see if this classification did reflect pulmonary vascular abnormalities, we compared the pulmonary arteriograms of these two groups of CDH infants for size of the main pulmonary arteries (PAs), size of the lungs, and degree of peripheral vascular obstructive disease (PVO). Infants in group 2 had significantly smaller ipsilateral and contralateral main PAs, as well as smaller ipsilateral lungs with more severe PVO. We propose the postductal PaO2 as the clinical marker for identification of the degree of pulmonary perfusion.