EVALUATION OF A DISPOSABLE PLASTIC, LOW VOLUME, PUMPLESS OXYGENATOR AS A LUNG SUBSTITUTE

Extracorporeal Membrane Oxygenation in Critically Ill Children

Neonatal and pediatric extracorporeal membrane oxygenation (ECMO) has evolved over the past 50 years. Advances in technology, expertise, and application have increased the number of centers providing ECMO with expanded indications for use. However, increasing the use of ECMO in recent years to more medically complex critically ill children has not changed overall survival despite increased experience and improvements in technology. This review focuses on ECMO history, circuits, indications and contraindications, management, complications, and outcome data. The authors highlight important areas of progress, including unintubated and awake patients on ECMO, application during the COVID-19 pandemic, and future directions.

Extracorporeal Membrane Oxygenation in Pediatric Liver Transplantation: A Multicenter Linked Database Analysis and Systematic Review of the Literature

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) can be used to maintain oxygen delivery and provide hemodynamic support in case of circulatory and respiratory failure. Although the role of ECMO has emerged in the setting of adult liver transplantation (LT), data in children are limited. We aimed to describe the characteristics and outcomes of children receiving ECMO support at the time of or following LT.

METHODS

All pediatric LT recipients (≤20 y) requiring ECMO support peri-/post-LT were identified from a linked Pediatric Health Information System/Scientific Registry of Transplant Recipients dataset (2002-2018). The Kaplan-Meier method and Cox regression analysis were used to assess post-ECMO survival. A systematic literature review was conducted in accordance with the PRISMA statement.

RESULTS

Thirty-four children required ECMO peri-/post-LT. The median time from LT to ECMO was 5 d (interquartile range, 0.0-12.3), and the median ECMO duration was 1 d (interquartile range, 1.0-6.3). Children started on ECMO within 1 d of LT exhibited superior survival compared with those started on ECMO later (P = 0.03). When adjusting for recipient weight, increasing time from LT to ECMO initiation was associated with increased risk of mortality (hazard ratio, 1.03; 95% confidence interval, 1.00-1.06; P = 0.049). Overall, 55.9% (n = 19 of 34) of the patients survived. Twenty-two children receiving ECMO in the peri-/post-LT period were systematically reviewed, and 15 of them survived (68.2%).

CONCLUSIONS

With an encouraging >55% patient survival at 6 mo, ECMO should be considered as a viable option in pediatric LT recipients with potentially reversible severe respiratory or cardiovascular failure refractory to conventional treatment.

Extracorporeal Membrane Oxygenation and Continuous Kidney Replacement Therapy: Technology and Outcomes - A Narrative Review

The number of patients using critical care is increasing as our populations live longer thanks to advances in medical therapies. This is reflected by an increase in both usage and number of critical care beds as compared with total hospital beds across the United States. As this aging population suffers more and more from multiorgan dysfunction, including but not limited to respiratory failure, cardiac failure, and acute kidney injury, technologies are used to facilitate recovery in those that would have assuredly passed away years ago. Some of these advancements include extracorporeal membrane oxygenation and continuous kidney replacement therapy. In this article, we review the literature regarding the history, technology, indications, and outcomes of synchronous extracorporeal membrane oxygenation and kidney replacement therapy.

A materials-science perspective on tackling COVID-19

The ongoing SARS-CoV-2 pandemic highlights the importance of materials science in providing tools and technologies for antiviral research and treatment development. In this Review, we discuss previous efforts in materials science in developing imaging systems and microfluidic devices for the in-depth and real-time investigation of viral structures and transmission, as well as material platforms for the detection of viruses and the delivery of antiviral drugs and vaccines. We highlight the contribution of materials science to the manufacturing of personal protective equipment and to the design of simple, accurate and low-cost virus-detection devices. We then investigate future possibilities of materials science in antiviral research and treatment development, examining the role of materials in antiviral-drug design, including the importance of synthetic material platforms for organoids and organs-on-a-chip, in drug delivery and vaccination, and for the production of medical equipment. Materials-science-based technologies not only contribute to the ongoing SARS-CoV-2 research efforts but can also provide platforms and tools for the understanding, protection, detection and treatment of future viral diseases.

Extracorporeal membrane oxygenation as rescue therapy for severe hypoxemic respiratory failure

Extracorporeal membrane oxygenation (ECMO) has been used for more than 50 years as salvage therapy for patients with severe cardiopulmonary failure refractory to conventional treatment. ECMO was first used in the 1960s to treat hypoxemic respiratory failure in newborns. On the basis of its success in that population, ECMO began to be used in the early 1970s to treat adult hypoxemic respiratory failure. However, outcomes for adults were, somewhat perplexingly, quite poor. By the 1980s, use of ECMO for severe hypoxemia was rare outside of the pediatric population. ECMO technology, however, continued to evolve and improve. Multiple case reports and small series describing ECMO use as rescue for adults with severe hypoxemia from various lung pathologies have appeared in the literature over the past three decades. Adult respiratory distress syndrome (ARDS) is often the final common pathway of various pathologies affecting adults and causing hypoxemic respiratory failure. It is prevalent in intensive care units throughout the world and has, since it was first described in 1967, carried a high mortality. No specific therapy for ARDS has been found, and current care is supportive, primarily by mechanical ventilation. Results from recent randomized controlled trials, however, suggest that ECMO may have a place in the treatment of these patients. This article reviews these studies and recommends adding severe ARDS to the list of established indications for ECMO in patients with hypoxemic respiratory failure.

Decisions to Withdraw Extracorporeal Membrane Oxygenation Support: Patient Characteristics and Ethical Considerations

OBJECTIVE

To describe the prevalence and context of decisions to withdraw extracorporeal membrane oxygenation (ECMO), with an ethical analysis of issues raised by this technology.

PATIENTS AND METHODS

We retrospectively reviewed medical records of adults treated with ECMO at Mayo Clinic in Rochester, Minnesota, from January 1, 2010, through December 31, 2014, from whom ECMO was withdrawn and who died within 24 hours of ECMO separation.

RESULTS

Of 235 ECMO-supported patients, we identified 62 (26%) for whom withdrawal of ECMO was requested. Of these 62 patients, the indication for ECMO initiation was bridge to transplant for 8 patients (13%), bridge to mechanical circulatory support for 3 (5%), and bridge to decision for 51 (82%). All the patients were supported with other life-sustaining treatments. No patient had decisional capacity; for all the patients, consensus to withdraw ECMO was jointly reached by clinicians and surrogates. Eighteen patients (29%) had a do-not-resuscitate order at the time of death.

CONCLUSION

For most patients who underwent treatment withdrawal eventually, ECMO had been initiated as a bridge to decision rather than having an established liberation strategy, such as transplant or mechanical circulatory support. It is argued that ethically, withdrawal of treatment is sometimes better after the prognosis becomes clear, rather than withholding treatment under conditions of uncertainty. This rationale provides the best explanation for the behavior observed among clinicians and surrogates of ECMO-supported patients. The role of do-not-resuscitate orders requires clarification for patients receiving continuous resuscitative therapy.

Survival analysis of extracorporeal membrane oxygenation in neonatal and pediatric patients - A nationwide cohort study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) provides short-term cardiopulmonary support for patients with acute cardiac and respiratory failure. This study reported the survival rate for pediatric patients from Taiwan's national cohort.

METHODS

Patients under the age of 18 who received ECMO from January 1, 2002 to December 31, 2012 were identified from the Taiwan National Health Insurance Research Database. The underlying etiology for ECMO use was categorized into post-operative (n = 410), cardiac (245), pulmonary (146) groups, and others (120). A Cox regression model was used to determine hazard ratios and to compare 30-day and 1-year survival rates using post-operative group as a reference.

RESULTS

The average age of all 921 patients was 4.83 ± 5.84 years, and 59.1% were male. The overall mortality rate was 29.2% at 1 month, and 46.9% at 1 year. The cardiac origin group, consisting mostly of congenital heart disease without surgical intervention, myocarditis, and heart failure had a better outcome with an adjusted hazard ratio of 0.69 (95% CI 0.49-0.96, p = 0.008) at 30 days and 0.50 (95% CI 0.38-0.66, p < 0.001) at 1 year, as compared to the post-operative group.

CONCLUSION

In contrast to the widespread use of ECMO in respiratory distress syndrome in western countries, pediatric ECMO in Taiwan was more often applied to patients with underlying cardiovascular diseases. Mortality rates varied according to age groups and various etiologies. The results of this large pediatric cohort provides a different prospective in critical care outcomes in medical environments where ECMO is more widely available.

The contribution of arterio-venous extracorporeal lung assist to gas exchange in a porcine model of lavage-induced acute lung injury

This prospective large-animal study was performed to evaluate the contribution of arterio-venous extracorporeal lung assist (AV-ECLA) to pulmonary gas exchange in a porcine lavage-induced acute lung injury model. Fifteen healthy female pigs, weighing 50.39±3.8 kg (mean±SD), were included.

After induction of general anaesthesia and controlled ventilation, an arterial line and a pulmonary artery catheter were inserted. Saline lung lavage was performed until the PaO2 decreased to 51±16 mmHg. After a stabilization period of 60 min, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. Under apnoeic oxygenation, variations of sweep-gas flow were performed every 20 min in order to evaluate the membrane lung's efficacy, in terms of carbon dioxide (CO2) removal and oxygen (O2) uptake. Although AV-ECLA is highly effective in eliminating CO2, if combined with apnoeic oxygenation, normocapnia was not achievable. AV-ECLA's contribution to oxygenation during severe hypoxemia was antagonized by a significant increase in the pulmonary shunt fraction.

Neonatal Extracorporeal Membrane Oxygenation: A Review

The history of extracorporeal membrane oxygenation (ECMO) therapy is summarized. The adult and pediatric experiences are described, but emphasis is placed on the development of neonatal ECMO, now an accepted therapy for newborns with severe respiratory failure. The technical aspects of neonatal ECMO are outlined, as are the clinical criteria for its use. Experience at Children's Hospital National Medical Center, Washington, DC, is reported. Promising new technological developments, and their implications for future applications of neonatal ECMO, are presented.

Evolution of membrane oxygenator technology for utilization during pediatric cardiopulmonary bypass

The development of the membrane oxygenator for pediatric cardiopulmonary bypass has been an incorporation of ideology and technological advancements with contributions by many investigators throughout the past two centuries. With the pursuit of this technological achievement, the ability to care for mankind in the areas of cardiac surgery has been made possible. Heart disease can affect anyone within the general population, but one such segment that it can affect from inception includes children. Currently, congenital heart defects are the most common birth defects nationally and worldwide. A large meta-analysis study from 1930 to 2010 was conducted in review of published medical literature totaling 114 papers with a study population of 24,091,867 live births, and divulged a staggering incidence of congenital heart disease involving 164,396 subjects with diverse cardiac illnesses. The prevalence of these diseases increased from 0.6 per 1,000 live births from 1930-1934 to 9.1 per 1,000 live births after 1995. These data reveal an emphasis on a growing public health issue regarding congenital heart disease. This discovery displays a need for heightened awareness in the scientific and medical industrial community to accelerate investigative research on emerging cardiovascular devices in an effort to confront congenital anomalies. One such device that has evolved over the past several decades is the pediatric membrane oxygenator. The pediatric membrane oxygenator, in conjunction with the heart lung machine, assists in the repair of most congenital cardiac defects. Numerous children born with congenital heart disease with or without congestive heart failure have experienced improved clinical outcomes in quality of life, survival, and mortality as a result of the inclusion of this technology during their cardiac surgical procedure. The purpose of this review is to report a summary of the published medical and scientific literature related to development of the pediatric membrane oxygenator from its conceptual evolutionary stages to artificially supporting whole body perfusion in the modern pediatric cardiac surgical setting.

Extra Corporeal Membrane Oxygenation (ECMO) review of a lifesaving technology

Extra Corporeal Membrane Oxygenation (ECMO) indications and usage has strikingly progressed over the last 20 years; it has become essential tool in the care of adults and children with severe cardiac and pulmonary dysfunction refractory to conventional management. In this article we will provide a review of ECMO development, clinical indications, patients' management, options and cannulations techniques, complications, outcomes, and the appropriate strategy of organ management while on ECMO.

Extracorporeal membrane oxygenation as an alternative to ventilation

PURPOSE OF REVIEW

Following the recent H1N1 epidemic, there has been renewed interest in using extracorporeal membrane oxygenation (ECMO) as a treatment for acute respiratory failure. Currently, following the advances in technology, ECMO is now recommended as a definitive treatment for acute respiratory failure. However, there have been limited randomized trials and cohort studies evaluating this therapy.

RECENT FINDINGS

Currently, results imply that ECMO is superior to conventional ventilation providing lung rest. There is expansion in the indications for ECMO including a bridge to lung transplantation, the use of ECMO in awake patients, liver transplantation, as well as in adult respiratory distress syndrome. This article looks at the current indications and uses.

SUMMARY

Further studies are warranted to define and validate the role of ECMO, including studying the pharmacodynamics and pharmacokinetics of patients receiving support. The use of sedatives and antibiotics may be required to be changed significantly. If the incidence of intracerebral haemorrhage can be decreased, then in the author's opinion it may become the first-line treatment for acute respiratory failure.

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

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

Advances in extracorporeal ventilation

Mechanical ventilation remains the signature tool of critical care; however, within the past decade, a growing body of evidence suggests that positive pressure ventilation in acute respiratory failure is a double-edged sword that is associated with life-threatening complications such as nosocomial pneumonia and low cardiac performance. Essentially, solutions are required to provide adequate gas exchange and stable acid-base status while optimizing and maximizing pulmonary as well as remote organ protection. Recently, the first commercially available extracorporeal membrane ventilator was approved for clinical lung support, the Interventional Lung Assist. This article gives an overview of the potential indications for this device and the current clinical evidence in extracorporeal ventilation.

Expanded application of extracorporeal membrane oxygenation in a pediatric surgery practice

OBJECTIVE

To examine the breadth of application and resulting outcomes in a university-based extracorporeal membrane oxygenation (ECMO) program directed by pediatric surgeons.

SUMMARY BACKGROUND DATA

Several randomized control trials have supported the use of ECMO in neonates with respiratory failure. No comparable data exist for older children and young adults who may be afflicted with a variety of uncommon conditions. The indications for ECMO in these patients remain controversial.

METHODS

Patient data were recorded prospectively and reported to the Extracorporeal Life Support Organization. These data were analyzed by indications and outcomes on all patients treated since the inception of the program.

RESULTS

Two hundred sixteen patients were treated with 225 courses of ECMO. Neonates (188 [87%]) outnumbered 28 older patients (aged 6 weeks to 22 years). Overall, 174 patients survived (81%). Sixty-four of 65 (98.5%) neonates with meconium aspiration syndrome survived. ECMO support after heart (3), lung (2), heart-lung (1), and liver (1) transplant yielded a 57% survival to discharge. ECMO also resulted in survival of patients with uncommon conditions, including severe asthma (1), hydrocarbon aspiration (1/2), congestive heart failure due to a cerebral arteriovenous malformation (1), tracheal occlusion incurred during endoscopic stent manipulation (2), meningitis (1), and viral pneumonia (3/5).

CONCLUSIONS

ECMO can potentially eliminate mortality for meconium aspiration syndrome. Survival for other causes of respiratory failure in neonates and older children, while not as dramatic, still surpasses that anticipated with conventional therapy. Moreover, survival of transplant patients has been comparable to that achieved in other children.

Artificial lungs: a new inspiration

An estimated 16 million Americans are afflicted with some degree of chronic obstructive pulmonary disease (COPD), accounting for 100,000 deaths per year. The only current treatment for chronic irreversible pulmonary failure is lung transplantation. Since the widespread success of single and double lung transplantation in the early 1990s, demand for donor lungs has steadily outgrown the supply. Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device (VAD), which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. The current methods for supporting patients with lung disease, however, are not adequate or efficient enough to act as a bridge to transplantation. Although occasionally successful as a bridge to transplant, ECMO requires multiple transfusions and is complex, labor-intensive, time-limited, costly, non-ambulatory and prone to infection. Intravenacaval devices, such as the intravascular oxygenator (IVOX) and the intravenous membrane oxygenator (IMO), are surface area limited and currently provide inadequate gas exchange to function as a bridge-to-recovery or transplant. A successful artificial lung could realize a substantial clinical impact as a bridge to lung transplantation, a support device immediately post-lung transplant, and as rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure.

Extracorporeal membrane oxygenation for severe respiratory failure

The use of extracorporeal technology to accomplish gas exchange with or without cardiac support is based on the premise that "lung rest" facilitates repair and avoids the baso- or volutrauma of mechanical ventilator management. Extracorporeal membrane oxygenation (ECMO), a modified form of cardiopulmonary bypass, has been shown to decrease mortality of neonatal, pediatric and adult respiratory failure and is capable of total gas exchange. In neonates, over 20,638 patients have been treated with an overall survival of 77% in a population thought to have 78% mortality.

Following the learning curve: the evolution of kinder, gentler neonatal respiratory technology

Immense progress has been made in all aspects of neonatal critical care during the past 4 decades, particularly in the realm of respiratory support. A historical overview of the evolution of neonatal respiratory support illustrates how technological advances are improving survival and outcome for many sick newborns. Major milestones in this history include continuous positive airway pressure, conventional ventilation, exogenous surfactant, extracorporeal membrane oxygenation, and high frequency ventilation. Changes in clinical and nursing care highlight the significant impact of technological and practice advances on neonatal respiratory morbidity. Although bronchopulmonary dysplasia still occurs, the incidence and severity have decreased. The nature and outcome of the neonatal intensive-care experience has been redefined for many infants; however, great challenges remain in the care of infants on the edge of viability.

Extracorporeal life support for neonatal respiratory failure. A 20-year experience

OBJECTIVE

The authors reviewed their experience with extracorporeal life support (ECLS) in neonatal respiratory failure; they define changes in patient population, technique, and outcomes.

SUMMARY BACKGROUND DATA

Extracorporeal life support has progressed from laboratory research to initial clinical trials in 1972. Following a decade of clinical research, ECLS is now standard treatment for neonatal respiratory failure refractory to conventional pulmonary support techniques. Our group has the longest and largest experience with this technique.

METHODS

Between 1973 and 1993, 460 neonates with severe respiratory failure were treated using ECLS. The records of all patients were reviewed.

RESULTS

Overall survival was 87%. Primary diagnoses were meconium aspiration syndrome (MAS; 169 cases [96% survival]), respiratory distress syndrome/hyaline membrane disease (91 cases [88% survival]), persistent pulmonary hypertension of the newborn (37 cases [92%]), pneumonia/sepsis (75 cases [84% survival]), congenital diaphragmatic hernia (CDH; 67 cases [67% survival]), and other diagnoses (21 cases [71% survival]). Common mechanical complications included clots in the circuit (136; 85% survival); air in the circuit (67; 82% survival); cannula problems (65; 83% survival) and oxygenator failure (34; 65% survival). Patient-related complications included intracranial infarct or bleed (54 cases; 61% survival), major bleeding (48 cases; 81% survival), seizures (88 cases; 76% survival), metabolic abnormalities (158 cases; 71% survival) and infection (21 cases; 48% survival). Since 1989, treatment groups have been expanded to include premature infants (13 cases; 62% survival), infants with grade I intracranial hemorrhage (28 cases; 54% survival) and "non-honeymoon" CDH patients (15 cases; 27% survival). Since 1990, single-catheter venovenous access has been used in 131 patients (97% survival) and currently is the preferred mode of access. Follow-up ranges from 1 to 19 years; 80% of patients are growing and developing normally.

CONCLUSIONS

Extracorporeal life support has become standard treatment for severe neonatal respiratory failure in our center (460 cases; 87% survival), and worldwide (8913 cases; 81% survival). The availability of ECLS makes the evaluation of other innovative methods of treatment, such as late elective repair of diaphragmatic hernia and new pulmonary vasodilators, possible. The application of ECLS is now being extended to premature and low-birth weight infants as well as older children and adults.

Complications of neonatal extracorporeal membrane oxygenation

From 1973-1985 to 1988 the average patient complications per case were 1.44 per case and significantly increased during 1990 to 1992 to 2.10 per case (Figure 3). During the same periods patient survival significantly decreased from 84% (1973-1985 to 1988, n = 2463) to 80% (1990 to 1992, n = 4005) (Figure 4). The association between total complication rates and survival rate was examined by regression analysis (Table 5). The correlation of patient complication rate and total complication rate with survival is highly significant; however, causality cannot be established. When comparing different entry criteria (Table 2) for incidence of mechanical and patient complications, no significant differences are apparent. This is not surprising since each of the entry criteria were designed to identify the same patient population. When premature neonates (> 35 weeks) were placed on ECMO, 36% of them had intracranial haemorrhage (ICH) with 62% mortality while only 12% of the neonates < 35 weeks had ICH and a 49% mortality. Similar findings were noted with low birthweight neonates (< 2.2 kg), 28% had ICH with 64% mortality while only 12% of the neonates > 2.2 kg had ICH with a 50% mortality. Selection criteria remain problematic for a variety of reasons. They cannot be viewed as absolute because of variability between centres. What represents likely 80% mortality in one centre may not apply to another. Historical controls are misleading because changing respiratory therapy strategies make historical populations difficult to compare. Also, once an ECMO centre becomes established, a more challenging group of patients will be attracted than previously was the case. Further, a single entry criterion cannot be generalized for all entry diagnoses. Criteria for an 80% predicted mortality is probably not the same for MAS, CHN, PPHN, and sepsis. Subsequent patients registered in the Neonatal ECMO Registry of the Extracorporeal Life Support Organization will address these issues more thoroughly, as specific details of the pre-ECMO condition and therapeutic strategies are collected. This collective review should help to identify trends which require reassessment of technique or patient management.

Extracorporeal membrane oxygenation and indications for cardiopulmonary bypass in the neonate

Extracorporeal membrane oxygenation (ECMO) is a rescue technique used for term and near-term neonates who have respiratory failure that is unresponsive to conventional therapy. The complexity of the equipment necessitates intensive training of a specialized team before setting up an ECMO unit. An understanding of the physiology underlying ECMO and the criteria used for patient selection assists the nurse in identifying neonates who might benefit from the technique.

Extracorporeal membrane oxygenation (ECMO) in neonatal respiratory failure. 100 cases

Extracorporeal membrane oxygenation (ECMO) was used in the treatment of 100 newborn infants with respiratory failure in three phases: Phase I (50 moribund patients to determine safety, efficacy, and risks); Phase II (30 high risk patients to compare ECMO to conventional ventilation); and Phase III (20 moderate to high risk patients, the current protocol). Seventy-two patients survived including 54% in Phase I, 90% in Phase II, and 90% in Phase III. The major complication was intracranial bleeding, which occurred in 89% of premature infants (less than 35 weeks) and 15% of full-term infants. Best survival results were in persistent fetal circulation (10, 10 survived), followed by congenital diaphragmatic hernia (9, 7 survived), meconium aspiration (44, 37 survived), respiratory distress syndrome (26, 13 survived), and sepsis (8, 3 survived). There were seven late deaths; in follow-up, 63% are normal or near normal, 17% had moderate to severe central nervous system dysfunction, and 8% had severe pulmonary dysfunction. ECMO is now used in several neonatal centers as the treatment of choice for full-term infants with respiratory failure that is unresponsive to conventional management. The success of this technique establishes prolonged extracorporeal circulation as a definitive means of treatment in reversible vital organ failure.